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XU Wenjie, ZHOU Qian, FENG Zekang, ZHANG Yangyang, WANG Junhao, CHEN Yongzhi, OUYANG Penghao
2025,45(2):247-262, DOI: 10.13409/j.cnki.jdpme.20250216002
Abstract:
Multi-process, multi-phase, and multi-scale (or "3M") phenomena are critical challenges in nature systems and industrial and engineering fields. Numerical calculation serves as an essential paradigm in modern scientific research and engineering analysis. Starting from the physical-mechanical mechanisms of "3M" and leveraging the strengths of diverse numerical methods, this study developed coupled algorithms to achieve complementary advantages among these methods. A distinctive characteristic of "coupling" between algorithms was formed, supported by GPU parallel acceleration to enable large-scale, high-performance calculation analysis. This led to the development of a novel highperformance numerical calculation platform—Coupling Simulator (CoSim). Currently, the CoSim software includes solid mechanics, fluid mechanics, and couplings between different algorithms, with 16 solver modules and 1 CAE module in total. It overcame the limitations of most existing software that relied on single-algorithm approaches and struggled to simulate complex "3M" problems. Additionally, CoSim enabled coupled analyses—including continuous-discontinuous, continuum-to-fracture, fluidsolid, and micro-macro—for geotechnical and other materials throughout the entire process of "deformation→progressive failure→catastrophe". The software more accurately approximated complex realworld physical-mechanical behaviors, providing a powerful new-quality productivity for tackling intricate "3M" challenges.
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LIU Junle, SHUM Kihing, Tse K.T. 1, HU Gang
2025,45(2):263-270, DOI: 10.13409/j.cnki.jdpme.20241219002
Abstract:
Turbulent flow is ubiquitous in mechanical engineering, fluid mechanics, civil engineering, and other related disciplines. Traditionally, acquisition of turbulent flow data mainly depended on numerical simulations and wind tunnel tests. However, numerical simulations require substantial computational time, and wind tunnel tests involve high economic costs. With the rapid development of modern technologies, artificial intelligence technologies have attracted widespread attention in engineering fields due to their high efficiency, high precision, and reliability. This study developed an artificial intelligence algorithm named Turbulent-Flow-Vision Transformer (TF-ViT), which enabled spatiotemporal forecast of turbulent flow based on data-driven approaches. Specifically, the TF-ViT mainly consisted of two components: Transformer framework and UNet structure. In TF-ViT, each component had distinct functions. The Transformer framework served as the encoder, mainly responsible for processing and extracting spatiotemporal features of turbulent flow. Meanwhile, the UNet functioned as the decoder to decouple the encoded spatiotemporal turbulent flow information. The overall framework enabled the forecast of future spatiotemporal turbulent flow information. This study used the classical problem of the flow past rectangular cylinders to validate the developed TF-ViT algorithm. The open-source computational solver OpenFOAM was utilized to simulate the flow past rectangular cylinders, and the obtained wake flow field data was then used for the training and validation of the TF-ViT model. 8 continuous frames of transient turbulent flow data were used to forecast the subsequent 8 frames of turbulent flow information. The results showed that the developed TF-ViT algorithm in this study could accurately forecast the short-term spatiotemporal development of turbulent flow in the wake region. This study demonstrates the strong capability of TF-ViT in forecasting spatiotemporal turbulent flow, providing an effective method for turbulent wake field acquisition.
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JIANG Ren, SHI Yanchao, HUANG Hong, ZHANG Ji, DONG Jingliang, ZHUANG Haiyang
2025,45(2):271-281, DOI: 10.13409/j.cnki.jdpme.20241114002
Abstract:
This study investigated the blast damage range and computational efficiency of progressive collapse analysis for reinforced concrete (RC) frame structures by combining investigations of blast damage to building structures with refined numerical simulations. The validity of the RC frame structure model based on LS-DYNA was verified, and a substructure-based method for collapse resistance analysis of RC frame structure under blast loading was proposed, including selecting substructures from blast-damaged regions and properly calculating their boundary conditions. By conducting collapse resistance analysis on a typical 5-story RC frame structure under blast loading using full-structure and the proposed substructure methods, the effectiveness and efficiency of the proposed substructure method were examined. The results showed that the proposed substructure method could accurately predict the damage range and collapse behavior of RC frame structures under given blast loading, while reducing computational time by 72.7% compared with the full-structure method.
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ZOU Wanjie, LIANG Minrong, LI Chuangdi, GE Xinguang, JING Chenggui
2025,45(2):282-294, DOI: 10.13409/j.cnki.jdpme.20241001002
Abstract:
To address the complexity in solving responses of high-rise structures with Tuned Liquid Dampers (TLDs) under random seismic excitations, using the finite element dynamic analysis and the quadratic decomposition method of the power spectrum, this study developed a simplified closed-form solution method for the spectral moments of the dynamic responses in high-rise structures with TLDs installed on the top floors under Hu Yuxian seismic excitation spectrum. Firstly, based on the linear mechanical model of TLD, the coupled seismic equations for the TLD-high-rise building structure were established. Then, finite element analysis technology was used to obtain the dynamic characteristics of the high-rise building structure. The equivalent dynamic equations for TLD-high-rise building structures expressed in real modes were reconstructed, resolving difficulties in acquiring the dynamic characteristics of complex controlled structures. Secondly, the simplified closed-form solutions for absolute structural displacements, inter-floor displacements, variance, and 0-2 order spectral moments of high-rise building structures were derived using the complex modal method and quadratic decomposition method. Finally, a real structure was used as a case study. The comparison between the floor and node spectral moments obtained by the proposed method and the results calculated by the virtual excitation method verified the correctness of the derived response spectral moments, and the effects of the number of structural vibration modes and the TLD parameters on vibration reduction performance were explored. The results showed that the first three orders of structural vibration modes could ensure the accuracy of the response results, and the seismic performance of high-rise structures could be effectively improved by appropriately increasing the length and height of the TLD and selecting a suitable damping ratio.
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WU Daoqi, DU Ke, LUO Huan, MA Jialu, NIE Guibo
2025,45(2):295-306, DOI: 10.13409/j.cnki.jdpme.20231220003
Abstract:
In the current engineering and scientific research, finite element models for large-scale structural optimization face limitations due to high computational costs and complexity. The integration of response surface models has emerged as an effective approach to overcome these challenges, enabling researchers to significantly reduce computational costs while maintaining acceptable accuracy. Howev-er, when fitting response surfaces for complex models, conventional parameter screening methods often lead to reduced accuracy and efficiency, particularly when considering individual variations and the high costs of sensitivity analysis. Focusing on the finite element model of a 26-story frame-shear wall structure, this study integrated two preprocessing steps—single-factor experiments and hill-climbing tests—during response surface construction. These steps aimed to narrow the search space, screen key factors, and provide gradient information,making the construction of the response surface more accurate and operable, and providing a reliable foundation for subsequent model processing. By integrating multiple intelligent algorithms, this study completed the model updating and optimization operations for the response surface. The research results showed that the response surface constructed using parameters screened through preprocessing steps maintained consistently low error rates with identification results when multiple algorithm types were applied. This study provides valuable guidance for future engineering practices and research on related fields, offering a more flexible and universal optimization solution for enhancing the accuracy and efficiency of finite element model updating in largescale structural optimization.
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WANG Yicheng, MIN Yintong, LIU Chun, LI Wanchong
2025,45(2):307-316, DOI: 10.13409/j.cnki.jdpme.20241203002
Abstract:
Distributed acoustic sensing (DAS) can obtain real-time vibration signals from engineering events, and identifying these signal characteristics facilitates early warning and prevention of engineering disasters. To systematically investigate the characteristics of DAS signals under different conditions, a DAS monitoring model for geotechnical vibration signals was established using the high-performance discrete element method (DEM) software, MatDEM. The elastic Clump model was employed to construct optical fiber structures and record relative strain data in real time. By integrating DAS vibration signal data from field drop-weight impact tests, the model's validity and effectiveness were verified from three aspects: time-domain characteristics, frequency-domain characteristics, and variation patterns of signals influenced by vibration source parameters. The results demonstrated consistency between simulated and experimental signal characteristics. The signal waveforms consistently exhibited a single-peak pattern with rapid attenuation. Signal frequencies were concentrated, and amplitudes gradually decreased with increasing frequency. As the drop height and mass of the impact weight increased, the signal amplitudes and corresponding signal-to-noise ratios increased. This model can be used for research on vibration mechanism characteristics and for generating large-scale datasets of vibration signals, thereby facilitating further interpretation of DAS signals and their recognition through artificial intelligence technology.
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2025,45(2):317-328, DOI: 10.13409/j.cnki.jdpme.20241227001
Abstract:
The cyclic force characteristics of seabed foundation soils and their evaluation methods are recognized as critical scientific issues in the design and stability analysis of marine engineering structures such as dikes, offshore wind turbines, subma-rine pipelines, offshore oil platforms, and breakwaters. To systematically investigate the cyclic strength of marine clay and its evaluation method, undrained cyclic triaxial tests and in-situ cone penetration test CPTu were conducted on clay from the Yangjiang offshore area. The primary objective of this study is to provide more reliable geotechnical investigation guidance for the rapid development of offshore wind farms. The results showed that the cyclic characteristics of marine clay significantly differed from those of onshore Fujian standard sand. Marine clay mainly exhibited tensile failure under cyclic loading. The double-amplitude axial strain (εda) of samples under cyclic loading showed two development patterns: slow-sudden and rapid-stable. The power-law relationship between εda and the number of cycles (N), and that between excess pore pressure ratio and cyclic ratio (N/NL) conformed to a hyperbolic relationship. The applicability of existing liq-uefaction evaluation methods based on CPTu data for undisturbed marine fine-grained soils was analyzed. Based on the correlation between field and laboratory stress conditions of unit soil, an evaluation method for the cyclic strength of ma-rine clay was developed using CPTu data and burial depth (H).
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DENG Maolin, PENG Xu, WEI Dong, ZUO Qingjun, LIANG Zhikang, ZHOU Mengting, SU Pengmin, ZHU Xiaohan, LI Yuzhou, TONG Shuai
2025,45(2):329-337, DOI: 10.13409/j.cnki.jdpme.20241023005
Abstract:
At about 11:00 a.m. on July 10, 2024, a shallow soil landslide triggered by heavy rainfall occurred in Sanxingdian Village, Shazhenxi Town, Zigui County, Yichang City, Hubei Province. The landslide volume was approximately 30×10? m3. Thanks to the timely detection by community-based monitoring and prevention staff, 206 individuals from 74 households were successfully evacuated. To investigate the formation process and disaster-inducing mechanism of Zhangjiahongwuchang Landslide, this study explored its dynamic processes and genesis mechanisms through field surveys, borehole data analysis, rainfall data, and numerical simulations. The results of field surveys and borehole data analysis showed that the landslide material consisted of Quaternary gravelly soil with a soil-torock ratio of 6: 4. The sliding surface was characterized by a "smooth" bedrock-overburden interface, and the catchment area at the rear edge of the slope was 27 545 m2. Numerical simulation results demonstrated that 16 hours of cumulative rainfall from July 3rd to July 4th led to a significant decrease in landslide stability, and the heavy rainfall on July 9th directly triggered landslide failure. Preliminary research suggested that the landslide was located on a unilateral slope on the western flank of the Zigui Syncline. Loose Quaternary gravelly soil and a "smooth" bedrock-overburden interface were internal factors triggering this landslide. External factors included cumulative rainfall of 212 mm from July 3rd to July 4th and heavy rainfall of 170 mm on July 9th, surface runoff from rainfall on the extensive slope outside the landslide that converged into the landslide mass, and abandoned drainage systems on the slope surface of the landslide mass.
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DANG Zhiying, CAO Zelin, WANG Keyi, SUN Zhiyu
2025,45(2):338-348, DOI: 10.13409/j.cnki.jdpme.20240417003
Abstract:
On February 6, 2023, two strong earthquakes with magnitudes of MW7.8 and MW7.5 occurred along the East Anatolian Fault Zone in southeastern Turkey. Large near-fault velocity pulses were observed during both major earthquakes occurring on the same fault zone within one day. This study investigated the characteristics of pulse-type ground motions and the effects of the source of the Turkish earthquake sequence. First, horizontal-component ground motions recorded during the two earthquakes were collected, and 28 and 8 velocity pulse records were extracted, respectively, using a wavelet-based identification algorithm. The spatial distribution characteristics of the pulse records, as well as the variations in parameters such as velocity pulse period and response spectrum amplification factors, were analyzed. By comparing these results with empirical relationships for pulse parameters, the individual characteristics of the Turkish earthquakes were discussed. Subsequently, velocity pulses observed at the same stations during both earthquakes were compared to explore the effect of source rupture process on velocity pulses. The results showed significant variations in velocity pulses of the two earthquakes, with pulse periods notably differing from previous empirical relationships due to complex source effects. The response spectrum amplification factors by pulses ranged from 1.8 to 7.5. Most pulse-recording stations were located in areas adjacent to the fault, and pulse periods exhibited increasing trends with fault distance. Source slip distribution had a significant effect on the characteristics of near-fault velocity pulses. These findings contribute to a deeper understanding of the relationship between near-fault velocity pulses and source, providing scientific references for establishing prediction models for near-fault velocity pulses and determining seismic inputs for pulse-type ground motions in earthquake-resistant engineering.
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CHANG Chaoyu, QIAO Feng, BO jingshan, ZHAN Beilei, GU Jiapei, LI Haoyu, TIAN Huajun
2025,45(2):349-356, DOI: 10.13409/j.cnki.jdpme.20240131003
Abstract:
On December 18, 2023, a 6.2 magnitude earthquake in Jishishan County, Linxia Prefecture, Gansu Province triggered a special flowslide, which differed significantly from conventional landslides. Currently, the causes and mechanisms of such disasters are unclear, and their early identification remains challenging. This study conducted detailed field investigation and analysis of the Zhongchuan Township flowslide, which could provide important theoretical and practical implications for preventing such disasters. The geological disaster triggered by the Jishishan earthquake was a low-angle loess slope flowslide, with a long sliding distance and viscous mud outbursts in the accumulation area, submerging multiple houses and leaving 20 people missing. Through in-depth field investigation and analyses, the causes, movement patterns, and surge velocities of the flowslide were explored. The results showed that: (1) the flowslide occurred on the second and third terraces of the Yellow River,with an elevation difference of 79.2 m, a sliding distance of approximately 3.1 km, and an overall slope angle of merely 1.5°. This event was identified as a low-angle loess slope flowslide triggered by a strong earthquake. (2) The primary causes of the flowslide included high saturation of source loess induced by continuous irrigation, structural collapse of under-consolidated saturated loess triggered by a strong earthquake, flow failure of low-plasticity-index loess, and enhanced damage due to embankment failure and gully constriction.
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ZHANG Yanming, LIAO Shirong, CHEN Huifang, HU Shufang
2025,45(2):357-364, DOI: 10.13409/j.cnki.jdpme.20231129005
Abstract:
To evaluate the performance of the Real-Time Intelligent Seismic Processing (RISP) system in processing earthquake sequences in marine areas with poor seismic station coverage, continuous waveform data for 21 days before and after the MS6.2 earthquake in the Taiwan Strait on November 26, 2018, were processed offline. A comparative analysis was conducted between the automated processing results and manual cataloging results. The completeness of the automated earthquake catalogs generated by the system and the reliability of parameters, including hypocenter location, magnitude, and seismic phase arrival time, were quantitatively evaluated. A total of 407 earthquake catalogs were generated by the RISP system. Among these, 93 matched the multi-station manual catalogs (100% matching rate), and 200 matched the single-station manual catalogs (93.9% matching rate). The remaining 114 catalogs were events of the Taiwan Strait earthquake sequence that were undetected by manual cataloging. Statistical results of the matched events showed that 96.77% had origin time deviations less than 1.0 s, 100% showed epicenter location deviations less than 10 km, 50.54% had focal depth deviations less than 10 km, and 98.92% exhibited magnitude deviations less than 0.5. The RISP system could rapidly generate earthquake sequence catalogs for the Taiwan strait, with significantly better completeness than manual cataloging and comparable accuracy of seismic parameters to manual cataloging. Using the automated processing results, this study inverted the focal mechanism solution of the mainshock and performed precise relocation for earthquakes with ML≥3.0. It was believed that the seismogenic structure of MS6.2 Taiwan Strait earthquake was likely an east-west trending blind fault. The automated processing results of the RISP system enable rapid identification of seismogenic faults, providing support for earthquake prediction and forecasting, along with emergency response operations. The distribution characteristics of the earthquake sequence and the focal mechanism of the mainshock generated by the RISP are of great significance for understanding the seismogenic structure of this earthquake sequence.
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CHEN Qinghe, YUAN Saijie, LI Ruihua, LUO Haisheng, CHEN Xujun, TAN Junfeng
2025,45(2):365-374, DOI: 10.13409/j.cnki.jdpme.20230914001
Abstract:
To investigate the potential effect of different global warming scenarios on future typhoon track, this study utilized the predicted values of sea surface temperature (SST) over the next century under three global warming scenarios provided by CCCma to conduct full-track typhoon simulations in the Northwest Pacific. The annual frequency of typhoons was randomly simulated according to the probability density function (PDF) of historical observations, which followed a time-invariant negative binomial distribution. Typhoon tracks and intensities were simulated using the Vickery model. For the gradient wind field model of typhoons, improvements were made based on the Georgious gradient wind field model. An artificial neural network (ANN) was used to refit the relation for the radius of maximum wind speed, with typhoon central pressure deficit, latitude, and SST as inputs. This enabled the integration of climate change effects into the time-varying PDF of annual extreme wind speeds. It revealed the potential effects of SST increases caused by climate change on the frequency of typhoon landfalls, typhoon movement speed, typhoon movement direction, and typhoon central pressure deficit. The results showed that the effect of global warming on annual extreme wind speed PDF exhibited regional variability. In most regions, the mean and dispersion of the annual extreme wind speed PDF tend to increase, while in a few regions, the long-term trend remained unaffected by global warming. The Gumbel distribution was employed to fit the annual extreme wind speed PDF. Both the location and shape parameters of the Gumbel distribution exhibited time-varying characteristics. The errors in linear fitting were quantified using a normal distribution and were referred to as estimation uncertainty.
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WANG Xinzheng, KONG Gangqiang, CHEN Yonghui, TANG Yexin, YAO Donglei
2025,45(2):375-383, DOI: 10.13409/j.cnki.jdpme.20240825001
Abstract:
The resource utilization of engineering residual soil and industrial solid waste is one of the key measures for advancing the development of "zero-waste cities". Using modified diatomite, phosphogypsum, and carbide slag as eco-friendly and low-carbon solid waste-based stabilizers, stabilization and resource utilization tests were conducted on excavated residual soil from Suzhou foundation pit projects. With a stabilizer mix ratio of modified diatomite: carbide slag∶ phosphogypsum=0.39∶ 0.23∶0.38 (8% dosage), the effects of initial moisture content and compaction pressure on the compaction degree and unconfined compressive strength (UCS) of stabilized soil were investigated. Taking compaction pressure and duration as variables controlling compaction degree and subsequent strength, the optimal parameters of compaction technology for strength enhancement were refined. The results showed that under test conditions in this study, when the initial moisture content reached the liquid limit, the optimal compaction parameters were 0.92 MPa for 20 minutes, achieving 2.39 MPa UCS on day 28. When the initial moisture content fell below 20%, the hydration of the stabilizers among soil particles was insufficient. Increasing the compaction pressure significantly promoted the reaction of stabilizers among soil particles, resulting in a relatively significant influence on strength enhancement. When the initial water content exceeded the liquid limit, a water film was formed between soil particles and the stabilizers that isolated their contact, reducing cementation capacity and strength.
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LI Ningbo, ZHU Qingshuai, ZHOU Yu, SHU Qingdong, CHENG Cai
2025,45(2):384-392, DOI: 10.13409/j.cnki.jdpme.20231212006
Abstract:
To investigate the seismic vulnerability of in-service bridges, considering the uncertainty of system parameters in finite element modeling, this study presents a bridge model modified by a back-propagation (BP) neural network. A variable cross-section continuous girder bridge in East China was taken as an example. Utilizing Midas Civil software, a refined finite element model was established, where the bridge's dynamic responses served as inputs and structural parameters as outputs. The original finite element model was modified using the measured modal data of the bridge. The modification results showed that the BP neural network reduced model error from 22.92% to 4.58%, enhancing computational accuracy. Following the seismic isolation design theory in China's "Code for Seismic Design of Highway Bridges", lead rubber bearings were installed. The incremental dynamic analysis (IDA) method was employed to conduct nonlinear time-history analyses on three models: original model, modified model, and isolation-optimized model. Structural responses under different seismic waves were extracted to develop vulnerability curves. The data results indicated that the modified model had slightly lower damage probability than the original one. The use of seismic isolation bearings effectively reduced the probability of structural failure under seismic load, with the maximum damage probability decreasing by approximately 42%, demonstrating significant isolation effectiveness.
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ZHANG Hao, YANG Siwei, LI Hongnan, GUO Xin
2025,45(2):393-404, DOI: 10.13409/j.cnki.jdpme.20231104001
Abstract:
This study investigated the influence of floor slab restraints on the mechanical performance of precast shear walls with vertically segmented dry energy-dissipating connections. Three finite element models were developed: one specimen without a floor slab (PC-0), and two specimens with different types of cast-in-place slabs (PC-1, PC-2). A simplified structural measure was implemented in PC-2 to reduce the influence of the slab restraint. Numerical simulations under low-cycle reversed loading were conducted to evaluate the mechanical performance of these specimens and to preliminarily assess the impact of slab restraints. Furthermore, the effectiveness of simplified structural measures in mitigating slab restraints and improving the energy-dissipating capacity of the shear walls was explored. The results showed that the inclusion of slab restraints slightly enhanced the stiffness and bearing capacity of the precast energy-dissipating shear walls. However, slab restraints limited the energy dissipation efficiency of the damper connectors, leading to insufficient energy dissipation in some connectors and thus reduced overall energy-dissipating capacity and ductility. When slab restraint was alleviated through structural measures, the energy dissipation efficiency of the damper connectors improved significantly, leading to a notable enhancement in both energy-dissipating capacity and ductility, albeit with a slight reduction in stiffness and load-bearing capacity. The effect of slab restraints on the mechanical performance of precast shear walls is non-negligible and should be considered in seismic design and analysis.
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SHAN Zhicheng, YU Xu, ZHUANG Haiyang, WU Xiaofei
2025,45(2):405-415, DOI: 10.13409/j.cnki.jdpme.20231009002
Abstract:
To explore the influence of aspect ratio on the seismic responses of base-isolated structures built on flexible foundations, four traditional seismic-resistant and base-isolated frame structure models with different aspect ratios were established using ABAQUS finite element software. For different site conditions, models of base-isolated structures on both flexible and rigid foundations were established for comparison, so as to analyze the influence of Soil-Structure Interaction (SSI) effect on the seismic response patterns and isolation efficiency in structures with different aspect ratios. The results showed that with the increase of the aspect ratio, peak floor accelerations in isolated structures first decreased and then increased with increasing floor levels. Meanwhile, the displacement of the isolation layer continuously decreased, and the isolation efficiency gradually decreased. However, the variation patterns of the isolation efficiency with increasing floor levels were inconsistent among structures with different aspect ratios. For structures with smaller aspect ratios, the isolation efficiency was optimal at the top floor. As the aspect ratios increased, the optimal isolation efficiency layer appeared in the upper middle floors. Furthermore, by using peak floor acceleration, isolation layer displacement, and isolation efficiency as research parameters, it was concluded that SSI effect showed significantly stronger influence on isolation layers and top floor of structures compared to other floors. The SSI effect increased the displacement response of isolation layer in isolated structures and reduced the isolation efficiency of the isolation system. This adverse influence intensified with increasing aspect ratios of isolated structures.. Therefore, when designing isolated structures, the combined influence of the aspect ratio of the superstructure and the SSI effect on structures should be comprehensively considered.
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HE Wei, ZHANG Yu, LIU Qianquan
2025,45(2):416-426, DOI: 10.13409/j.cnki.jdpme.20230927002
Abstract:
Current studies on downbursts mainly employ impinging jet models. However, research on jet inclination angles remains limited, and small scaling ratios hinder investigations of downburst wind field characteristics. To address this, the study first investigated the wind field characteristics of inclined impinging jets using computational fluid dynamics (CFD), deriving an expression for the wind speed attenuation coefficient in the outflow region under different inclination angles. Subsequently, wall jets were used to simulate large-scale outflow wind fields in downbursts, but the effect of inclination angles on speed attenuation was neglected. Therefore, co-flow was in-troduced to mitigate viscous resistance around the jet. Smoke-wire wind tunnel tests and CFD methods were employed, yielding an expression for the co-flow-induced attenuation coefficient. Finally, the feasibility of simulating inclination-induced effects in downbursts using wall jets was evaluated. The results showed that: (1) the inclined impinging jet exhibited three-dimensional asymmetry. The atten-uation rate of the maximum horizontal wind speed on the front side decreased with increasing inclination angle, while the half-height wind speed in the wind profile increased by 77.8% at 30° inclination angle. (2) Smoke-wire wind tunnel tests and numerical simulations confirmed that wall jet wind fields resembled the frontside outflow section of downbursts, and the incorporation of co-flow effectively reduced the attenuation rate of horizontal wind speed. (3) By establishing a correlation between co-flow-induced and inclination-induced wind speed attenuation coefficients, it was feasible to simulate average wind profiles of downbursts at any inclination angle using wall jets, providing a novel approach for simulating largescale downbursts with inclination angles.
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2025,45(2):427-435, DOI: 10.13409/j.cnki.jdpme.20231024005
Abstract:
High-voltage transformers are critical components in high-voltage substations, performing essential voltage transformation and power distribution functions for power grids. Their seismic performance significantly affects the earthquake resistance and post-earthquake recovery capacity of related power grids and power supply areas. High-voltage transformers mainly consist of oil tank system and elevated platform-porcelain bushing system. Both systems are seismically vulnerable, requiring rigorous seismic reliability and vulnerability assessments. Currently, common methods for seismic performance analysis include shaking table tests and finite element analysis. However, their financial costs and computational expenses are relatively high, making them unsuitable for seismic performance analysis that requires multiple seismic response analyses, such as seismic reliability and vulnerability assessments. To reduce the cost of single seismic response analysis for high-voltage transformers, this study investigated simplified analysis methods for their seismic seismic performance and then established a simplified dynamic model for seismic response analysis of high-voltage transformers. The model decomposed the high-voltage transformer into oil tank system and elevated platform-porcelain bushing system. The acceleration response of the oil tank system was simplified using the acceleration amplification factor of the tank roof, and the seismic response of the elevated platform-porcelain bushing system was simplified as a 4-degree-of-freedom vibration system that incorporated their rocking characteristics. Subsequently, the simplified models of both systems were coupled, thereby developing a rapid calculation method for the seismic response of high-voltage transformers. A comparative analysis between finite element analysis results and simplified calculation results for the displacement response at the top of porcelain bushings in a 220 kV transformer under typical natural seismic waves validated the calculation accuracy of the simplified dynamic model established in this study.
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SHI Jintao, JIANG Shungen, WANG Jianye, ZHANG Dingwen, LIU Hua, Yu Zhilong, YANG Songsong
2025,45(2):436-445, DOI: 10.13409/j.cnki.jdpme.20231024003
Abstract:
To investigate the influence of construction technology and parameters of rod-extended deep mixing piles on the pile formation quality, a typical soft soil site along the Liansu Expressway was selected for field trial piling. Ground improvement was conducted using rod-extended deep mixing piles with varying construction parameters and methods. Following pile formation, standard penetration tests (SPT), core recovery tests, and 28-day unconfined compressive strength (UCS) tests were conducted to evaluate pile quality and identify the optimal construction method and parameters. The test results showed that a top-down construction method, with a blade rotation speed of 60r/min, drilling and lifting speed of 1.0m/min, and a cement content of 80kg/m, was well-suited for marine silty soil in Lianyungang. In practical engineering applications, construction parameters should be combined and matched based on site-specific geological conditions and the empirical formula for the number of mixing passes per soil layer. Ensuring that the soil at any point within the reinforcement zone is mixed at least 25 times contributes to achieving better pile formation quality and ground improvement effects. Although conventional deep mixing piles typically demonstrate higher pile quality due to the absence of complex processes such as rod coupling and decoupling, rod-extended deep mixing piles still meet the required technical specifications. Therefore, under construction conditions with height limitations, rod-extended deep mixing piles can serve as effective substitutes to conventional piles, meeting strength requirements and achieving satisfactory engineering performance.
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SUN Baoyin, ZENG Zhenrui, SUN Tianshu, ZHANG Zhe
2025,45(2):446-457, DOI: 10.13409/j.cnki.jdpme.20231026002
Abstract:
Time-history analysis based on finite element models is a primary method for vibration control optimization design of high-rise structures. However, its application in practical engineering is limited due to high computational costs and time-consuming processes. To address this, this study proposes an efficient viscous damper optimization design based on the gradient projection method. Considering the uncertainty of earthquake ground motions, the strategy used the maximum mean inter-story drift angle obtained from multiple ground motions as the objective function, with constraints on the total damping coefficient and the upper limits of damping coefficients for each story. The inter-story drift response was obtained via the modal decomposition method, and damper parameters were optimized using the gradient projection method. Under frequent earthquakes of 8-degree intensity, a 6-story shear model and a 15-story planar frame structure were analyzed using both the modal decomposition method and finite element time-history analysis for viscous damper optimization. The simulation results showed that the optimized damper parameters obtained from the two methods were nearly identical. Additionally, sensitivity analysis and parameter analysis of constraint conditions were conducted on the 6-story shear model to further validate the effectiveness of the optimization strategy. Finally, the optimized scheme obtained from the modal decomposition method was applied to the 15-story planar frame. Elastic-plastic analyses were conducted for three cases: the structure without additional damping, and the structures before and after optimization under three working conditions. A typical earthquake ground motion is selected for energy dissipation analysis of the structures before and after optimization under the three conditions. The results confirmed the strategy's reliability under rare earthquakes (8-degree intensity). The optimized damper parameters can significantly reduce the maximum inter-story drift angle and increase the proportion of energy dissipated by additional damping.
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LIU Feiyu, WANG Di, FU Dongping
2025,45(2):458-467, DOI: 10.13409/j.cnki.jdpme.20230826001
Abstract:
As a widely used subgrade filler, soil-rock mixtures form reinforced structures with geogrids that serve as critical components for bearing and transferring traffic loads. Their strength and stability are affected by the dynamic shear characteristics at the soil-reinforcement interface under normal cyclic loading. A series of dynamic direct shear tests were conducted on soil-rock mixture-geogrid interface using a large-scale dynamic shear apparatus. The effects of normal loading frequency (0.05, 0.1, 1 Hz) and normal stress amplitude (20, 40, 60 kPa) on the interface shear characteristics of soilrock mixture-geogrid interface at different fines content (0%, 20%, 40%, 60%, 80%, 100%) were analyzed. The results showed that under normal cyclic loading, both the shear stress and normal displacement exhibited periodic variations. The interface shear strength initially increased and then decreased with increasing fines content, reaching its maximum value at a 40% fines content. Furthermore, the interface shear strength increased with the amplitude but decreased with the frequency. Increasing fines content reduced interface shear shrinkage, whereas increasing the amplitude and frequency enhanced it. The interface friction coefficient and normal stress demonstrated the same periodic variation, with a phase difference of approximately 0.5 cycles. Notably, the interface friction coefficient, both at peak and residual stages, showed a trend of first increasing and then decreasing as the fines content rose.
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2025,45(2):468-476, DOI: 10.13409/j.cnki.jdpme.20230824002
Abstract:
Tunnel engineering projects are particularly vulnerable to seismic liquefaction hazards due to their long spans. In this study, researchers propose an electrolytic desaturation method based on the principle that reducing foundation saturation improves liquefaction resistance. For cut-and-cover tunnel projects in deep liquefiable sandy soil foundations, shaking table model tests were conducted to evaluate the reinforcement performance of the electrolytic desaturation method. Additionally, the soil acceleration around the tunnel, pore pressure variation, and tunnel uplift displacement were monitored. The test results showed that the electrolytic desaturation method provided excellent anti-liquefaction reinforcement performance, significantly restraining the uplift of tunnel structures. Pore pressure variation was the key factor affecting liquefaction occurrence. After the electrolysis of saturated sandy soils, a significant reduction in excess pore pressure was observed. Compared with the untreated condition, two conditions with different electrolytic treatments achieved maximum reductions of 68.1% and 70.3% in peak excess pore pressure. The positions of maximum reductions were all located at the bottom of the tunnel model, and the anode-cathode arrangement had a certain effect on both desaturation efficiency and anti-liquefaction performance. Both electrolytic treatments reduced the maximum uplift displacement of the tunnel model compared to the untreated condition, with reduction amplitudes exceeding 35%. The research findings demonstrate that the electrolytic desaturation method effectively controls the uplift deformation of tunnel structures in liquefiable foundations.
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2025,45(2):477-484, DOI: 10.13409/j.cnki.jdpme.20231215002
Abstract:
As one of the technical solutions for ultra-low-energy buildings, energy pile technology has been attracting growing attention from engineering professionals. To address the heating/cooling demands of ultra-low-energy buildings, a demonstration green building at the pilot site of "BeSTDR Infrastructure Hospital" was used as an example. Using Revit software, models were established for ultra-low-energy buildings integrated with ground-source heat pump systems with pile foundation (energy piles) and borehole buried pipes. Combined with TRNSYS software, the annual load demands of ultra-low-energy office buildings in Pingyu, Henan Province were analyzed. A comparative study was then conducted on the supply-side performance between ground-source and air-source heat pump systems. The temperature differences between supply and return water on both the source and load sides were investigated, aiming to explore the variation patterns of soil layers during the operation and maintenance of ground-source heat pump systems. Moreover, a preliminary feasibility analysis of replacing some borehole buried pipes with energy piles was conducted. The results showed that ground-source heat pump systems composed of pile foundation and borehole buried pipes achieved an energy-saving rate of over 30% compared to the air-source heat pump systems. After a cooling or heating season, the soil layer temperature of the buried pipe systems increased by 1.84℃ or decreased by 1.40℃ , respectively. After the system was in operation for 10 years, the average temperature of the soil layer of the energy pile rose to 17.40℃, and the average temperature of the soil layer of the underground pipe rose to 18.00℃ , resulting in "thermal accumulation" in the soil layer. Therefore, under engineering conditions, replacing some borehole buried pipes with pile foundation buried pipes can reduce the initial investment cost by approximately 25%, while achieving over 30% energy-saving rate in system operation.
Volume 45,2025 Issue 2
“防灾减灾工程高性能计算方法(HPC)”专题
Research Article
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Dynamic Incompatible Deformation and Failure Mechanism in A Long Deep Buried Fault-crossing Tunnel
WANG Yunxiao, ZHANG Cong1, WANG Hui, WANG Shanyong, LIU Jiayou, SHAO Tangsha
Abstract:
Dynamic problem of the long deep burial fault-crossing tunnel has always been a hot issue in deep underground engineering. It is the key to ensure the safety and stability of the tunnel after earthquakes post-disaster rescue. To explore the dynamic response of the surrounding rock of the long deep fault-crossing tunnel, relying on the Xianglushan tunnel project, the indoor shaking table tests and theoretical analysis were illustrated to explore the dynamic response of the tunnel surrounding rock under different inclination angles. Finally, the dynamic deformation and failure mechanism of the long deep buried tunnel were revealed, draw the conclusions: Under strong earthquake load, the dynamic response of the tunnel surrounding rock was the most significant when the inclination angle was 30°, and the peak acceleration, peak strain and peak displacement of the fault were the most intense. The dynamic response suggested the significant fault amplification and hanging wall effect by shaking table tests, which caused the incompatible deformation of the tunnel surrounding rock. This dynamic incompatible deformation caused the deformation and destruction of the long deep buried fault-crossing tunnel. The Xianglushan tunnel near-fault and cross fault locations was induced a cyclic back-and-forth tension, compression and dislocation by vibrational loads and residual tension-compressive stress. The longitudinal, transverse and annular cracks were produced to lead large deformation and even destruction. The research results can provide guidance and reference for the stability analysis and security assessment of the long deep buried tunnels in a strong seismic area.
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Prediction of Unsaturated Soil Water Characteristic Curve Based on Machine Learning Algorithms
ZHANG Xiayang, GAO You, YU Xiang, HE Wei
Abstract:
The soil water characteristic curve (SWCC) is the foundation for studying the permeability, strength prediction, and constitutive relationships of unsaturated soils. The machine learning algorithm has the characteristics of efficient processing of large amounts of data and feature extraction. Six machine learning algorithms (four ensemble learning algorithms and two traditional machine learning algorithms) were utilized to model 154 SWCCs comprising 1976 data points sourced from the American Unsaturated Soil Database. The performance of the algorithms was assessed using four performance evaluation indicators (R2, EVS, MAE and RMSE). Two types of data input methods were selected: logarithmic processing of pressure head and untreated. The results indicate that, under the two input types, the impact on the LightGBM, GPR, XGB and AdaBoost algorithms is minimal; however, in the case where pressure head is not logarithmically processed, the impact on the GPR and SVM two traditional machine learning algorithms is significant, R2 drops sharply and it may even result in the inability to model SWCC. Additionally, LightGBM outperforms other models in simulating the SWCC test set, with high trend evaluation indicators (R2 and EVS) and low error measurement indicators (MAE and RMSE). The ranking of the six algorithms in terms of the quality of SWCC simulation is as follows: LightGBM, GPR, XGB, RF, AdaBoost and SVM. Finally, utilizing the LightGBM model trained on the aforementioned database, predictions were made for 9 SWCCs not included in the database. The study revealed that LightGBM can effectively predict the soil water characteristics of unsaturated soils. These research findings have important implications for improving SWCC models for different types of soils.
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State of the art on fire resistance of reinforced concrete structure
LIU Zejian, WANG Yuzhuo, XU Tiangui, GONG Junlin
Abstract:
The occurrence of fires in reinforced concrete (RC) structures increases with the growing occurrence of building fires. The mechanical properties of building materials are greatly reduced in fire, which leads to the failure or even collapse of RC structures. Extensive experimental studies have been conducted in the early stages to investigate the fire resistance of RC beams, columns and joints. Due to the different experimental conditions, the accuracy of the fire resistance calculation formula is relatively low in other conditions. Therefore, the state of the art of RC beams, columns, joints and frames was summarized in this paper. Among them, parameters such as concrete cover thickness, load ratio and reinforcement ratio were considered. The theoretical analysis such as strut-and-tie-model, Rankine method and nominal stiffness method was summarized, and the finite element analysis and fire resistance calculation formulas were also summarized. The results indicated that the fire resistance of RC beams was greatly affected by parameters such as load ratio, concrete cover thickness and reinforcement ratio. The fire resistance of RC columns was greatly affected by parameters such as load ratio and load eccentricity. The fire resistance of RC joints depends on the fire resistance of RC beams and columns near the joint. Furthermore, a large amount of test data on RC beams and columns was collected from 129 references, and the influencing rules of parameters such as load ratio, concrete cover thickness and reinforcement ratio were summarized. The test data under different conditions were standardized, and the parameter analysis was conducted on the test data. The parameters with a correlation degree greater than 0.1 were identified as important parameters. The fire resistance calculation formulas of RC beams and columns were proposed by the machine learning and regression analysis. The results indicate that the proposed formulas with of 0.935 and 0.895 exhibit high accuracy, and the calculated values are highly consistent with the test values. The proposed formulas can be regarded as a reliable reference for the fire resistance design of RC structures.
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Fatigue Test on Socket and Spigot Joint of Ductile Iron Pipe under Traffic Load
Abstract:
Traffic load is one of the main live loads of pipelines buried under the road surfaces. The urban water supply pipelines are subjected to repetitive traffic loads during their operational lifespan, which may potentially lead to the fatigue failure of the pipelines. However, existing research mostly focuses on the static or dynamic mechanical responses of pipelines, with limited studies on the fatigue mechanical performance of pipe joints.This paper considered the statistical data on highway vehicle loads alongside constant loads such as soil pressure and pipe self-weight at first. The mechanical responses of ductile iron pipe joints under traffic loads were calculated using ABAQUS. Subsequently, to simulate cyclic loading under actual traffic conditions, bending fatigue tests of ductile iron pipe joints were conducted under internal water pressurebased on the principle of equivalent rotation angle. The study established the relationship between the maximum rotation angleat pipe joints and leakage rate under various fatigue load amplitudes. Finally, the fatigue life of pipelines under variouscombinations of traffic load was analyzed using the cumulative damage theory and the relationship between the fatigue load amplitude and cycle number of DN200 ductile iron pipe was obtained based on the test data. The research results indicate that: (1) the maximum rotation angle at pipe joint is an important indicator for evaluating the degree of fatigue failure, (2) the maximum rotation angle of pipe joint is positively correlated with the leakage rate, with leakage accelerating as rotation angle increases continuously; (3) the degradation of rubber ring at pipe jointssignificantly contributes to seal failure and subsequent leakage.
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Seismic design and numerical verification of self-centering double-column bridge with replaceable posttensioned strands
Pang wei, Jiang Hao, Jia Junfeng, Zhu Anjing, Bian Jiachen
Abstract:
To enhance the post-earthquake functionality and structural repairability of bridge projects, a rocking self-centering double-column pier equipped with replaceable curved prestressing tendons and its structure and construction are proposed. Taking a municipal bridge project as the engineering background, the seismic performance objectives, design method and design process of the self-centering double-column pier were studied and determined. Based on the OpenSees platform, a numerical model of the rocking self-centering double-column pier was established to analyze the seismic capacity of the columns under the horizontal cyclic loading conditions at the top of the pier, and to verify the reasonableness of the key design parameters, such as the initial tensioning stress of prestressing tendons, the reinforcement rate, and the ratio of area of the energy dissipation devices, which were calculated based on the proposed direct displacement-based seismic design method. The results showed that the lateral stiffness and horizontal bearing capacity of the double-column pier were basically not reduced when the loading drift ratio at the top of the pier reaches 5%; the residual drift ratio after unloading was only 0.14%, which has excellent self-centering capability.The proposed rocking self-centering double-column pier structure and its seismic design method can realize the expected seismic performance objectives, and the reasonable design parameters of the structure can be obtained according to the method. The research in this paper can provide reference for the seismic design of municipal and highway bridges in high intensity areas.
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Numerical Simulation Study on Deformation Mechanism of Existing Tunnel Induced by Shield Under-crossing
LU Dechun, SONG Tao, LIN Qingtao, MENG Xu, DU Xiu
Abstract:
Shield construction underpasses existing operating tunnels, which can easily lead to excessive deformation of existing lines and bring safety hazards to subway train operation. Considering the key factors such as the interaction between shield machine and soil, the interaction between lining?grouting layer and soil, and the synchronous grouting hardening process and pressure dissipation, a numerical simulation method for the whole process of shield construction is developed. Combined with the actual project, a three?dimensional finite element numerical model of shield tunneling under the existing tunnel is established. The structural deformation, internal force response, surrounding rock pressure and the development and change law of surrounding strata stress during the process of shield tunneling under the existing tunnel are obtained, and the deformation mechanism of the existing tunnel is revealed. The results show that the existing tunnel has flexural and torsional deformation in the longitudinal direction. The flexural deformation presents a ‘V’?shaped deformation with uplift at both ends of the middle settlement. The torsional deformation of the section is distributed in the form of large in the middle and small at both ends, and first reverses clockwise and then reverses clockwise with shield tunneling. For the tunnel cross section, the tunnel section presents the deformation mode of lateral flattening and vertical elongation in the range of x = ?0.8D to 0.8D, and the tunnel section presents the deformation mode of lateral elongation and vertical flattening outside x = ± 0.8D.In the range of x = ?0.8D to 0.8D, the deformation of tunnel section is caused by the unloading of soil caused by shield excavation, and the tunnel section outside x = ± 0.8D.
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Experimental Study of a Tunnel-Group Metro Station in Rock Site under Strong Earthquakes
LI Ruozhou, HE Weiguo, YUAN Yong, LI Qingfei
Abstract:
Abstract:To investigate the dynamic characteristics of the tunnel-group metro station in rock site under earthquake, a large-scale shaking table test model of the structure with a scale of 1:30 was designed. The model was subjected to transverse inputs of peak accelerations of 0.07 g, 0.15 g, 0.21 g, 0.30 g, 0.50 g, 0.70 g, and 1.0 g, representing seven different intensities of artificial seismic waves.The study focused on the acceleration response characteristics, displacement response characteristics, structural damage modes, and dynamic strain response characteristics of the tunnel-group metro station under strong earthquakes. The results showed that the amplification factors curve of Arias Intensity reveals that the model rock and the hall lining structure entered into the plastic damage state after the peak acceleration of 0.5 g. The platform lining structure gradually entered into the damage state from the plastic state after the peak acceleration of 0.3 g, and the energy dissipation increases gradually. With the increase of earthquake intensity, the relative displacement of the hall cross-section increases significantly, and the gap between the peak relative displacements of the open section and the non-open section widens further. The cracks of the structure are mainly distributed in the longitudinal direction, and the longitudinal cracks in the middle of the straight wall of the platform are wide and long, while the middle of the straight wall of the hall did not produce obvious cracks. With the increase in seismic motion intensity, the main frequency of the structural transfer function gradually decreased, with the main frequencies being 22.7 Hz and 18.5 Hz in the elastic and plastic damage stages, respectively. The tensile strains at the same locations in the VL section (the lower section of the vertical connecting passage) are larger than those in the HR section (the right section that connects the horizontal connecting passage) under transverse excitations, and the maximum tensile strain occurs in the arch shoulder of the VL section.
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Effect of Variability of Soil Dynamic Parameters on Ground Motion Parameters for Deep Soft Sites
CHEN Guo-xing, LIU Xue-zhu, WANG Bing-hui
Abstract:
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LIU Hanlong, REN Huiqi, CHEN Jun, ZHANG Wengang, LI Zhe, YIN Yueping, ZHANG Qin, WANG Luqi
2023,43(5):917-922, DOI: 10.13409/j.cnki.jdpme.20230921004
Abstract:
In the context of global climate change and increasingly active geological activities， China urgently needs to achieve rapid and efficient emergency response to natural disasters， and the corresponding upgrading of disaster prevention and control industries is also imperative. This study employs a comprehensive research methodology， encompassing literature review， on-site research， expert consultation， and questionnaire survey. Furthermore， combined with the development objectives of key steps within natural hazard mitigation， the issues and challenges faced by the natural disaster prevention and control industry were analyzed to propose the development paths of technology breakthroughs. On this basis， the following strategies were summarized. A more comprehensive standardization system should be established to seriously verify professional qualifications， control the market dynamics of industries in real-time， and ensure efficient competition in the industrial market. Leveraging advantages of localized development， the development of natural hazard prevention and control industries should be clustered to connect multiple chains. Led by the basic research on natural hazard prevention and reduction， the upgrading of natural hazard industries should be completed through theoretical innovation and technological iteration. Moreover， the industry should highlight the overall， systematic， and synergistic characteristics to enhance international competitiveness within disaster prevention and reduction. This paper aims to provide forward-looking， targeted， and evidence-based scientific references to facilitate the high-quality and expeditious development of the natural disaster prevention and control industry.
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PEI Zhenwei, NIAN Tingkai, WU Hao, ZHANG Yanjun, ZHANG Chaofeng, WANG Rui
2021(6):1382-1394, DOI: 10.13409/j.cnki.jdpme.20201130001
Abstract:
In China，landslide geological hazards with the characteristics of wide distribution and high frequency constantly pose serious threats to the safety of people's lives and property，and the construction and long-term operation of national key projects. In order to effectively mitigate the landslide disaster and maximize the benefit of disaster preventions，mitigations and relieves，it is urgent to develop more efficient emergency disposal technologies for landslide geological hazards. This paper systematically summarizes the state-of-the-art of emergency disposal technologies for landslide geological disasters，including emergency rescue technologies，emergency treatment technologies，emergency disposal technologies for special engineering，and emergency monitoring and warning technologies. Subsequently，the paper indicates the major problems at present and further development trends in the hope of promoting the rapid development and standardization of emergency disposal technologies for landslide geological disasters，and providing useful suggestions for disaster relief work.
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WANG Jun, LIU Honggui, ZHOU Yuchen
2021(4):874-882, DOI: 10.13409/j.cnki.jdpme.202105007
Abstract:
This paper briefly reviews the development process of earthquake early warning and introduces the basic principles of earthquake early warning as well as the main determination methods for key parameters such as earthquake location，early warning magnitude and predicted intensity. As an effective means to mitigate earthquake disasters，earthquake early warning systems have been set up in many countries and regions of the world. Taking the system construction and application effectiveness as the breakthrough point，this paper introduces the main earthquake early warning systems in the world and the related progress in China. And then，based on the main challenges faced by the earthquake early warning，new and potentially innovative technologies and methods for future earthquake early warning system are prospected from the aspects of sensors，signal processing algorithms and networking modes.
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YANG Dongxu, YOU Yong, WANG Junchao, YANG Dong, LIU Jiankang
2020(6):841-851, DOI: 10.13409/j.cnki.jdpme.2020.06.001
Abstract:
The southeast region of Tibet is the largest marine glacier area in China. For investigating the physical and mechanical characteristics of glacial tills along the Sichuan-Tibet railway， and evaluating their stability as a geological hazard source and engineering foundation， 32 points of glacial tills in the Parlung Zangbo basin were taken as cases. A series of in-site and indoor tests on natural density， grain size analysis， large direct shear， triaxial shear， compressive strength， permeability coefficient and so on were carried out. Combining with field investigation methods such as sectional surveying and mapping， the distribution， morphological characteristics， physical and mechanical properties of glacial till and their correlation were analyzed. The result shows that physical and mechanical properties are closely related to moisture content， void ratio and clay content. The natural density and compression modulus are negatively linear related to the void ratio. The vertical permeability coefficient and the free expansion ratio show a quadratic relationship with clay content. The shear strength and compressive strength are binary relationship with void ratio and moisture content. Start-up patterns in three different deposit sites (modern glacier tongue， middle reaches of the valley， and the main river bank) were summarized， and the stability of the glacial tills was preliminarily discussed. The countermeasures for dealing with the glacial tills in Sichuan-Tibet railway and highway projects were suggested， such as passing by bridges or tunnels， engineering slope， and cutting or foundation， etc.
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ZHOU Yun, CHEN Zhangyan, GUO Yangzhao, ZHANG Chao
2021(4):753-767, DOI: 10.13409/j.cnki.jdpme.2021.04.005
Abstract:
In order to improve the seismic performance of conventional infilled masonry wall，an innovative configuration named damped infilled wall/wallboard(DIW)was proposed by introducing the principle of viscoelastic damper. DIW has a simple construction，explicit working mechanism and independent intellectual property right. In this paper，the configuration and working mechanism of DIW was introduced. The material suitable for damping layer construction and its corresponding hysteretic performance were given. Seismic performance tests were carried out on DIW unit as well as plane frame structures with DIW. The in-plane working mechanism that the shear hysteretic deformation which is casued by relative movement between adjacent subpanel of DIW dissipates the input seismic energy was revealed. The double bracing macro-modelling method was proposed. The proposed model was used in the time-history analysis of a 3D frame structure with DIW. Results show that DIW is able to significantly reduce the influence on the dynamic characteristic and seismic performance of the main structures，and to protect the wall from suffering damages through decreasing the stiffness effect of wall/wallboard on structure. Out-of-plane performance of DIW was also studied by tests. The results reveal that the out-of-plane mechanism is the arching mechanism and the failure mode is fourhinge arching.The problems and directions that need to be further studied were given.
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LIU Hanlong, MA Yanbin, ZHANG Wengang
2021(4):710-722, DOI: 10.13409/j.cnki.jdpme.2021.04.002
Abstract:
In recent years，frequent geological disasters such as landslides，debris flows，and rock collapses，which are featured by severe harm and wide spread，threaten people’s lives and property safety，and restrict economic and social development and people’s desire for a better life. After years of technical research，mass prediction and disaster prevention，China has achieved remarkable success in geological disaster risk and hidden danger investigation. In order to improve the accuracy of national geological disaster survey and evaluation，comprehensive use of a series of new technical methods， such as synthetic aperture radar，high-resolution satellite remote sensing，unmanned aerial vehicle remote sensing and airborne lidar measurement，is underway. With the innovation and development of computer technology in the new era，the monitoring and early warning for geological disasters based on big data technology provide a new thinking paradigm and experience guidance for the prevention and control of geological disasters. For promoting an in-depth understanding of the new development direction in this field，key techniques in big data methods for acquisition，storage and analysis of geological disaster information are introduced，and progress on geological disasters analysis and prevention by worldwide scholars using big data techniques are reviewed.
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ZHANG Lei, SHI Bin, WEI Guangqing
2020(5):698-705, DOI: 10.13409/j.cnki.jdpme.2020.05.003
Abstract:
Among other factors,artificial slope cutting is one of the most common triggering factors oflandslide. In this paper,a series of model tests and numerical simulation have been conducted to investigate the failure mechanism and evolution process of the slope under slope cutting. As the coupling between sensing cables and soil directly affects the accuracy of monitoring results. Firstly,a new pullout apparatus is designed and the coupling deformation relationship between sensing cables and soil isacquired through pull-out tests under different confining pressures. According to the pull-out tests,asurcharge loading test model was designed. Strain-sensing cables that can capture the strains at different positions of the model slope were embedded in the soil mass. The measurement data of the cutslope were analyzed. It can be found that an abnormal strain-field area obtained by horizontal and vertical sensors coordinated with the location of the potential slip surface. This is verified by a comparisonbetween the measurements of the cables and numerical simulation results. Based on the BOTDA data,an empirical relationship is explored between the horizontal characteristic maximum strain and thesafety factor to estimate the slope stability condition and perform early-warning of landslide under theaction of slope cutting. The conclusions drawn in this study are of great significance to stability evaluation of artificial cut slopes.
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GAO Yufeng, DAI Denghui, ZHANG Ning
2021(4):734-752, DOI: 10.13409/j.cnki.jdpme.2021.04.004
Abstract:
Local irregular topographies have significant effects on seismic waves. Topographic features can cause scattering and diffraction of incoming seismic waves，resulting in amplifications and de-amplifications of earthquake ground motions. The problem is an interdisciplinary research topic of seismology，earthquake engineering and civil engineering. The canyon，a common topographic feature， can significantly modify the ground motions. A large number of infrastructures such as dams and bridges have been built in such sites. Thus，the effect of seismic amplification on the engineering facilities in the canyon sites cannot be ignored. The paper summarizes the research results on the topographic amplification effects of seismic wave in canyon sites，sums up the research methods in this field，and puts forward the prospect for the future development of this field，aiming to provide reference for relevant researchers.
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ZHEN Yiwei, LIU Shuguang, ZHONG Guihui, ZHOU Zhengzheng, FANG Qi, ZHENG Weiqiang, LIANG Jiyu
2022(1):1-11,23, DOI: 10.13409/j.cnki.jdpme.20210416004
Abstract:
Due to the strong surface disturbance caused by the "5.12" Wenchuan earthquake，mountain torrent disasters have occurred frequently in Wenchuan County in recent years，causing serious damage to local houses. In Wenchuan County，two mountain torrent disasters，"8.20" and "8.17"，occurred in 2019 and 2020. Taking some of the damaged village buildings in the two disasters as research objects，this paper summarized the damage characteristics of different structural types of buildings，the spatial variability of the damage degree of buildings along the river and the building masking effect，as well as the damage modes of impact，scouring，siltation and immersion through disaster data mining and typical case analysis. Based on the research and analysis，this paper improved the existing building damage grading criteria by combining the characteristics of mountain torrent damage，and then proposed the classification of mountain torrent damage to rural buildings. Applying random forest algorithm and statistical analysis methods，the main influencing factors of building flood damage and their relationships were comprehensively analyzed in terms of water depth exposure，site exposure，and physical vulnerability. Finally，based on the analysis of building damage，some suggestions were proposed to improve the flood mitigation capacity of buildings in mountainous villages. The research results lay the foundation for further research on the physical mechanism of building flood damage，and also provide references for flood prevention planning and disaster mitigation design of buildings in mountainous villages and towns.
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ZHOU Yang, QI Zhengxin, GUO Xun
2021(4):860-873, DOI: 10.13409/j.cnki.jdpme.202106030
Abstract:
Multi-storey RC frame has been applied widely because of its flexible layout and economic applicability. Due to the complex behavior of materials and influence on nonstructural components， there is still no generally rational method for predicting the seismic failure mode and evaluating the anti-collapse capacity of RC frame structures. In the past decades，based on the seismic analysis，model tests and FE simulation，massive amount of studies have been carried out to investigate the seismic failure mode and collapse mechanism of RC frame. This paper summarizes these studies from the following aspects：the failure mode and collapse mechanism，the yielding mechanism and the anti-collapse design theories. Furthermore，the latest research progress is presented，the existing problems are pointed out and the research trends are prospected.
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CHEN Dawei, WU Zhijian, LIANG Chao, ZHOU Hanxu
2022(1):24-33, DOI: 10.13409/j.cnki.jdpme.20201024001
Abstract:
On September 14，2019，a large loess landslide occurred in Tongwei County，Dingxi City， Gansu Province. Through on-site investigation of the loess landslide and drone aerial survey，the topography，geomorphology，hydrogeology and other conditions that gave birth to the landslide were ascertained，and the morphological characteristics，structural characteristics and movement patterns of the landslide body were studied in-depth，revealing the Tongwei landslide Disaster mechanism. The high-density electrical method is used to detect the stratum structure，thickness of the sliding body， groundwater distribution and spatial distribution of the landslide area. Combining the finite element method and Morgenstem-Price method to calculate the stability of the slope，the distribution of the maximum shear strain and the variation of slope stability with rainfall duration are obtained. The results show that：(1)the shape of the Tongwei landslide is a chair-like shape，which is divided into three typical failure areas，forming a large number of vertical ridges，and the thickness of the loess sliding is approximately 8~50 m；(2)the Tongwei landslide belongs to the "traction-push" type of bedding landslide，and the movement mode is "pull toe instability traction-hindered sliding in the middle partinstability shift in the rear part"；(3)the groundwater is mostly fissure karst water，and the geological structure is not obvious. The geological structure activities such as early earthquakes have a great influence on the stratum；(4)the stability of loess slope decreases continuously with rainfall duration，and the maximum shear strain region is mainly distributed in the middle and upper part of the slope，and develops from mudstone contact to slope surface；(5)rainfall is the most direct factor triggering the Tongwei landslide，and the development of gullies，river erosion and agricultural production activities are important disaster-generating conditions
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Yu Shengsheng, Zhang Xiyin, Chen Xingchong, Wang Yi, Wang Wanping
2021(1):181-192, DOI: 10.13409/j.cnki.jdpme.2021.01.022
Abstract:
The influence of site conditions on structural seismic damage has become a well-known fact. How to conduct quantitative analysis of site seismic response has become one of the urgent problems to be solved in seismic engineering. This paper gives a summary of the research status of the site conditions and the influence of ground motion input on the site seismic response and the analysis methods of the site seismic response. It is shown that site conditions and ground motion input have a significant impact on analytical results of site seismic response. However，there are still some problems：The effects of the frozen soil layer are not fully considered when the site seismic response analysis is carried out in the frozen soil areas；there is no reasonable ground motion model to describe the actual ground motion accurately；the influence law of incident angle of seismic wave on seismic response of site has not been clarified；the widely used equivalent linearization method cannot fully reflect the real motion state of soil mass under the action of ground motion，so its calculation results are not reasonable. Combined with the above problems，the further research contents are prospected，which provide reference for the future research of site seismic response analysis.
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JIANG Haolin, ZHENG Jiangrong, HE Bin, BAO Haiying, DAI Xianpeng, SHAN Han, WANG Dawei
2021(4):909-916, DOI: 10.13409/j.cnki.jdpme.202107015
Abstract:
Jiangsu earthquake monitoring began with the establishment of Nanjing Beijige Seismic Station in 1930. Through the unremitting efforts，exploration and innovation of several generations of seismic workers，the ability and technical level of earthquake monitoring have made a great progress. Looking back on the development of Jiangsu earthquake monitoring system，we can find that it has developed from the operation of weicher seismograph in June 1932 into a multidisciplinary observation network covering the whole province including seismometry，geomagnetism，geoelectricity，deformation and fluid. Seismic monitoring has gone through a process from introducing foreign seismic instruments to completely independent research and development of devices，from analog observation to digital network observation，from manual waveform recognition to AI automatic recognition of seismic events. With the rapid development of science and technology in recent years，the continuous development of observation technology，and the innovation and updating of seismic observation equipments， rich seismic monitoring results have been achieved from the seismic observation network，precursor network and mobile monitoring network covering the whole province. A large number of obtained observation data have been widely used in earthquake quick report，earthquake prediction research， earthquake disaster prevention，earthquake emergency rescue and earthquake scientific research. It has provided a solid earthquake safety guarantee for the rapid economic and social development of Jiangsu. Things present are judged by things past.This paper reviews the development process of earthquake monitoring in Jiangsu，pays tribute to the efforts of the older generation of scientists. The development of earthquake monitoring science and technology is passing down from generation to generation， serving the high-quality development of the whole province，and writing a new development history of earthquake monitoring in Jiangsu.
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YU Feng, ZHANG Chenrong, HUANG Maosong
2020(4):623-632, DOI: 10.13409/j.cnki.jdpme.2020.04.017
Abstract:
The monopile for offshore wind turbine sustains long-term cyclic load due to environment and scouring in the seabed. The long-term cyclic loading behavior of the pile foundation under scouring is an important problem in the design of monopile for an offshore wind turbine. Laboratory model tests were conducted to investigate the performance of a large diameter pile and a small diameter pile in sand subjected to scouring and long term lateral cyclic loadings, in which the influence of scour depth and cyclic loading amplitude on the long-term behavior of the two foundations was discussed. The test results show that the applied cyclic loading improves the post-cyclic capacity of single pile, especially for the small diameter pile. Scour leads to the reduction of post-cyclic capacity of single pile, the effect of which increases with the scour depth. Comparing with the large diameter pile, the increment of residual cumulative deformation of the small diameter pile is smaller in early cyclic loading stage. When the cycle number is larger than 1000 and the scouring depth is twice of the pile diameter, the development of the cumulative deformation of the small diameter pile approaches to be stable, while a further development of deformation appears in the large diameter pile. By bringing the scour affected capacity into the dimensionless cyclic loading amplitude parameters, the lateral cyclic cumulative displacement calculation model of the two kinds of piles under scouring is established, which is applicable to the prediction of long-term lateral cyclic cumulative deformation of single pile considering scouring.
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WU Peisong, WANG Jian, OU Jinping
2020(3):317-325, DOI: 10.13409/j.cnki.jdpme.2020.03.001
Abstract:
Superstructures of seismically isolated structure keep in elastic or slightly elastic-plastic range subjected to rare earthquakes, thereby protecting superstructure effectively. However, very-rare earthquakes may happen in design reference period due to uncertainty of earthquake intensity and character. On basis of “survive rare earthquakes by sustaining significant damage but without globally collapsing” design, horizontal deformation of isolation bearings and overturning resistance under very-rare earthquakes, performance and cost of seismically isolated structure based on “survive very-rare earthquakes” are worth researching. Dynamic responses of three seismically isolated structures with different heights are obtained from elastic-plastic time history analysis. Main failure modes of seismically isolated structures subjected to very-rare earthquakes are presented by comparing the responses such as inter-story drift ratios, horizontal displacements of isolation bearings and overturning moments. The results show that under very-rare earthquakes, horizontal displacements of isolation bearing in all three classic seismically isolated structures are excessive, while other two responses both meet the requirements. With isolation bearings increasing suitably, new structures can avoid destruction by deformation of isolation layer increasing and survive very-rare earthquakes, while isolation effectiveness reduce slightly. Reducing the aspect ratio of superstructure appropriately can control the overturning of whole structure especially high-rise structure subjected to very- rare earthquakes. Therefore, considering both safety and economy, it is an effective and economical way to increase the ultimate displacement of isolation bearing, appropriately reduce the aspect ratio of high-rise seismically isolated structures, and realize resistance ability of isolated buildings subjected to very-rare earthquake.
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FU Xianwen, LIU Jinchun, SUN Ni, SHA Haiyang
2023,43(5):1076-1083, DOI: 10.13409/j.cnki.jdpme.20220228003
Abstract:
In order to explore the impact mechanical properties of 6061-T6 aluminum alloy and its application prospects in protective structures， the method of combining experiments and numerical simulations was used to carry out analysis and research. Based on multiple sets of quasi-static compression and impact compression experimental data， the corresponding parameters of the Johnson-Cook constitutive model were fitted； Conduct further numerical simulation analysis and compare the results of the numerical simulation with the experimental results. Finally， the yield strength， peak stress and other mechanical parameters of 6061-T6 aluminum alloy at room temperature are obtained. The corresponding parameters of the J-C model of 6061-T6 aluminum alloy are fitted； The results show that 6061-T6 aluminum alloy is a strain rate-sensitive material. Its yield strength and flow stress peak increase with the increase in strain rate， and the energy absorption to the impact load is also increases； When the strain rate is 1 600 s-1 ， the yield strength and ultimate bearing capacity increase by 30% and 78%， respectively， compared with the quasi-static state； The numerical simulation results are in good agreement with the experimental results， indicating that the fitted J-C model can better represent the stress flow behavior of 6061-T6 aluminum alloy at high strain rates. The research results can provide a basis and reference for the impact dynamic analysis of 6061-T6 aluminum alloy and its application in anti-explosion structure. It has broad application prospects in the fields of protection engineering， disaster prevention， and reduction engineering.
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Bu Yifan, Chen Guoxing, Zhou Zhenglong, Wu Qi
2021(2):343-349, DOI: 10.13409/j.cnki.jdpme.20191017003
Abstract:
One of the key issues in the deformation behavior of soil is the measurement of dynamic shear modulus and damping ratio. In order to fundamentally understand the measurement of dynamic shear modulus and damping ratio，using the resonant column apparatus and the cyclic loading triaxial testing system made by GCTS，the resonant column and cyclic triaxial tests on the variation characteristics of the normalized shear modulus(G/Gmax)and damping ratio(λ)with increasing shear strain (γ)were performed. It revealed that the variation trends of G/Gmax and λ with increasing γ obtained from resonant column tests were consistent with those obtained through cyclic triaxial tests，and the consistency was independent of the depth and soil type. Moreover，the two test methods can be combined to obtain the G/Gmax and λ of soil with a strain range of 10?6 to 10?2，which can provide reasonable curves of the G/Gmax and λ for nonlinear analysis on seismic site response of major projects.
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LI Yang, XU Chengshun, DU Xiuli
2020(3):326-336, DOI: 10.13409/j.cnki.jdpme.2020.03.002
Abstract:
During the Kobe earthquake in Japan, different degrees of earthquake damage occurred on the subway underground structures. Only one zone of the standard section of Daikai station totally collapsed, while the other zones of Daikai station, its running tunnels and other subway underground structures did not have serious earthquake damage. In this paper, the earthquake damage responses of the standard section, central hall and running tunnel structure of Daikai station were analyzed based on nonlinear finite element analyses which can reasonably simulate the damage of underground structures. Numerical results indicate that different width of structural cross section and burial depth lead to different overlying earth pressure on the structures at the standard section, central hall section and running tunnel section. The different overlying earth pressure generated different axial compression ratio of the three structural columns. In addition, the three structures with different lateral racking stiffness had different degree of damage and stiffness degradation, and further led to different lateral racking deformation. Eventually, the columns of Daikai station standard section destroyed due to the excessive relative deformation under the high axial compression ratio, which caused the total collapse damage to the entire frame structure. On the contrary, the columns of central hall and running tunnel section have not destroyed because there were not excessive relative deformation under the lower axial compression ratio, which kept the bearing capacity of the entire frame structure.
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ZHUO Weidong, WANG Zhijian, LIAO Liyun, CAI Zhehan, WANG Hongda
2020(4):483-489, DOI: 10.13409/j.cnki.jdpme.2020.04.001
Abstract:
To improve the seismic performances of bridges with very tall piers in high seismicity area, design concept of the bridge with very tall piers, which is composed mainly of concrete-filled steel tubular (CFST) columns and energy dissipating mild steel plates (EDMSP), is proposed based on the principle of earthquake restorable structures. Trial design of a bridge with the proposed innovative composite box section tall piers is carried out based on a typical continuous rigid frame highway bridge with tall RC box section piers. The static and seismic performances of the bridge according to fundamental loading combination and E2 level seismic action are analyzed respectively. The seismic performance of the designed bridge under E2 level seismic action is compared with the bridge with conventional RC box section piers. The results show that: (a) under fundamental loading combination, the bridge with innovative composite box section piers can well meet the requirements of structural strength and stability; (b) under E2 level seismic action, the conventional designed bridge experiences medium damage in the piers, while only the replaceable EDMSP elements of the innovative designed bridge undergo plastic deformation, indicating the innovative designed bridge is earthquake restorable; (c) the seismic displacement responses of the innovative designed bridge is significantly smaller than that of the conventional designed bridge under E2 level seismic action.
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LIU Guoyang, LI Junjie, KANG Fei
2020(5):679-689, DOI: 10.13409/j.cnki.jdpme.2020.05.001
Abstract:
A three-dimensional discontinuous deformation analysis(3D DDA)method was used tooutput the kinetic energy and motion trajectory of rolling blocks. Compared with the results of the existing laboratory experiment and numerical simulation method,the accuracy of the 3D DDA methodwas verified. By analyzing the influence of the rockfall platform on the kinetic energy,motion trajectory and movement law of blocks along rock slopes with different slope heights,slope angles and foldingpoint positions,the influence law of the rockfall platform on the block movement was studied. Finally,the rockfall slope with a complex slope shape at Lang village in Tibet was simulated,and the protective effect of the rockfall platform on rockfall disaster was analyzed. The results show that the rockfall platform can decrease the kinetic energy of the rolling block,change the block motion trajectory,and reduce the impact of the rolling block on the protection structure or the traffic line at the slope bottom. Meanwhile,the general laws including the block movement and the corresponding platform design width under different slope characteristics are given,and they provide a basis for the design ofrockfall platform.
