超高延性混凝土加固砌体墙抗震性能研究∗

Study on Seismic Performance of Masonry Walls Reinforced with Ultrahigh Ductile Concrete

摘要:

为研究超高延性混凝土（Ultra-High Ductile Concrete，UHDC）加固砌体墙的抗震效果，对两个实心墙和两个空斗墙进行了低周反复加载试验。结果表明，与未加固墙相比，加固后实心墙承载力提升31% ，峰值位移降低了30% ；加固后空斗墙承载力提升了223% ，峰值位移提高了471% 。利用OpenSees 软件对UHDC 加固砌体墙进行了建模，分析了不同加固层厚度、加固方式及竖向压应力等因素对抗震性能的影响。结果表明：对于实心墙，加固层厚度为10、20、30 mm 时，峰值承载力分别提高16.0% 、36.2% 、56.1% ，峰值位移分别降低了28.3% 、26.7% 、26.7% ；对于空斗墙，加固层厚度为10、15、20 mm 时，峰值承载力分别提高117.4% 、179.5% 、243.4% ，峰值位移分别提高345.5% 、522.7% 、506.1% 。当竖向压应力为0.6 MPa 和0.9 MPa 时，实心墙峰值承载力较0.3 MPa 时分别提高16.8% 和33.0% ，峰值位移分别降低12.0% 、16.0% ；空斗墙峰值承载力较0.15 MPa 时提高6.5% 和10.5% ，峰值位移分别提高2.8% 、0.0% 。当分别采用整面加固、斜交条带加固、正交条带加固时，实心墙峰值承载力分别提高36.2% 、12.0% 、5.4% ，峰值位移分别降低26.7% 、28.3% 、28.3% ；空斗墙峰值承载力分别提高179.5% 、80.1% 、39.3% ，峰值位移分别提高522.7% 、203.0% 、203.0% 。最后提出了UHDC 加固砌体墙抗剪承载力计算公式，与试验和模拟结果比较，具有较好的精度，可为加固设计提供理论支持。

Abstract:

To investigate the seismic performance of masonry walls reinforced with ultra-high ductileconcrete (UHDC), low-cycle repeated loading tests were conducted on two solid walls and two cavi-ty walls. The results showed that, compared to unreinforced walls, the load-bearing capacity of thesolid walls and cavity walls increased by 31% and 223%, respectively, while the peak displacementdecreased by 30% and 471%, respectively. The UHDC-reinforced masonry walls were modeled us-ing OpenSees software to assess the impact of various factors on seismic performance, including re-inforcement layer thickness, reinforcement mode, and axial compressive stress. The results indicat-ed that, for solid walls, when the reinforcement layer thickness was 10, 20, and 30mm, the peakload-bearing capacity increased by 16.0%, 36.2%, and 56.1%, respectively, while the peak dis-placement decreased by 28.3%, 26.7%, and 26.7%, respectively. For cavity walls, the peak loadbearingcapacity increased by 117.4%, 179.5%, and 243.4%, respectively, and the peak displace-ment increased by 345.5%, 522.7%, and 506.1%, respectively, when the reinforcement layerthickness was 10, 15, and 20mm. When the axial compressive stress was 0.6 MPa and 0.9 MPa,the peak load-bearing capacity of solid walls increased by 16.8% and 33.0%, respectively, com-pared to 0.3 MPa, while the peak displacement decreased by 12.0% and 16.0%, respectively. Com-pared to 0.15 MPa, the peak load-bearing capacity of cavity walls increased by 6.5% and 10.5%,with peak displacement increasing by 2.8% and 0.0%, respectively. When full-surface, obliquestrip, and orthogonal strip reinforcement methods were used, the peak load-bearing capacity of solidwalls increased by 36.2%, 12.0%, and 5.4%, respectively, with peak displacement decreasing by26.7%, 28.3%, and 28.3%, respectively. For cavity walls, the peak load-bearing capacity in-creased by 179.5%, 80.1%, and 39.3%, respectively, with peak displacement increasing by522.7%, 203.0%, and 203.0%, respectively. Finally, a formula for calculating the shear bearingcapacity of UHDC-reinforced masonry walls was proposed, which showed reliable accuracy whencompared with experimental and simulation results. The formula provides theoretical support for re-inforcement design.