抗风化大体积土工袋工程应用与抗压性能研究

Engineering Application and Compressive Performance of Weathering‑resistant Large‑volume Soilbags

摘要:

抗风化大体积土工袋在抢险防灾减灾工程中有着广泛应用，但目前对其性能要求和工程使用规范尚不明确。 通过总结国内外结合工程实践，阐述了关于该工法的多项基本性能要求指标，并发现对大体积土工袋在性能上起控制性的指标是下部土工袋在上部土工袋的自重作用下的抗压性能。对土工袋进行三种不同密实度土体的等应变压缩试验，研究其抗压性能。然后以增量广义胡克定律为基础，考虑土工袋侧向非线性变形条件，得到其大体积土工袋的极限抗压强度理论公式和袋体内部土体的剪胀方程，该方程可用于计算土工袋的破坏荷载和沉降。研究结果表明：①对大体积土工袋破坏起控制因素的是袋体中部筋材的抗拉强度；②通过抗压试验结果与理论值对比， 表明极限抗压强度理论公式与试验结果基本一致，成果可以为实际工程提供参考；③提出了土工袋鼓胀度系数 m， 可反应土工袋侧边的鼓胀程度，对确定大体积土工袋侧胀的工程指标具有一定指导意义；④经过土工袋加固后土体的剪胀性更加明显，其抗剪强度也更高。

Abstract:

Weathering-resistant large-volume soilbags are widely used in disaster prevention and mitigation engineering. However, their performance requirements and engineering application standards remain unclear. By summarizing domestic and international engineering practices, multiple fundamental performance requirement indicators for this construction method were presented. It was found that the key controlling indicator for large-volume soilbag performance was the compressive property of the lower soilbags under the self-weight of upper bags. Compression tests at equal strain were conducted on soilbags filled with soil of three different compaction levels to explore their compressive performance. Furthermore, based on the incremental generalized Hooke's law and considering the lateral nonlinear deformation of soilbags, a theoretical formula for the ultimate compressive strength of largevolume soilbags and a dilatancy equation for the soil inside the bags were derived. These equations could be used to calculate the failure load and settlement of the soilbags. The results showed that: (1) the controlling factor for the failure of large-volume soilbags was the tensile strength of the reinforcement materials in the mid-section of the bags. (2) Comparison between compression test results and theoretical values demonstrated that the theoretical formula for ultimate compressive strength was basically consistent with the experimental results, and these findings could serve as a reference for practical engineering. (3) A bulging degree coefficient m for soilbags was proposed, which could reflect the degree of lateral bulging of the soilbags and provide guidance for determining engineering indicators of lateral bulging of large-volume soilbags. (4) The soil after soilbag reinforcement exhibited more pronounced dilatancy and increased shear strength.