环保型土袋柔性挡土墙的稳定机理及抗震性能研究

Soilbag retaining wall (“SRW”) is a neoteric reinforced retaining structure, which counteracts earth pressure through the friction and occlusion between adjacent soilbags and performs well in reducing vibration as well. Compared with common concrete retaining wall, SRW can prevent structural cracks by earthquakes for its flexibility and its economy and environment value is more obvious. However people have known little about the theoretical mechanism of soilbag reinforcing and few applications of SRW are found. This research will conduct a further exploitation on existing discrete element computing program, through which the deformation and displacement of SWR under static and dynamic loads can be investigated from the microscopic view. Thus the tension of bags and distribution of earth pressure in SRW can be obtained by computing simulation. Besides, a series of model tests in laboratory will be carried out to reveal the failure modes of SRW under ultimate loads, integrated with the simulation results. And the effect of vibration reduction of SRW will be studied through shaking table tests with various of vibration frequencies. This research can deepen our understanding of the stability mechanism and seismic performance of SRW, and provide technical guidance for practice applications.

土袋挡土墙作为新型加筋土挡墙结构，通过袋子之间的摩擦力和嵌固咬合力抵消墙后土压力，还具有减振隔振效果，与常规混凝土挡墙相比，可以避免地震作用下产生裂缝甚至结构物垮塌事故，成本低廉、绿色环保。但是至今由于对土袋柔性挡土墙稳定机制的研究和认识匮乏，人们对土工袋仍停留在感性认识、尝试应用的阶段，致使土工袋用于加筋挡土墙的工程实例在国内并不常见。本项目拟对颗粒离散元计算程序进行二次开发，从细观角度观测土袋挡土墙在静动力作用下的变形和位移情况，并得到袋子张力的发挥程度（加筋效果）及土压力在挡墙内部的分布情况；开展室内等比模型试验研究土袋挡土墙在极限荷载下的破坏模式，与数值模拟结果进行对比分析；并利用小型振动台试验研究土袋挡土墙在不同频率震动作用下的位移和加速度响应。本项目研究可以深化对土袋柔性挡土墙稳定机理的认识，挖掘土袋挡墙抵抗地震破坏的潜力，为其在工程实践中的应用提供有力的技术支撑和理论指导。

土袋挡土墙作为新型加筋土挡墙结构，通过袋子之间的摩擦力和嵌固咬合力抵消墙后土压力，还具有减振隔振效果，与常规混凝土挡墙相比，可以避免地震作用下产生裂缝甚至结构物垮塌事故，成本低廉、绿色环保。但是至今由于对土袋柔性挡土墙稳定机制的研究和认识匮乏，人们对土工袋仍停留在感性认识、尝试应用的阶段，致使土工袋用于加筋挡土墙的工程实例在国内并不常见。本项目对颗粒离散元计算程序进行二次开发，从细观角度解释土工袋加筋机理以及力学强度公式，结合室内模型试验观测了土袋挡土墙在静动力作用下的变形和位移情况及土压力在挡墙内部的分布情况；研究了土袋挡土墙在极限荷载下的破坏模式，推导出土袋挡墙墙后土压力计算公式；并利用小型振动台试验研究土袋挡土墙在不同频率震动作用下的位移、动土压力和加速度响应。本项目研究深化了对土袋柔性挡土墙稳定机理的认识，解明了土袋挡墙减振机理，为其在工程实践中的应用提供有力的技术支撑和理论指导。