郑俊杰 邵安迪 谢明星 景丹

摘要：在剛性挡土墙后设置柔性垫层能有效减小墙背土压力。聚苯乙烯土工泡沫（EPS）是一种常见的柔性材料，具有受力易压缩的特性。通过开展室内挡土墙模型箱试验，对铺设不同弹性模量以及不同厚度的EPS板的各工况下墙背土压力分布规律进行了研究，详细分析了弹性模量和厚度对EPS板在不同填土表面荷载作用下的减压性能的影响;并通过FLAC3D建立有限差分数值模型，对不同压缩量情况下土压力分布规律进行了分析。研究结果表明：EPS板能有效地减小挡土墙墙后土压力;EPS板的弹性模量越小、厚度越大、墙后填土表面的外荷载越大，EPS板的减压效果越明显;EPS板厚增加到一定程度后，EPS板的减压效果不会再有明显提升，EPS板厚达到0.1倍墙高即可获得最佳减压效果。

关键词：挡土墙;聚苯乙烯土工泡沫;模型试验;数值模拟;土压力

中图分类号：TU432 文献标志码：A 文章编号：20966717（2020）04000109

收稿日期：20200305

基金项目：国家重点研发计划（2016YFC0800200）;国家自然科学基金（51678267、51878313、51808243）

作者简介：郑俊杰（1967 ），男，教授，博士生导师，主要从事岩土工程与隧道研究，Email：zhengjj@hust.edu.cn。

Received：20200305

Foundation items：National Key Research and Development Program （No. 2016YFC0800200）; National Natural Science Foundation of China （No. 51678267， 51878313， 51808243）

Author brief：Zheng Junjie （1967 ）， professor， doctorial supervisor， main research interests： geotechnical engineering and tunnel engineering， Email： zhengjj@hust.edu.cn.

Model test study on decompression performance of EPS boards behind retaining walls

Zheng Junjie， Shao Andi， Xie Mingxing， Jing Dan

（School of Civil Engineering and Mechanics， Huazhong University of Science and Technology， Wuhan 430074， P.R. China）

Abstract： Setting a flexible pad cusion behind the rigid retaining wall can effectively reduce the lateral earth pressure. Expanded polystyrene （EPS） geofoam is a common flexible material that has the characteristic of easy compression. In this paper， through the retaining wall model test in laboratory， the lateral earth pressure distribution of different EPS boards with different elastic modulus and thickness is studied; the influence of elastic modulus and thickness on the decompression performance of EPS boards under different loadings on the filling surface is analyzed in detail. The influence of compression value of EPS board on the lateral earth pressure on retaining wall is also analyzed by FLAC3D numerical modeling. The research results show that the EPS board can effectively reduce the lateral earth pressure behind the retaining wall; the smaller the elastic modulus of the EPS board， and the larger the thickness， as well as the external load on the surface of the backfill wall， the decompression effect of the EPS board becomes more significant. After the EPS board thickness increases to a certain extent， the decompression effect of the EPS board will not increase significantly. The best decompression effect can be obtained when the EPS board thickness reaches 0.1 times the wall height.

Keywords：retaining wall; EPS; model test; numerical simulation; earth pressure

挡土墙是土木工程、交通工程领域重要的结构物之一，其主要功能是抵抗侧向土压力，并防止墙后土体发生滑动或坍塌，目前已广泛应用于房屋建筑、水利工程、公路与铁路工程中。减小挡土墙墙背土压力对于保障工程安全、降低工程造价具有重要意义。迄今为止，诸多学者对挡土墙土压力进行了大量试验研究。Terzaghi[12]最早开展模型试验，证实了挡土墙土压力沿墙高呈非线性分布，该结论在岳祖润等[3]的离心试验中得到再次验证。……