擋土墻后EPS板減壓性能模型試驗研究

鄭俊杰 邵安迪 謝明星 景丹

摘要：在剛性擋土墻后設置柔性墊層能有效減小墻背土壓力。聚苯乙烯土工泡沫（EPS）是一種常見的柔性材料，具有受力易壓縮的特性。通過開展室內擋土墻模型箱試驗，對鋪設不同彈性模量以及不同厚度的EPS板的各工況下墻背土壓力分布規律進行了研究，詳細分析了彈性模量和厚度對EPS板在不同填土表面荷載作用下的減壓性能的影響;并通過FLAC3D建立有限差分數值模型，對不同壓縮量情況下土壓力分布規律進行了分析。研究結果表明：EPS板能有效地減小擋土墻墻后土壓力;EPS板的彈性模量越小、厚度越大、墻后填土表面的外荷載越大，EPS板的減壓效果越明顯;EPS板厚增加到一定程度后，EPS板的減壓效果不會再有明顯提升，EPS板厚達到0.1倍墻高即可獲得最佳減壓效果。

關鍵詞：擋土墻;聚苯乙烯土工泡沫;模型試驗;數值模擬;土壓力

中圖分類號：TU432 文獻標志碼：A 文章編號：20966717（2020）04000109

收稿日期：20200305

基金項目：國家重點研發計劃（2016YFC0800200）;國家自然科學基金（51678267、51878313、51808243）

作者簡介：鄭俊杰（1967 ），男，教授，博士生導師，主要從事巖土工程與隧道研究，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

擋土墻是土木工程、交通工程領域重要的結構物之一，其主要功能是抵抗側向土壓力，并防止墻后土體發生滑動或坍塌，目前已廣泛應用于房屋建筑、水利工程、公路與鐵路工程中。減小擋土墻墻背土壓力對于保障工程安全、降低工程造價具有重要意義。迄今為止，諸多學者對擋土墻土壓力進行了大量試驗研究。Terzaghi[12]最早開展模型試驗，證實了擋土墻土壓力沿墻高呈非線性分布，該結論在岳祖潤等[3]的離心試驗中得到再次驗證。……