格栅加筋Sandwich形黏土-砂混合填料挡土墙的破坏机理及抗震性能研究

项目名称： 格栅加筋Sandwich形黏土-砂混合填料挡土墙的破坏机理及抗震性能研究

项目编号： No.51478255

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 建筑科学

项目作者： 刘飞禹

作者单位： 上海大学

项目金额： 83万元

中文摘要： 格栅加筋 Sandwich 形黏土-砂混合填料挡土墙采用黏土与薄砂层间隔填筑而成，并在薄砂层中用土工格栅进行加筋,形成了黏土夹加筋砂层的三明治状构造。这种新型挡土墙既有良好的工程性能，又减少了粗颗粒土的使用，降低了工程成本。本项目拟先采用改进的大型直剪仪，对该类挡土墙的筋-土界面循环剪切特性进行研究，重点分析黏土和砂土的分层厚度对界面特性的影响，提出考虑循环剪切效应的筋-土界面相互作用的动力理论模型，并将该模型编制成 FLAC3D 的用户子程序，采用FLAC3D建立地震作用下该类挡土墙的三维流固耦合分析模型；通过振动台试验对该类挡土墙在地震作用下的破坏机理进行研究，并为数值分析模型提供验证依据；最后采用验证后的数值分析模型对影响该类挡土墙抗震性能的关键因素进行研究，提出相应的抗震设计方法。本项目的研究成果不仅具有很好的工程应用价值，而且还将丰富混合填料加筋挡土墙的理论，具有一定的理论价值。

中文关键词： 土工格栅；加筋土；破坏机理；抗震性能

英文摘要： The backfill of the geogrid reinforced sandwich earth fill retaining walls is made up of clay reinforced with geogrid encapsulated in thin layers of sand.The geogrid reinforced sandwich earth fill retaining walls have great engineering behavior and can reduce the construction cost.Firstly Monotonic and cyclic shear behavior of soil-geogrid interface will be studied through improved large direct shear apparatus.Special stress will be laid on the influence of sand and clay stratified thickness on interface behavior. And then a new constitutive model for the sand-geogrid interface of clay reinforced with geogrid encapsulated in thin layer of sand will be advanced.The new constitutive model will be incorporated into FLAC3D to set up a numerical analysis model for geogrid reinforced sandwich earth fill retaining walls subjected to earthquake loadings. The failure mechanism of geogrid reinforced sandwich earth fill retaining walls under earthquake will studied through shaking table tests. The results from the numerical analysis will be compared with the results from shaking table tests. Finally, the key factors affecting the earthquake resistance behavior of geogrid reinforced sandwich earth fill retaining walls will be studied by the validated numerical model. The conclusions from this project have a broad future in engineering applications. And also the conclusions can enrich the theory of reinforced earth wall with mixtures.

英文关键词： Geogrid;Reinforced soil;Failure mechanism;Seismic performances