考虑时间效应的软土地基上加筋土挡墙的长期性能研究

项目名称： 考虑时间效应的软土地基上加筋土挡墙的长期性能研究

项目编号： No.50808086

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 陈页开

作者单位： 华南理工大学

项目金额： 20万元

中文摘要： 加筋土挡墙出现以来，因其廉价美观、抗震性能好、对地基变形适应性大等多方面的优点而得到广泛重视和推广应用。然而，目前对软土地基上加筋土挡土墙的加固机理、设计方法以及加筋土挡墙长期性能的都认识很少，设计理论与方法远远落后于工程实践。因此，开展软土地基上加筋土挡墙的长期工作特性研究具有现实的迫切性和必要性。 本报告采用试验和数值分析方法，在以下几个方面开展系统研究，取得对工程实践有参考价值和推广意义的成果：首先，以双向土工格栅和单向土工格栅作为研究对象，通过室内蠕变试验研究了土工格栅的蠕变特性，并结合试验所得的蠕变参数建立考虑蠕变效应和松弛效应的本构模型。其次，对软土原状土样进行了三轴压缩试验和三轴蠕变试验，研究了软土的固结蠕变特性，并结合试验所得的蠕变参数建立软土固结蠕变的本构模型。最后，结合室内试验研究所建立的本构模型，采用有限元法，对一座软土地基上的加筋土挡墙实例工程的工作特性进行了数值分析，研究了加筋土挡墙面板侧向位移、填土表面沉降、地基表面沉降以及土工格栅最大拉力的长期变形特性，并进一步分析了土工格栅蠕变特性、软土地基蠕变特性、深厚软土地基以及坚硬地基对挡墙长期性能的影响。

中文关键词： 软土地基；土工格栅；加筋土挡墙；室内试验；有限元分析

英文摘要： With numerous advantages including low cost, aesthetic of appearance, high resistance to seismic load, good adaptability to large foundation deformation, etc., the reinforced retaining wall has been applied extensively.However, the mechanism, design method and long-term performance of reinforced retaining wall on soft foundation are known very few presently. Design theory and methods relatively lag behind the applications. Therefore, it is very important and urgent to study the long-term performance of reinforced retaining wall constructed on soft foundation. Based on experimental and numerical analysis, researches as below were carried out to obtain valuable results for engineering practices:Firstly, based on the laboratory experiments, the creep properties of geogrid was studied, and the constitutive model considering creep and relaxation effects with the creep parameters of test was set up. Secondly, the consolidation creep characteristic of soft soil was researched by triaxial compression test and triaxial creep test for undisturbed soil samples, and the constitutive model for consolidation creep of soft soil with the creep parameters of test was set up. Finally, based on the established constitutive model, the long-term performance of a practical reinforced retaining wall was analyzed with the finite element method. The numerical results including the lateral displacement of face, the settlement of fill surface, the settlement of foundation surface and the maximal tensile force of geogrid was analyzed, the long-term effects of creep properties of geogrid and soft, deep soft foundation and stiff foundation were further analyzed.

英文关键词： soft soil foundation; geogrid; reinforced retaining wall; laboratory experiment; finite element analysis