土工格栅加筋土地基载荷试验的数值模拟

采用FALC^3D对土工格栅加筋土地基载荷试验进行了进一步的数值模拟分析。根据计算结果,针对原型试验中难以量测的试坑变形及筋土界面摩阻力分布特征进行了讨论。利用数值模拟技术的优势,求解加筋地基的应变场,研究了加筋地基的破坏模式。结果表明:在竖向荷载作用下,试坑会发生侧向位移,通过加筋能有效减小试坑的侧向位移;筋土界面摩阻力的分布与筋土之间的相对位移直接相关;加筋地基的破坏机构因筋材的存在而发生改变,“深基础”效应以及“扩散层”效应都是加筋地基的增强机理,但地基的破坏模式随筋材的布置形式改变而有所不同。

Numerical Analysis of In-situ Plate Load Tests of Geogrid Reinforced Foundation

Numerical analysis of in-situ plate load tests of geogrid reinforced foundation is carried out by using FLAC^3D software. Based on results of numerical calculation, the displacement of test pit and the distribution of shear stress acting on the interface between reinforcement and soil are investigated. The failure modes of reinforced foundation under different layout of reinforcement are discussed according to the shear strain increment contour of reinforced foundation obtained by using FLAC^3D post-processing functions. It is revealed that the test pit would move outward under the vertical load and the use of reinforcement could reduce the lateral displacement of the test pit. The shear stress acting on the interface of soil and reinforcement is directly associated with the relative displacement of sand and geogrid. The failure mode of reinforced foundation differs from that of unreinforced foundation. The mechanism of reinforcement in reinforced foundation includes “deep-footing” effect and “wide-slab” effect. The failure mode differs when the layout of reinforcement is changed.