长短桩复合地基作用机理及敏感性分析

采用灰色关联分析方法,结合银西铁路甘宁段,研究了褥垫层厚度、填土高度和土工格栅层数对复合地基受力和沉降的影响程度。选取6个方案的计算结果作为模拟数据案例,以此研究长短桩复合地基在不同褥垫层厚度、填土高度和土工格栅层数作用下的受力特性和沉降规律。结果表明:三个因素对复合地基桩土应力比按影响程度大小排序依次为:填筑高度>格栅层数>褥垫层厚度。路堤填土高度对复合地基受力和沉降变形影响最大,在实际工程中应该适当调节路堤填土高度。

Mechanism and Sensitivity Analysis of Long and Short Piles Composite Foundation

In this paper,combined with the Ganning section of Yinchuan-Xi'an High-speed Railway,the influence of the thickness about the cushion layer,the height of the filling soil and the number of geogrid layers on the stress and settlement of the composite foundation was studied by using the grey correlation analysis method.The calculation results of six schemes were selected as simulation data cases to study the mechanical characteristics and settlement rules of long and short piles composite foundation under the action of different cushion layer thickness,filling height and geogrid layers.The results show that the influence of three factors on the stress ratio of pile-soil in composite foundation ranks in order according to the degree of influence are as follows:filling height>number of grid layers>thickness of cushion layer.The height of embankment filling has the greatest influence on the stress and settlement deformation of composite foundation,so the height of embankment filling should be adjusted properly in practical engineering.