双排桩基悬臂式挡土墙结构计算方法研究

Research on calculation method of double-row pile foundation cantilever retaining wall structure

基于双排桩基悬臂式挡土墙结构与传统支挡结构存在较大的差异性,通过探讨双排桩基悬臂式挡土墙结构的承载机理,提出该结构的简化分析模型以及结构内力与变形的解析计算方法,并通过典型工程的有限元建模计算,验证该计算方法的可行性。研究结果表明:双排桩基悬臂式挡土墙结构可分解为悬臂段、底板与桩基,依次采用悬臂梁模型、简支梁模型与弹性地基梁模型进行设计计算;悬臂段承受填筑体水平土压力荷载;底板承受悬臂段传递的重力、水平力与弯矩,以及上部填筑体的竖向均布土压力荷载;桩基承受荷段受水平土压力,锚固段承受由变形引起的弹性抗力;悬臂段底部、底板纵向跨中断面、底板与桩基连接处以及桩基顶部与锚固点附近为应力集中断面,设计时应注意截面安全检算;理论计算结果略大于数值计算结果,验证了该计算方法的合理性,为结构优化设计提供了思路。

There was significant differences between the double-row pile foundation cantilever retaining wall and the traditional retaining structure.And the bearing capacity and deformation behaviors of double-row pile foundation cantilever retaining wall are more complex.A simplified analysis model and the calculation method were proposed based on the bearing mechanism of the double-row pile foundation cantilever retaining wall.The reliability of theoretical calculation method was verified by contrasting the results of finite element calculation.The results show that:The structure of double-row pile cantilever retaining wall was decomposed into cantilever section,bottom plate and pile foundation,with the cantilever beam model,simply supported beam model and elastic foundation beam model were used to design and calculate.Cantilever section subjected to horizontal soil pressure load of the filling body;The gravity,horizontal force and moment of cantilever,and vertical uniform earth pressure acting on the floor;The load of the loaded section is the horizontal earth pressure,and the loaded of the anchorage section is subjected to elastic resistance caused by deformation.The structure design should pay attention to the bottom plate and the bottom plate and the pile cantilever joints,joints,pile and pile anchor point safety inspection section calculation.The theoretical calculation results are slightly larger than the numerical results,and the rationality of the calculation method is verified,besides the new thought about structural optimization design was proposed.