筏板上路基箱下铺砂土垫层分压性能研究

摘要

On the strong stiffness ground foundation,of welded grillage slabs effectively.When large cranes walking on the strong stiffness ground foundation like raft,welded grillage slabs were used to share the pressure and a certain thickness of sand soil cushion could optimize the sharing result.Base on the actual structures,the finite element numerical simulation was used to analyze the optimization of sandy soil cushion with different parameter.The results showed that the change of sand cushion thickness had influence on the sharing results of welded grillage slabs.Increasing the thickness of sandy soil cushion could weaken the largest base reaction;however enlarge the vertical displacement of welded grillage slabs.Increasing the loading could enlarge the sharing result of welded grillage slabs.With the results of the study,the optimal cushion parameters were got by calculation.The study could provide technical support for construction.%大型起重机在筏板上行走或作业时,经常采用路基箱分压.在筏板等刚度较大的地基上采用路基箱时,分压能力往往达不到预期效果.为优化路基箱在刚度较大地基上的分压效果,可采用在路基箱下铺设砂土垫层的措施.运用Ansys有限元软件,模拟不同厚度砂土垫层的分压情况,得到不同厚度下的基底反力分布及路基箱的竖向位移.分析结果表明铺设砂土垫层可以显著提高路基箱的分压效果,分压效果随垫层厚度的增加而有所提升,同时会增加路基箱竖向沉降;不同荷载等级下路基箱分压效果不同,较大的荷载等级下分压效果较好.通过分析,得到最佳的砂土垫层参数,兼顾经济性和结构安全性.研究结果对相应工程的施工安全有一定的参考意义.