纯地下室平板柱帽式筏板基础设计探讨

Discussion on design of flat column cap raft foundation in pure basement

对满堂地下车库的纯地下室部分,目前设计中大多采用平板柱帽式筏板基础,采用JCCAD或YJK软件进行有限元分析。对软件计算的结果,混规要求"应对分析结果进行判断和校核,在确认其合理、有效后方可用于工程设计",但目前缺少校核手段。针对该问题,从分析筏板地基土变形特征及受力特点入手,推导出由高水位控制筏板内力的近似解析解,并给出由裂缝控制配筋的计算公式。最后,通过工程算例对比分析解析解和有限元计算结果,论证了解析解的正确性,为设计提供一种校核手段。

For the pure basement part of the full underground garage, the flat column cap raft foundation is mostly used in the current design, and the finite element analysis is done with JCCAD or YJK software. For the calculation results of software, the concrete code requires that "the analysis results should be judged and checked, and can be used in engineering design only after they are confirmed to be reasonable and effective", but now lacking the means of checking. In view of this problem, starting from analyzing the deformation characteristics and stress characteristics of the raft foundation soil, the approximate analytical solution of the raft internal force controlled by high water level was deduced, and the calculation formula of reinforcement by crack control had been given. Finally, the correctness of the analytical solution was proved by comparing the analytical solution with the finite element calculation results, which provides a means of checking the design.