超深层岩溶地基上桩筏基础选型及工作性状数值分析

摘要

结合无锡世贸中心项目,对超深层岩溶桩筏基础选型进行讨论,同时利用ABAQUS对岩溶基础上桩筏基础共同作用进行数值模拟分析,地基土采用弹塑性模型,上部结构与桩筏基础采用弹性模型,对三者在竖向荷载条件下的共同作用进行非线性分析,并结合现场实测数据对岩溶基础上超高层结构桩筏基础工作性状进行研究.分析表明:桩筏基础采用摩擦桩与溶洞灌浆相结合方法处理超深层岩溶地基具有可行性;筏板内力分布及沉降的数值分析结果与实测值相吻合;采用超长摩擦桩可减轻上部结构对深层溶洞的影响;筏板内力分布与上部结构和布桩方式有关.%Combined with the Wuxi World Trade Center project,discussing the selection of pile-raft foundation on super-deep karst,at the same n'me.studyingnumerically on the interaction of the pile-raft foundation on the super-deep karst by ABAQUS. The soil material is elastic-plastic,the upper structure and the pile-raft foundation using elastic material,then doing nonlinear analysis on the interaction of the three on vertical load nonlinear and studying the behavior of pile-raft foundation of super-high building on karst with the measured data together. The analysis shows that the pile-raft foudation that using friction pile and combined the caves grouting method to deal with the deep karst is availible. The numerical analysis result of internal force distribution and settlement is agree with the measured data. Using super-long friction pile can reduce the effection on the deep karst. The internal force distribution of raft is related with upper structure and pile arrangement.