考虑上部结构的桩筏基础非线性共同作用分析

NONLINEAR ANALYSIS OF THE PILED RAFT FOUNDATION WITH INTERACTION OF ITS SUPERSTRUCTURE FOR REDUCING DIFFERENTIAL SETTLEMENTS

当前虽然已有考虑桩筏非线性的设计,但仍无人在此基础上,考虑上部结构。因此考虑上部结构,进一步认识其与桩筏基础非线性共同作用机理,优化桩筏基础设计,具有重要的现实意义。本文以子结构法凝聚上部结构的荷载及刚度,以平面壳体单元模拟筏板,按有限层法模拟桩土之间的弹性相互作用,用广义剪切位移法模拟桩的非线性工作性状,建立了一种考虑上部结构共同作用的桩筏基础非线性分析方法,并编制了分析程序。通过实例分析,探讨了上部结构与桩筏基础非线性共同作用的机理,研究了合理布桩方式,探讨了以差异沉降为目标的优化设计的可能途径。

Although currently nonlinear properties have been considered in some designs of the piled raft foundations, the superstructures are still not taken into account. It is meaningful to study the mechanism of the nonlinear interaction of the piled raft foundation and the superstructure and to optimize the design of piled raft foundations. In this paper, the sub - structure method is used to agglomerate the rigidity and load of the superstructure. The rafts is simulated by the plane - shell element, and the nonlinear performance of the piles is analyzed using the generalized shear displacement method, and the elastic interaction between the pile and the surrounding soils is determined by finite layer method. A new theoretical method and the corresponding computing program for the nonlinear analysis of the piled raft foundations with the consideration of their interactions with the superstructures are established. By the analysis to a real case, the nonlinear interaction mechanism and the reasonable layout of piles are further discussed. And finally the possible ways to optimize the design of the piles raft foundations are put forward in which the optimization object is the differential settlement.