减沉桩基础作用特性的有限元分析

合理地控制沉降是减沉桩基础设计的指导思想和目标,由于这种基础形式形成和发展较晚,实际工程中大都以以往的经验为依据进行设计。采用弹塑性有限元法模拟减沉桩基础,分析桩土共同作用的机理,结合典型工程,重点分析影响沉降量的各个要素,并充分发挥有限元分析方法的特长比较了沉降量对各个影响因素的敏感程度,为减沉桩的设计提供理论依据和有效途径。有限元分析结果与工程实测结果吻合较好,表明减沉桩基础中桩和桩间土协同工作,共同承担上部荷载,能很好地控制建筑物的沉降量;调整桩长是控制沉降量的最有效手段。

FE ANALYSIS OF BEHAVIOR OF SETTLEMENT REDUCING PILE FOUNDATION

The settlement reducing pile foundation is a new type of composite pile foundation, which has found its use for only twenty years. This type of foundation is designed with smaller pile diameter and less pile amount than the conventional pile foundations and therefore costs less. Up to now, the design method for this type of pile foundation is based on the existing experience to some extent. An elastoplastic FEM program has been developed to simulate the function of the settlement reducing pile foundation. More attentions have been paid on the factors which are concerned with the foundation settlements. Design procedures of this type of foundation are given and some related problems discusse. Observed data agree well with the calculation results. Analysis results show that the settlement of building can be controlled by selecting suitable length of the piles, which is more effective than increasing the number of piles or enlarging the foundation area.