基于共同作用下筏板基础的力学机理研究

Study on Mechanism of Raft Foundation Based on the Interaction of Ground, Foundation and Structure

砂卵石土由于其优良的工程特性而在高层建筑中逐渐开始应用,同时,其上部结构、基础同地基是统一的有机整体,若设计再沿用传统的设计理念,不考虑上下部的相互作用则不甚合理。本文以结构刚度凝聚法理论进行上部结构力学机理分析,并将上部结构所有刚度和荷载凝聚于基础上;其次,基于动三轴试验建立砂卵石地基模型;最后,详细分析筏板的各种计算模型,在工程实例有限元数值计算基础上进行共同作用分析,重点归纳了砂卵石地基上各种筏板计算模型的内力和变形特征。

Cobble-stone soil has been applied in high-storey buildings recently because of its excellent engineering properties. Superstructure, raft foundation and ground are a whole, so it＇s not advisable to adopt traditional concept, without considering the interaction of ground, foundation and structure. In this article, the superstructure analyzed by three-dimensional substructure method was divided into some substructures, which cohered the rigidity and load of the superstructure to raft foundation. Based on test data of dynamic triaxial, a model of cobble-stone foundation soil is obtained. Characteristics of the raft＇s diversified computing models are explained detailed. An engineering example is simulated by the Finite Element Analysis Method, features about inner force and deformation of the raft in different computing models are obtained in range of the thickness of raft foundations. Good agreement is achieved between the results from the present paper and test data.