一种新的本构理论及其在基桩分析中的应用

A new constitutive theory and its application to pile foundation analysis

首次将岩土体荷载与位移特征曲线划分为3种类型,并定义高地应力的判别标准。提出一种新的本构理论,可以描述在不同正压力(或不同围压)下应力(或荷载)与应变(或位移)的全过程特征,只有3个描述材料结构和状态的力学参数。该理论不仅可以描述单个材料,也可以描述多种材料组成的复合材料和两种不同材料界面等力学特性,变形可达任意值。对于长沙湾特大桥基桩,在不同静载荷作用下不同土体与桩之间的力学特性采用新本构理论进行数值模拟,结果表明该本构理论可以描述不同岩土体和岩土体与基桩之间的力学特性。

The classification as three types is proposed for the load-displacement relation curve of the rock-soil mass at first; a criterion of high earth pressure is defined. A new constitutive theory is at first proposed; the complete-process relation of stress-strain can be described under different normal stresses （or different confining pressures） by this theory. There only exist three mechanical parameters describing the geomaterial and stress state. It describes not only the mechanical behavior of geomaterial, but also of the complex material and of the surface between different media, the arbitrary deformation can be obtained. The relationship of stress-strain for the different rock-soil masses and the surface between rock-soil layer and pile are described by the proposed constitutive theory. The testing data of pile foundation of Changshawan bridge are simulated; the results show： that the mechanical properties of different rock-soil masses and interlayer between rock-soil mass and pile can be presented by this constitutive theory.