A SYSTEM OF SURVEY AND ANALYSIS FOR LARGE EXCAVATIONS IN JOINTED ROCK MASSES

实验证据强烈表明，由于断层和节理等地质不连续的存在，岩体的行为与固体基质（岩石本身）完全不同。引入一个张量（称为裂缝张量）作为反映地质不连续面地质特征的指标。利用裂缝张量，可以将任何不连续岩体建模为具有相应弹性柔度、屈服函数、塑性势函数和渗透率张量的各向异性弹塑性多孔介质。也就是说，用裂缝张量来定义不连续岩体的水力力学等效。利用这些本构方程，进行了三种类型的数值分析，取得了很大的成功；即1)大型地下开挖的三维弹性分析，2)节理岩体的弹塑性分析，3)节理岩体的应力与流体耦合流动分析。

Experimental evidences strongly suggested that rock masses behave in a completely different manner from the solid matrix (rock itself) due to the presence of geological discontinuities such as faults an joints. A tensor (called the crack tensor) is introduced so as to be an index showing the geological characteristics of the geological discontinuities. Using crack tensor, any rock mass, which is discontinuous in nature, can be modeled as an anisotropic, elasto-plastic porous medium with the corresponding elastic compliance, yield function, plastic potential function and permeability tensor. That is, a hydro- mechanically equivalent to the discontinuous rock mass is defined in terms of the crack tensor. Using these constitutive equations, three types of numerical analyses were performed with great success; i.e., 1) three-dimensional elastic analyses for large underground excavations, 2) elastic-plastic analyses for jointed rock masses and 3) coupled stress and fluid flow analyses for jointed rock masses.