一、引言用水压致裂法测量地壳应力的大小和方向,具有其它测量方法不可比拟的优点,不仅操作简单,而且可进行地表以下几百米甚至千米深度的应力测量,直接确定应力值和岩石力学参数等.我们研制的轻便水压致裂应力测量系统已在水电、石油、交通、煤炭等部门得到广泛应用. 常规水压致裂法的一个重要假设,即三向主应力之一与孔轴平行,从而确定平面应力 I. INTRODUCTION The size and direction of crustal stress measured by water pressure fracturing have the advantages unmatched by other measuring methods. It is not only easy to operate, but also can carry out the stress measurement in the depth of a few hundred meters or even below the surface to directly determine the stress value And rock mechanics parameters, etc. The lightweight hydraulic fracturing stress measurement system we developed has been widely used in hydropower, petroleum, transportation, coal and other departments.One important hypothesis of conventional hydraulic fracturing is that one of the three principal stresses Parallel to the axis of the hole, to determine the plane stress