本文从地下洞室的应力变化的实际应力途径出发,研究了在轴向加载的同时,减小侧压的三轴试验方法。为了比较,还对恒侧压,增加轴向荷载的方式进行了平行试验。试验表明,两种加载途径的强度特性大致相似,但变形特性、脆延性差异较大。本文认为通过应力途径符合于实际工程应力变化的三轴试验来确定岩石的力学特性是很必要的 In this paper, starting from the actual stress path of stress changes in underground caverns, the triaxial test method for reducing lateral pressure while axial loading is studied. For comparison, a parallel test was also conducted on the way of constant lateral pressure and axial load increase. The tests show that the strength characteristics of the two loading routes are roughly similar, but the deformation characteristics and brittle ductility are quite different. In this paper, it is considered that it is necessary to determine the mechanical properties of rock through the triaxial test that the stress path conforms to the actual engineering stress change.