水压致裂法测定深部地壳应力的经典理论认为,无论地壳应力的现场条件如何,都只发生张性破裂,仅在实验室条件下,轴向应力很大时,才发生剪切破裂。本文论述了以砂岩和大理岩进行的亚三轴室内模拟实验。结果表明,在水压致裂过程中,在一定的围压条件下,是先发生剪切破裂,再继之以张性扩展的。 The classical theory of hydrofracturing to determine the crustal stress in the deep crust holds that only the crustal fracture occurs regardless of the on-site conditions of the crustal stress. Shear fracture occurs only under the laboratory conditions when the axial stress is large. This paper discusses the sub-triaxial laboratory simulation of sandstone and marble. The results show that in the process of hydraulic fracturing, under certain confining pressure, shear failure occurs first, followed by tension expansion.