钻孔岩芯饼状断裂破坏机制

FRACTURE MECHANISM OF THE DISCAL DRILL CORE

本文首先阐述岩芯饼状断裂及其特征，进而用断裂力学的理论与方法对岩饼破坏进行了断裂扩张机制的分析，不但合理地解释了断裂特征及断裂破坏机制，且以二滩坝址为例，分析了产生钻孔岩饼的微裂纹条件及应力条件，为定量地评价坝址地应力状态，包括其大小及方向提供了一种新的方法。上述不仅具有重要的理论意义，而且具有重要的工程实际意义。

In this paper the discal fracture phenomena of some drill cores in China are described, some principal fracture characteristics of the discal core are summarized. After that an analysis of the fracture mechanism is made for discal fraclure of the rock core. The results show that the fracture spread of rock dics originates from the peripheral microfissure on the core surface. Then,according to the size of the microfissure in rock and the morphologic characteristics of rock discs at Ertan dam site, the maximum principal stress of the ground stress field on Ertan dam site is evaluated quantitatively(the value and the direction of the maxuimum principal stress or the tectonic stress).