裂隙水对节理岩体裂隙扩展影响的CT实时扫描实验研究

CT REAL-TIME TESTING STUDY ON EFFECT OF WATER ON CRACK GROWTH IN FRACTURED ROCK MASS

采用与 CT 机配套的加载装置,使用相似材料,对单裂纹含水和不含水的标准试件进行了 CT 实时监测实验,以观测裂纹扩展的全过程。探讨试件在不同复杂应力状态和原生裂纹处于不同地下水压的情况下,其裂纹的萌生、演化、发展及最终破坏形式。通过在试件中原生裂纹内不注高压水、含有压裂隙水和注水致裂来分别模拟岩体工程中裂隙不受水的影响、受有压水的影响及水压致裂的破坏过程。目的在于探讨 3 种情况下,岩体的不同破坏形式。从实验结果来看,3 种条件下,试件都经历了微裂隙被压密、损伤演化开始、微裂纹扩展贯通、宏观裂纹产生等阶段,但其破坏形式各不相同。说明了在分析岩体结构时要充分考虑地下水的存在状态对工程结构的影响。同时,也为进一步建立岩体结构合理的损伤演化方程、本构关系和研究岩石破坏机理提供了科学依据。

By using the accessory loading equipment corresponding to the CT machine and simulation material, the CT real-time testing of specimens with single crack with and without water in it is conducted to observe the complete process of crack growth. The failure form of the crack including its generation, evolution, development and final failure under complex stress and various underground water conditions is investigated. Different models of crack propagation in geotechnical engineering under the conditions with and without water and hydraulic pressure are constructed, respectively. It is shown that there exist different failure forms of rock mass under three conditions from the CT scanning, but the CT images with compressed microcrack, damage evolution, microcrack growth and macrocrack generation are clear. It is concluded that the influence of underground water conditions on rock engineering must be taken into consideration. At the same time, some scientific hypotheses of the damage evolution equations and stress-strain relationship as well as the failure mechanism of rock mass are also proposed.