Thermo-hydro-mechanical-damage coupling model of quasi-brittle material

A numerical model considering the thermal, seepage, stress and damage in quasi-brittle materials has been proposed on the basis of Rock Failure Process Analysis (RFPA) code. Simulation of the temperature varying with water flow indicates that water flow greatly influence the temperature distribution, which can be used to analyze the temperature anomaly in hydraulic structures, and detect whether the structures has formed seepage passages or not. Furthermore, the failure process of a quasi-brittle numerical sample under the Therom-hydro-mechanical-damage(THMD) coupling condition indicates that the microcracks in the sample close at the beginning of loading, resulting in the decrease of water velocity with load increasing. However, as the stress level up to the peak strength of the sample, damage will increase rapidly and form a water passage, causing a sudden change of temperature distribution. Therefore, the change of temperature distribution with stress state, failure and water velocity can be used to detect whether hydraulic structures formed leakage passages or not.