和理論分析
(1. 東北大學(xué) 資源與土木工程學(xué)院，沈陽(yáng) 110004；
2. 河南理工大學(xué) 能源科學(xué)與工程學(xué)院，焦作 454000)
摘 要: 用巖石破裂過(guò)程分析軟件(RFPA2D)，采用與常用的Kaiser效應(yīng)測(cè)原巖應(yīng)力過(guò)程相似的加載路徑，對(duì)巖石試樣進(jìn)行數(shù)值模擬實(shí)驗(yàn)。基于統(tǒng)計(jì)損傷力學(xué)理論，對(duì)Kaiser效應(yīng)的機(jī)理進(jìn)行分析，并在理論上驗(yàn)證數(shù)值實(shí)驗(yàn)的結(jié)果。結(jié)果表明：Kaiser效應(yīng)的本質(zhì)是對(duì)巖石內(nèi)部損傷程度的記憶，傳統(tǒng)用Kaiser效應(yīng)測(cè)原巖應(yīng)力的方法測(cè)得的應(yīng)力值往往比真實(shí)值要小，而且，巖樣在原巖中受到的側(cè)向應(yīng)力越大，用該方法測(cè)得的軸向應(yīng)力值與真實(shí)值相差越大。因此，要得到準(zhǔn)確的原巖應(yīng)力，必須根據(jù)巖石的損傷本構(gòu)關(guān)系對(duì)單軸加載測(cè)得的Kaiser效應(yīng)點(diǎn)應(yīng)力值進(jìn)行校正。
關(guān)鍵字: 原巖應(yīng)力；數(shù)值模擬；Kaiser 效應(yīng)；損傷
estimating in-situ stress by Kaiser effect
ZHAO Xing-dong1
（1. School of Resource and Civil Engineering, Northeastern University, Shenyang 110004, China;
2. School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454100, China）
Abstract:Numerical test was carried out by using software of Rock Failure Process Analysis (RFPA2D) to simulate the stress that the rock specimens were suffered in the process of estimating the in-situ stress by Kaiser effect. Based on statistical damage mechanics theory, the mechanism of Kaiser effect was analyzed, and the numerical test result was verified by rock strength theory. The results show that the mechanism of Kaiser effect is the memorizing ability of damage level in rock. The traditional method of estimating in-situ stress by Kaiser effect is not appropriate, for the result is usually smaller than real value, furthermore, greater confining compression that the specimen suffered in the rock mass would result in greater difference between the Kaiser effect stress acquired from uniaxial loading in laboratory and real level of in-situ stress. Consequently, to estimate the in-situ stress more accurately, the adjustment based on the damage constitutive relation must be done to the Kaiser effect stress value acquired from uniaxial loading.
Key words: in-situ stress; numerical simulation; Kaiser effect; damage
