针对井下开采转露天开采现状,分析了岩体材料蠕变力学特性对采空区和边坡稳定性的响应。采用改进的西原蠕变模型,对边坡安全系数的求解进行了推导,然后通过工程算例进行了数值计算,研究了采空区安全顶板的厚度和采空区边坡稳定性的影响。计算结果表明:蠕变效应下,采空区安全顶板的厚高比要比工程经验规定的值偏大,且采空区边坡垂直位移的变化对其稳定性有显著的影响,拉剪塑性区主要分布在边坡的中上部和深部采空区,并不是在矿体中,算例验证了该模型的计算是可靠的,为采空区边坡的稳定性分析提供了参考。
In view of open - pit mining transferred from underground mining, the influence of creep mechanical properties of rock material on stability of goal and slope was analyzed. An improved Nishihara creep model was established to compute the safety factor of slope. According to the numerical calculation of an engineering example, the influence of the safety roof thickness of goal on the stability of slope was analyzed. The results showed the thickness - depth ratio of safety roof was larger than its experience value under the creep effect, the vertical displacement change of slope above goaf had a great effect on slope stability, the plastic tension - shear zones occurred in the middle and upper regions of slope and at deep - seated mined - out area, not in ore body. The reliability of the model was verified by the analytical example, so it could provide some reference for stability analysis of slope above goaf.