反倾层状岩质高边坡开挖变形破坏机理研究

在龙滩工程工程地质条件、地应力测试和试验洞变形监测结果综合分析的基础上,建立了地质概化和边坡施工开挖模型。以监测信息为基础,假定初始地应力场近似符合线性分布,采用二维显式有限差分法对龙滩工程左岸进水口边坡1-1剖面进行了自重平衡和开挖施工的模拟。由分析获得了反倾层状岩质高边坡临界节理发展、节理张开度和变形等边坡破坏因素之间的规律。通过对开挖到480 m平台和313 m平台时情况的对比分析,找出了开挖对边坡破坏的影响,即会使临界节理发育和节理张开尺度增大。通过离散元程序(UDEC2D3.1)对边坡开挖的模拟分析,客观评价了边坡的稳定性及其可能的破坏形式。

ANALYSIS ON DEFORMATION AND FAILURE MECHANISM OF HIGH ANTIDIP SANDWICH ROCK SLOPE IN EXCAVATION

Based on the generalized analysis of the geological conditionst,est of rock mass stress and deformation monitoring of the test tunnel in the Longtan Project,the simplified geological model and the excavation model of the high antidip sandwich rock slope are set up.Based on the testing data of stress,initial stress is assumed to distribute linearly.The 2D explicit finite difference method is used to simulate the equilibrium with gravity and excavation process of section 1-1 of the slope of left-bank intake.By analysist,he relationship among development of critical joint,joint separation scale and deformation in high rock slopes is obtained.Comparison of flats of 480,313 m shows that excavation has great influence on critical joint and excavation will lead to development of critical joint and increase of joint separation scale.It is objective to estimate stability and possible failure form of slope by discrete element code,UDEC2D3.1.