基于Hoek-Brown准则下的非饱和岩质边坡库水位骤降渗透稳定性分析

Stability Analysis of Sudden Drop of Water Level in Unsaturated Rock Slope Reservoir Based on Hoek-Brown Criterion

考虑岩体的综合性质,基于非饱和渗流理论,利用Hoek-Brown准则推导岩质边坡的稳定系数公式,并采用Matlab与Geo-studio进行数值模拟。结果表明,库水位骤降情况下不同工况安全系数随时间呈现先减小、后保持不变的趋势,单轴抗压强度σc、岩体性状mi、地质强度指标GSI与安全系数大小成正相关,岩体损伤因子D与安全系数大小成负相关。整体孔压大小顺序为:下部监测点≥中部监测点≥上部监测点,库水位骤降速率越大,不同监测点孔压达到最小的时间越短,最终孔压趋于一致。

In order toconsider thecomprehensive properties of rock mass,based on the theory of unsaturated seepage, the stabilitycoefficient formula of rock slope is derivedby using Hoek-Browncriterion,and the numerical simulation is carried outby Matlaband Geo-studio. The results show that under thecondition of sudden drop of reservoir water level, the safety factor of different workingconditions decreasesat firstand then remains unchanged with time, uniaxial compressive strength σc, rock massbehavior m i. The geological strength index GSI is positivelycorrelated with the safety factor, while the rock mass damage factor D is negativelycorrelated with the safety factor. The order of the whole pore pressure is the lower monitoring point≥the middle monitoring point. When the point≥the upper monitoring point, the greater the sudden drop rate of the reservoir water level, the shorter the time for the pore pressure to reach the minimumat different monitoring points,and the final pore pressure tends tobeconsistent.