【摘要】 水库库岸失稳对水库安全运行有重大影响。采用土工试验和干湿循环试验,结合数值计算及理论分析,研究红土型库岸边坡倾角和库水位升降与库岸稳定性的关系。结果表明:(1)在一定初始干密度条件下,红土抗剪强度随水位升降循环次数增加而非线性减小,且在水位升降循环约10次时趋于稳定。(2)在一定水位升降速率、升降幅度和升降循环次数条件下,红土型库岸稳定安全系数随库岸边坡倾角的增加总体上呈减小的趋势,且在边坡倾角为50°左右存在稳定安全系数极小值。(3)在一定水位升降循环次数条件下,水位上升到坡高的60%左右为上升阶段的相对危险区域,且水位上升速率对库岸稳定安全系数影响很小;水位下降至坡高的70%左右为库水位下降阶段的相对危险区域,且水位下降速率越大,库岸稳定安全系数越小。(4)针对一定初始干密度,库岸稳定安全系数先随水位升降循环次数的增加而减小,但在水位升降循环次数约10次后逐渐趋于稳定。库岸岩土体性质及库岸边坡倾角、水位变化都会对库岸稳定产生影响。更多还原

【Abstract】 Reservoir bank instability poses great threat to the operation of reservoir. It is recognized that reservoir bank stability would be influenced by rock and soil properties, the inclination of bank slope and water level fluctuations. In this research, it investigated the relationships between slope angles, fluctuation of water level and the stability of a reservoir bank by joint works, including soil property tests, geotechnical experiments of dry and wet cycle for bank stability, numerical modelling and theoretical analysis. Results concluded:(1) under a certain initial dry density condition, the shear strength of laterite decreased nonlinearly with the increase of the number of water level fluctuation, and it tended to be stable when the number of fluctuation was about 10.(2) With a certain water level lifting rate, a certain lifting amplitude and a certain number of fluctuation times, the reservoir bank safety coefficient tended to decrease when the bank slope angle increased and the minimum of the bank safety coefficient existed when the slope angle was about 50°.(3) under a condition of a certain number of fluctuation times, the water level lifting rate did not affect the safety coefficient much, but the reservoir bank would be in risk when the water level raised up to about 60% of the bank slope height; however, during the water level drop, the bank safety coefficient decreased when the water level falling rate increased and the reservoir bank would be in risk when the water level reached about 70% of the bank slope height.(4) For a certain initial dry density, the safety coefficient of the reservoir bank firstly decreased with the increase of the number of water level fluctuation times, and gradually became stable after water level fluctuates 10 times.更多还原