基于双折减系数法的重力坝抗滑稳定性研究

Research on Anti-sliding Stability of Gravity Dams Based on Double Reduction Coefficient Method

鉴于岩土体失稳破坏过程中粘聚力和内摩擦角发挥的作用并不相同,采用同一折减系数并不能真实反映出重力坝滑动直至失稳的破坏过程。以我国西南某重力坝为研究对象建立坝体-地基三维仿真模型,基于对粘聚力和内摩擦角采用不同折减系数的双折减系数法研究该重力坝在设计地震作用下的抗滑稳定性问题。结果表明:等比例强度折减法计算结果夸大了重力坝的抗滑安全裕度;采用双折减系数法分析重力坝在地震作用下的抗滑稳定性是可行的,且能更加真实地反映出重力坝在滑动失稳过程中粘聚力和内摩擦角各自的安全储备。

Since cohesion and internal friction angle play different roles in the process of rock and soil mass failure,the same reduction coefficient cannot truly reflect the failure process of gravity dam from sliding to instability.Taking a gravity dam in southwest China as the research object,a three-dimensional simulation model of dam body and foundation is established.Based on the double reduction coefficient method with different reduction coefficients for cohesion force and internal friction angle,the anti-sliding stability of the gravity dam under design earthquake is studied.The results show that the safety margin of gravity dam against sliding is exaggerated by the equal proportion strength reduction method.It is feasible to use the double reduction coefficient method to analyze the anti-sliding stability of gravity dam under earthquake action,and can more truly reflect the safety reserve of cohesion force and internal friction angle during sliding instability of gravity dam.