怒江流域典型岩质边坡破坏模式及机理分析

Failure mode and mechanism analysis of typical rock slopes along the Nu River Basin

对怒江流域典型调查点的岩质边坡节理裂隙进行统计,采用Dips软件分析得出破坏类型图,结合怒江流域边坡破坏因素影响,探讨典型岩质边坡的破坏机理.结果表明,怒江流域岩质边坡破坏失稳的主要地质影响因素有结构面、岩性、地形地貌、构造活动等,降雨、开挖和地震等是破坏失稳的触发条件;将怒江流域岩质边坡破坏类型归纳为3种模式:倾倒破坏、平面滑动破坏和楔形体滑动破坏.破坏阶段可分为初始、蠕变和崩落;采用Swedge软件,分析降雨及地震影响下岩质边坡的稳定性系数,发现安全系数随着降雨引起的内摩擦角和黏聚力的减小而降低,安全系数与地震力系数呈反比,且在相同地震力条件下沿交叉方向地震力作用下的安全系数大于沿水平方向.

The joint fissures of rock slopes on typical survey points in Nu River Basin were investigated and counted,and the analysis diagram of failure types obtained via a Dips software analysis.Combined with the influence of slope failure factors in Nu River Basin,the failure mechanism of typical rock slopes was discussed.The results showed that the main geological factors affecting the failure and instability of rock slopes thereof were structural planes,lithology,topography,tectonic activities,etc.,and rainfall,excavation and earthquake were the triggering conditions for failure and instability.The failure types of rock slopes there were summarized into three models:toppling failure mode,plane sliding failure mode and wedge sliding failure mode.The failure stage was divided into initial,creep and collapse stage.The stability coefficient of a rock slope under the influence of rainfall and earthquake was analyzed with the Swedge software,and it was found that the safety factor decreased with the decrease of internal friction angle and cohesion caused by rainfall,and the safety factor was inversely proportional to the seismic force coefficient.Under the same seismic force,the safety factor under the action of seismic force along the cross direction was greater than that under the action of seismic force along the horizontal direction.