干湿循环及地震耦合作用下的库区红层泥岩边坡稳定性分析

针对库区蓄水诱发的低强度地震及库水位往复升降调节产生的干湿循环效应严重影响红层泥岩质岸坡稳定性问题,以某红层区库岸边坡工程为依托,通过室内试验和数值模拟方法研究了干湿循环条件下红层泥岩微观结构及强度劣化规律,并耦合地震作用模拟分析了边坡稳定性变化规律。结果表明,多次干湿循环后红层岩体微观结构疏松多孔,内部损伤逐步积累,力学参数显著降低。干湿循环对红层泥岩产生的劣化损伤作用为岸坡失稳提供了物理力学基础,地震动荷载则是岸坡进一步发生破坏的直接驱动力,在两者耦合作用中,库区红层泥岩岸坡更容易发生严重变形破坏。

Stability Analysis of Red Bed Mudstone Slope in Reservoir Area Under Coupling Effect of Dry-wet Cycle and Microquake

The low-intensity earthquake induced by water storage and the dry-wet cycle effect caused by water level fluctuation have significant impact on the stability of red mudstone bank slope.Based on the bank slope of a red bed reservoir,this paper studies the microstructure and strength degradation of red bed mudstone under the dry-wet cycle condition by laboratory test and numerical simulation,and analyzes the stability change law of slope through coupled seismic simulation.The results show that the microstructure of the red layer rock mass is loose and porous,the internal damage accumulates gradually,and the mechanical parameters decrease significantly under dry and wet cycles effect.The degradation damage of the red-bed mudstone caused by the dry and wet cycle provides the physical and mechanical basis for the bank slope instability,and the ground motion load is the direct driving force for further bank slope failure.Under the coupling action of the two,the red-bed mudstone bank slope in the reservoir area is more prone to serious deformation and failure.