降雨条件下边坡破坏机理离心模型研究

降雨是诱发边坡灾害的一个重要因素。雨水的入渗导致边坡土体含水量增加,土体强度下降,容重增大,引起边坡失稳。含水量对土体强度参数的影响试验表明,含水量对土体粘聚力影响较大,而对土体内摩擦角的影响较小。不同含水量土质边坡破坏机理离心模型试验表明,土质边坡破坏存在两种形式,整体滑坍破坏和拉裂破坏。松散类边坡在含水量小时形成坍落拱破坏,并最后形成拱形稳定。在含水量大时形成浅层滑坍破坏。引入损伤力学理论对不同含水量土体的损伤影响分析说明,随含水量增大,土体损伤程度加强,并存在损伤变量突变点。

Analysis of a Centrifugal Model of Slope Damage Mechanism during Rainfall

Rainfall is a main factor to cause slope geo-disasters. The penetration of rain into soil increases water content, decreases the strength of the body of soil, and increases its volume weight, thus leading to loss of slope stability. The tests for the effects of water content on the strength parameters of the soil body show that water content of soil has a strong effect on cohesion and relatively small effect on inner friction angle. The centrifugal model test for slope damage mechanism with different water contents indicates two types of damage, namely whole body slide and tensile rupture. Crumbling arch damage happens and finally arch stability is formed for a loose slope with a small water content. Landslide damage occurs in the shallow layers with a big water content. According to damage mechanical analysis, the soil body damage level increases with increasing of water content of soil and a catastrophe point of damage variable exists.