5·12汶川地震引发了数以万计的崩塌、滑坡、泥石流等地质灾害。为了研究双面坡在强震条件下的动力响应规律,本文在大量野外调查的基础上,采用振动台物理模拟试验手段,设计完成了四类11个模型试验,从改变模型的坡度和坡顶宽度、软岩硬岩结合、阶梯状坡形等角度,较系统地研究了双面坡在强震作用下的响应规律。试验结果显示:强震条件下地震水平惯性力是导致边坡破坏的主要原因;在地震情况下边坡变形破坏表现出明显的初动破坏效应;振动过程中双坡具有明显的共剪效应,坡面为阶梯状时其共剪效应更明显;坡体结构为上软下硬时下部硬岩对振动具有一定的放大效应,上硬下软时坡体易整体偏移产生变形破坏。试验结论与实际情况基本符合。
5·12 Wenchuan earthquake triggered thousands of rock-collapses,landslides,debris flows and other geological disasters.In order to study the response of the double-sides slope to the earthquake,we designed a total of 11 models according to the field investigation.We took four factors into consideration to study the seismic response of the slope.The four factors are the slope-degree,the top width of slope,structure combination and the shape of the double-sides slope.The tests manifested that(a)seismic inertia force is the main factor that results in slope failure;(b)the deformation and failure of the slope has a relation to the initial seismic direction;(c)the double-sides slope shows an conjugated-shear phenomenon;(d)different structure combinations of slopes result in different failure modes;e)the conjugated-shear phenomenon is more obvious on the ladder-shaped double-sides slope.The test findings are well in line with the results of field investigation.