强震条件下双面坡变形破坏机理的振动台物理模拟试验研究

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。

SHAKING TABLE SIMULATION EXPERIMENT ON DEFORMATION-FAILURE MECHANISM OF DOUBLE-SIDES SLOPE IN CONDITION OF INTENSE EARTHQUAKE

512 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．