强震触发横向坡失稳的力学模式研究

横向坡是岩层走向与坡面走向垂直,天然状态下整体稳定性较好的一种坡型,通过汶川大地震灾区大型滑坡调查发现在强震作用下横向坡失稳模式为拉裂—溃滑型。研究结果表明,以平武县新坪村滑坡为例,横向坡在强震作用下,斜坡后缘界面处出现拉应力,拉裂缝不断加深,坡体下部也因垂向和水平震动出现张剪性破坏,从而形成统一滑面,溃裂的坡体随之似＂散粒体＂溃散、滑动下来,冲过坡体前缘农家,造成9名村民死亡,进入郑家沟受到对面山体阻挡后震荡堆积形成堰塞湖。本研究在一定意义上更新了对横向坡稳定性评价的传统观念。

Mechanical Modes of Instability Horizon Slope Triggered by Intensive Earthquake

Horizon slope is strata towards the slope strike vertical which is a good overall stability slope under natural state,In large-scale earthquake disaster areas of Wenchun County,it could found that instability model of horizontal slope under intensive earthquake are tension-crushing by large landslide survey.Instability mode is tension-trushing slippery under intensive earthquake.Based on Xinping village,Pingwu County landslide as an example,slope edge at the interface between tensile stress appears under the intensive earthquake,and the cracks apper unceasingly deepened,lower slope body appears stretch shear destruction because of the vertical and horizontal vibration,thus forming a uniform sliding surface,the crushing slippery slope body then cracks and slides down as "granular mixture" which rushes to slope bottom margin of peasant caused 9 villagers deaths,and it enters Zhengjia ditch blocked by the opposite mountain,then it moves like post-concussion and forms a barrier lake.These achievements are update in a certain sense to the traditional concept of stability evaluation of the horizontal slope.