水利水电技术2017，Vol.48Issue(12)：146-152,7.DOI:10.13928/j.cnki.wrahe.2017.12.024
陡倾顺层岩质斜坡动力倾倒变形机理研究
Study on dynamic toppling deformation mechanism of inclined steep-dip bedding slope
摘要
Abstract
It is generally considered that the dynamicdeformation and failure of inclined bedding rock slope are mainly dominated by the modes of sliding-tensile fracturing and sliding-bending,however,it is found out through the relevant in situ investigation that another kind of dynamic deformation failure mode——toppling deformation is there for the inclined steep-dip bedding slope.In order to obtain the dynamic toppling deformation mechanism of this kind of inclined slope,the instability of the inclined steepdip hard rock and soft rock interbedded slope at Shuimogou of Wenchuan County in Sichuan Province under the effect of 5.12 Wenchuan Earthquake is taken as the study case,from which the relevant study is carried out with the 2-D discrete element numerical simulation method after fully summarizing the engineering condition of the landslide area and analyzing its dynamic failure characteristics.The result shows that the PGA amplification factor on the slope surface presents a rhythmic change along with the increase of the elevation,while its peak value occurs at the slope-shoulder.The instability mechanism of the inclined slope is the sudden decline of the shearing strength of the bedding-plane caused by the differential tensile-shear failures of the soft rock and hard rock in the slope,which makes rock-soil mass slide down along the superior bedding-plane therein.Due to the blocking effect of the rock layer at the lower part of the slope,the downward slide of the slope body is restricted and the rock-soil mass warps and protuberates at the slope toe,while the toppling deformation of the shattered and relaxed rock-soil mass at the slope crest to the free-face arisesdue to the obstruction from the "key block" of the slope shoulder during its sliding and shearing out along the superior structural planeunder the great earthquake inertia force,and then the instability failure of the whole inclined slope,i.e.sliding-bedding at the lower part-toppling of the upper part occurs.The study result can provide a basis and reference for the analysis on the slope instability caused by earthquake in the similar region.关键词
汶川地震/软硬相间岩层/顺层倾倒/动力响应/失稳机理/优势结构面/斜坡震前概化模型/汶川地震天然波中强波段Key words
Wenchuan Earthquake/hard rock and soft rock interbedded layer/bedding toppling/dynamic respond/instability mechanism/preferred structural plane/pre-earthquake generalized model of slope/middle strong band of natural wave in Wenchuan Earthquake分类
天文与地球科学引用本文复制引用
邓天鑫,巨能攀,李龙起,蒋彦彬,卢向涛..陡倾顺层岩质斜坡动力倾倒变形机理研究[J].水利水电技术,2017,48(12):146-152,7.基金项目
国家自然科学基项目(41372306,41502299) （41372306,41502299）
四川省教育厅科研项目(16ZB0105) （16ZB0105）
