摘要
受青藏高原地质构造作用和末次冰期暖湿气候的影响,金沙江深切成谷,高山峡谷区发育大量的大型滑坡,在降雨和河(库)水升降等作用下复活。为了分析降雨型深切河谷的斜坡稳定性机制,以百胜滑坡为例,采用地面调查和地质力学分析方法,对滑坡的演化过程、形成机制、地质力学模型进行研究。研究表明,滑坡形成及复活演化过程可分为原始斜坡、岩体卸荷劣化、挤压塑性流变、降雨诱发失稳、滑体解体压密蠕滑、局部复活等6个阶段。在深切河谷的形成过程中,斜坡岩体在卸荷拉裂、后期水弱化和泥化等多种耦合作用下由稳态逐步演化至失稳。计算结果表明,天然工况下稳定性系数为1.12,处于基本稳定状态;暴雨及库水位涨落工况下稳定性系数为0.98,失稳破坏。
Affected by the Qinghai-Tibet Plateau tectonic structures and the warm-humid climate during the Last Glacial Epoch,the Jinsha River was incised into deep valley,on which numerous largescale landslides are distributed and revived under the effects of rainfall and water-level fluctuation.In this study,the Baisheng landslide was studied using field investigation and geo-mechanical analysis for its formation evolution,geo-mechanical model and stable mechanism of rainfall-type water-level fluctuation slopes in deep-incised river valleys.According to the study results,the geological evolution and sliding processes of landslides are divided into six stages,including the initial sta tu s,unloading and degradation of rocks»extrusion and plastic flow,instability triggered by rainfalls,disintegration and compaction of deposit,and local resurrection by water-level fluctuation in the front of landslide.The stability of slopes gradually reduces due to unloading of rocks,water softening,and creepage by rainfalls or water fluctuation of reservoir.The slopes are stable when the stability coefficient is 1.12 under the natural condition;while landslides failure when the stability coefficient is 0.98 under heavy rain conditions and fluctuation of reservoir water level.
作者
白永健
王运生
葛华
倪化勇
Bai Yongjian;Wang Yunsheng;Ge Hua;Ni Huayong(Station Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection,Chengdu University of Technology,Chengdu 610059,China;Chengdu Centery China Geological Survey,Chengdu 610081,China)
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2019年第6期1680-1688,共9页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(41702374)
中国地质调查局项目(DD20160274,DD20190640)~~
关键词
金沙江
深切河谷
演化过程
成因机制
地质力学模型
Jinsha River
deep-incised valley
genetic evolution
formation mechanism
geomechanical model
