降雨作用下堆积体岸坡变形破坏模式模型试验  

Model Test on Deformation and Failure Modes of Accumulated Bank Slope under Rainfall

作　　者：王乐华 尹思杰 许晓亮 陈星 徐义根 WANG Le-hua;YIN Si-jie;XU Xiao-liang;CHEN Xing;XU Yi-gen(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education,Yichang 443002,China;Three Gorges Complex Administration Bureau,Yichang 443133,China;Power China Huadong Engineering Corporation Limited,Hangzhou 310000,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室,宜昌443002 [2]三峡枢纽建设运行管理局,宜昌443133 [3]中国电建集团华东勘测设计研究院有限公司,杭州310000

出　　处：《科学技术与工程》2018年第32期77-82,共6页Science Technology and Engineering

基　　金：国家重点研发计划(2016YFC0402003);国家自然科学基金(51309141)资助

摘　　要：为了进一步探究降雨作用下堆积体岸坡变形破坏模式,自主设计制作了物理模型试验系统,通过三峡库区某堆积体滑坡现场取样,在测定土样基本物理力学参数后,开展了降雨作用下不同坡角的堆积体岸坡模型试验,主要分析了不同坡角下岸坡模型的变形破坏特征及破坏模式。结果表明:坡度对岸坡变形破坏特征影响显著,坡角较大(60°与50°)时,坡体易出现浅层滑动破坏,坡角较缓(40°)时,容易出现深层滑动,坡角35°及更小时,未出现明显的变形破坏;浅层滑动破坏规模较小,变形自下而上牵引,演化发生所需的时间较短,而深层滑动破坏规模较大,变形自上而下推移,所需时间更长;降雨作用下堆积体岸坡变形破坏可分为软化剥蚀-蠕动变形-明显滑动三个阶段,变形破坏模式表现为雨水入渗→表层饱和→土体软化→饱和区扩大→土体沉降→坡顶裂隙出现→坡脚变形/坡体整体变形→浅层滑面/深层滑面→浅层破坏/深层破坏。In order to further explore the deformation and failure modes of bank slopes under the effect of rainfall,a physical model test device was independently designed and manufactured.The pebbled soil of bank slopes in the three gorges reservoir area was taken as the research object,and the basic physical properties of the soil samples were determined through experiments,the accumulation body bank slope model tests under rainfall were carried out for analyzing the deformation failure characteristics and failure modes of bank slope models at different slope angles.The results show that the slope has a significant effect on the deformation and failure characteristics of the bank slope(40°).Shallow seated slope failures were observed at steep slopes(60°and 50°).Moreover,deep seated slope failures were observed at mild slopes(40°).Nonetheless,smaller slopes(≤35°)did not have clear deformation characteristics.The shallow failure scale was small,the deformation was bottom-up traction,and the time required for the evolution took place was short,while the deep sliding failure scale was large and the deformation was from above.The time required for the next passage is longer;under the effect of rainfall,the bank slope deformation failure can be divided into three stages:softening erosion-creep deformation-obvious sliding,and the deformation failure mode is rainwater infiltration→surface saturation→soil softening→saturation zone expansion→soil settlement→slope cracks appear→slope foot deformation/slope body deformation→shallow slip surface/deep slip surface→shallow damage/deep damage.

关 键 词：堆积体岸坡 降雨作用 模型试验 坡角 破坏模式 

分 类 号：TU458[建筑科学—岩土工程]