摘要
为了研究地下水位雍高条件下坡体的变形破坏特征和失稳的机理,以黑方台焦家滑坡为地质原型。通过在离心模型后部安置排水挡板和临时水箱,其能较好得模拟灌溉水通过集中通道快速入渗补给坡体地下水,再现地下水位雍高诱发黄土滑坡变形破坏的全过程。此外,在离心模型试验期间,对边坡的孔隙水压力、土压力和变形演化特征进行实时监测和研究。研究表明:地下水雍高造成底部黄土层软化,潜蚀作用和不均匀沉降致使边坡产生塑性流动,从而导致滑坡的顶部形成不同程度的平行错拉裂缝。造成这类滑坡的后壁形态大多呈现直立状。地下水位雍高造成坡体内土体的局部剪缩变形导致孔隙水压力持续以及急剧增高,最终诱发此类滑坡发生突发性破坏,呈现出高速泥流破坏特征。因此地下水位雍高诱发滑坡的形成机理过程为:牵引式蠕滑-半坡以及后缘拉裂-锁固段累进性滑移剪断-滑带贯通高速溃滑破坏。
Taking the Jiaojia landslide in Heifangtai area as the geological archetype,we study the deformation and failure characteristics and the mechanism of instability of the slope under the condition of continuous enrichment of groundwater.To simulate the irrigation water quickly recharging into the groundwater through the concentrated channel,we arrange the drainage baffle and temporary water tank at the rear of the centrifugal model.It is designed to reproduce the whole process of deformation and failure of a loess landslide induced by the enrichment of groundwater.Additionally,the real-time monitoring and analysis of the pore water pressure,the change of the earth pressure and the deformation and evolution characteristics of the slope are conducted.The results show that a series of parallel steep tension cracks are induced at the top of the landslide,resulting in the plastic flow of the slope body.It is caused by the softening of the bottom of loess layer,the suffusion erosion and the uneven settlement of the loess slope.The rear wall of this kind of landslide is often of straight shape.The local shear dilatation deformation of the soil caused by the enrichment of groundwater leads to the continuous and sharp increase of the pore water pressure,and ultimately induces the sudden destruction of such landslides,with the failure characteristics similar to high-speed mud flow.Generally speaking,the failure mechanism of the loess landslide induced by the enrichment of groundwater is as follows:traction creep-half slope and trailing edge rupture-locking section progressive slip shear-slip belt piercing and high speed crushing failure.
作者
裴向军
张硕
黄润秋
张晓超
王思铎
常志璐
范珊
PEI Xiangjun;ZHANG Shuo;HUANG Runqiu;ZHANG Xiaochao;WANG Siduo;CHANG Zhilu;FAN Shan(State Key Lab.of Geohazard Prevention and Geoenvironment Protection,Chengdu Univ.of Technol.,Chengdu 610059,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2018年第5期55-63,共9页
Advanced Engineering Sciences
基金
国家重点基础研究发展计划资助项目(2014CB744703)
国家自然科学基金重大项目资助(41790445)
国家创新研究群体科学基金资助(41521002)
国家自然科学青年基金资助项目(41702335)
关键词
黑方台
地下水雍高
离心模型试验
黄土滑坡
heifangtai
enrichment of groundwater
centrifuge model test
loess landslide
