降雨作用下含炭质泥岩夹层边坡的变形破坏机理
The mechanism of deformation and failure of carbonaceous mudstone interlayered slopes under rainfall
谢腾 1黎正龙 2李盛南 3刘新喜 2莫晓庆2
作者信息
- 1. 株洲城发城市更新投资建设运营有限公司,湖南 株洲 412007
- 2. 长沙理工大学 土木工程学院,湖南 长沙 410114
- 3. 长沙理工大学 土木工程学院,湖南 长沙 410114;湖南工程学院 建筑工程学院,湖南 湘潭 411100
- 折叠
摘要
为揭示降雨诱发含炭质泥岩夹层边坡的变形破坏机理,通过对株洲市蓝天花园小区边坡进行降雨量、地下水位和深层土体水平位移的监测,发现边坡不同部位地下水位变幅受降雨影响差异显著,将单孔地下水位变幅按从大到小的顺序排列,依次为滑坡后缘(变幅0.1～1.6 m)、坡体(变幅0.4～1.1 m)、坡脚(变幅0.1～0.6 m);边坡滑动面在全风化炭质泥岩夹层所在的位置.在此基础上,开展不同含水率的炭质泥岩直剪试验和边坡数值分析,结果表明:随着含水率的增加,炭质泥岩的黏聚力和内摩擦角均有所减小,夹层含水率增加和坡脚开挖均是边坡变形破坏的重要原因;随着含水率的增大,边坡塑性区面积逐渐增大,并由坡脚到软弱夹层底部再到坡顶发展贯通;最大水平位移随着夹层含水率的增大而增大,最大水平位移由第三级边坡坡脚向第二级边坡坡脚再向软弱夹层转移;坡脚开挖后,塑性区和最大水平位移的变化规律与开挖前的一致,但边坡的塑性区和最大水平位移增加得更为明显.
Abstract
The deformation and failure mechanism of carbonaceous mudstone interlayered slopes induced by rainfall was revealed.The slope of Lantian Garden in Zhuzhou City was monitored for rainfall,groundwater level,and horizontal displacement of deep soil layers.The groundwater level in different parts of the slope is significantly affected by rainfall,arrange the single hole groundwater level fluctuations in order of magnitude from largest to smallest,namely,landslide trailing edge(fluctuation range of 0.1-1.6 m),slope body(fluctuation range of 0.4-1.1 m),and slope toe(fluctuation range of 0.1-0.6 m).The sliding zone of the slope is located in the interlayer of fully weathered carbonaceous mudstone.Moreover,direct shear tests and numerical analysis of slopes were conducted on carbonaceous mudstones with different water contents.The results showed that as the water content increased,the cohesion and friction angle of carbonaceous mudstones decreased.The increase in moisture content in the interlayer and excavation at the foot of the slope are important reasons for slope deformation and failure.As the moisture content of the interlayer increases,the plastic zone area of the slope gradually increases,and it develops and connects from the foot of the slope to the bottom of the weak interlayer and then to the top of the slope.The maximum horizontal displacement increases with the increase of water content in the interlayer,and the maximum horizontal displacement shifts from the foot of the third-level slope to the bottom of the second-level slope,and then to the weak interlayer.After excavation at the foot of the slope,the changes of plastic zone and maximum horizontal displacement are consistent with those before excavation.However,the increase of plastic zone and maximum horizontal displacement is more significant.
关键词
边坡/炭质泥岩/软弱夹层/数值模拟/变形机理Key words
slope/carbonaceous mudstone/weak interlayer/numerical simulation/deformation mechanism引用本文复制引用
基金项目
国家自然科学基金资助项目(51674041)
国家自然科学基金资助项目(52108405)
湖南省自然科学基金资助项目(2022JJ40122)
长沙理工大学道路灾变防治及交通安全教育部工程研究中心开放基金项目(kfj230501)
出版年
2024
NETL
NSTL
万方数据