摘要
随着城市化进程的加快,因渣土堆填引发的边坡稳定性问题日益受到工程界的关注。由于渣土的性质差异,边坡往往呈现出多层结构特征。针对潜在滑体剖面“中间厚两边薄”的形态特点,提出了抗剪贡献率的概念,对渣土的堆填顺序进行了分析;然后基于饱和-非饱和渗流理论与刚体极限平衡原理,分析了降雨前后不同分层结构边坡的孔隙水压力与稳定性变化过程。结果表明:当底部堆填内摩擦角较大的渣土,上部堆填凝聚力较大的渣土时,能够充分发挥渣土的抗剪强度,利于边坡整体稳定;此外在强降雨工况下,边坡因分层结构差异,稳定性会产生不同程度的降幅以及稳定性系数最小时刻也表现出不同的滞后性。若考虑在渣土填筑前铺垫一定厚度的粗粒渣土(如砖渣等),能够加快坡体水分排出以及雨后稳定性的恢复。
With the rapid development of urbanization, the problem of slope stability caused by land filling has aroused increasing attention in engineering field. Construction solid waste (CSW) slopes are often composed of different attribute discarded soil, and have characteristic of multilayer structure. Aiming at the feature of “thick in middle, thin on both sides” of slope profile in the sliding direction, a concept of shear strength contribution rate is proposed to identify the optimal sequence of land filling. The evolution processes of pore water pressure and stability of different multilayer slopes before and after rainfall are studied based on the theory of saturated-unsaturated seepage and the principle of rigid body limit equilibrium. The results show that stability of slopes increase when CSW of larger friction angle is filled at the bottom of slope and the CSW of large cohesion is filled at the top of slope. In addition under rainfall infiltration, degradation of stability and hysteresis of appearing time of smallest safety factor vary due to the stratification differences from multilayer structures of the slope. If highly permeable CSW (e.g., gravel) is filled prior to the landfill construction, the discharge of water in the slope can be enhanced and the slope stability will also rise more rapidly.
作者
杨龙
姚文敏
曾江波
肖林超
YANG Long;YAO Wenmin;ZENG Jiangbo;XIAO Linchao(Faculty of Engineering, China University of Geosciences(Wuhan), Wuhan 430074, China;Shenzhen Geotechnical Investigation and Surveying Institute Co., Ltd, Shenzhen 518028, China)
出处
《人民长江》
北大核心
2019年第10期175-181,共7页
Yangtze River
基金
深圳市科技创新委员会深圳市科技计划技术攻关项目(JSGG20160331154546471)
中国地质大学(武汉)中央高校基本科研业务费专项资金资助项目(1810491A23)
关键词
渣土边坡
堆填分层
边坡稳定性
降雨
非饱和土
slope of construction solid waste
filling stratification
stability of slope
rainfall
unsaturated soils