摘要
弃渣场边坡是一种常见的人工斜坡,其稳定性关系到区域内的道路交通,弃渣场潜在引发的地质灾害对下游地区人民生产生活也有不可忽视的危害。现有的数学统计、摄影-图像分析以及筛分试验等方法在弃渣场边坡的粒径分级特征研究中并不能真实反映弃渣场边坡在堆积过程中不同粒径颗粒的分布特点和引起的破坏模式影响效应。为突破这一局限,本文结合泸州市古蔺县叙大(叙永至大村镇)铁路沿线的弃渣场工程实际,采用物理模拟方法重现了弃渣体的堆积过程,研究了弃渣场边坡内的渣体粒径分级特征,以及弃渣堆积体的坡体结构特征。并根据物理模拟的试验结果,结合PFC离散元数值模拟研究了弃渣场边坡在考虑粒径分级情况下由降雨引起的斜坡变形失稳过程。物理模拟研究结果表明:弃渣堆积体的形成是一个动态的过程,在重力及颗粒间相互作用下,形成的堆积体粒径分级程度高,不均匀性强。从上至下颗粒的平均粒径逐渐增大,密度逐渐减小,空隙率逐渐增大。典型弃渣场边坡变形破坏过程的离散元PFC模拟研究表明:在降雨作用下,弃渣堆积体固结沉降、孔隙率降低、抗剪强度降低,弃渣场边坡的稳定性随之降低。整个过程分为应力重分布、中部覆盖层剪切破坏、后缘拉裂、后缘下错、前缘鼓胀、潜在滑面形成及滑面贯通几个阶段。
Slag dump is a common man-made disaster body. Its stability is related to the road traffic in the region. The potential geological disasters caused by the slag dump also have a great harm to the people’s production and life in the downstream areas. Based on the engineering practice of an abandoned slag yard along the Xuyong-Dacunzheng Railway,the accumulation process of the abandoned slag is reproduced by the physical simulation method,and the grading characteristics of the slag particle size and the slope structure characteristics of the abandoned slag deposit are studied. Based on the experimental results of the physical simulation and PFC discrete element numerical simulation,the deformation and instability process of the slope of the abandoned slag yard considering particle size classification is examined. The physical simulation results show that the formation of the waste slag deposits is a dynamic process. Under the interaction of gravity and particles,the size of the deposits is highly graded and uneven. From top to bottom,the average particle size increases,the density decreases and the void fraction increases. The discrete element PFC simulation study of the deformation and failure process of slope in the typical abandoned slag yard shows the stages of the back edge down fault,front bulging,potential slip surface formation and slip surface penetration.
作者
罗浩
霍宇翔
巨能攀
赖若帆
解明礼
段亮
LUO Hao;HUO Yuxiang;JU Nengpan;LAI Ruofan;XIE Mingli;DUAN Liang(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,Sichuan 610059,China;College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu,Sichuan 610059,China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2020年第1期69-79,共11页
Hydrogeology & Engineering Geology
基金
国家创新研究群体科学基金项目资助(41521002)
关键词
弃渣堆积体
边坡稳定性
粒径分级
物理模拟
离散元PFC
变形失稳过程
dreg accumulation
slope stability
size classification
physical simulation
discrete element PFC
process of instability
