摘要
黄土崩塌是黄土高原区最常见、致灾最为严重的一种地质灾害。首先,从黄土地形地貌、黄土类型及结构、黄土垂直节理、坡脚侵蚀、降雨、人类工程活动等方面分析了黄土崩塌的成因,认为黄土中的垂直节理和坡脚侵蚀作用是造成黄土崩塌的主要原因;其次,通过野外黄土崩塌变形破坏特征及地质现象分析,将黄土崩塌归纳为拉裂-坠落式、拉裂-倾倒式、拉裂-下挫式和拉裂-滑移式4种主要破坏机制,并概化出了各类破坏示意图;通过离散元数值模拟,对黑龙沟黄土崩塌的形成破坏过程进行了再现和分析,其破坏过程为侵蚀剥落-坡脚局部凹进-垂直节理张开-下挫解体-堆积坡脚。
Loess collapse is a type of very common geological disasters in the loess plateau area of Northwest China.At first,this paper studies loess topography,loess type and structure,loess vertical joints,slope erosion,rainfall and human activities.The results show that both the vertical joints in loess and erosion at the toe of slope are the main causes of loess collapse.Secondly,based on field investigation and analysis on the geological phenomena,four typical failure modesare put forward to describe different types of loess collapses.They are tensile crack-falling,tensile crack-toppling,tensile crack-subsiding and tensile crack-sliding.By means of discrete element method,a typical loess slope of Heilonggou is simulated.The failure process of loess collapse includes erosion flaking,local recessing,vertical joints opening,drop breakup,accumulation at the toe of the slope.Research findings in the paper are significant to prevention and treatment for loess collapse in the loess plateau area of Northwest China.
出处
《工程地质学报》
CSCD
北大核心
2011年第4期541-549,共9页
Journal of Engineering Geology
基金
中国博士后科学基金(20090450565)
交通部西部交通建设科技项目(200831822353)
关键词
垂直节理
黄土崩塌
坡脚侵蚀
破坏机制
离散元数值模拟
Vertical joints
Loess collapse
Toe erosion
Failure mechanism
DEM numerical simulation
