摘要
黄土-泥岩接触面滑坡是黄土沿下伏泥岩等接触面滑动的黄土滑坡,是黄土高原广泛分布的主要黄土滑坡类型之一.黄土-泥岩接触面滑坡发育的黄土斜坡一般为坡度10°~20°的地势低洼部位.上部黄土、下部泥质岩的＂双层异质＂斜坡结构,倾向坡外的接触面构成的软弱结构面,是黄土-泥岩接触面滑坡发育的地质基础.地下水作用是黄土-泥岩接触面滑坡的重要引发因素.斜坡上部黄土的渗透性较好,且垂直节理和落水洞发育,有利于降水入渗,而下部泥质岩的渗透性差,地下水易在接触面及其低洼部位汇集,使黄土底部接触面一带岩土长期处于过湿软塑-饱和状态,成为滑坡发育的软弱结构面.黄土-泥岩接触面滑坡具有滑动速度低、滑动距离短,滑体稳定性差、易复活滑动等活动特征.受斜坡地质结构和水文地质条件的控制,黄土-泥岩接触面滑坡变形破坏的地质力学模式为滑移-拉裂型或塑流-拉裂型.
Loess-mudstone interface landslide is the loess slipping along the underlying mudstone,which is the major type of loess landslides that widely happens in Loess Plateau. The loess-mudstone interface landslide usually develops in low-lying parts with slope of 10° ~ 20°. The＂double heterogeneous＂slope structure with loess lying on mudstone,as well as a flabby structural plane trending outside,is the geological foundation of developing loess-mudstone interface landslide. Effect of groundwater is an important trigger factor for loessmudstone interface landslide developing. The penetrability of the upper slope in loess is well,together with welldeveloped vertical joints and sinkhole,but the penetrability of the lower mudstone is poor,which benefits to infiltration of precipitation and groundwater collecting in the interface,resulting in the rock and soil over wetting and soft with a saturated loess bottom for a long time. Thus the interface becomes a weak structural plane of landslide. The loess-mudstone interface landslides have the characteristics of low sliding speed,short sliding distance,unstable slip mass and repeatedly sliding. Under the control of the slope geological structure and hydrogeological condition,the geological mechanics model of the loess-mudstone interface landslide is sliding-pull crack or plastic flow-pull crack.
出处
《冰川冻土》
CSCD
北大核心
2014年第5期1167-1175,共9页
Journal of Glaciology and Geocryology
基金
国家自然科学基金项目(41362014)
甘肃省科学院应用研发项目(2012JK-07
2013JK-07)资助
关键词
黄土-泥岩接触面滑坡
接触面
地下水
复活滑动
特征
成因
loess-mudstone interface landslide
interface
ground water
revived sliding
characteristics
cause
