成对节理对废弃黄土窑洞边坡稳定性的影响  

Influence of Paired Joints on Slope Stability of Abandoned Loess Cave

作　　者：肖云飞 张晨 徐辉 薛丹璇 XIAO Yun-fei;ZHANG Chen;XU Hui;XUE Dan-xuan(North China Municipal Engineering Design & Research Institute Co., Ltd., Tianjin 300381, China;College of Geology Engineering and Surveying, Chang’an University, Xi’an 710000, China;Henan Institute of Geological Science, Zhengzhou 450001, China)

机构地区：[1]中国市政工程华北设计研究总院有限公司,天津300381 [2]长安大学地质工程与测绘学院,西安710000 [3]河南省地质科学研究所,郑州450001

出　　处：《科学技术与工程》2021年第32期13808-13816,共9页Science Technology and Engineering

基　　金：国家自然科学基金面上项目(41672285)。

摘　　要：节理在黄土地区普遍发育,一般成组成对出现,它的存在破坏了土体的整体性和连续性,形成的软弱面对黄土洞室和边坡的稳定性造成安全隐患。通过实地调查、数学统计等方法,对研究区节理分布特征和灾害类型进行系统研究,在此基础上将废弃黄土窑洞边坡变形破坏归纳为窑洞冒顶破坏和窑洞崩塌破坏2种模式。通过建立不同成对节理条件下的有限元模型,对废弃黄土窑洞边坡稳定性进行计算分析。结果表明:成对节理远离拱顶且间距越大时,稳定性越低,同时发育X节理时的稳定性比垂直节理时更低;成对节理对竖直位移的影响比对水平位移的影响大,而发育的X节理倾角越小时,窑洞更容易发生洞口局部崩塌及窑脸冒顶灾害;Mises等效应力在窑腿、立壁和拱顶不规则处更为集中,成对节理远离拱顶和间距增大时节理两侧的围岩应力差距越小,且当成对X节理倾角时变小时,最大等效应力值增大,节理附近更容易发生破坏。Joints are generally developed in loess areas and appear in pairs.Their existence destroy the integrity and continuity of the soil mass,and the resulting weakness causes safety hazards to the stability of loess caverns and slopes.Through field investigation,mathematical statistics and other methods,the joint distribution characteristics and disaster types in the study area were systematically studied.On this basis,the deformation and failure of the abandoned loess cave dwelling slopes were classified into two modes,cave dwelling roof fall failure and cave dwelling collapse failure.Through the establishment of finite element models under different pairs of joints,the stability of abandoned loess cave dwelling slopes was calculated and analyzed.The results show that when the paired joints are far away from the vault and the distance is larger,the stability is lower,and the stability when the X joints are developed is lower than when the vertical joints are developed.The influence of paired joints on vertical displacement is greater than that on horizontal displacement,and the smaller the inclination angle of the developed X joint is,the more likely the cave dwelling is to local collapse of the cave entrance and roof fall of the cave face.The Mises equivalent stress is more concentrated in the irregularities of the kiln leg,vertical wall and vault.When the pair of joints are far away from the vault and the distance increases,the stress gap between the surrounding rock on both sides of the joint becomes smaller,and when the inclination angle of the pair of X joints becomes smaller,The maximum equivalent stress value increases,and damage is more likely to occur near the joints.

关 键 词：废弃黄土窑洞 黄土节理 窑洞灾害 数值模拟 

分 类 号：TU361[建筑科学—结构工程]