摘要
为研究天生三桥岩溶景区深秀洞层状岩质基坑边坡变形破坏机制,及时制订有效的治理措施,保证下方施工人员生命安全和基坑的继续施工。通过对深秀洞陡崖工程地质条件研究,并在此基础上结合FLAC^3D进行数值模拟,对层状岩质基坑边坡进行深入研究。结果表明:层状岩质基坑边坡开挖破坏坡体内部原有力学平衡,其变形破坏机制为开挖卸荷-滑移-拉裂过程;数值模拟显示两侧崖壁及基坑边坡,极易向外倾结构面发生变形,北东侧基坑边坡上部变形以沉降为主,下部向外倾结构面发生变形,边坡内部剪切应变增量较大区域易发生剪切破坏,并伴随挤压、拉裂现象。针对层状岩质基坑边坡变形破坏机制,提出以“框架锚索”和“肋柱锚杆”为主的分区治理方案,加固效果良好,目前基坑边坡及崖壁处于稳定状态。
In order to study the deformation and failure mechanism of Shenxiudong bedded rock foundation pit slope in Tianshengsanqiao Karst scenic area,effective control measures were formulated in time to ensure the safety of the construction workers and the continued construction of the foundation pit.Based on the study of engineering geological conditions of Shenxiudong steep cliff,and on this basis,combined with the numerical simulation of FLAC 3D,the deep research on foundation pit slope was carried out.The results show that the original mechanical equilibrium of the inner part of the slope was destroyed by the excavation of the bedded rock foundation pit slope,and its deformation and failure mechanism was the excavation unloading-sliding-cracking process.The numerical simulation show that both sides of the cliff wall and the foundation pit slope were prone to deform towards the outward structural plane.The upper deformation of the north-east side foundation pit slope was dominated by the settlement,and the lower part of the foundation pit slope deformed towards the outward structural plane.The shear failure was prone to occur in areas with large increment of shear strain in the slope,accompanied by extrusion and cracking phenomenon.Aiming at the deformation and failure mechanism of the bedded rock foundation pit slope,the partition treatment scheme based on "frame anchor rope" and "rib column anchor rod" was proposed,and the reinforcement effect was good.At present,the slope of the foundation pit and cliff wall are in a stable state.
作者
熊超
赵鹏
武超
刘光华
XIONG Chao;ZHAO Peng;WU Chao;LIU Guang-hua(208-Branch of Hydrogeology & Engineeing,Chongqing Bureau of Geology and Minera Exploratio;Chongqing 208 Survey and Design Institute ,Chongqing 400700,China;School of Geology and Environment,Xi′an University of Science and Technology ,Xi′an 710054,China)
出处
《科学技术与工程》
北大核心
2019年第29期260-265,共6页
Science Technology and Engineering
基金
重庆市国土资源和房屋管理局科技计划(CQGT-KJ-2014042)资助
关键词
基坑边坡
数值模拟
变形特征
破坏机制
应急治理
岩溶区
foundation pit slope
numerical simulation
deformation characteristics
failure mechanism
urgent treatment
Karst area
