走滑断层作用下上覆土层的变形破坏机理  

Deformation and failure mechanism of overlying soil lavers under strike-slip fault action

作　　者：裴鹏程 黄帅 袁静 张智康 PEI Pengcheng;HUANG Shuai;YUAN Jing;ZHANG Zhikang(School of Civil Engineering,Institute of Disaster Prevention,Sanhe,Hebei 065200,China;National Institute of Natural Hazards,Ministry of Emergency Management,Beijing 100085,China)

机构地区：[1]防灾科技学院土木工程学院,河北三河065200 [2]应急管理部国家自然灾害防治研究院,北京100085

出　　处：《中国地质灾害与防治学报》2024年第6期115-127,共13页The Chinese Journal of Geological Hazard and Control

基　　金：国家重点研发计划项目(2022YFC3070103-01);地震数值预测联合实验室开放基金(2021LNEF04);博士后基金项目(2021M691391)。

摘　　要：随着西部大开发的推进,工程项目难免需要跨越断裂带。断裂带具有地震活动频繁、岩层错动等特点,这给工程建设和资源开发带来了不小的挑战。为探明跨断层工程结构的敏感性影响因素,文章研究了不同基岩位错量、不同基岩错动速率、跨越断层角度、不同场地土类型和不同场地土厚度对上覆土层的变形破坏和竖向应力的影响机制。结果表明:基岩位错会导致覆土层产生应力集中、破裂、滑动等破坏现象,这些破坏可能会引起土体位移,从而引发山体滑坡、地滑和地面变形等地质灾害的问题,将提高对地下管道、道路、桥梁等工程设施造成损伤破坏的风险。文章聚焦基岩位错造成地面沉降变形、塌陷等问题,发现随着基岩位错量的增大,不同场地土对覆土层的沉降位移、竖向应力都有不同幅度的增长,例如坚硬土基岩位错量2 m时比0.4 m时沉降变形和竖向应力增长5倍左右。此外,发现在跨越断层时选择以90°跨越断层,可以减小沉降变形和应力。相关研究旨在揭示上覆土层的变形破坏以期对不可避免的跨断层工程结构的变形以及抗剪切破坏加固提供技术支撑。With the advancement of the western development,engineering projects inevitably need to traverse fault zones.However,fault zones are typically characterized by frequent seismic activities and rock layer dislocations,which bring certain challenges to both construction and resource development.To explore the sensitivity factors affecting the sensitivity of cross-fault engineering structures,this study investigates the effects of different bedrock dislocation amouts,bedrock dislocation rates,fault-crossing angles,different types of soil at the site,and varying soil thicknesses on the deformation,failure,and vertical stress mechanisms of overlying soil layers.The results show that bedrock dislocation can lead to stress concentration,fractures,sliding,and other destructive phenomena in overlying soil layers.These damages may cause soil displacement,potentially triggering geological hazards such as landslides,ground slides,and ground deformations.This poses a high risk of damage and destruction of the underground pipelines,roads,bridges,and other engineering facilities.This paper focuses on issues such as ground settlement deformation and collapse caused by rock dislocation,revealing that with an increase in rock dislocation amount,different types of soil at the site exhibit varying degrees of increase in settlement displacement and vertical stress on the overlying soil layer.For example,with the bedrock dislocation amount of 2 m compared to 0.4 m in hard soil,settlement deformation and vertical stress increase by around five times.In addition,it was found that selecting a 90°angle for fault crossing can reduce settlement deformations and stresses.The study aims to reveal the deformation damage of the overlying soil layer,providing technical support for the inevitable deformation of cross-fault engineering structures as well as the reinforcement against shear damage.

关 键 词：走滑断层 基岩位错 覆土层 变形破坏 剪切破坏 

分 类 号：P642.21[天文地球—工程地质学]