双桥山群变质砂岩区含软层滑坡机理  

Landslide mechanism of metamorphic sandstone area containing weak interlayers in Shuangqiaoshan Group

作　　者：刘清 甘建军[1] 陈浩 李小明 刘玉伟 LIU Qing;GAN Jianjun;CHEN Hao;LI Xiaoming;LIU Yuwei(School of Hydraulic Engineering,Nanchang Institute of Technology,Nanchang 330096,China;Hydrogeology Corps.,Jiangxi Province Geology Bureau,Nanchang 330096,China;Jiangxi Natural Resources Policy Investigation and Evaluation Center,Nanchang 330045,China)

机构地区：[1]南昌工程学院水利工程学院,南昌330096 [2]江西省地质局水文地质大队,南昌330096 [3]江西省自然资源政策调查评估中心,南昌330045

出　　处：《地质科技通报》2025年第1期185-193,共9页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(42162025);2022年度江西省自然资源厅科技创新项目(ZRKJ20222310);2021年度浙江省山体地质灾害防治协同创新中心开放基金项目(2PCMGH-2021-02);河北省高校生态环境地质应用技术研发中心开放基金项目(JSYF-Z202201)。

摘　　要：双桥山群地层在华东地区广泛揭露,岩性与地层复杂,断层及褶皱发育,常形成软弱夹层斜坡,在降雨入渗的作用下极易发生滑坡。为揭示其在降雨条件下变形演化机理,以江西省修水县一典型含粉质黏土软弱夹层堆积体滑坡为例,分析了该软弱夹层滑坡的形成原因和变形破坏特征,建立了堆积体滑坡的地质力学模型,采用GeoStudio数值分析软件模拟了该滑坡在不同降雨强度条件下的形成机理。研究结果表明:(1)滑坡后缘EW向断层与韧性断裂带共同作用,发育了4组控制坡体稳定性的裂隙,在滑床之上形成厚达8.8 m的船形软弱夹层。(2)降雨入渗到碎屑和黏土物质组成的滑带,使滑体经历前期蠕变-中期滑动面贯通-后期剪切变形3个变形破坏阶段。(3)当降雨强度达9.9 mm/d时,滑坡坡体开始蠕变;当降雨强度增加到40 mm/d时,坡体沿着软弱结构面剪切变形增大;当降雨强度上升至120 mm/d时,坡体沿着软层结构面产生贯通性破碎面,最终加速失稳破坏。研究结果对今后该类似岩群的滑坡灾害的防治具有一定的参考价值。[Objective]The Shuangqiaoshan Group strata are widely exposed in East China,with complex lithology and stratigraphy,developed faults and folds,often forming weak interlayer slopes.These characteristics often create weak interlayer slopes that are prone to landslides under rainfall infiltration.[Methods]This study aims to reveal the deformation and evolution mechanisms of such slopes under rainfall conditions.Taking a typical silty clay-bearing soft interlayer landslide in Xiushui County as an example,the formation reasons and failure characteristics of the weak interlayer landslide were analyzed.A geomechanical model of accumulation landslides was established,and the landslide's response under different rainfall intensities was simulated using GeoStudio numerical analysis software.[Results]The findings are as follows:(1)An EW-trending fault zone and ductile fault zone at the landslide's rear edge combine to form four groups of cracks that control slope stability,forming a boat-shaped weak interlayer approximately 8.8 m thick in the sliding bed;(2)Rainfall infiltrates into the sliding zone composed of debris and clay,triggering the sliding body to undergo three deformation stages:early creep,mid-stage sliding surface penetration,and late-stage shear deformation;(3)Creep deformation begins when rainfall intensity reaches 9.9 mm/d.At 40 mm/d,shear deformation increases along the weak structural plane and progressively intensifies.At 120 mm/d,a connected fracture surface forms along the weak interlayer structure,ultimately accelerating instability and landslide failure.[Conclusion]These findings provide valuable insights into the prevention and management of landslide disasters in similar lithological settings.

关 键 词：双桥山群 岩质滑坡 软弱夹层 降雨入渗 数值模拟 变质砂岩 

分 类 号：P642.22[天文地球—工程地质学]