摘要
济南市区北部黄河两岸地区地表以下6~8 m存在一层淤泥质土,相近深度基坑出现大量滑坡,表现出与现有基坑圆弧滑动法不同的整体破坏模式。基于大量工程滑坡性状,针对具体案例判断:含软弱夹层基坑边坡为圆弧-平面整体破坏模式,结果得到Plaxis有限元软件数值分析验证,基于整体的静力和力矩平衡方程推导出含软弱夹层基坑边坡圆弧-平面整体稳定性分析解析解,提出最优支护方案并经过数值和监测数据验证。结果表明:济南市区北部黄河冲积平原地貌单元地层基坑边坡受软弱夹层影响,边坡整体破坏模式呈圆弧-平面滑动模式,基坑设计如果采用圆弧滑动计算会存在安全隐患,基坑支护结构选型须设置抗剪构件贯穿软弱夹层,将圆弧-平面破坏模式改变为圆弧滑动模式,从而确保基坑安全。
In the northern area of Jinan City,along the banks of the Yellow River,there was a layer of silty soil approximately 6 to 8 meters below the surface.A large number of landslides were observed in nearby excavations at this depth,demonstrating a different overall failure mode from the conventional circular sliding method for excavations.Based on extensive engineering landslide characteristics,a specific case analysis indicated that the slopes of excavations containing weak interlayers were subjected to a combined circular-plane overall failure mode.This conclusion was validated through numerical analysis using Plaxis finite element software.An analytical solution for the overall stability analysis of excavation slopes with weak interlayers was derived based on statics and moment equilibrium equations.The optimal support scheme was proposed and validated through numerical and monitoring data.The findings suggested that excavation slopes in geological units of the Yellow River alluvial plain in northern Jinan City were influenced by weak interlayers,exhibiting an overall failure mode of circular-plane sliding.The conventional circular sliding calculation method for excavation design posed safety risks.Therefore,the selection of excavation support structures should incorporate shear-resistant elements penetrating the weak interlayers to transform the circular-plane failure mode into circular sliding mode,thus ensuring excavation safety.
作者
李连祥
吕桂青
张尚儒
赵永新
汪楚涵
LI Lianxiang;LÜ Guiqing;ZHANG Shangru;ZHAO Yongxin;WANG Chuhan(School of Civil Engineering,Shandong University,Jinan 250061,Shandong,China;Foundation Pit and Deep Foundation Engineering Research Center,Shandong University,Jinan 250061,Shandong,China;Shandong High-Xin Geotechnical Engineering Co.,Ltd.,Jinan 250102,Shandong,China;Jinan City Urban and Rural Construction Development Service Center,Jinan 250014,Shandong,China)
出处
《隧道与地下工程灾害防治》
2024年第3期1-11,共11页
Hazard Control in Tunnelling and Underground Engineering
基金
国家自然科学基金资助项目(51508310)
山东省优秀中青年科学家科研基金资助项目(BS2013SF024)
济南市科技计划资助项目(201201145)
关键词
软弱夹层
基坑边坡
整体稳定性
圆弧-平面破坏模式
weak interlayer
foundation pit slope
overall stability
circular plane failure mode
