紧邻地铁内支撑结构深基坑监测分析  

Monitoring and Analysis of a Deep Excavation Adjacent Metro Tunnels with Internal Strut Structure

作　　者：张伟帆 ZHANG Weifan(Shenzhen Geokey Group Co.,Ltd.Shenzhen 518000,China)

机构地区：[1]深圳市工勘岩土集团有限公司,深圳518000

出　　处：《广东土木与建筑》2024年第11期25-29,共5页Guangdong Architecture Civil Engineering

摘　　要：紧邻地铁的深基坑支护施工,由于开挖深度大、周边环境复杂敏感,导致其施工难度极大,风险性较高。建立此类结构的监测预警系统,进行动态化设计施工是保障基坑及周边环境安全运行的有效手段,针对此类深基坑结构的监测研究亟待开展。以深圳地区某紧邻地铁的内支撑结构深基坑为例,通过对整个基坑开挖过程中的监测数据进行分析总结,揭示了基坑支护结构顶部水平位移、深层水平位移、周边地表沉降、地下水位变化以及内支撑轴力等监测指标的发展趋势。结果表明,支护结构水平位移、周边地表沉降值以及地下水位下降量基本出现随基坑开挖深度加深而逐渐增大的趋势,三道内支撑中第二支撑轴力值较大,是抵抗土压力的主要结构。通过及时有效的预警反馈机制,基坑支护结构在全生命周期处于安全可控状态,依据本研究结果提出的基坑优化设计建议可为相关工程提供有益参考。The construction of deep foundation pit support adjacent to the subway is extremely difficult and risky due to the large excavation depth and complex and sensitive surrounding environment.Establishing a monitoring and early warning system for such structures and conducting dynamic design and construction is an effective means to ensure the safe operation of foundation pits and surrounding environments.Research on monitoring for such deep foundation pit structures is urgently needed.Taking a deep foundation pit adjacent to a subway in Shenzhen as an example,the monitoring data during the entire excavation process were analyzed and summarized to reveal the development trend of monitoring indicators such as top horizontal displacement,deep horizontal displacement,surrounding surface settlement,groundwater level changes,and internal support axial force of the foundation pit support structure.The results show that the horizontal displacement of the support structure,the settlement value of the surrounding surface,and the decrease in groundwater level gradually increase with the depth of excavation.The second support axis force value among the three internal supports is relatively large,which is the main force to resist soil pressure.Through timely and effective warning feedback mechanisms,the foundation pit support structure is in a safe and controllable state throughout its entire life cycle.Based on the results of this study,the optimization design suggestions for foundation pits can provide useful references for related projects.

关 键 词：紧邻地铁 深基坑 内支撑结构 施工监测 变形规律 

分 类 号：U655.54[交通运输工程—港口、海岸及近海工程]