浅埋超大直径盾构下穿大体量建筑物影响分析  

Effect of Shallow Embedded Large Diameter Shielded Tunnel Underpass Large Buildings

作　　者：邱守慧 QIU Shouhui(China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430060)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430060

出　　处：《土工基础》2022年第3期350-354,共5页Soil Engineering and Foundation

摘　　要：为研究高富水砂层段浅埋超大直径盾构隧道下穿对大体量单体建筑的影响,采用有限元软件Midas对无保护措施下上部建筑的沉降变形进行数值计算,提出了以洞内掘进控制为主、辅之洞内深孔二次注浆的保护措施,通过数值分析和现场监测,对实施保护措施后的上部建筑沉降变形进行验证。结果表明:(1)无保护措施时,数值计算得出隧道的正上方位置出现最大沉降约18.2 mm,内部框架相邻柱的最大差异沉降为6.45 mm,隧道开挖完毕后,正上方土体的最大沉降量为28.2 mm,内部框架柱沉降已超出预警值。(2)采取掘进控制为主,辅之洞内注浆加固措施后,数值计算得出最大柱基差异沉降约2 mm。(3)双线隧道穿越后,最大柱基实际差异沉降约0.8 mm。符合数值模拟推测数据,满足安评提出的控制指标及相关规范要求。In order to study the influence of shallow-buried and excessive-large diameter shielded tunnel excavation in the saturated sand layer underneath of a large footprint building,a numerical finite element model was established by using commercial software MIDAS GTS.The settlement and deformation of above building without protective measures were numerically evaluated.From the numerical results,the proposed protective measures included tunnel excavation control as the primary measured and aided by the secondary grouting.The deformations of the building with and without protective measures were compared with the monitoring data.The results show that:1.Without protective measures,the maximum settlement at the crest of the tunnel was about 18.2 mm,and the maximum differential settlement of the adjacent columns of the inner frame was 6.45 mm.After the completion of the tunnel,the maximum settlement of the soil mass above the tunnel was 28.2 mm,and the settlement of the inner frame column has exceeded the warning value.(2) The maximum differential settlement of pillar foundation was about 2 mm by the numerical prediction after the primary excavation control and supplementary grouting reinforcement measures applied in the tunnel.(3) Based on the analysis of on-site monitoring data,the monitored differential settlement of the maximum pillar foundation was about 0.8 mm after the two-cell tunnel passing through.The predicted data from the numerical simulation and the monitored data were consistent and the of control indices for the construction safety control met the requirements.

关 键 词：超大直径 泥水平衡 超浅埋 建筑物保护 大体量 

分 类 号：TU473[建筑科学—结构工程]