杭州地铁青年路站深基坑监测分析

Construction Monitoring and Analysis of Youth Road Metro Station in Hangzhou

以杭州市地铁5号线青年路车站深基坑为背景,对开挖过程中地表沉降、地下连续墙和土体深层水平位移、内支撑轴力等监测数据进行分析。研究结果表明:基坑开挖引起的地表沉降具有明显的时空效应,且大部分监测点的累计沉降值超过报警值,需提高施工水平控制其沉降;基坑测斜数据在一定程度上可以反映局部土质好坏情况,土体深层水平位移与墙体深层水平位移密切相关,土体深层水平位移在一定程度上可以反映墙体深层水平位移;要提高轴力的监测频率,防止第一道支撑受拉过大与地下连续墙脱开,另外,支撑设计偏于保守,后续设计有待优化。

This paper presents a case history of construction monitoring and analysis of foundation excavation of Metro No.6 Line at Youth Road Station in Hangzhou.The ground subsidence,deflection at the slurry wall and in various soils and the axial force in the supporting system are monitored and analyzed.The results indicated:the deep excavation resulted in the ground subsidence to a wide zone around the excavation and more importantly,the acuminated settlement at the majority of the monitored points exceeded the threshold value.Construction methods that could better control the adjacent ground subsidence are therefore needed in the similar subsurface conditions.The lateral deflection data measured from the ground inclinometer can reflect the local soil conditions;the deflection in various soil depths are closely related to the slurry deflections.The results also recommended that the frequency of axial force monitoring is necessary so that the first layer of internal support system separate with the slurry wall due to the excessive axial force.In addition,the internal support system could be further optimized.