杭州地铁长期运营监测分析

Long-term Monitoring and Analysis of the Hangzhou Metro Under Operation

针对杭州地区地质情况复杂多变的情况,对杭州地铁监测数据分析,为将来的设计施工以及运营管理提供参考。统计分析5年的长期运营监测数据,结果表明:在淤泥质粘土中采用冻结法施工联络通道时,对地基土扰动较大,淤泥质粘土渗透性差、固结时间长,会产生较大沉降变形;U型槽是地下结构过渡到地面车辆段的特殊区段,结构不同位置受地下水浮力影响差异较大,应加强地基处理,避免运营后产生较大的不均匀沉降;合理的隧道埋深,可以有效避免钱塘江"洪冲潮淤"的影响,反之隧道埋深较浅时易受外界影响,产生较大沉降变形;为有效保护地铁,当旁侧基坑基底处在软弱土层时,宜采用满堂或裙边加抽条的加固形式,以对围护结构底部形成较好的支档效果,应避免角撑等传力不直接、受力复杂的支撑体系。

The subsurface conditions in Hangzhou area are complicated and might vary significantly. In order to provide reference data for the future tunnel design and operation after the construction, this paper presents the five(5) years long-term monitoring results of the Hangzhou Metro tunnels under operation. The results indicated that, large ground disturbance and large consolidation settlement on the foundation bearing soils could be observed in the mucky clay soils and the communication pass was constructed by using soil freezing method due to the poor permeability and long consolidation period under the foundation loading. The U-shaped trench is a special transition zone between the underground structure and the surface structure. Buoyancy is different at different locations. To avoid large differential settlement after the construction and during the tunnel operation, appropriate ground improvement measures are necessary. The appropriate tunnel embedment depth can avoid the influence of Qiangtang River, which is famous for the "scouring during the flood period and sediment during the tidal period". Otherwise, a shallow buried tunnel is easily affected by the adjacent environment and large settlement could be induced. When the tunnel structure is within the soft clay zone, the ground improvement within different patterns are necessary and the simple supporting structures are also necessary.