近加固区富水砂层换刀方案比选及应用研究

STUDY ON THE COMPARISON AND APPLICATION OF TOOL CHANGING SCHEMES IN WATER RICH SAND LAYER NEAR THE REINFORCEMENT AREA

盾构施工是在复杂多变的地下掘进,因调查不详细或资料缺失,难免碰上不明地下障碍物,不可避免地发生刀具磨损、掉落和刀盘损害等现象,为解决刀具掉落导致盾构无法掘进必须换刀但工期受限须快速处置等问题,依托杭州地铁9号线渔人码头站~三堡站盾构区间换刀工程实践,根据水文、地质和周边环境选择化学加固常压开仓、地面冻结加固常压开仓、带压进仓换刀和钢套管辅助常压换刀等4种换刀方案,从安全性、经济性、工期等方面进行比选研究,确定了钢套管辅助常压换刀方法并有效实施。现场实施和监测结果表明,在有效降低地下水位的情况下,采用钢套管辅助常压换刀是一种经济、快速、便捷的换刀处置方法。

Shield tunneling is carried out in the complex and changeable underground world.Due to the lack of detailed investigation or data,it is inevitable to encounter unknown underground obstacles,which will inevitably lead to tool wear,falling and cutter head damage.In order to solve the problem that the shield cannot be driven due to the falling of the cutter,it is necessary to change the cutter,but the construction period is limited and it must be handled quickly.Based on the practice of the cutter change project between Fisherman's Wharf Station and Sanbao Station of Hangzhou Metro Line 9,according to the hydrology The geology and surrounding environment selected four tool change schemes,including chemical reinforcement atmospheric opening,ground freezing reinforcement atmospheric opening,warehousing tool change with pressure and steel casing auxiliary atmospheric tool change,and compared and studied from the aspects of safety,economy,duration,etc.The steel casing auxiliary atmospheric tool change method was determined and effectively implemented.The field implementation and monitoring results show that,under the condition of effectively reducing the groundwater level,it is an economic,fast and convenient tool change method to use steel casing to assist the atmospheric tool change.