冻结法联络通道工程前期阶段风险管控——以福州市轨道交通2号线紫阳站—五里亭站区间超长联络通道及泵站冻结工程为例

Risk Management in Early Stage of Connection Gallery with Freezing Method: a Case Study on Freezing Project of Super-long Connection Gallery and Pump Station on Ziyang Station-Wuliting Station of Fuzhou Rail Transit Line 2

冻结法联络通道工程是自身风险工程,为弥补联络通道冻结法工程施工之前(前期阶段)风险管控方面的缺失,以风险管控为主线,从工程技术角度对联络通道冻结工程的风险源识别与风险等级评价进行分析,提出减小或规避联络通道冻结工程风险的技术措施,包括:1)合理选择联络通道的位置,尽量避开重大环境风险和工程地质风险;2)适当增加联络通道处钢管片的数量,增强隧道结构整体强度和抵御风险的能力;3)对联络通道前后一定范围的隧道管片背后进行二次注浆,适当加固地层;4)优化联络通道及泵站的结构尺寸,以利于冻结施工;5)合理进行冻结法加固专项设计,避免出现冻结薄弱面。

The connection gallery with freezing method is a self-risk project, and there is not any risk management measures for early stage of connection gallery with freezing method.Hence, the risk source identification and risk level evaluation of the connection gallery with freezing method are analyzed.The technical measures that can reduce or avoid the risk of the connection passage with freezing method are proposed, which include:(1) The location of the connection gallery should be rationally selected by avoiding areas with serious environmental and geological risks.(2) The number of steel pipe pieces at the connection gallery should be appropriately increased to enhance the overall strength of the tunnel structure and the ability to resist risks.(3) The secondary grouting should be carried out behind segments ahead of and behind connection gallery, and the ground should be reinforced.(4) The structural dimensions of the connection galley and pump station should be optimized to facilitate freezing construction.(5) The special design of freezing method reinforcement should be rationally carried out to avoid freezing weak surface.