沿海深埋富水松散地层土压盾构水中接收技术

Technology of EPB Shield Arrival in Water in Deep-Buried Water-Rich Loose Stratum of Coastal Area

沿海地区的深埋富水上软下硬地层、砂层、淤泥质砂层等松散地层中,地下水受潮汐影响较大,造成盾构接收端头加固效果较差,常规的盾构接收方法风险较大,可以采用水中接收技术来确保安全。结合工程案例,从风险分析和针对性应对措施入手,制订详细的土压盾构水中接收作业流程,并对施工中的重要和关键工序进行重点把控,确保了盾构接收安全。结果表明,盾构水中接收时端头松散地层损失不可避免但可控,洞内注浆加固和对洞门及时有效的封堵是减小地层损失的关键。

In the deep-buried water-rich upper-soft and lower-hard stratum,sand layer,muddy sand layer and other loose stratum in the coastal area,the groundwater is greatly affected by the tide,resulting in poor reinforcement effect of shield arrival end.The conventional shield arrival has great risk,and the technology of arrival in water can be used to ensure safety.In this paper,based on engineering cases,started with risk analysis and targeted countermeasures,detailed operation processes of EPB shield arrival in water are formulated.Furthermore,it is focused on the control of important and key processes in construction,so as to ensure the safety of shield arrival.The results show that the loss of loose stratum is inevitable but controllable during shield arrival in water.Grouting reinforcement in the tunnel and timely and effective plugging of tunnel portal are the key to reduce the loss of stratum.