Analysis of lining water pressure and groundwater discharge of undersea tunnel after 10-years operation
The undersea tunnels with a"V"shaped slope normally require a mechanical discharging system.Undersea tunnel groundwater control affects the magnitude of discharge and water lining pressure,which in turn affects the cost of construction and operation.There are also many international research or studies on the ground-water infiltration of undersea tunnels,however only a few have been conducted in conjunction with the actual measurement of discharging capacity and water pressure during the operation.This study investigated the drainage volume and lining water pressure in subsea tunnels,focusing on their temporal variations and the rationality of original design parameters,based on long-term monitoring data.By using the Qingdao Jiaozhouwan Tunnel as a case study,methods such as engineering analogy,numerical simulation,and statistical analysis of 10 years of construction and operational monitoring data were applied.This research delved into an intricate analysis of relationships critical to subsea tunnel construction,including the correlation between seepage models and permissible discharging volumes,the dynamics between water pressure and actual daily drainage volumes,and the interplay between structural leakage and monitored water pressure.Additionally,the seepage behavior of rock drilling and blasting methods,alongside assessing lining water pressure values and allowable groundwater discharging volumes was examined.The original designed drainage was a maximum ratio of 0.4 m3/(d∙m)for the main tunnel and a maximum ratio of 0.2 m3/(d∙m)for the service tunnel.The lining water pressure reduction factor was 0.6.Statistical analysis of the measured results of drainage,water pressure,and structural leakage during the operation,the following results reveal that drainage volume decreases annually,stabilizing at approximately 0.2 m3/(d∙m)for the main tunnel and 0.1 m3/(d∙m)for the service tunnel during operation,while the water pressure on the secondary lining is 5%～10%of the full head pressure.Minimal correlation was observed between drainage volume,water pressure,and atmospheric precipitation after five years of operation.The findings confirm that the original design standards,including permissible drainage volumes and lining water pressure reduction coefficients,are reasonable with adequate safety margins.Observed self-sealing behaviors of rock mass fractures provide further validation.This comprehensive analysis provides valuable insights and serves as a reference for the planning and execution of future subsea tunnel projects.
undersea tunnelallowable drainagewater pressureseepagecleftinessrockdrilling and blast
万方数据
维普
