深埋矿山法海底隧道排水设计探讨——以珠江口铁路隧道为例

Drainage Design of a Deep-Buried Subsea Tunnel Using Mining Method:a Case Study of Pearl River Estuary Railway Tunnel

矿山法海底隧道排水量无规范标准可依,且排水量所受影响因素复杂,随施工推进动态变化,排水系统无法精准设计。针对这一难题,以珠江口铁路隧道为背景,结合国内外已建成工程的实际排水量和理论计算值,采用选定标准—过程控制—动态调整的方法,保证排水系统设计参数精准。同时,通过分析不同潜水泵适用工况、运行效果、故障率及其对土建的要求,建议海底隧道采用工艺简单、产品稳定、技术成熟的单级潜污泵;从系统稳定性、可靠性上分析,认为当排水扬程超过单级潜污泵提升限值时,单级潜污泵多级提升比多级潜水泵单级提升更具有优势。

At present,a standard for drainage volume control for subsea tunnels constructed using the mining method does not exist.Drainage volume is affected by various complex factors,which vary with construction advancement and hinder the precise design of the drainage system.A case study is conducted on the Pearl river estuary railway tunnel to address these problems,and a drainage volume control method combining standard selection,process control,and dynamic adjustment is proposed.The study guarantees precise design parameters of drainage systems based on actual and theoretical drainage data of some projects built globally.Then,the applicable conditions,operational effects,malfunction rate,and engineering demands of submerged pumps are analyzed.Based on the results,it is recommended to adopt single-stage submerged pumps with simple craft,stable performance,and mature technology.Through stability and reliability analyses,it is also revealed that when the pump head exceeds the lifting power limit of the single-stage submerged pumps,the multigrade lifting of the single-stage submerged pumps becomes superior to the single-grade lifting of multistage submerged pumps.