富水地铁车站大管幕隔水工法研究

Superpipe roof water-isolating method for metro station in water-rich strata

在分析总结深埋地铁车站现有建设工法优缺点的基础上,提出了一种新型地铁车站大管幕建设工法(SPR).该工法最大的特点是可在深埋富水地层中做到不降水施工地铁车站.结合双层双跨单柱结构站型对SPR工法的基本原理和施工步序做了详细叙述.SPR车站是一种全新的"类骨架结构",是纵向与横向共同受力的复杂组合体系.采用有限元软件建立了地铁车站模型,对SPR工法车站进行了变形和受力分析.结果表明:采用逆作法施工时管幕结构变形量较小;大管幕纵梁内力远小于其极限强度,结构柱和内撑环梁受力相对较大,极值出现在边墙与底拱交接处,经验算SPR工法车站构件均满足结构强度要求.最后,介绍了SPR工法的防水体系,并详细描述了环向和纵向防水做法.

A new metro station construction method,super pipe roof method(SPR),is proposed in this paper based on the analysis and summary of merits and demerits of existing construction methods.The most important feature of SPR is that it can realize subsurface excavation of metro station in deeply buried and water-rich condition without dewatering.The construction principle and procedure of SPR are described in detail by using double-storey and double-span with single column station model.SPR station is a new 'framework like structure'and a complicated bearing system in vertical and horizontal.A metro station model is built by using finite element software,then deformation and stress of SPR station are analyzed.The results show that deformation of pipes is small and stress of longitudinal beams is far less than its ultimate stress when top-downmethod is adopted for excavating.And the stress of steel concrete permanent column and internal-support-beam is comparatively larger,extreme values appears in the junction of sidewall and bottom plate,while all the components of SPR structure can meet the strength requirements through calculation.Finally,waterproof system of SPR method is introduced and waterproofing method in circumferential and longitudinal is specified.