深层排水盾构隧道接缝防水密封垫形式试验研究

Experimental Study on Joint Waterproofing Gasket Patterns for Deep Sewage Tunnels Excavated by Shield Machines

国内大型深层排水隧道的建设目前尚无先例,技术上存在很多难题。深层排水隧道埋深一般达40 m及以上,需承受的水压力很高。深层排水隧道接缝采用内外双道密封垫,受盾构机规模的限制,其装配力不宜过大,且密封垫尺寸较小,不具备目前国内大型水下隧道密封垫厚、大的特点,防水能力将受到极大考验。因此,进行密封垫防水试验,确保弹性密封垫具有稳定的长期耐高水压性能显得格外重要。文章以广州深层排水盾构系统东濠涌试验段工程为依托,根据工程实际尺寸1∶1制作了弹性密封垫和混凝土试件,并利用自主设计的可三向加载高水压防水性能试验系统,进行了多组防水性能试验,总结了试验现象与规律,对接缝不同张开量、错位量情况下的接缝防水能力进行了比较,得到了相关规律,验证了深层排水盾构隧道接缝防水采用密封垫方案的可行性。

There is no precedent regarding the construction of large deep sewage tunnels in China and there are many related technical problems. Generally, these tunnels are more than 40 m deep and have to withstand high wa- ter pressure. Usually they use dual-sealed gaskets, but a large assembling force is detrimental due to the size limit of the shield machines; additionally, there are challenges regarding water tightness since the gaskets are not thick enough or big enough compared with those used in common domestic underwater tunnels. It is particularly important to use a waterproofing test to ensure the elastic gasket is capable of a long-term and stable performance while resist- ing high pressure. For the Guangzhou Donghaoyong deep sewage tunnel project, the gasket and concrete test speci- mens were produced according to the actual engineering size. Several waterproofing performance tests were conduct- ed using a three-dimensional loading system. The tests compared the waterproofing joints with different openings and misalignments, and verified the feasibility of the gasket scheme for deep sewage shield tunnels.