宜万线别岩槽隧道出口DK406+422特大突水分析

Analysis of Extreme Large Water Bursting in Area of DK406+422 at Bieyancao Tunnel Exit of Yichang-Wanzhou Railway

研究目的:宜万线别岩槽隧道出口DK 406+422大突水引起地质灾害,本文分析形成突水溶腔的条件和原因,以便采取有效的整治措施。研究结论:通过对这一特大突水进行分析,得出:与暗河相通储水溶腔,宜排(水量较大宜采用泄水洞泄水)不宜堵;建议在隧道外部打泄水洞(约400 m),替代庙坪暗河的等效作用,不致造成环境影响,又可降低水位,确保隧道施工安全,消除可能存在的隐患;跨越隧道溶腔建议采用桩基承台跨越,因揭示的溶腔周边岩体完好、整体稳定、宽度不大(11 m),采用板拱形式跨越亦是有可能的。

Research purposes： The analyses of the forming conditions and cause for the extreme large water bursting in the area of DK 406 ＋ 422 are made for the purpose of taking the effective treatment measures. Research conclusions： From the analyses of this extremely large water bursting, it can be seen it is suitable for draining the water in dissolved chamber connecting with underground river, but not for blocking it. Sluice culvert can be used if the water is large. It is proposed the sluice culvert of about 400 m can be excavated at the outside of the tunnel, which has the same effects as Mengping Underground River. In this way, there is no bad influence on environment and the water height can be lowered, which can guarantee safe construction of tunnel and eliminate the latent danger. It is also proposed cap of pile trestle can be used for the dissolved chamber crossing tunnel with plate arch because the rocks around the chamber are complete with good stability and width of 11 m .