新中梁山隧道近接隧道段设计

Design of the Adjacent Tunnel Section of New Zhongliangshan Tunnel

研究目的:市区枢纽隧道设计中经常会存在与其他隧道(或其他构筑物)的上跨、下穿等立交关系,而这些近接、立交关系往往又是隧道设计中的重难点,成为设计、施工中的控制因素。成渝客专新中梁山隧道与既有隧道存在不同的立交关系,受既有隧道现状和立交关系的影响,不同的近接隧道设计、施工又千差万别,如何确保新中梁山隧道施工安全与既有隧道运营安全是本文研究的重点。研究结论:通过研究得出:(1)当新建隧道下穿既有隧道时,可以通过采用超前支护及控制爆破保证隧道施工安全和既有线安全;(2)新建隧道超小净距上跨既有隧道时,在净空限界允许的情况下,可以通过对既有隧道加固和衬砌背后注浆,通过改善既有隧道结构受力来达到保证既有隧道的安全;(3)对于拟建隧道下穿正在施工的隧道,对拟建隧道可以通过在建隧道施作辅助措施提前施作立交影响段,减小拟建隧道对既有隧道的影响,保证安全;(4)对于两条拟建隧道,当先期施工下部隧道时,需考虑后期上跨隧道施工荷载和运营荷载的影响,对初期支护和二次衬砌考虑适当的加强;(5)当上跨隧道先期施工时,应优先考虑上下隧道同期施工,减小因下穿隧道施工对上跨隧道的影响;(6)该研究成果可应用于隧道近接隧道段的设计。

Research purposes： In urban area, the design of tunnel usually needs to consider certain interchange relations with other tunnels （or other structures）, such as overpass, underpass, etc. These adjacent and interchange relations are the difficult and important points for designing tunnel, so they become the control factors for tunnel design and construction. New Zhongliangshan Tunnel of Chengdu - Chongqing Passenger Line has different interchange relations with existing tunnels and it is highly influenced by the existing tunnels and interchange relations. Different adjacent tunnel design requires quite different construction method, which means how to guarantee the construction safety and operation security of the existing tunnels are the research focuses in this paper. Research conclusions：According to the research, it can be drawn： （1）When the new tunnel under wear both tunnel, can through the adoption of forepole controlled blasting and ensure the safety of the tunnel construction safety and existing lines. （2）New super small clear distance tunnel across both the tunnel, in the case of clearance limit llowed, can through the tunnel reinforcement and grouting behind the lining, by improving the existing tunnel structure to ensure the safety of the existing tunnel. （3） For the proposed subway down through the tunnel under construction, the proposed subway can be applied through the tunnel under construction for auxiliary measures can be applied in advance for interchange effect, reduce the influence of the planned tunnel on existing tunnel, ensure safety. （4）For two proposedtunnel, when the first a lower tunnel construction, should be considered in the late on across the tunnel construction load and operating load, the influence of the primary support and secondary lining consider appropriate to strengthen. （5） When across the tunnel on the early construction, priority and tunnel construction during this period, reduce the wear on the tunnel construction on across the influence of the tunnel. （6）This research result can be applied in tunnel near the design of the tunnel section .