中国白银山隧道施工技术

白银山隧道全长390m,采用新奥法原理施工。利用光面爆破技术,Ⅲ类围岩全断面一次开挖,Ⅱ类围岩和断层破碎带半断面正台阶开挖。初期支护为锚喷及钢筋混凝土护拱,二次衬砌为模筑混凝土、洞内防排水采用复合式衬砌中间设聚氯乙烯薄膜结合纵向、环向育管及橡胶止水带的综合治理方案。对于特殊地质中的浅理、特浅理进洞的施工,坚持“护拱稳定边仰坡,大管棚注浆加固土体,浅打眼、弱爆破、强支护”的原则,做到安全进洞;对于断层破碎带,则采取了管棚注浆,超前锚杆预先加固围岩并结合钢格栅支撑等有力措施,顺利通过了不良地段。最后分析了浅理段荷载的计算,阐述了新奥法的岩体动态性质的力学概念。

Construction technology of Baiyinshan Tunnel in China

The 390-meter Baiyingshan Tunnel is constructed with the application of theory of NATM.Applying the technology of smooth blasting,the complete section of the III surrounding rock and the half section of the broken and the II s urrounding rock have been excavated at the obverse step.The bolt and the protecting arch m ade by steel and concrete as supporti ng structure have been used in the previous period,and the secondary lining is model-b uilding concrete.The water-proof a nd drainage system within the tunnel has adopted the com prehensive treatment project of the combined linings and setting the PVC pellicle in the middle,the connection of the longitudinal,loop pipes and the rubber-se aling belt.Concerning the construction of the shallow cover and the special shallow cover i n the tunnel under the special geology conditions,the principle of"To stabilize the slopes with protecting arch;to strengthen the earth with the pipe-shield support grouting;to dig a hole shallowly;to blast slightly;to use strong supporting structure."has been adopted to enter the tunnel s afely;in terms of the broken belt,th e effective actions such as the pipe-shield support grou ting,strengthening the surroundin g rock in advance with advanced bolt a nd steel grids,and so on,are taken to pass the poor condi tioned part smoothly.At last,The paper analyzes the calculation of the s hallow cover load part,and states the mechanic co ncept of rock dynamic properties of t he NATM.