复杂山区铁路隧道软岩大变形防治

Prevention and Control of Large Deformations of Soft Rock in Railway Tunnels in Complex Mountainous Area

高地应力软岩隧道大变形是复杂山区隧道建设的世界性难题之一。本文以原铁道部科技研究开发计划《艰险困难山区高速铁路复杂地质隧道修建技术》课题为依托,从设计和施工两个方面对软岩隧道大变形的控制进行研究,提出了"让抗结合,柔刚相济,组合围岩,共同承载"的大变形控制理念、大变形四级分级方法、适宜于大变形的三种断面轮廓、不同变形等级的长锚杆的支护参数、台阶法施工时"长短锚杆结合,先短后长分次施作"的锚杆施工方法等研究成果,并对软岩大变形隧道采用"大断面+仰拱"法和全断面法的开挖工法进行了探索。

Large soft rock deformation in tunnels under high crustal stress constitutes one of the greatest difficulties in tunnel construction.On the basis of scientific research and development program of Construction Technologies of High-Speed Railway Tunnels in Dangerous Mountainous Areas with Complex Geological Conditions of the former Ministry of Railways,this Article summarizes the large deformation control technologies of tunnels in soft rock from two perspectives of design and construction.After that this Article puts forward the design philosophy of"Combination of accommodation with resistance,rigidity with flexibility,surrounding rock with supporting structure to form an integrated bearing system"for the control of large deformations in tunnels,recommends the four-tier classification method of large deformations,proposes three types of support contour section suitable for large deformations,illustrates long anchor bolt support parameters for different classifications of large deformations,and concludes that the principle of"Combination of long and short anchor bolts,Erection of short anchor bolts first and long anchor bolts second"should be adopted for the bench construction method.In addition,it thoroughly studies the construction methods of"large section+inverted arch"and full-face excavation adopted for tunnels with large soft rock deformations.