重载铁路隧道设计技术探讨

为解决重载运输条件下铁路隧道设计难题，通过大秦线铁路隧道病害的调查资料，对重载运输诱发的隧道病害及其原因进行总结分析。依托山西中南部铁路通道隧道设计经验，提出重载铁路：〖JP〗 1）软弱破碎围岩大于1000m或软岩高地应力段长大于500m的隧道、4km以上突水突泥风险等级较高的岩溶隧道优选采用2个单线隧道方案； 2）单线隧道仰拱矢跨比取1/6.5、双线取1/10.5，可以满足30t列车轴质量要求； 3)隧道内坡度不应小于3‰、富水地层不小于5‰，提出防排水措施实现运营可维护； 4)计算确定了轨下结构设计参数； 5)对隧道内轨道结构过渡、轨下及隧底结构过渡段采取了设计措施； 6)提出了隧道基底普查及承载要求。

Discussion on Design of Heavy-haul Railway Tunnel

The diseases and their causes of tunnel induced by heavy-haul transportation are analyzed, with the disease data of tunnel on Datong-Qinhuangdao railway as examples. Conclusions drawn are as follows： 1 ） Two single-line tun- nels might be the best choice when karst tunnel with water and mud bursting section longer than 4 km and soft and weak surrounding rocks section longer than 1 000 m or section with soft rocks and high ground stress longer than 500 m. 2） Single-line tunnel crown with rise-span ratio of 1/6.5 and twin-line tunnel with rise-span ration of 1/10.5 can meet the running requirements. 3 ） The gradient in the tunnel should lower than 3%0, ground with rich water Should less than 5%0. Water draining technologies are presented. 4） The design parameters of the structure under the track bed are de- cided. 5 ） Countermeasures of the connection sections are adopted. 6 ） The general investigation and load bearing re- quirements of the tunnel foundation are proposed.