铁路特长隧道分、合修影响因素及原则探讨

Discussion on Influencing Factors and Principles of Single-hole and Double-hole Scheme of Extra-long Railway Tunnel

双线铁路特长隧道采用分修还是合修方案对建设和运营影响巨大,是项目决策需研究的重大技术问题。在调查国内外现状的基础上,对影响因素进行系统梳理,提出量化评价方法,并结合某高原铁路进行阐述。研究结论如下:(1)建设期影响分、合修的最重要因素为相邻工程及投资,运营期为养护维修、运营保通和防灾救援;(2)软岩大变形严重、运营维护、保通或工法有要求的隧道,不论长短均应采用分修方案;(3)防灾救援及养护难度较高的铁路,当隧道长度超过15 km时应考虑采用分修方案,当采用合修方案时应进行技术经济比选;(4)采用分修方案的隧道,应结合相邻工程、洞口地形及地质条件,综合研究洞口的分、合修方案,当洞口分修时应研究采用小净距的可行性。

The adoption of double-hole or single-hole scheme for double-track extra-long railway tunnel has great influence on construction and operation, which is a major technical problem to be studied in project decision-making. By investigating the current situations at home and abroad, the author systematically sorts out the influencing factors, puts forward a quantitative evaluation method, and expounds it with a plateau railway. Research results show that(1)The most important factors affecting the single-hole and double-hole schemes in the construction period are adjacent projects and investment, and those in the operation period are maintenance, unobstructed operation, disaster prevention and rescue;(2)For tunnels with large deformation of soft rock, in operation and maintenance, with requirements for unobstructed operation or construction method, double-hole scheme should be adopted regardless of their length;(3)For railways with high difficulty in disaster prevention, rescue and maintenance, and the tunnel length exceeding 15 km, double-hole scheme should be adopted;when the single-hole scheme is adopted, the technical and economic comparison should be made;(4)For the tunnel with double-hole scheme, the scheme of the entrance should be comprehensively studied in combination with adjacent projects, the topography and geological conditions of the entrance, and the feasibility of the scheme with small spacing should be studied when the entrance is double-hole.