1.0.1 This code is established to implement relative national rules and railway technical policies, unify designing technical standard of railway tunnel, and make railway tunnel design to meet the requirements of safety and usability, state-of-art technology, economic feasibility.
1.0.2 This code is applicable to the designs of Level I and II standard track gauge railway tunnel used for mixed passenger and freight line-shared run, passenger train which the design running velocity is equal to or less than 160 km/h, and freight train which the design running velocity is equal to or less than 120 km/h.
1.0.3 According to the length, the tunnels are classified as:
Super long tunnel full length 10000m or more;
Long tunnel, full length 3000m ~ 10000m;
Medium tunnel full length 500m ~ 3000m;
Short tunnel full length 500m or less.
Note: Tunnel length is referred to the distance between end wall surfaces of inlet and outlet openings, and shall be calculated from the crossing point of railway central line and the intersecting line formed by end wall surface or oblique cut of oblique opening and design inner rail top surface. For double-line tunnel, this distance is calculated according to the length of downlink; for tunnel within station, this distance shall be calculated according to the length of main line; the length of tunnel equipped with bumping structure shall be calculated from the starting point of bumping structure.
1.0.4 In the tunnel survey and design, national policies and regulations must be complied with, and the influence of tunnel project on ecology and water resources shall be emphasized. In tunnel construction, optimal land utilization, energy conservation and irrigation protection shall be considered, and noise, spoil and drain shall be treated properly.
1.0.5 Based on reliable complete data, operation and construction conditions shall be compromised in tunnel design according to terrain, geologic and ecological characteristic. The adopted plans, design principle and building structure of tunnel design shall meet the requirements of safety and usability, economic feasibility and environmental protection through technical and economic comparison / analyses.
1.0.6 Inner contour of newly-built railway tunnel must meet the requirements of current national standard "Structure Gauge for Standard Gauge Railways" (GB 146.2), and prospective rail type upgrade. As for newly-built railway tunnel for passenger train with running velocity 160 km/h, the inner contour shall be identified according to such factors as engine type, carriage sealability and passenger comfort. For single line tunnel, the cross-sectional area of clearance above the tunnel rail level shall not be less than 42m2; for double-line tunnel, shall not be less than 72m2; curve widening shall be considered additionally for curved tunnel. The section of tunnel arranged with rescue paths shall be increased according to the dimension of rescue paths, and the width of rescue path shall not be less than 1.25m.
The structural approach limit of tunnel for double-layered containerized traffic shall meet the relative regulations of the Ministry of Railways.
The inside contour of tunnel within the station shall meet the requirements of station yard design.
1.0.7 In renovation of existing line and second line extension, new railway standard shall adopted for newly-built tunnel, and should be adopted for renovated tunnel.
1.0.8 Tunnel structure shall meet the permanent structural design of 100-year normal service, and built tunnels shall meet the operating demand, facilitate maintenance work and be arranged with necessary facilities like safety protection.
1.0.9 Tunnel structure, water-proof / drainage design and constructional material shall be adopted in consideration of the influence on local environment.
1.0.10 In the tunnel design, relative national technical economic policies shall be implemented, and new theory, technology, material, equipment and process shall be adopted positively.
1.0.11 Applicable construction scheme shall be selected in tunnel design in accordance with engineering geology, hydrogeological conditions, combining with factors such as section size, lining type, tunnel length and construction period requirement.
1.0.12 For the designs of long tunnel, super long tunnel and tunnel with complicated geologic condition, the preparations for construction shall be established. As for tunnel suffered with gas or higher gas, implementation preparations for construction shall be established to prevent higher coal gas, coal exploring, coal revealing and coal pasting in accordance with this code and relative standards.
1.0.13 Means of construction transportation shall be adopted in tunnel design, based on ventilation and hole-inside hygiene standard.
1.0.14 Besides this code, the railway tunnel design shall comply with provisions of relative current compulsory standards.
