1 General provision
1.0.1 This code is formulated with a view of unifying technical requirements of railway tunnel construction, guaranteeing the construction quality, and making the tunnel construction comply with requirements of safety and usability, state-of-the-art technology as well as economic feasibility.
1.0.2 This code is applicable to construction and acceptance of newly built and renovated full-gauge railway tunnel works.
1.0.3 Tunnel works must be constructed according to the approved design documents, and shall be implemented according to current modification management method if the modification is necessary.
1.0.4 When railway tunnel is constructed through drilling and blasting, the shotcrete-bolt construction method should be adopted in priority and the dynamic management should be implemented.
1.0.5 Length grade division of railway tunnel shall comply with the following provisions:
1 Those less than 500m in length are short-length tunnels;
2 Those more than 500m and less than 3000m in length are medium-length tunnels;
3 Those more than 3000m and less than 10000m in length are long-length tunnels;
4 Those more than 10000m in length are over-length tunnels.
1.0.6 Division of excavated section grade of railway tunnel shall comply with the following provisions:
1 Cross-section areas less than 10m2 are small sections;
2 Cross-section areas more than 10m2 and less than 50 m2 are medium sections;
3 Cross-section areas more than 50m2 and less than 100m2 are large sections;
4 Cross-section areas more than 100m2 are oversize sections.
1.0.7 According to the general construction plan of railway construction, the following works shall be well implemented on the base of the specific conditions of the construction organization for the tunnel construction:
1 Against the in-site characteristics and on the basis of the survey and design documents, the proper construction method shall be selected;
2 The construction preparation works and tunnel opening ancillary works shall be well implememted so as to create favourable conditions for tunnel construction;
3 Rational arrangement for working procedure and operation of key work program shall be made, and stable production shall be organized;
4 According to construction conditions and requirement of construction period, model selection and matching for construction machinery shall be implemented, integrative capability of the equipment shall be fully used, and the level of mechanized construction shall be gradually improved;
5 conditions for ventilation, illumination and dustproof shall be improved. It is also required to lower the temperature and prevent harmful gas so as to keep the operators in good condition;
6 Relevant safety measures shall be formulated, and the safety code shall be strictly observed so as to ensure the construction safety;
7 Explanation for all the technologies and in-site test shall be well implemented, all operation specifications shall be strictly observed so as to ensure the construction quality;
8 It is alsi required to positively deploy new technologies, new process, new materials and new facilities; continuously improve construction technology and perfect in-site management, improve the level of construction technology; save energy and reduce material consumption, as well as improve integrated economic benefit of tunnel construction.
1.0.8 Tunnel construction
”’ shall comply with the specified survey accuracy, adopt relevant measurement, establish recheck system, and guarantee that midline, level correction, excavated section, lining thickness and clear opening size comply with specifications.
1.0.9 When the tunnel is completed, it is required to compile specific and overall summary for construction technology according to construction characteristics, as well as submit complete documents. During the construction, it is required to collect raw data and documents at any moment and get done with concerned construction note.
1.0.10 Tunnel construction shall protect the environment against pollution, carry out civilized construction. Relevant measures must be adopted when influence to environment can't be avoided.
1.0.11 For construction of railway tunnel project, not only the requirements stipulated in this code, but also those in the current relevant mandatory standards of the nation shall be complied with.
2 Terms and symbols
2.1 Terms
2.1.1 Tunnel boring machine
It is a sort of mechanized tunneling equipment, comprises different kinds of models such as single arm, double arms and full face.
2.1.2 Rock-self stability time
It refers to the period surrounding rock keep stability without any support when it is excavated and expose.
2.1.3 Loosening pressure
When tunnel is excavated, the surrounding rock will get loosen and distort, then looseness and interspace will appear, so that some incompact rock mass will form load (pressure) and act on support.
2.1.4 Clastic pressure
It refers to the pressure acts on support structure when the tunnel is excavated and surrounding rock periphery distorts.
2.1.5 Full face excavation method
It refers to the construction method of full face one-time formation.
2.1.6 Bench cut method
It refers to the construction method simultanously excavate the second half section after excavating the first-half section to certain distance. According to different advanced distance of the first half section, it comprises long bench method, short bench method and micro-bench method.
2.1.7 Ring cut method
It refers to the construction method that excavateing the top drift until form a ring, support it and then excavate the core soil in center and side walls at both sides.
2.1.8 Both slde drift method
It refers to the construction method that first excavating drifts at both sides of tunnel, then carry out preliminary support, and excavate the rest sections.
2.1.9 Center drift excavation methcd
It refers to the contruction method that firstly excavate upright post (or middle wall) between two tunnels at pipe socket section of multi-arch tunnel or single line tunnel, then complete concrete pouring for upright post (or middle wall), and lastly carry out excavation for two tunnels.
2.1.10 Center diagram method (CD method)
1 General provision
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Construction preparations
3.1 Construction survey
3.2 Check of design documents
3.3 Operational construction organization plan
3.4 Control measurement
3.5 Construction machinery preparation
3.6 Construction yard and temporary works
3.7 Operation staff
4 Tunnel opening project
5 Construction methods
6 Excavations
6.1 General provisions
6.2 Provisions on tunnel overexcavation and under-excavation
6.3 Drilling and blasting excavation
6.4 Machine excavation
7 Ballast loading and transport
8 Supports
8.1 General provisions
8.2 Shotconcrete
8.3 Bolt
8.4 Reinforcing mat
8.5 Steel frame
8.6 Advanced support and pre-reinforcement
9 Supervision and measurement
10 Lining
10.1 General provisions
10.2 Composite lining
10.3 Integral lining
10.4 Shorcrete-bolt lining
10.5 Reinforced concrete lining
10.6 Inverted arch and soleplate
11 Open tunnels
12 Service galleries
12.1 Generl provisions
12.2 Transverse gallery and parallel drift
12.3 Inclined shaft
12.4 Vertical shaft
13 Waterproofing and drainage
13.1 General provisions
13.2 Waterproofing and drainage of construction
13.3 Waterproofing and drainage of structure
14 Construction machineries
14.1 General requirements
14.2 Type-selection for the construction machinery
15 Ventilation, dustproof and air-water-power supply
15.1 Ventilation and dustproof
15.2 Air supply
15.3 Water supply
15.4 Power supply
16 Tunnel construction in special rocks and poor geologic zones
16.1 General requirement
16.2 Water-rich, slightly-cracked surrounding rock
16.3 Karst
16.4 Aeolian sands and water sands
16.5 Swelling rock
16.6 Gas
16.7 Rock blasting
16.8 Surrounding rock of squeezing property
17 Tunnel reconstructions
17.1 General requirement
17.2 Construction of reconstructed tunnel
17.3 Tunnel construction of the second track
18 Acceptance of Project
Appendix A The main construction (digging) methods of railway tunnel
Appendix B Test method of blasting cracking
Appendix C pattern of charges of surrounding holes
Appendix D The construction diary of lock bolt support with shotcrete
Appendix E The relevant test and measuring method of lock bolt support with shotcrete
Appendix F Grading decision making of surrounding rock of railway tunnel
Appendix G decision making card of Grade of surrounding rock in construction phase
Appendix H The prophylaxis and treatment of tunnel landslip
Wording Explanations
