1.0.1 This code is formulated with a view to provide technical criteria for design of mountain ridge road tunnel.
1.0.2 This code is applicable to all kinds of two-lane tunnels with major excavation mean of drilling and blasting method, road tunnel of other forms may also comply with this.
1.0.3 Tunnel layout and design shall abide by first principles of give full play to tunnel function, safety and economically construct tunnel.
Design of the tunnel shall have a complete investigation and survey information; it shall takes topography, geology, hydrology, meteorology, earthquake, trafficking and its components, as well as the construction and operation conditions into consideration, and then makes multivariate comparison on technology, economy, and environmental protection to make the design of the tunnel meet the requirement of safe and practical, reliable quality, reasonable economy and state-of-art technology.
1.0.4 Road tunnel may be divided into four types according to its length, see table 1.0.4.
Table 1.0.4 Classification of the Road Tunnel Length
Classification Special long tunnel Long tunnel Middle tunnel Short tunnel
Length (m) L>3000 3000≥L>1000 1000≥L>500 L≤500
Note: Length of the tunnel refers to distance between intersecting line of portal wall face and pavement at both ends and intersecting point of the channel center line.
1.0.5 Main structure of the tunnel must be designed as permanent building: with provided strength, stability and durability; established tunnel shall be able to adapt to the needs of long-term operation to facilitate maintenance operations.
1.0.6 It shall strengthen coordination between design of the major structures like tunnel support lining, drainage-proof, roads and design of operating facilities like ventilation, lighting, power supply/distribution, fire, and traffic control operation to a rational comprehensive design. If necessary, it shall carry out special design and studies to deal with relevant technical issues.
1.0.7 Civil design of the tunnel shall reflect the concept of dynamic design and informatization construction and be established general program on geological observations and monitor measurements; tunnels with complicated geological conditions shall be established geological prediction program to timely judge reasonableness for the design, and to adjust support parameters and construction program. By dynamic design, it makes supporting structure adaptable to the actual situation in the surrounding rock, and makes it with greater security and more economy.
1.0.8 Design of the tunnel shall implement relevant technical economy policies of the nation; positively and prudently adopt new techniques, new materials, new equipments and new technology.
1.0.9 Design of the tunnel must meet the requirement of state regulations like state land management, environmental protection, water and soil conservation. It shall pay attention to the economic use of land, farmland protection and water conservancy facilities, to protect the existing vegetation as possible and properly handle the waste slag and sewage.
1.0.10 Not only the requirements for design of road tunnel, but also those specified in the current relevant compulsory ones of the nation shall be complied with.
