1 General Provisions
1.0.1 This Specifications is formulated to avoid the damage of surface water and groundwater against the highway and ensure structure stability and driving safety.
1.0.2 This Specifications is applicable to drainage design of newly constructed, renovated and extended all-class highways.
1.0.3 Internal drainage facilities at road boundary shall be in overall planning, rational layout and reasonable connection with external drainage systems and facilities at road boundary.
1.0.4 Drainage design of highway shall attach importance to environmental protection and water and soil conservation as well as prevention of water pollution.
1.0.5 For the drainage design of highway, new technique, material and process shall be actively adopted based on continuously summarizing practical experiences and scientific research achievements.
1.0.6 Drainage design of highway shall not only comply with this Specifications, but also meet the relevant requirements of current relevant national standards.
2 Terms and Symbols
2.1 Terms
2.1.1 Drainage system
The system consisting of facilities for intercepting, collecting, conveying and discharging surface water and groundwater within the range of highway land.
2.1.2 Dike
A stripe structure arranged along the outer edge of hard shoulder or pavement for intercepting road surface water.
2.1.3 Filter layer
The filter layer for ensuring the passing of water flow and preventing water flow from carrying away the fine particles in soil and blocking drainage facilities.
2.1.4 Evaporation pond
The pond arranged outside the range of road boundary and for temporarily storing water drainage within the road boundary and removing it via evaporation etc.
2.1.5 Underdrains
A ditch structure arranged under the ground or in the subgrade for collecting and discharging groundwater or water in the subgrade.
2.1.6 Percolation well
A shaft structure vertically arranged under the ground for collecting and discharging the surface water or groundwater, which may be filled with pervious materials.
2.1.7 Blind drain
A ditch structure arranged under the ground or in the subgrade for guiding water flow to discharge outside the range of road boundary, without functions of water seepage and catchment.
2.1.8 Sensitive section of water environment
The section where the line of highway passes through such areas whose discharge water quality shall not be not less than Class IV water quality standard in GB 3838 Environmental Quality Standards for Surface Water, or the section where the line of highway passes through such sea areas whose discharge water quality shall not be less than Class III water quality standard in GB 3097 Sea Water Quality Standard. The section that the line of highway passes through such area whose water quality shall not be less than Class II or such sea area whose water quality shall not be less than Class I is defined as strongly-sensitive section of water environment, the section whose water quality shall not be less than that of Class III area or Class II sea area is defined as sensitive section of water environment, the section whose water quality shall not be less than that of Class IV area or Class III sea area is defined as weakly-sensitive section of water environment
Foreword I
1 General Provisions
2 Terms and Symbols
2.1 Terms
2.2 Symbols
3 General Requirements
4 Surface Drainage at Road Boundary
4.1 General Requirements
4.2 Pavement Surface Drainage
4.3 Median Drainage
4.4 Drainage of Super-high Section
4.5 Slope Drainage
5 Pavement Subsurface Drainage
5.1 General Requirements
5.2 Pavement Edge Drainage System
5.3 Drainage Base
5.4 Drainage Cushion Layer
6 Underground Drainage of Road Boundary
6.1 General Requirements
6.2 Exploration of Groundwater
6.3 Underground Drainage Facilities
7 Drainage of Highway Structures, Underpass Road and Roadside Facilities
7.1 Bridge Deck Drainage
7.2 Drainage of Bridge (Culvert) and Retaining Structure
7.3 Tunnel Drainage
7.4 Drainage of Underpass Road
7.5 Drainage of Roadside Facilities
8 Drainage in Special Area and Special Section
8.1 Permafrost Area
8.2 Expansive Soil Areas
8.3 Loess Area
8.4 Salty Soil Area
8.5 Landslide Section
8.6 Sensitive Section of Water Environment
9 Hydrological and Hydraulic Calculation
9.1 Hydrological Calculation
9.2 Hydraulic Calculation of Ditch and Pipe
9.3 Hydraulic Calculation of Discharge Opening
9.4 Hydraulic Calculation of Underground Drainage Facilities
Appendix A Strength Requirements of Masonry Materials for Various Drainage Structures
Appendix B Calculation Table for Hydraulic Radius and Discharge Section Area of Various Ditches (Pipes)
Appendix C Calculation Nomograph for Interception Ratio of Open-Type Discharge Opening
Explanation of Wording in this Specifications
