Highway Pavement Surface Drainage Design Method And Drainage Capability Studies

The rainwater that permeates into the foundations of the road may cause settlement, the squirt of mud and the weakening of the materials'strength. The rainwater that flows on the surface of the road may make the tires too slippery to go normally. Therefore, a high-speed and effective drainage design on the surface of the road (road surface drainage) is of great importance to both the usage and safety of the road. This thesis is mainly about the researches on the design methods of the road surface drainage and the drainage capacity of the outlet.Firstly, the forms of road surface drainage are analyzed at the beginning of the thesis, and on the basis of which, the width of the cross-section of the flowing water, the rainfall, design reappearing periods, the design frequency, runoff coefficient, etc. are analyzed or supplemented. The hydrology parameter of the road surface drainage installations are ascertained by analyzing the hydrology. The dimensions of the road surface drainage installations under the circumstances of different lane numbers, different gradients, and different outlet intervals in an area with a certain rainfall are ascertained by calculating the hydraulic power, and an elaboration of calculating process is followed. On the basis of the research above, a Computer Aided Design program is written to design the surface drainage installations on the expressway in the area with a rainfall q_{5 ,10}=2.0. By inputting different parameters, the program can calculate the rates of flow, choose different drainage installations and recommend suitable dimensions, which can be applied to the choice of various surface drainage installations mentioned in this thesis on the expressway in this area.Outlets is an important part in the road surface drainage installations and greatly helps the rainwater flow together and drain. This thesis uses special software Fluent to have a numerical simulation of the capacities of different outlets, makes a comparison with the experience method and revises the formula of the experience method according to the data. Thus some reference materials are provided for the design of outlets in different positions. Finally, according to Fuzzy Comprehensive Evaluation Theory, this thesis proposes an evaluation indicator and evaluation standard of the road surface drainage installations. Linked with the project, this thesis states the process and procedure of Fuzzy Comprehensive Evaluation Theory and makes it more practicable.