Study On Rainwater Infiltration And Optimal Design Of Fill Subgrade

In recent years, the highway construction of our country is developed more rapidly and with the high traffic volume,multiple heavy load vehicles,high speed of traffic, there is a higher request to the mechanical intensity and stability of the roadbed and road surface.While there are much more highway diseases due to rainfall infiltration which caused more and more economic loss and social loss directly and indirectly to our country.The thesis is based on the problem of infiltration of subgrade under the condition of rainfall, and researched on two aspects--rainfall infiltration of fill subgrade slope and medial divider,and proposed the optimization design to control the rainwater infiltration.The following work has been done:(1) Based on the unsaturated flow theory,mechanism of slope rain erosion and rainfall infiltration was studied,and three methods of slope ecological protection were proposed,that is short tube protection,cement mortar protective and geotextiles wrap sand protection.The structure and protective mechanism of each method were introduced detailly,then,the indoor simulation experiment was carried out.According to the experiment results, changes of simulation slope rain erosion and rainfall infiltration under different protection type were contrasted and analysed,the capacity to reduce rain erosion and rainfall infiltration was studied, which can provide a reference for slope ecological protection design to make it more reasonable,economy,environmental friendly and effective.(2) The reasons caused subgrade and pavement diseases by rain infiltration on medial divider were investigated and the mechanism was analysed. And the methods of the medial divider drainage design commonly used presently were summarized including surface drainage design pattern and underground drainage design pattern.The advantages and disadvantages of each method was compared and analyzed, and then a integral median waterproof and drainage design is proposed,the construction technology and technical key points is explored. Finally, summarizeand analyse the optimization scheme of innovations and technical advantages.