The Water On The Subgrade And Pavement Stability And Control Study

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. But the recently drainage system of roadbed and road surface usually pay much attention to drain surface water out of the highway side, and think less of draining internal backwater in road surfacing structures which is caused by raining, without setting the effective drainage system of road surfacing structures , the internal backwater will be more damage to the roadbed and road surface, it will change the mechanic characteristic of roadbed and road surface material, and influence the mechanical intensity and stability of the roadbed and road surface, it becomes a main factor causing road surface damage in our country.In this thesis, drafted to the existence question of roadbed and road surface drainage, the corresponding treatments are proposed. Mainly research has been done as follows:(1) Many kinds of factors which influence the mechanic characteristic of soil are discussed, and then the internal backwater in roadbed and road surfuce as a key factor to influence the mechanical intensity and stability of the roadbed and road surface is obtained.(2) Based on the theoretical of saturated-unsaturated seepage, we use the finite element analysis software to calculate and reasearch the roadbed and road surface about saturated-unsaturated seepage. According to the actual conditions of road engineering, seventeen methods about drainage system of road surfacing structures are set. Different methods are calculated and analyzed about the water content of roadbed and road surfuce under the conditions of different raining and after raining, the differences of the moisture content transfer between the different models of roadbed and road surface are obtained, and evaluate the adoptability of different methods. (3) The first time we measure the water content of roadbed in field, and the relationship between the moisture content of roadbed and different climate conditions as well as the roadbed department. Also the calculation and analytic results about saturated-unsaturated seepage are tested.