Analysis On The Differential Defomation Of Embankment Filled By Expansive Soils Under Rainfall Condition

The engineering problem induced by expansive soil is a technical bottleneck in highway construction in our country. Because expansive soils have strong expansive and shrinkage characteristic, muticrevice and strength reduced by dry-wet circulation , slopes in expansive soils often lose stability, and the pavement often crack and turn on different rising. These disease cause great economic losses to the highway engineering. At present, the highway communication in the west of our country is in energetical developing period, and some western provinces are the most serious area of expansive soil, so expansive soil engineering problems have already become one of the technological difficult problems demanding prompt solution in road construction in the west of our country.In this paper combining the tested embankment in NanYou Expressway, the differential deformations of the embankments all filled by expansive soil and various kinds of treated embankments under the rainfall condition are analyzed. Based on the results, the stability of the slope and road' s mechanics response are investigated. The main content of this paper as following:1) Using non-saturated soil influent theory to analyse the transient influent in the expansive soil embankment under rainfall, and obtain the distribution of water pressure and volumetric water in the embankment.2) According to the analysis of transient influent in expansive soil embankment, the compatible deformation between the expand soil embankment and the pavement upon it have been analyzed. The expansive soil embankment' s differential deformation is calculated by using humidity stress field theory, and the pavement' s mechanics response is also researched.3) According to the calculation of the expansive soil embankment' s differential deformation , the stability of the slope in expansive soil is analyzed by using Mohr-Coulomb strength criterion.