Study On The Properties Improvement Of Expansive Soil And The Construction Technology Of High-Type Roadbed

Expansive soil is one kind of high plasticity clay which may bring civil engineering heavy damage. It may make construction, especially the engineering of high-type roadbed, appear failure deformation. It is a kind of long-term latent danger to people's life. Based on the theory of unsaturated soil mechanics and the properties of compacted expansive soil, this paper takes the northern part K12+840-K12+920 of Nanning urban highway as an example to studies some aspects of lime improvement of expansive soil and the technology of construction. The chief content of this paper is : the lime improvement mechanism of expansive soil; confirm the technical parameters of lime mixed from the results of test in laboratory; the scale-down test to define the maximum effective grain size of expansive soil when it is improved by lime; by building bank slope model and making use of finite element seepage flow program of saturated-unsaturated to calculate the examples, this paper simulates the humidity site in order to checkout the effect of lime improvement; studies and proves that it is feasible to mix blocky expansive soil and pulverous lime, and to fill roadbed by common construction machines etc..