Study on the Impact of Initial Dry Density on the Resilient Modulus of Expansive Soil Improved by Weathered Sand

This paper takes the expansive soil as the research object and uses weathered sand to modify expansive soil in Yichang,Hubei.It changes the initial density of mixed materials to do the resilient modulus test with the weathered sand content of 3%,5%,7%,9%.The study shows that both the content of weathered sand and initial density have obvious effects on the resilient modulus test of expansive soil.The resilient modulus of modified expansive soil increases first then decreases along with the increases of weathered sand and it has the maximal value when the content is 10% with a certain initial density.The resilient modulus of modified expansive soil increases with the increase of initial density at a certain content of weathered sand and the growth rate is faster and then slower.The resilient modulus of modified expansive soil shows a logarithmic relationship with initial density at a certain content of weathered sand.It is helpful to increase the bearing capacity of subgrade and guarantee the strength,rigidity,stability of subgrade by controlling the initial density(compaction degree)in the process of construction.