Study of the swelling deformation characteristics of red clay

Abstract

The paper is aimed at the phenomenon of red clay subgrade disease,taking the subgrade filling from the Yuqing-Kaili Expressway as the research object,doing the expansion test on the red clay,analysing of red clay expansion deformation law. The results showed that in the same compaction degree, different initial moisture content, the expansion rate of the sample with the optimum moisture content is minimum. And in the same initial moisture content, different compaction degree, the sample of high compaction degree has the small expansion quantity. The absolute expansion rate gradually increases with the expansion time, relative expansion rate decreases with the expansion time. That is the sample's speed of expansion is very high in 30min after the start, then the speed of expansion will slow down. Foreword Because the red clay has high moisture content, high plasticity, high void ratio and other special engineering properties,the red clay project achieve design goal during the period of the construction,with the operation time of the highway growing,the slope begin sliding and the pavement begin cracking.The primary cause is the degradation of strength properties of red clay filling under the action of wetting-drying cycles and repeated traffic load,the strength of the soil is gradually reduced, the stability of the soil is decreased, and the failure of the subgrade is eventually caused.Therefore, it is of practical significance to study the law of red clay expansion for the road construction in red clay areas.