On the Swelling-Shrinkage Characteristics of Weakly Expansive Soil with Different Initial Water Contents

Abstract

The swelling-shrinkage characteristics of expansive soils have great influence on the stability and settlement of electricity transmission towers, so that it is very important to estimate accurately the climate-dependent volume/stress change of the expansive soil foundations. In this paper, a kind of weakly expensive soil taken from a transmission tower foundation in Henan province were studied. One-dimensional swelling tests and constant volume tests were conducted to study the swelling ratio and swelling pressure of the expensive soils under different water contents which were chosen in accordance with the actual climate conditions. Results show that both swelling ratio and swelling pressure decrease linearly with the increase of initial water content, while the swelling rate increases with the decrease of water content; shrinkage ratio is linear to initial water content, while shrinkage anisotropy becomes more obvious with the increase of initial water content.