Effects of dry bulk density and water content on compressive characteristics of wet clayey paddy soil

Abstract

The application of soil compaction models is limited by the lack of soil compression properties and their variations as a function of different physical parameters. This study aimed to explore the effect of dry bulk density and water content on the characteristics of the soil compression curves and compression properties for wet clayey paddy soil. In order to investigate large‐scale soil initial conditions, uniaxial compression tests were conducted on a total of 25 soil states by controlling five soil water contents and five dry bulk densities. Soil compression curves were obtained from fitting uniaxial compression test results, and the swelling index, compression index, and precompression stress were measured. The swelling index of paddy soil ranged from 0.003 to 0.138 and showed a significant positive dependence on water content and a significant negative correlation with dry bulk density. The compression index ranged from 0.115 to 0.839. A quadratic polynomial function was established between water content and compression index, whereas the compression index showed a significant negative correlation with dry bulk density. The precompression stress ranged from 33 to 127 kPa. The precompression stress showed a prominent negative dependence on water content and a significant positive correlation with dry bulk density. The pedo‐transfer functions of the swelling index, compression index, and precompression stress could be used in soil compaction models as input parameters for risk evaluation of compaction damage of wet clayey paddy soil.