Abstract

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Title:: Swelling-shrinking Characteristics of Red Clay Under Coupling Effect of Dry-wet Cycles and Loading

Author(s):: CHEN Kai-sheng; LI Zhen; College of Civil Engineering, Guizhou University

Keywords:: dry-wet cycle; loading; red clay; swelling-shrinking characteristic; coupling effect

Abstract:: In order to obtain the actual parameters conforming to the engineering design, the conventional consolidation apparatus was reconstructed. A new dry-wet cycle test method of simulating soil under load was invented. The dry-wet cycle experimental research of red clay was carried out under load conditions, and the change rule of swelling-shrinkage deformation of red clay was obtained. The results show that the method can realize the dry-wet cycle test without disassembly, and overcome the defects of the dry-wet cycle test of soil with zero load. The method can provide more reasonable technical indicators for engineering design. The swelling-shrinkage deformation of red clay under dry-wet cycle cannot be fully recovered, and the overlying load can restrain its expansibility and enhance its shrinkage. When the load is less than 50 kPa, the sample expands, and the greater the compaction degree and the smaller the initial moisture content, the stronger the swelling. When the load is more than 100 kPa, the sample shrinks, and the smaller the compaction degree and the greater the initial moisture content, the stronger the shrinkage. The first wet-dry cycle has the most significant effect on the swelling-shrinking characteristics of red clay. The swelling-shrinking curve becomes more and more gentle with the increase of the number of dry-wet cycles, and the swelling-shrinking characteristics of the sample tend to be stable.