Laboratory Investigation on Engineering Properties of Soil Due to Cyclic Drying and Wetting

Abstract

Due to world-wide distributions and extensively used as construction materials, geotechnical engineers are interested in understanding the Engineering behavior of expansive soils which are sometimes referred in the literature as problematic soils. The climatic zones where expansive soils occur are often experienced by many Drying-Wetting cycles due to seasonal variations. This seasonal variation in the water content termed as Drying-Wetting cycle is regarded as the most destructive environmental factor that may cause many foundation diseases. Considering these, the purpose of this study is to understand the effects of drying-wetting cycles on shear strength(C,Ø ) characteristics of undisturbed soil. A series of unconfined compression test, CBR, Permeability tests are conducted on multiple drying-wetting soil specimens to analyze these engineering properties. The results of the tests conducted indicate about 22 % reduction in cohesion from 54.190 kN/m2 to 42.342 kN/m2 until fifth cycle of drying and wetting and a constant value of nearly equal to 42 kN/m2 thereafter. Also the study of change in CBR of the soil specimen due to cyclic drying and wetting was conducted and found to decrease with the increase in number of cycles and vice versa in the case of coefficient of permeability. Dry density, Degree of saturation , Bulk density goes on decreasing with increase in number of Drying and Wetting cycles and obtain the constant value after the 5th cycle of drying and Wetting. However, void ratio increases with the number of Drying and Wetting cycles due to development of cracks.