Experimental Study on the Swelling Behavior of Expansive Soil at Different Depths under Unidirectional Seepage

Abstract

The swelling properties of expansive soil at different depths were investigated by the laboratory model test. It was experimentally found that the swelling deformation of different expansive soil layers was obviously different under unidirectional seepage. Pore solution collection boxes were designed to collect the pore solution of different soil layer interfaces during the saturation process. Cation concentration tests were then used to analyze the migration regulation of cations in these soil layers. Results showed that the divalent cations in the surface soil layer migrated downward along with water molecules and aggregated around clay particles to form the electrical environment in expansive soil. Additionally, swelling tests were performed to compare with their initial values to research the variation of swelling behavior of expansive soil at different depths after completion of the model test. It was observed that the swelling potential of the surface expansive soil layer at a depth of 0–30 mm was released while that of the middle and bottom ones at depths of 90–120 mm and 180–210 mm was inhibited. An analysis on the above results was used to clarify the mechanism controlling the swelling difference of different expansive soil layers. This swelling difference may be explained by the joint effect of two factors that can be treated as an electric charge effect, namely (i) the modification effect, (ii) the electrical environment.

Combined effect of mineralogical and chemical parameters on swelling behaviour of expansive soils

“…3 , 4 , and 5 , the maximum S a of 18% and S p of 93 kPa is measured at MMC of 43%, (Ca/Na) T of 10–14, and (Ca/Na) L of 2–7. The results obtained in the present study are in well agreement with the studies reported by Shi et al 24 , She et al 72 , and Abd-Allah et al 73 , who have reported properties of MMC, chemical and swelling parameters that are found to be falling in the range of data produced by the presented study.…”

Evaluation on the Mechanical Properties of Ground Granulated Blast Slag (GGBS) and Fly Ash Stabilized Soil via Geopolymer Process

“…Usually, the soil will shrink with the reduction of moisture content and swell with the increase in moisture content [ 8 , 9 ]. Clay soil has high plasticity, low support, and high shrinkage when the soil contains water [ 9 , 10 ]. This condition encouraged civil engineers to seek solutions in order to strengthen the soil through soil stabilization [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”

“…Clay soil has high plasticity, low support, and high shrinkage when the soil contains water [ 9 , 10 ]. This condition encouraged civil engineers to seek solutions in order to strengthen the soil through soil stabilization [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Soil stabilization aims to increase the mechanical properties of the soil and also to control plasticity and shrinkage in soils containing excess water [ 4 , 8 , 9 , 10 ].…”

“…This condition encouraged civil engineers to seek solutions in order to strengthen the soil through soil stabilization [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Soil stabilization aims to increase the mechanical properties of the soil and also to control plasticity and shrinkage in soils containing excess water [ 4 , 8 , 9 , 10 ]. In order to successfully withstand superstructure loads, soil stabilization techniques are essential to ascertain the excellent stability of soil [ 6 , 9 , 10 ].…”

“…Soil stabilization aims to increase the mechanical properties of the soil and also to control plasticity and shrinkage in soils containing excess water [ 4 , 8 , 9 , 10 ]. In order to successfully withstand superstructure loads, soil stabilization techniques are essential to ascertain the excellent stability of soil [ 6 , 9 , 10 ].…”