Effects of salt solutions on the hydro-mechanical behavior of compacted GMZ01 Bentonite

• Published in: Environmental earth sciences 2014-10, Vol.72 (7), p.2621-2630
• Main Authors: Ye, Weimin M, Zhang, F, Chen, B, Chen, Y. G, Wang, Q, Cui, Y. J
• Format: Article
• Language: English
• Subjects: Abiotic stress; Bentonite; Biogeosciences; compressibility; Distilled water; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering Sciences; Environmental science; Environmental Science and Engineering; Exact sciences and technology; Geochemistry; Geology; hydraulic conductivity; Hydrology/Water Resources; Marine and continental quaternary; Mechanics; Mechanics of materials; Original Article; Pollution, environment geology; Salinity; Sodium chloride; Soil mechanics; Strain; Surficial geology; Terrestrial Pollution; Void ratio
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-014-3169-x

In this study, the effects of salinity of infiltrating solutions on the swelling strain, compressibility, and hydraulic conductivity of compacted GMZ01 Bentonite were investigated. After swelling under vertical load using either distilled water or NaCl solutions with concentrations of 0.1, 0.5 M, and 1 M, laboratory oedometer tests were conducted on the compacted GMZ01 Bentonite. Based on the oedometer test results, hydraulic conductivity was determined using the Casagrande’s method. Results show that the swelling strain of highly compacted GMZ01 Bentonite decreases as the concentration of NaCl solution increases. The compression index C c * increases and then turns to decrease with an increase in the vertical stress or a decrease in the void ratio for different solutions, and the C c * decreases as the concentration of NaCl solution increases. The secondary consolidation coefficient C α increases linearly with the increase of the compression index C c * . Furthermore, a bi-linear relationship between the swelling index C ₛ * and the secondary consolidation coefficient C α can be characterized clearly. The hydraulic conductivity increases as the concentration of NaCl solution increases, however, this increase can be prevented if a high confining stress is applied.