Abstract: A new kind of test equipment was designed and manufactured to testify the principle of heavy cover replacement technique for foundation treatment of coarse sulphate saline soil. Indoor tests examined the effects of temperature, salt content and water content, minimum void ratio on expensive behaviour of coarse sulphate saline soil and validated the heavy cover replacement technique. The study shows that the deformation of coarse sulphate saline soil is temperature sensitive in the range of 0 ℃ to 2.5 ℃, and the expansibility of sample is subtle during the cooling process below -5 ℃. The swelling phenomenon is found less prominent as the void ratio decreases. Both water content and salt concentration affect on expansion of saline sample. The rate of swelling pressure change decreases as the expansive strain increases. The expansive stress and vertical strain show a linear relationship. The linear coefficient depends on the depth of replaced soil. The exploratory testing equipment and method provide engineering implications for the practical design.

Key words: saline soil foundation treatment, heavy cover replacement technique, coarse sulphate saline soil, volume expansion strain, expansion stress