Abstract: In order to reveal the physical mechanics of soil-chemicals-water interaction， soil samples were artificially made in three different pH environments induced by immersed in sulfuric acid solution for a long term to carry out experiments on the compressible and deformable properties， consolidated undrained triaxial test and limit moisture content. Results showed that: the compressive deformation for soils immersed in sulfuric acid solution became greater， including the elastic deformation brought about by the remove of pore water and the plastic deformation resulting from the destruction of the soil structure and the conjugation; the lower the pH， the more the sulfuric acid contents， the severer the chemical corrosion， the greater the void ratio of soil， the greater the compression coefficient， the smaller the compression modulus; the pH reduction led to thinner diffuse double layer， so the plasticity became weaker and liquid limit and plasticity index were smaller; all the soils exhibited strain-hardening in the three different pH environments; the strength slightly increased when the pH of pore fluids decreased to 6.0 but significantly decreased at low pH conditions (pH=4.0)， which is related with the mineral composition of the clay fraction; as the pH decreased， effective stress path deflected towards the left due to greater increment rate of pore water pressure.

Key words: polluted soil, soil-chemicals-water interaction, acidic geo-environment, mechanical properties, pH