Abstract: An experimental research on the mechanical indexes, swelling-shrinkage properties and pore size distributions of intact Guangxi laterite at different stages of dehydration, has been carried out systematically. The results reached are that, Guangxi laterite is a kind of stiff-plastic clay with well-developed fissures, and the mechanical indexes and swelling-shrinkage properties of intact samples are mainly controlled by the matrix suction during the relative high range of moisture content, while by the fissures instead during the relative low range of moisture content; additionally, the moisture content of the turning points are close to the optimum moisture content of heavy-duty compaction tests; the pores of intact Guangxi laterite are mainly small pores with diameters from 0.01 μm to 0.05 μm, during the process of dehydration, the dry density increases, the total pore size volume decreases, and the pores with diameters from 0.01 μm to 0.05 μm and from 0.1 μm to 1.0 μm represent the most obvious decrease in volume.

Key words: laterite, mechanical properties, fissure, swelling-shrinkage properties, matrix suction, pore size distribution