Pre-soaking treatment is a kind of important means on loess mechanics and foundation treatment in loess area. The necessity of in-situ soaking test is briefly analyzed. The historic development and the present researches on in-situ soaking test in China are concluded; and some comments are accordingly given. The main achievements are emphatically recommended
including key technology of soaking test
law of collapse deformation and collapsibility evaluation
etc. The main problems existing in the current criterion and some relevant suggestions are pointed out on collapsibility evaluation
the thickness of foundation treatment
remnant collapse and the standard of cutting off the water