The method of soft soil consolidation by the mean of lime-cement-sand piles is a new method, which has been effectively applied in some construction works. However, to widely apply this method in large and small scale construction works it should need a firm theory basis for this method. The basis should be based on analyzing the nature of existing mechanism and chemical-physical processes when consolidating the soil foundation of the works, such as: mechanic pressure process, consolidating or rally process, pile and soil reinforcement process, as well as measurement principles of load standing capacity and foundation deformation after consolidating process.