The study and test to enhance bearing capacity of the large diameter pile under the highrise building

Based on the defective piles under the highrise building,the paper investigate the laws of the shear strength ( τ ) on the face between pile and cement treated soils around the pile with different percents of cement ( α w ) injected into soils, and an experimental relation between the shear strength τ and the percent of cement ( α w ) is obtained. Then it is used to design the cement stabilization of the soils arround the piles, the results of the case record and the field observation confirm that, the bearing capacity increases by more than 2000kN, and the settlement is allowable provided that the depth of soils injected is about 15m.