Abstract: The re-pressed tests on jacked pipe piles in soft clay indicate that the re-pressed starting pressure is greatly improved after finishing the installation and increases more rapidly in early period than in later one. Through the study of the time effect mechanism, it is found that the increment of the ultimate bearing capacity of a single pile is mainly caused by side soil resistance. The end resistance has little influence on the time effect of bearing capacity of the pile. According to the simulated results of the test data, the relationship between pile side resistance and time can be described by use of logarithmic curve. By means of this new computing model, the side frictional resistance in different time of reponse as well as the ultimate bearing capacity can be obtained. It is proved that the prposed method is feasible because the values of side soil resistance calculated by the computing model with software are consistent with the field test results.