Evaluation on Bearing Capacity Improvement of Cast-in-situ Bored piles Using Post-grouting Technology

Post-grouting technology is an effective method of improving mud cake in the pile tip and debris in the pile side. What's more, it is also considered as a great method to improve the bearing capacity of the cast-in-situ bored pile. The post-grouting technology is used in the foundation of a tall office building in Shan Dong province. For this project, comparing results of the static load test and the theoretical calculation, some conclusions can be made that the bearing capacity of post-grouting pile is 126.5% more than that of unpost-grouting one, the ratio between the tip resistance and the side resistance of the post-grouting pile are 39.8% and 60.2% respectively, and the ratio between the tip resistance and the side resistance of the unpost-grouting pile are 28.9% and 71.1% respectively. It is estimated that the cost of cast-in-situ bored piles using post-grouting technology is 45%similar to 50% cheaper than the unpost-grouting piles.