Research on the Load Settlement Relationship of Post-Grouted Based on the Load Transfer Function Method on Yueqing Bay Bridge

Yueqing Bay Bridge test pile program is located in Zhejiang Province, China. To improve the bearing capacity and decrease the settlement of the pile, a pile is conducted in the filed by the method of tip pressure grouting. The analyzed drilled shaft has a diameter of 2.0 m and a length of 88 m. The post grouted pile compared to non-grouted pile are believed to be related to the side friction reinforcing effect, which is due to the grout penetration upward along the sides of the pile. It is also related to an enlarge tip area due to the formation of grout bulb, which pre-compresses the soil under the pile tip, and results in tip resistance and stiffness improvements of piles due to tip pressure grouting. This paper investigates the contribution of these factors based on load transfer function method analyses applied to a case history. The bearing capacity of post grouted pile is analyzed by single factor, which shows that the single factor is not sufficient to predict the load settlement curve of post grouted pile. Considering the combined influence of these three factors, the prediction of the load settlement curve is consistent with the measured curve. The results indicate that the effect factor of post grouted pile is improved by these three factors.