Field study on pile side grouting reinforcement for in-service pile foundation using segmental localized grouting

Grouting is an effective method to enhance the bearing capacity of in-service pile foundations. The effect of optimizing grouting parameters for in-service pile foundation grouting reinforcement was verified through static load tests. The field tests of the pileless stratum show that the cement-sodium silicate slurry is more favourable for increasing the grouting pressure and more convenient to control the slurry diffusion than cement slurry. The grouting parameters of cement-sodium silicate slurry were determined according to the maximum grouting pressure and quantity. The slurry grouting parameters were cement slurry 1.6g/cm3 and cement slurry to sodium silicate ratio 2.29:1. Moreover, the effective range of segmental localized grouting reinforcement was detected by the resistivity method and in-situ standard penetration test, and the grouting position should be less than 2m from the side of the in-service pile foundation. Finally, it is found that pile side grouting can improve the bearing capacity of in-service pile foundation by 98% through static load test. The research results have reference value and guiding significance for the design and effect detection of pile foundation grouting reinforcement.