Field study on the application of combined grouting for the super-long drilled shaft

According to the field static loading test performed on the super-long drilled shaft, the influence of combined grouting on bearing capacity and displacement control ability of super-long drilled shaft was explored. Test results showed that the combined grouting improved the bearing capacity of super-long drilled shafts by about 70%-80%. The combined grouting enhanced the shaft side resistance, and the proportion of side resistance fncreased after combined grouting. The displacement control ability of super-long drilled shaft was improved after combined grouting, and the maximum shaft base displacement decreases by about 20 mm after grouting. The improvement effect of side resistance was related to the buried depth and soil type. The engineering test results provided references for the application of combined grouting in the super-long drilled shaft.