ANALYSIS AND DISCUSSION OF THE LOAD TEST OF MANUALLY DIGGING PILES OF QINGDAO JIAODONG INTERNATIONAL AIRPORT

Based on the data of file load test of Qingdao Jiaodong International Airport, vertical load transfer characteristics of the manual digging large-diameter rock-embedded pile under the influence of construction evolution and retaining wall as superimposed components is analyzed and discussed. The analysis shows that the excavation and unloading of pile holes has obvious disturbances to the upper soil and fully weathering rock layers, while the disturbance to the lower strong weathered rocks and medium-weathered rock layers is small. The pile is under a large vertical load, the upper retaining wall will crack at the junction section. Continuing to excavate the weathered rock under the retaining wall will disturb the surrounding rock mass. The influence of actual excavation should be considered, when we calculate the end resistance of the “hanging” retaining wall which does not reach the bottom of the pile. The depth of rock embedding of the pile was 1.92D~3.15D (D is the pile diameter), and the end resistance accounted for 10.5%~31.5%, which shows the characteristics of friction pile. The depth of rock embedding is adjusted to 1.0D~1.5D, and the proportion of pile end resistance to loading capacity can be 38.2%~76.1%, and piles can work more reasonable.