Calculation and analysis of bearing capacity of pile foundation based on PMT

The foundation of a bridge in Africa passes through thick sandy soils.In order to study the bearing characteristics of bored piles in thick sandy soils, two 2.0 m-diameter pile foundations(TP-1 and TP-2)of the main bridge are chosen to conduct field tests, and pressuremeter tests(PMT)on adjacent boreholes are performed.The test results show that the thick sandy soils have an important influences on pile quality, and the thicker sandy soils will induce serious pile base sediment.The pile base sediment will significantly affect the settlement of the pile foundation, resulting in weakening and strengthening of the pile base resistance.In addition, the prediction of the bearing capacity of piles based on the PMT of European Code(BS EN 1997—2)will overestimate about 95%~140%of the bearing capacity of the pile foundation, and the bearing capacity calculated by the China's specification for design of foundation of highway bridges and culverts is significantly larger than the measured value.A new method by performing three-stage linear classification of the PMT can directly predict the bearing capacity of piles.The proposed method is more suitable for the prediction of the bearing capacity of piles in thick sandy soil areas than the European Code and the China's specifications for design of foundation of highway bridges and culverts.