Analytical analysis of vertical load-transfer of large-diameter cast-in-situ concrete tubular piles

The reason for the appearance of internal friction in tubular piles is that the relative displacement or its trend exists between the soil core and piles.With linear elastic-plastic load transfer function,on the basis of foregoing work,a set of analytical equations for the axial load-settlement curves of thin-wall cast-in-situ tubular piles were deduced with the internal friction exerting along with the outer friction.Correlative parameters of the pile-soil system could be obtained from the measured load-settlement curves,and the distribution equations of axial force and friction along piles could be calculated.A case study was given to validate the present method.