Calculation of negative skin friction of pile based on effective stress method

Negative skin friction problems of the pile foundation engineering widely exist in the new fill area. A thorough study of the calculation methods are of important practical significance. The piecewise calculation model of negative skin friction is established based on the effective stress method and pile skin friction occurring mechanism. According to the deformation assumption and the static equilibrium equation of the pile-soil system, pile side friction of piecewise interval and neutral point position are determined. The displacement and pile axial force control equation are used to derive a piecewise interval pile displacement and axial force of the analytical solution. Based on the engineering example, the rationality of the results is verified. The results show that the method can accurately describe the transmission characteristics and distribution range of negative skin friction, and the calculation parameters are easy to obtain. The results are of significant reference significance in the practical engineering.