Calculation Method for Jacking Force of Straight Steel Pipe Jacking Considering Circumferential Deformation Effect

Flexible steel jacking pipes undergo circumferential deformation under external loads, causing soil pressure redistribution and additional frictional resistance. To accurately predict jacking forces, 2D numerical simulations were utilized to reveal a “quasi-elliptical” soil pressure redistribution evolving with burial depth, soil friction angle, and radius-to-thickness ratio. Based on Spangler’s theory and a full pipe–soil contact model, a novel analytical model incorporating soil arching is proposed. The elastic center method is employed to solve for bidirectional deformations. Crucially, an iterative fitting algorithm is introduced to quantify the non-linear coupling between bidirectional pipe deformation and soil pressure redistribution under various burial depths. Accounting for annular slurry lubrication, a comprehensive jacking force calculation framework is established and validated through an engineering case study. Results indicate: (1) Significant circumferential deformation renders traditional rigid pipe earth pressure assumptions inapplicable. (2) Case study horizontal deformation reaches 8‰ of the pipe diameter, inducing a maximum additional horizontal soil pressure of 125.26 kN/m2, far exceeding traditional active earth pressure. (3) Measured jacking forces successfully fall within the model’s prediction envelope, with the lower limit yielding a −19.3% average error, significantly outperforming current specifications. These findings optimize the design and construction control of large-diameter flexible steel jacking pipes.