LAUSR

During steel pipe jacking (SPJ), if improper control of jacking force or excessive water and earth pressure occurs, axial overall buckling and local buckling may happen. To reveal the stability mechanism of SPJ in the construction stage, cylindrical thin shell elastic stability theory was introduced. Theoretical analysis was used to derive the analytical equation of axial elastic buckling critical load under the combined action of uniform axial pressure and uniform confining pressure for engineering application. The finite element method was then employed to verify the analytical equation. Subsequently, the influence of pipe geometry parameters and uniform confining pressure on the axial buckling critical load was analyzed using the variable analysis method. The results show that: the analytical formula proposed in this study is in good agreement with the finite element calculation results; the critical load under the action of uniform axial pressure decreases with the increase of diameter–thickness ratio of the pipe when the slenderness ratio is less than 3; the critical load of axial buckling under different wall thickness decreases with the increase of uniform confining pressure, under the combined action of uniform axial pressure and uniform confining pressure; the thinner the wall thickness and the longer the pipe length, the greater the decrease of critical load; in actual construction, if the conditions allow, the axial stability of the SPJ can be improved by controlling the burial depth or wall thickness to avoid axial instability. This study provides a good reference for verifying whether the burial depth and wall thickness of a pipe meet the stability requirements.