Buckling analysis of steel jacking pipes embedded in elastic tensionless foundation based on spline finite strip method

Buckling of steel jacking pipes subjected to axial compression and surrounded by soil is investigated. The jacking pipes are simplified as simply-supported circular cylinders embedded in tensionless Winkler-Pasternak foundation that reacts to soil compression only. The governing equation for tensionless buckling analysis is established based on the spline finite strip method (SFSM), and the critical buckling load is obtained by solving the governing equation through an iterative procedure. Numerical examples are analyzed, and the comparison of buckling loads with available solutions and finite element results shows good accuracy of the SFSM. Based on a parametric study, the variation of tensionless buckling loads with slenderness ratio of jacking pipes is first studied. Moreover, the effects of diameter-thickness ratio and foundation stiffness are also investigated. The present SFSM-based tensionless buckling analysis is applicable to cylinders of any length and on tensionless foundation, and it is capable of efficiently and effectively predicting buckling of steel jacking pipes subjected to axial compression and surrounded by soil.