Structural design of linings encased in four points cracking deformed host pipe

摘要

This paper describes a new design method for linings encased in four points cracking deformed pipe subjectrnto external groundwater pressure. Four points cracking is the prime cause of deformation of rigid circularrnpipe and must be distinguished from the elliptical deformation of flexible pipe. A closed-form analyticalrnsolution has been developed, computing the combined effect of the four points deformation and the initialrngap (due to thermal shrinkage of liner). The method gives formulas for the buckling pressure, the bendingrnmoment, the axial force and the deflection of the lining. Comparisons with finite element analysis with largerndeflection and contact nonlinearities are presented. A calculation example is also treated.