Simplified uncertainties analysis of continuous buried steel pipes on an elastic foundation in the presence of low stiffness zones

In conventional design, continuous buried steel pipes are designed based on their transverse behavior where low stiffness zones of soil, uncertainties in soil and structure properties are not considered. Winkler's analytical model and the FOSM method are used to estimate uncertainties in terms of the coefficient of variation in the differential settlement (CVΔ) and the bending moment (CVM) as the function of the uncertainties in the subgrade reaction modulus (ks) and the low stiffness zone length beneath the pipe. Results show that the values of CVΔ and CVM are very different depending on the uncertainties of ks and the length of the low stiffness zone.