Modeling of Buried Pipelines in Dense Sand for Oblique Movement in Vertical-Lateral Plane

摘要

Finite-element modeling of pipelines buried in dense sand under oblique loading in vertical (upward)-lateral load space is presented. The prepeak hardening, postpeak softening, density, and confining pressure-dependent behavior of sand are considered in simulations. A monotonic displacement-controlled loading is applied where pipe is displaced at an angle ranging from 0 degrees (vertical upward) to 90 degrees (lateral). The plots of vertical and lateral components of oblique force (load paths) resulting from the displacement-controlled loading show a significant nonassociated response for shallow burial depths and lateral loading cases. The restraint to vertical displacement during lateral displacement increases the lateral resistance. A simplified approach based on maximum vertical and lateral restraints, together with an inclination factor, is proposed to estimate the maximum oblique resistance. (c) 2020 American Society of Civil Engineers.