A Modified Uniaxial Bouc-Wen Model for the Simulation of Transverse Lateral Pipe-Cohesionless Soil Interaction

摘要

This paper proposes a modified uniaxial Bouc-Wen model to evaluate reaction force-displacement backbone curve for transverse lateral pipe-cohesionless soil interaction. The model is capable of representing the nonlinearity and the smooth transition zone of the curve. Using unscented Kalman filter, the model parameter k that controls the smoothness of transition zone is derived, on the basis of results from high-fidelity validated finite element analyses, κ is larger in loose sand compared to that in dense sand, implying a smoother transition zone of the curve for loose sand. There is a slight change of κ with pipe burial depth in case of dense sand, while the change is clearer and larger in loose sand. The variation of κ is related to the "passive-wedge" and "plow-through" failure mode of soil. The model is subsequently implemented in a series of soil-pipe interaction configurations, and the reaction force-deformation curves are found in good agreement with experimental data.