Jung, Jai2013-07-232016-06-012011-01-31bibid: 8213838https://hdl.handle.net/1813/33543Permanent ground deformations associated with geohazards such as earthquakes, liquefaction and landslides can introduce substantial axial and bending strains on buried pipeline systems. Longitudinal and transverse bending strains depend on the force imposed on the pipeline by relative displacement between the pipeline and surrounding soil. Analytical models used currently in design are based on p-y, t-x, and q-z for interaction relationships, and they require reliable p-y, q-z and oblique forcedisplacement relationships. Moreover, to advance the state-of-the-art for soil continuum models, it is necessary to develop better simulations of soil-pipeline interactions rather than rely on empirically based p-y and q-z relationships. In this study, various modeling procedures are developed for simulating soilpipeline interactions under lateral and vertical relative movement between soil and pipe as well as relative movement at oblique angles with respect to the pipeline for dry and partially saturated sand. Mohr-Coulomb (MC) strength parameters applied in FE analyses for both dry and partially saturated sand are developed from direct shear test data and from multiple linear regression. To represent strain softening, the model proposed by Anastasopoulos, et al. (2007) is used in this work to diminish both the friction and dilation angles to residual values. The MC parameters are applied in the FE simulations to produce dimensionless force vs. dimensionless displacement plots. The results show excellent agreement with large-scale 2D experimental results in terms of pre-peak, peak, and post-peak for both dry and partially saturated soil. The modeling process is expanded to investigate and characterize the maximum lateral force as a function of pipe depth. The analytical results from simulations of lateral, vertical, and oblique pipe movement for semi-infinite, plane strain soil conditions are summarized in dimensionless form. They are plotted on a polar coordinate graph from which the maximum force can be estimated for any size pipe at any depth in response to any orientation of relative movement between the pipe and soil for both dry and partially saturated sands.en-USSoil-Pipe InteractionPlane Strain ConditionsNumerical Analysisdissertation or thesis