Localized soil subsidence can cause pipeline failures, yet relevant studies remain limited. This research uses 1 g scaling tests to explore granular soil behavior over a subsiding area with a crossing pipeline, employing Particle Image Velocimetry (PIV) and pressure sensors beneath trapdoors. Results reveal various failure mechanisms impacting load on pipelines, especially due to water-drop-shaped slip surfaces above the pipeline. The long side of the rectangular subsidence zone exhibited stronger load transfer compared to the short side. Neglecting the three-dimensional soil arching effect risks underestimating the pipeline load, particularly when the pipeline axis aligns with the long side of the subsidence. Greater distances between the subsidence zone and pipeline improve protection, though very close proximity can also be beneficial. The study suggests that inducing controlled soil failure above the pipeline may help reduce additional load, providing insights into mitigating pipeline damage from subsidence.

Purpose: The study aims to investigate the behavior of buried steel pipelines in different layouts under the influence of various permanent ground movements that may occur as a result of earthquakes. In addition, different factors such as pipe diameter, pipe material properties, burial depth, and lateral earth pressure were varied to form 8 different analysis groups to determine their effects on the performance of pipelines. The results will contribute to the practical design and preliminary evaluation of the pipelines by the operating institutions. Theory and Methods: The effects of 10 different axial ground motion lengths, 9 different ground displacements, 8 different pipe layout models and 16 different variables (e.g. burial depth) were evaluated by finite element analyses. In order to observe the interdependent effects of the changes, analyzes were carried out by considering over ten thousand combinations. Results: The effects of the length of the PGD zone and the amount of displacement on pipeline behavior are assessed relative to boundaries (Fig. A) for different pipeline layouts. Moreover, the effects of the investigated variables on pipe stress and strain are explained one by one in the study. Conclusion: The effect of variables such as burial depth and pipe material properties on the analysis results varies depending on pipeline layouts and other parameters such as displaced ground block length and displacement amounts. Contributions of all these factors on pipeline performance are explained in detail to provide guidelines for the design and preliminary evaluation of the pipelines by institutions which operates the systems.

The seismic landslide-pipe problem was investigated numerically using finite-difference code and a bounding surface soil constitutive model [Simple ANIsotropic SAND constitutive model (SANISAND)]. The SANISAND model was calibrated using triaxial monotonic and cyclic tests at the element level and shaking-table test results at the boundary value level. The results show that the calibrated parameters of the SANISAND model can predict monotonic and cyclic triaxial test results and slope displacement response properly. After the verification process, the dynamic response of a slope with the presence of buried pipes under sinusoidal input acceleration was evaluated in terms of slope displacement and the pipe axial strain. The results show that the presence of buried pipes in the slope can reduce slope surface displacement by 50%, especially for shallower burial depths of pipe (i.e., 1-1.5 m). The results of the axial strain of the pipe for changes in the burial depth and location indicate that for pipes buried in the downslope and upslope sections, deeper and shallower burial depths, respectively, lead to less axial strain being imposed on the pipe under landslide actions. The variations of slope geometric parameters (slope width and inclination angle) on slope displacement response and pipe strain patterns show that with increasing slope width and inclination angle, the displacement of sliding mass increases, and the depth of the slope failure wedge decreases. Moreover, the maximum strain of the pipe increases by 150% as the width-to-height ratio (W/H) of the slope increases from 1 to 4. With the increase in soil density, the pipe axial strain increases. The results of dynamic analysis under earthquake records showed that the axial strain of the pipe has a high correlation with the cumulative absolute velocity of seismic input.