Analysis of pipe-soil interaction under lateral loads using random fields of soil strength parameters

This study presents a comprehensive method for investigating the interaction between buried pipelines and soil under lateral loads, considering factors such as landslides, earthquakes, fault activity, and other sources of lateral movement. By employing Abaqus finite element simulation and its secondary development function, the study focuses on analyzing the contact pressure at the pipe-soil interface, which plays a crucial role in understanding the problem of pipe-soil interaction. To account for soil heterogeneity, the study utilizes a random field approach to simulate the variability of soil strength parameters. Three different coefficients of variation representing various working conditions are considered for a single buried pipeline configuration. The simulation results are compared with deterministic results obtained under homogeneous soil conditions. Additionally, parameter analysis and probability research are conducted to investigate the stochastic analysis simulation results. The findings reveal that the proposed method effectively captures the pipe-soil interaction under lateral loads. The bearing capacity of the pipe-soil structure interaction is found to be lower when soil shear strength exhibits spatial variability compared to deterministic analysis results. The influence of soil heterogeneity on the failure mechanism of shallow buried pipelines under lateral load is observed as soil failure occurring in areas with weak strength. Furthermore, the horizontal correlation distance of random parameters for soil undrained shear strength significantly affects the bearing capacity of the pipe-soil structure interaction. The bearing capacity follows a lognormal distribution when the pipeline reaches the preset displacement. Considering engineering design standards, the failure probability of the pipe-soil structure decreases considerably with an increase in the safety factor. A safety factor of 2.5 ensures a failure probability of less than 1%, which meets the desired level of engineering reliability.