Uncertainty's Effects Assessment and the Relevant Parameters on Soil-Pipe Interaction (SPI) System Responses Using Sobol Sensitivity Analysis

Buried pipes play a crucial role in the transportation and distribution of various substances, such as energy, fluids, and waste, influencing daily life and industrial activities. The interaction between soil and pipes significantly affects the distribution of forces and stresses in the soil-structure systems. This study focuses on the soil-pipe interaction (SPI) system, employing the simplified Winkler model to represent SPI. The uncertainty in soil and pipe parameters is a major source of variability in the response model. To address this, five semi-empirical models for computing the soil reaction modulus are analyzed. A global sensitivity analysis, specifically the Sobol method, is employed to quantify the effects of uncertain input parameters on soil reaction modulus and pipe flexural strains. Results indicate that soil parameters, particularly Young modulus, have the most substantial impact on the soil reaction modulus, while pipe parameters exhibit negligible effects. The sensitivity analysis provides insights into the influential factors and their interactions. Moreover, a probabilistic analysis is conducted to assess the variability of soil reaction modulus and pipe displacement, revealing differences among semi-empirical models and soil types. This study contributes to identifying key parameters affecting the SPI system, allowing for better-informed decision-making in pipeline design and management. The findings emphasize the importance of considering uncertainties in soil and pipe properties for accurate predictions of soil-pipe system behavior.