Evaluation of Mobile Equipment Loads on Buried Pipelines during Forestry Operations Using API RP 1102 and Empirical Soil–Tire Contact Models

Abstract

This study applies the API RP 1102 (7th Edition) standard to assess the combined stresses on a buried API 5L X65 steel pipeline located in the Yumbo–Buenaventura section, subjected to heavy forestry machinery traffic. The load model was updated using the approach by Saarilahti (2002) for theoretical contact area (P/p), the elliptical tire–soil contact representation from Ala-Ilomäki et al. (2012), and deflection and surface roughness adjustments proposed by Cambi et al. (2015). This integration provides a more realistic estimation of the effective ground pressure transmitted to the buried pipeline. Results indicate that, at a burial depth of 1.4 m and wall thickness of 0.300 in, the effective combined stress (Seff) remains within the allowable limits defined by API RP 1102, ensuring the mechanical integrity and stability of the system under mobile loads. It is concluded that incorporating empirical field-based contact models enhances analytical accuracy and strengthens the applicability of API RP 1102 in tropical forestry environments.