Trenchless Technologies in Railroad Utility Crossing: Considerations, Allowed Construction Methods, and Economic Implications

Abstract

Demand for underground pipelines and the rehabilitation of existing utility infrastructure has been increasing due to urban expansion, continuous development, and the deterioration of existing buried assets. Often, conventional cut and cover (e.g., open-trenching) is the method of choice when rehabilitating or installing new pipelines. However, some underground utilities cross under railroads, and an interruption of railway operations may result in significant economic losses that make it impractical to consider open-trench installation. Moreover, many railway owners will not consider permitting conventional cut and cover utility installations within their rights-of-way. As an alternative, railroad construction guidelines allow the implementation of certain trenchless technologies for new installation and the replacement of the existing pipelines and/or utilities. The purpose of this paper is to provide a general overview of the considerations, typical construction methods, and economic implications concerning railroad underground utility crossings. The paper summarizes the current guidelines provided by the American Railway Engineering and Maintenance-of-Way Association (AREMA) pertaining to a trenchless installation. Additionally, this paper presents a brief case study to introduce an economic analysis for railroad freight transportation and proposes a decision-making model to select the most appropriate trenchless technology method for a specific project.