COMPARISON OF CONSTRUCTION METHODS FOR BUILDING AN UNDERGROUND FREIGHT TRANSPORTATION IN TEXAS

Abstract

Freight transportation by trucks constitutes approximately 80% of total freight transportation in Texas and it is expected to approximately double by the year 2040. Social and environmental costs are adverse impacts of moving freights by trucks. Underground Freight Transportation (UFT) significantly reduces these negative impacts and is more sustainable method of freight transportation. UFT includes close-fitting vehicles carrying freight through underground pipelines or tunnels between terminals. The main objective of this research is to compare two construction methods: (1) tunneling using tunnel boring machine (TBM) and (2) tunneling using open-cut. To conduct this research, a comprehensive literature search on various construction technologies for building large diameter pipes or tunnels was conducted. Additionally, interviews with tunneling experts and stakeholder committee members were made, and a survey on comparison of tunneling vs. open-cut methods was performed. The result of this thesis shows that tunneling with TBM is more constructible, applicable and cost-effective than open-cut construction. This is due to several factors, such as, large tunnel size needed for UFT, difficulties in transportation and delivery of large precast diameter pipe sections for open-cut method, social and environmental impacts of open-cut, limitations in right-of-way and natural and man-made obstacle, such as, bridges, rivers, existing utilities, difficult ground conditions, etc., as described in this thesis.