Two Underground Pedestrian Passages Using Pipe Jacking: Case Study

Abstract

This case report presents two pedestrian passages underneath an urban expressway with a spacing of 0.5 m, which were constructed using rectangular pipe jacking technology in Nanjing, China. To better understand the field performance and the geoenvironmental impacts of rectangular pipe jacking technology, real-time monitoring was conducted with the installation of measurement devices at 43 measurement points. These points were set up to measure lateral earth pressure, excess pore water pressure, soil lateral displacement, and ground surface settlement. By analyzing field measurement data and operational parameters, this study documents operational parameters throughout the jacking process of two successively constructed tunnels and presents geoenvironmental impacts of the rectangular pipe jacking technology. In this process, the study finds that large ground settlements around the jacking shaft were due to the strong soil-carrying effect of the rectangular pipe jacking technology.