Observations of Ground Movement during Pipe Ramming Operations under a Railway Embankment

For the development of Ramsey Town Center, which is a large commercial and residential development north of Minneapolis, Minnesota, additional stomwater conveyance capacity was needed, requiring the design and installation of one 60-inch and two 54-inch diameter storm water pipes under an active railway embankment. The storm water pipes were to be installed in steel casing pipes with diameters (ID) of 86-inch and 78-inch respectively. These three casing pipes were installed under the two-track railway embankment by employing pipe ramming methods. An embankment monitoring system consisting of 74 mini prisms, mounted on the tracks and jacking pit, and a Leica automated theodolite located adjacent to the track, were installed several weeks prior to the ramming operations to monitor embankment movement during the operations. The monitoring system was fully automated with Internet access to real time data plots. The cost of the installation of monitoring system and performance of continous monitoring with daily reports for a four months period was approximately $90,000.