Project Information

  • Location: Bethlehem PA, USA
  • Owner: Pennsylvania Department of Transportation, District 5
  • Associate: American Geotechnical and Environmental Services Inc. (AGES)

I-78 Easton Road Bridge Abutment Project

The project needed rehabilitation work on the existing I-78 dual road bridge on Interstate 78 over Easton road near Bethlehem, PA. The inspections revealed settlement and rotation of the MSE walls that support the bridge as abutments. There was a separation noticed between the MSE walls and the bridge. The bridge was built in 1984 as a dual three-span continuous composite steel multi-girder bridge.


The installation grounds were quite muddy, making it difficult to have a clean installation in the boreholes. Furthermore, since the installation was close to a busy highway, heavy salt settled over the area after snowstorms. All the installations required special traffic rated utility vault and ABS boxes to house the data loggers and interface unit for long term protection and correct readings. It was also difficult to keep the boreholes open during the caving in of gravel layers.

Solution offered

Encardio-rite planned instrumentation and monitoring program to address the deficiencies and issues mentioned in the maintenance report. The rehabilitation work was carried out to investigate the movement pattern for both west and east of the bridge abutments. The sub-surface deformation data and the change in pore water pressures under the bridge abutments were recorded. The scope of work included the supply of geotechnical instruments, installation of geotechnical instruments, automatic monitoring with compact dataloggers and an online web-based data management system (WDMS) with pre-set alarms.

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