PILE DRIVING EFFECTS ON A STEEL TRUSS RAILWAY BRIDGE DURING REHABILITATION

This paper summarizes the performance of a steel truss railway bridge near Saskatoon, SK,
which remained in service during pile driving activities for pier rehabilitation and new pier
construction.
289 H section piles were driven to embedment depths of 9 m for rehabilitation of existing
concrete piers, and 12 m for new piers, for the western portion of the bridge, over an
approximate one-month timeline. Piles for existing piers were driven within one metre of the
existing pile caps, which were supported on timber piles. Monitoring instrumentation included
surveying of prisms mounted to the bridge deck and piers and installation of tilt loggers, and a
vibration monitoring system, to monitor the lateral deflection and accelerations, respectively, of
the structure during pile driving. The collected data provides an understanding of the response
of the bridge structure from pile driving into the hard foundation till, along with expansion and
contraction effects due to extreme temperature variations. Survey and tilt logger data were
found to correlate well together, and with changes in ambient temperature.

Wave Equation Analysis of Pile Driving (WEAP) was conducted to estimate pile termination
criteria and driving hammer performance. Pile Dynamic Analyzer (PDA) testing was conducted
on 10% of the piles; 9 and 12 m long piles driven into Sutherland Till exhibited average vertical
capacities in the range of 1,940 kN and 2,700 kN, respectively.