Bridge 269 Nimt, Taupiri

This project consisted of the replacement of an existing timber rail bridge over a small creek as part of Ontrack’s bridge renewal programme.

The new bridge was founded on four no. 750mm diameter bottom driven piles with the steel casings driven to a depth of 33 metres, before installation of reinforcing cages and pouring of the concrete.

Two new pile caps were then constructed with integral reinforced concrete wingwalls along each side to form the new bridge abutments.

This work was undertaken under and around the existing structure in order to maintain the existing track and train movements throughout this period.

Two 10m long structural steel girder spans were refurbished including the replacement of the top and bottom flange plates.

These were then installed together with the railway line and sleepers over two 12-hour Block of Line periods (one for the up main and one for the down main) in the same weekend.

Innovation

The conforming methodology for construction of the abutment wingwalls was using insitu concrete however we chose to precast the panels on site resulting in time and cost savings.