Nashwack River Bridge Demolition, NB


The Nashwack River Bridge was an 80 m long single span through truss bridge to be replaced by a new panel bridge used in a permanent installation. The panel bridge was to be launched from one of the existing approaches on the same alignment as the existing bridge, and was to re-use the foundation of the existing structure.

The contractor faced very costly penalties for late completion of the project and engaged HEC late in the schedule to aid in developing a plan that would allow for the rapid installation of the new panel bridge.

HEC undertook the project and in a very short period of time developed a full demolition plan that horizontally launched the existing truss structure to temporary abutments immediately adjacent to the existing foundations so as to allow the installation of the new panel bridge.

The scope of work included the full development of the demolition plan including construction phasing and generation of detailed construction drawings, phasing for the segmental removals of the trusses by cranes on each approach, calculation of center of gravity for lifts, stability measures for the trusses in interim support conditions, design of the temporary abutments, design of the horizontal pull assemblies, rollers and rail beams, analysis of the panel bridge to support boom trucks to aid in the demolition of the existing trusses, full submittal of design calculations and procedure for review by NBDOT.

The horizontal launch and demolition were completed and the panel bridge installed and opened to traffic without penalties being incurred.

Client: Concreate USL

Value: $1 M (Approximate)

Year: 2010

Role: Lead Engineer