Overview:

Designed, produced the full technical package, and supervised installation of bridge-mounted supports on a ~110 m span to carry an existing water main and a new rising main conveying most of the city’s sewage to the WWTP. Scope included support design and detailing, load checks on the bridge elements, constructability planning, and staged works to keep services operating.

Challenges:

• Pre-purchased pipes with fixed type and material (no substitutions allowed).

• Water main required continuous operation during installation.

• No as-built drawings available for the bridge (unknown reinforcement/layout).

• Lateral mounting required due to the thin, deteriorated overhang slab.

 Outcome and lessons learn:

• Added intermediate supports to increase safety factors given bridge age and maintenance condition.

• A high-strength, lightweight support design simplified handling and reduced installation time.

• Procurement should follow design: pipe type and jointing material ought to be selected based on design criteria - not purchased in advance.