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A new pedestrian bridge was required to span a three metre wide river in Richmond, Christchurch. This residential area had been affected by the Canterbury earthquakes. The project was completed in 2014.
The bridge had to be cost effective.
The site was in close proximity to residential properties, upon which installation was not allowed to have a disruptive impact.
Installation had to be rapid, and equipment needed to have a small site footprint.
We designed the bridge to be 10m long with a 9m clear span between the piled foundations.
Two TTT MultiPole Deep Pile Foundations were installed high up each bank to a depth of approximately 8m deep. The unique hollow core of these MultiPoles allowed for fast installation using high frequency vibration. This method enabled the poles to penetrate dense intermediate ground layers until the founding layer was reached. Pile tops were then cut level and scalloped on site to receive TTT MultiPole UniLog beams, to which timber decking and handrails were then fixed.
Once the bridge was completed, the hollow core of each MultiPole UniLog beam was utilised to run water pipes and fibre optic cables.
Installation was carried out within three days, and neighbouring properties were not negatively impacted during this time.
The bridge had to meet the requirements of the Transit New Zealand Bridge Manual for pedestrian and earthquake loads.
Because of the project’s proximity to water, the health and safety of installers had to be taken into account during the design phase.
The bridge could not become a choke point in the river it was spanning.
There were multiple dense intermediate ground layers that had to be penetrated in order to reach a founding layer.