48 | HEB Construction: Beaumont Bridge T T Hugh de Lacy River’s rise and fall tests contractor The new bridge offered special challenges to the builders, not least being the need to drill, directly into the bed-rock, the four holes for the piers and the 24 others for the abutments. REGIONAL DEVELOPMENT The locals were adamant they wanted the new Beaumont Bridge over the Clutha River on SH8 to keep feeding the traffic past the front of the Beaumont Hotel, just as the old single-lane one did for nearly 140 years. And that’s what HEB Construction is delivering: a 195m steel girder bridge with two lanes for traffic, and a two-metre-wide shared pedestrian and cycle lane. Designed to modern earthquake standards, the new bridge will meet the current and future needs of Otago businesses and communities by safely connecting people, products and places, HEB Project Manager Simon Potts says. The new bridge and approaches are scheduled for completion late this year, despite labour shortages, the late arrival of key components, and unhelpful weather. The 41m old plate-girder bridge, which started out as a railway bridge, will be retained as part of the Clutha Gold cycle and pedestrian Trail. The new bridge offered special challenges to the builders, not least being the need to drill, directly into the bed-rock, the four holes for the piers and the 24 others for the abutments. Drilling into the bed-rock was a novel experience for many on a construction team more used to piling in alluvial layers and soils, but they completed the job to specification with no hiccups. The four holes for the piers are 2.2m in diameter and are sunk between 9m and 14m into the rock, while the abutment holes are 700mm in diameter and range between 5m and 6m deep. Part of the challenge of working on the Clutha River at that point is having to factor in the rapid rising and falling of the river level in response to electricity demands from the succession of upstream hydro dams. “It takes four hours for the flow rate changes to get from the Roxburgh Dam to Beaumont,” HEB Structures Engineer Todd Wilkins says. “We get to work for a 7am start and the river’s generally low because of minimal generation and electricity demand overnight. “As electricity demand rises between 6am and 7am the dam increases its generation to meet it. “We then see the resultant sharp rise in the river level at the Beaumont Bridge around 10am each day. “That gives us just a two or three-hour working window on tasks close to the river. Available Job Opportunities: • Carpenters • Hammer Hands • Labourers • Leading Hands • Fore People • Site Managers • Heavy Machine Operators Your one-stop shop for labour hire and recruitment. Tim 021 730 334 tim@npl.nz | Robelyn 022 082 0132 robelyn@npl.nz Branches Nationwide | www.npl.nz Structural Concrete • Commercial Buildings Retaining Walls • Carpentry Works 027 249 9198 www.kstruct.co.nz admin@kstruct.co.nz
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