June 11, 2012

Roadwork will eliminate challenging switchback

SHANNON MONEO

correspondent

A $12.6 million bridge replacement and road improvement project on Vancouver Island will not only make travel safer, but will improve access for the growing number of tourists making their way via Highway 14 to Port Renfrew, B.C.

The project, which started in early May and is slated to finish by late October, includes replacing a single-lane bridge with a two-lane bridge, construction of 1.2 km of new road that will replace a menacing switchback and the resurfacing of 5.4 km of existing road.

The switchback is notorious for causing motorcycle crashes and making it difficult for anglers to haul their boats to Port Renfrew, an internationally-known fishing destination.

Even large tour buses can’t make it up that section of the road, said Brian Bennett, project manager with Windley Contracting, the Nanaimo-based company that was awarded the Ministry of Transportation and Infrastructure contract.

The work is being done about 15 kilometres east of Port Renfrew on Highway 14, also known as West Coast Road, that is part of the Pacific Marine Circle Route, which is touted as a tourist attraction.

By October, the switchback will be decommissioned after the new 1.2 km section is built with tie-ins off the existing highway.

The project also includes paving and realigning the bridge approaches and construction of 1.5-metre paved shoulders on the bridge.

“Building the new road won’t be too challenging,” said Bennett, who has worked for Windley for eight years.

But, blasting will be necessary.

Roughly 16,000 cubic metres of earthen material, sourced on-site, will be used to build the highway, Bennett said.

Blasting will also be done when the new Sombrio No. 1 bridge is erected.

The original log bridge, built in 1957, was likely constructed by a logging company, according to Ministry of Transportation spokeswoman Kate Trotter.

It was rebuilt in 1983 by the ministry.

In 1999, a steel, single-lane temporary Acrow bridge was installed on top of the log structure.

The new steel and concrete 124-metre long bridge will be a double-span structure, crossing the Sombrio River.

One span will be 40 metres with a concrete pier at that point, and the second, 80 metres, Bennett said.

One interesting feature of this bridge is that it will be erected using the incremental launch method, a procedure that requires a considerable degree of expertise and specialized equipment.

In this method, the bridge superstructure will be built on one side of the river and then pushed longitudinally, or “launched” into its final position.

Launching is usually done in a series of increments.

It’s estimated that more than 1,000 bridges have been built worldwide using the incremental launch method, with the first one in the U.S. being built in 1977.

One of the first was in Canada, when the Canadian Pacific Railway launched a 415-foot railroad truss span in 1907 near Sudbury, Ont.

Usually cranes are used to build bridges, but in this case, crane access was difficult due to the confined work space, Bennett explained. The reach required for the crane wasn’t possible at the site.

One drawback is that using the incremental launch method takes longer than using a crane.

Yet, the incremental launch happens to be a better option when working in environmentally sensitive areas.

This is because of minimal disturbance to surroundings since a smaller, but more dense work area, is used.

Also, worker safety is improved because erection work is done at a lower elevation.

Environmental monitors will be onsite, since construction is happening over a river, Bennett said.

Construction debris, water use/discharge and sediment control will all be monitored.

Vancouver’s Surespan Construction is the sub-contractor for the bridge installation.

Rapid-Span Structures, from Armstrong, B.C., is supplying the steel.

Given recent complaints about lengthy delays caused by Highway 14 roadwork, Bennett said a traffic management plan was prepared with input from local residents.

Windley is committed to having single-lane traffic for the duration of the project. Full closures are unlikely.

Bennett noted that during one of his site visits, three vehicles travelled through within one hour.

The replacement of Sombrio Bridge No. 1 will complete Highway 14 upgrades that included improvements to the Baird and Murton Bridges, replacing Sombrio Bridge No. 3 with a new concrete structure in 2009 and about 22 kilometres of Highway 14 resurfacing near Port Renfrew since 2010, according to Trotter.

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