May 9, 2014

Liberty Lake roundabout

CONCRETE PAVING

Photo courtesy of WACA [enlarge]

The roundabout was completed in fewer than 35 working days.

Location: Liberty Lake, Spokane County

Owner/developer: City of Liberty Lake, Washington State Department of Transportation

Project team: Wm. Winkler Co., general and concrete contractor; Michael Terrell—Landscape Architect; Central Pre-Mix, ready-mix supplier

A new roundabout was built in Liberty Lake at the westbound Interstate 90 off-ramp to Harvard Road and Mission Avenue.

Work involved removing the existing pavement, modifying utilities, excavating over 2,500 cubic yards of roadway, installing a new stormwater biofiltration system, constructing the roundabout, and installing a masonry wall, sign and over 2,000 plants and trees.

The roundabout was operationally complete in fewer than 35 working days, earning the maximum early completion incentive.

The project required coordination with 14 subcontractors and numerous suppliers.

Approximately 600 cubic yards of fast-setting concrete was used to allow traffic on the newly constructed pavement less than 24 hours after placement.

Additionally, there were two separate concrete suppliers: One supplier provided the concrete for the pavement and the second provided the concrete for the curb and sidewalks. The project included use of colored and textured concrete.

Although the project specifications allowed for temporary closures of the I-90 off-ramp and Mission Avenue, the closures were avoided by revising the traffic-control plans, building a ramp bypass road and adjusting the project phasing.

Extensive communication with local business owners helped ease their initial apprehension regarding the project and its impacts to their customers. Businesses were able to remain open during the entire construction process, and business owners welcomed the avoidance of the road closures.

Throughout construction, more than 18,000 vehicles traveled through the core of the project daily, along with pedestrians and bicyclists.

Over the course of more than 9,000 man-hours (including prime, subcontractor and inspectors) there were no accidents, injuries or near misses — no small task considering the traffic, weather and round-the-clock working hours at times.

Other Stories:

• Revised structural concrete ‘cookbook’ will follow a simpler recipe
  
• Cascade Middle School
  
• Estancio I
  
• Grand Ridge Plaza blocks 2, 3, 17 and 18
  
• Hendricks residence
  
• Diamond S Ranch
  
• Lower Baker Unit 4 Powerhouse
  
• Satus Creek Bridge replacement
  
• Husky Stadium renovation
  
• Clearwater Casino parking garage
  
• Providence Medical Office Building at Hawks Prairie
  
• Chief Joseph Fish Hatchery
  
• The Martin apartments