New Tool Helps Colorado Contractor Tackle Tough Ground Conditions

August 2010 Vol. 65 No. 8

Brighton, CO, has a successful formula for growth. The community of 30,000 just outside of the Denver metropolitan area has added 750 new businesses since 1990 and is home to a wind turbine and nacelle manufacturing plant that will eventually employ 1,350 people. Part of the formula is a sound infrastructure that provides businesses with access to up-to-date facilities and services.

The city has taken steps to upgrade and expand its infrastructure as a means to attract new businesses to the area. One recent project involved the expansion of a 24-inch water distribution line in a quadrant bordered by Colorado Highway 85 and E-470 located within the metropolitan Denver area with close proximity to Denver International Airport. This area has the potential for residential and commercial growth that will ultimately create jobs.

Extending the water line required passing under Highway 85 and a Burlington Northern railway. This portion of the project required some planning as the highway and railway were adjacent to each other, and the area included an existing array of telecom, fiber, gas, sewer and water lines, not to mention the ground conditions, which consisted of sand, gravel and clay.

When the project went out to bid, Northern Colorado Constructors knew they had the equipment and expertise for the job. The company was formed in 1979 and specializes in utility construction utilizing open cut and auger boring methods.

“We introduced auger boring to our customers in the 1980s,” says Chris Zadel, who is the construction manager for Northern Colorado Constructors (NCC). “Now we have one entire crew dedicated to this installation method, and we’re one of few utility contractors in the area with auger boring capabilities.”

Planning pays dividends
The project called for a 36-inch casing, which would house a 24-inch water main, to be installed under Highway 85 and the Burlington Northern Railway. The total length of the bore was approximately 700 lineal feet. As Zadel and his team reviewed the project, they decided trying to complete the full bore in one shot would be difficult considering the soil conditions. Additionally, the project required precision placement of the casing both vertically and horizontally to avoid the existing infrastructure and a house that sat within 20 feet of one of the receiving pits.

“We took our time with the planning stage, but we wanted to be proactive due to the tight requirements and traffic flows in the area,” says Zadel. “We had to hit on both sides within a couple of feet horizontally, so we made sure to get it right the first time.”