Underground Installation Projects: Determining the Best Approach

August 2008 Vol. 63 No. 8

The first decision a contractor should make when preparing a bid for any trenchless job is to identify the application that will be most efficient to complete the project. Each trenchless method has its advantages and works better in specific situations. However, sometimes the most efficient approach may involve using a combination of applications, requiring equipment that contractors may not have in their fleet.

“Determining which trenchless method is the most appropriate is project specific,” says Eric Nicholson, director of global and key accounts with HammerHead. “If you have a project that requires the relocation of a line, then horizontal directional drilling (HDD) or pipe ramming may be a good option. If you are installing a new line on grade; auger boring, ramming or HDD are considerations. In the case of a water or sewer line rehabilitation project, bursting may be the best method.”

It’s important to look at each project individually and consider the space available, number of bores or bursts and their length to select the most effective trenchless method. Engineers should also involve the contractor in the planning phase and encourage their input as to which trenchless methods may be the most cost effective way to complete a project.

Right combination

Among the first things a contractor considers when bidding an underground installation project is which method will be most effective to complete the job. Since most underground projects are unique, contractors need to be careful to analyze each job in advance to develop a plan. Involving contractors as early as possible can minimize the owner’s potential liability.

“The process of determining which method is most appropriate varies based on a number of factors,” says Tom Davey with Cutting Edge Group, Lake George, N.Y. “Much will be dictated by access restrictions, ground conditions, project installation specifications and a combination of any or all of these variables. It’s not an exact science, however. When we estimate a job, we have to make some assumptions because you really never know what you’re going to encounter until you get into it. We usually have a pretty good idea of how we plan to approach it before going in, but the plan often changes along the way.”