Underground utilities are everywhere. EVERYWHERE!!! They are a vital part of our modern society – But if you’re a Construction Engineer, they are nothing but mines in a a minefield.
In my article on Knowing your Project, I pointed out how it is vital that a Resident Engineer have a full understanding of the utility systems within and around your jobsite. Don’t leave it to one of your subordinates to be “in charge” of utilities – YOU ARE THE COMMANDER – YOU MUST UNDERSTAND YOUR BATTLESPACE BETTER THAN ANYONE ON THE JOBSITE!!!!
IDOT Article 213 – EXPLORATION TRENCH
If you’re on a typical IDOT-sponsored project, then you’ve likely seen this pay item. You’ve probably read that this provision is written for field tiles – Not a common utility needing to be located in an urban setting. Most Resident Engineers will utilize this item if quantity is provided in the contract for you to use.
The trouble lies in dealing with the width & depth provisions: Because the pay item is based on a measure length of trench, to determine, say, the location of an underground cable, it really doesn’t lend itself to this type of work since you don’t need more than a foot or two of utility to be encountered to locate it.
VACUUM-BASED UTILITY EXPLORATION
In the past 10 years or so, the use of vac trucks has become the best way of locating utilities. If you haven’t seen it performed, check out this video – Using a water-induced pressure gun, soil is liquefied under pressure and removed with a vac truck. It is an extremely effective & safe means of unearthing existing utilities.
(Thanks to digDIFFERENT Magazine for the image)
TIP: If you are looking to implement a hydro-excavation type pay item for your project, check out the attached Special Provision (CLICK HERE FOR A PDF COPY) was used in one of our company’s design projects: It’s a great provision to have in your toolbox in the event that your project has use for it and you need a guide for a field order-type authorization where you can specify additional work to your Contract.