Get Ahead By Going Under: 3 Common Ways to Bore Under Paved Surfaces

Here’s the challenge, front and center: You need to install a row of pipes, cables, or lines underneath a paved surface. Maybe it’s a roadway or a sideway. Perhaps it’s a driveway or a large slab of concrete.
Either way, two options present themselves. One isn’t very appealing:
  • Break up the paved surface.
  • Add the required utility lines.
  • Then repair the pavement.
Easy, right?
Not quite. This method is absurdly time-consuming. It also comes gift-wrapped with an array of extra labor, expenses, and challenges.
How can replacing a substantial portion of concrete, paired with the exceptionally steep expenses of installing what you need to install, be in any way cost-effective?
It’s not.
And imagine if you’re breaking up a roadway or highway? Oh, the traffic! All that congestion and car-honking delays, especially in well-developed, urbanized areas, are sure to make unwanted headlines.
There’s one effective way to eliminate all the above challenges: Go below the paved surface.
Yes, it can be done and has been for years. It’s called boring. As decades of technological advancements have unfolded, so, too, have your boring options, each presenting their assortment of physical, safety and budgetary requirements, and restrictions.
Let’s discuss three prevailing boring methods for larger-scale projects—and whether each one is right for the big-time project you have in mind.
Why Impact Moling is a Time-Tested Technique for Small Projects
Looking for the simplest type of trenchless installation for under-pavement crossings? Consider impact moling, experts suggest.
One of the oldest types of trenchless methods, impact moling, is highly effective for installing pipes, wiring and cables under roadways, sidewalks, dams, and other paved crossings of 150 feet or fewer.
Impact moling creates a bore by using a percussive hammer within a torpedo-shaped cylindrical steel body that is either hydraulically or pneumatically powered. In other words, the bore head essentially hammers its way through compressible soil right under the paved surface.
Easy to operate, the equipment displaces soil; it does not remove it. That’s key. So is this: Research suggests impact moling is still one of the most well-used trenchless installation methods available, widely implemented by utility companies for installing small- to medium-sized diameter pipes and cables for an assortment of industries such as telecommunications, gas, electricity, water, and sewerage.
A couple of potential hiccups: One is costs. Per reports, the equipment needed can be a turnoff for projects with smaller budgets. Sure, the expenses are marginally less compared to other boring methods we’ll soon discuss, but with these reduced costs comes another potential glitch: the diameter and length of the bore, which is limited. These hitches make this boring method a better fit for simple road crossings and installing short-drive service connections from distribution networks to end-users.
Auger Boring: The Pluses—and The Negatives
Another old form of trenchless technology available to you is auger boring, which continues to be a go-to method because of its cost-efficiency and effectiveness over long distances compared to other types of large-diameter installation methods—in some cases, up to 600 feet.
That, too, is a strength: Unlike impact moling, auger boring offers larger diameter capabilities, offering the kind of size versatility that, experts say, makes auger boring an effective solution for installing small sewers and waterlines placed inside steel casings as well as culverts under freeways.
Auger boring is ideal for soft ground conditions. Because of casing installation and soil excavation, there is a reduced risk of seepage or soil collapse. No drilling fluid is used, which ensures that the integrity of the surrounding soil is primarily unscathed.
Auger boring also has another advantage: costs, which are fewer when matched to the last type of boring we’ll touch on. Another plus: using an auger boring machine is simpler compared to other, more high-tech trenching equipment—and when something is easier to use, it requires less training, as well as costs.
But there are some disadvantages, and they’re particularly noteworthy.
First, auger boring offers minimal steering abilities, which makes its alignment in the entrance pit so crucial. It’s the only way to ensure the device travels along the path you desire.
Also, while a plus for softer ground applications, auger boring is a strict no-no for wet running ground conditions or applications where there is a high frequency of boulders.
Though few, these setbacks can make or break a project’s success—which is why the final form of boring below is often best for larger-scale projects.
Why Horizontal Directional Drilling is the Boring Champ
In the two instances above, we discussed how crucial precise steering capabilities were to prevent soil cave-ins and maintain the integrity of the ground surface?
And how imperative it was to do as much as you can with the equipment you order and use to limit your environmental footprint?
These are all reasons why horizontal directional drilling (HDD) has become the most common boring technique used today.
HDD’s unmatched power, accuracy, and improved safety, per construction news outlets, make it a universally effective solution for nearly every larger-scale project.
Here’s how it works: A drill is launched from one end of a designed bore path, then retrieved at the other end. Apart from the launch and retrieving spaces above ground, the entire process takes place underground.
It’s essentially the method experts use when they must avoid trenching altogether—and a godsend for environmentally sensitive areas, including rivers, lakes and wetlands.
Its steering abilities are unmatched. Courtesy of advanced HDD steering technologies, crews have continuous monitoring and control capabilities through even the most constrained spaces—like, say, between two existing utility lines. This steering technology ensures that no accidental nicks or dings are sustained, leading to budget-crushing incidents later down the road.
Another benefit of HDD’s steering capability is how crews can install pipelines, wires, and cables below clustered city streets without interrupting vehicular or foot traffic above. It also avoids what you have too often seen: Construction blocking your access to a local business.
The one lone disadvantage, according to experts? Costs. Directional drills are high-tech, high-cost, and high in demand, a trio that will drive your prices up. Also, its pinpoint steering necessitates expert navigation—which, yes, unlike auger boring, means more training from the contractors you hire to make sure the job is done right.
It’s a lot. All the options listed are. But how much is too much? Does it exceed the expenses your credibility, budget, and reputation will undoubtedly sustain for a job not so well done? Likely not.
Choose wisely and contact the right boring contracting specialists for your project today.
Posted: 8/4/2021 2:12:56 PM