New Rowing Club a Model for Advanced Pile Foundation Technology

We recently spoke with Matthew Conte, of Conte Company, about a foundation project they completed for a 2-story rowing club in Norwalk Harbor. Rowing clubs often prove especially difficult to build due to their proximity to the water, and the ground on which they are built. Building near or above water brings its own set of challenges for pile foundation technology, along with strict guidelines to which builders have to adhere.

In the case of this building, the ground floor of the rowing club is to be used for storage of the boats and equipment, while the upper floors are used for meetings, offices and social areas. Crew has always been a mainstay in the Connecticut area and rowing clubs are an important piece in the community, serving as both an athletic and social gathering place. Matt and his team were eager to finished this project quickly and efficiently, in order to get the general construction started on the 6,000 sqft, pre-fab, metal butler building, so it will be ready for the upcoming season.

In order to build this rowing club, Conte Company installed 56 27′ Drivecast piles. They tied those piles to a grade beam grid, on which a heavy slab of concrete was poured. The soil conditions, which were waterlogged every time the tide came in and composed of organics, fill and silty material, were not suitable for traditional building. The engineering team ultimately determined that there were only a few cost-effective pile foundation technology options for a site plan like this. The only other alternatives to Drivecast were helical piles, or H-Piles.

According to calculations and field tests, utilizing helicals would have maxed out at around 40-50 kips (1 kip = 1,000 pounds of force), whereas each Drivecast pile supported a staggering 120 kips! Matt explained to me that the other alternative, using H-Piles, would require pile lengths of up to 75ft in length, and would’ve taken significantly longer to install. For starters, H-Piles typically come in 50 foot lengths, so each pile would need to be spiced together to produce the full 75′. What’s more, when you’re talking about driving piles of this enormous length, you need some enormous equipment to do the job. In this case? A massive crane would be needed to drive each of the H-Piles deep, deep into the earth. By contrast, Conte Company’s Drivecast piles only required a 14 ton excavator to get the job done. Matt explains it best:

“A 14-ton Ex looks like a toy, sitting next to a crane like that. We pulled up our machine on a trailer and were in-and-out of the job site quickly.”

Matt and his team installed all of their Drivecast piles within 5 days; start to finish, and had no issues installing them. The grouted columns were allowed to dry for 5 days before testing, and again had no issues, even in the salty, waterlogged silt. As an added bonus, the site was located on property owned by a chemical plant, regulations for which are far more stringent than other environmentally regulated industries. Again, no worries, Conte Company sailed through all requirements with ease. The entire project went off without a hitch.

The building Matt and his team recently built is located on Norwalk Harbor, and will be a great addition to the community. Matt and his team, along with the revolutionary pile foundation technology called Drivecast from Hubbell-Chance, allowed this project to be done faster and cheaper with less work, and smaller equipment than H-piles or helical piles.

What more do you need? Download the official Drivecast brochure below:

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The Drivecast™ Displacement Pile is Revolutionizing Deep Foundation Systems

Conte Company helped create the Hubbell-Chance displacement pile product known as Drivecast™.

If you haven’t considered grout displacement piles for your project, you really should. There are many benefits to using such a system and more testing and performance data is produced each-and-every day. Here’s a little background on the product and how it performs, which explains why we’re so excited to tell you about it.

This patented grouted displacement pile was designed to be used in high side friction and end bearing applications. This combination of load carrying capacity allows the pile to be used in most soil conditions and load requirements. The added rigidity and larger grout shaft resist buckling and high lateral loads, where segmental piles systems wouldn’t normally be considered. Since each coupling joint is completely encased in grout, the finish pile acts as one solid piece in the soil.

During early Spring of 2018, Conte Company performed a load testing program that compared Drivecast piles to traditional driven and helical piles. (8) different piles were installed within the same site, to a similar depth. These piles were all tested in compression and lateral resistance. We even used a tell-tale testing method on one of the Drivecast piles—which is a method for isolating the side friction from the end bearing resistance of a pile. The results were extremely interesting and educational.

  • The (3) different Drivecast size piles outperformed the (3) driven piles and (2) helical piles in compression
  • Two of the Drivecast piles were laterally tested during a week of torrential rainstorms and they still held respectable numbers
  • The RS4500DC pile achieved the largest of the group at over 20 kips

With the help of GZA GeoEnvironmental, Inc., the results of all the testing were cataloged and evaluated. You can download the full report here. We would like to extend our deepest gratitude to King Industries, Inc. for offering the use of their property for the testing location. We would also like to give a special thanks to Gary and Charlie Wetmore at G&C Marine for bringing out their new blow hammer to help with the driven pile installation!

If you’d like to learn more about Drivecast

Send us a message give us a call at (203) 853-2400. We’re happy to tell you all about it.

You can also watch our promo video here:

What are Displacement Piles?

Generally, displacement piles are load-bearing columns designed to be installed without spoil material (soil that’s removed from the ground). Instead, special equipment is used to displace soil laterally, compacting it into the surrounding terrain. While not ideal for every situation, displacement piles can sometimes support higher capacities than alternative helical piles or bored piles, as more of the load is placed on the grout and dissipated evenly into the earth.

Over the years, commercial construction engineers have created dozens of displacement pile styles, all of which are either pre-cast or cast-in-place, and most are either driven, drilled or screwed into the ground.

The most common and generally accepted types of displacement piles fall into the following 4 categories:

Precast Driven Displacement Piles

Preformed concrete piles have wide application in a variety of soil conditions. Concrete pillars are hammered into the ground until enough friction or an end-bearing point can support the required capacity. Because of the enormous force and violent vibration on the pile during installation, pre-cast driven concrete piles are almost always pre-stressed or reinforced in some way.

Pre-cast driven displacement pile

Cast-in-place Driven Displacement Piles

Another form of driven pile requires large, hollow steel tubes to be driven into the ground, creating a void to be filled on-site with concrete. These tubes are capped on the nose to force the soil outwards in the same way a nail is driven into wood. For uncased piles, the tube is removed while the concrete is being poured, and reused to form each new grout column. In other situations, the tube is left underground, as a permanent casing for the pile.

Cast-in-situ driven displacement pile

Cast-in-place Drilled Displacement Piles

Drilled displacement piles are similar to fully bored piles, except without the spoils. Specially designed displacement tools are drilled into the ground and force soil outward, creating a more compact and stable column for the concrete. Once the drill has reached the appropriate depth, grout is pumped in continuously as the drill is extracted. This ensures the column stays intact and the grout has a chance to fill every available crevice. A rebar cage is also typically used to reinforce the remaining concrete column.


Cast-in-place Screw Displacement Piles

As the name suggests, these piles are installed similarly to the very popular screw pile. Permanent steel pipes are twisted into the ground with specially designed screw flight attachments which also displace the soil laterally. As the pile spirals its way down, concrete is continuously gravity fed into the voided column. Once the piles has achieved its required depth, it is left there as reinforcement to the concrete column. This method is particularly useful in areas with limited accessibility, as only small machinery is needed to install screw piles.


Need advice on the right types of piles for your job?

Displacement piles are a valuable tool in an engineer’s toolbox when devising structurally sound foundations. Which style of displacement pile will depend on the project, soil conditions, load bearing requirements and accessibility for installation.

Talk to Conte Company Today

What is a Helical Pile?

What is a helical pile? and other questions about helical pier foundation solutions

If you’re in commercial construction, you probably know a lot about what happens above ground as you watch structures rise from the earth. What happens below ground, at the foundational level, might be more of a mystery to some. Helical piles are an important piece of underground construction technology which invisibly hold buildings and bridges in place. So what is a helical pile?

Helical piles literally do all the heavy lifting.

Below are some basic facts about helical piles. Once you understand what they do, what they’re made of and how they work, you’ll gain a whole new appreciation for these invisible, deep-foundation champions.

What Do Helical piles Do?

The purpose of a helical pile is to provide foundational support for structures of all types and sizes. Just like old-fashioned pile-foundations, helical piles (also referred to as screw piles, helical piers, helical anchors, etc.) are embedded deep underground in order to disperse the enormous weight which sits atop them. Multiple piles are installed to create a platform, on which a building, a bridge or any number of other large structures can rest.

You may also be wondering what is a helical pile for? Learn more about what helical piles do and how they’re used on our deep foundations page.

What are Helical Piles Made of?

Most helical piles are round hollow shafts or square solid shafts, extruded from steel and come in a wide variety of diameters and gauges, to serve different types of projects.

One or more steel screw threads (or helical bearing plates) welded onto the shaft, in order to supply ample downforce to the soil as it’s being screwed into the earth. Technically, this is what makes it a helical pile. The plane (or angle) of the screw is standard, although the size and shape can vary based on the application and soil specifications.

At the head of the pile is a shear lug, which fits machine-driven, rotary hydraulic attachments. These, in turn, are powered by small or large excavators, depending on the size of the pile.

For grouted pile applications, a lead displacement plate is fitted onto shaft extensions. This small disc pushes soil out of the way as it’s being screwed, leaving room for concrete to follow.*


What is a helical pile? a line diagram of a round shaft helical pile

How do Helical Piles Work?

Helical piles are installed by twisting them into the soil, just like a corkscrew is twisted into a bottle of wine. As the shaft of each pile disappears below the surface, additional extension segments are connected with bolted couplers and screwed into the soil as well—ultimately resulting in a single pile which can extend 100s of feet below ground.

In many cases, the steel pile itself is enough to meet the load requirements of the project. However, for more robust deep foundation systems, concrete (also known as grout) can be incorporated. In a grouted column, concrete is continuously poured down the sides of the column, following the displacement plate and encasing the steel shaft. This technique produces a reinforced pillar that will withstand the most extreme compressive, uplift, and lateral forces.

*Conte Company also helped develop the DRIVECAST™ Grouted Soil Displacement Pile (manufactured by HUBBELL-CHANCE®), which incorporates displacement functionality directly into the screw bearing plate.


So, what is a helical pile? We’re happy to answer any other questions you have…

Set up a phone call or a meeting with the helical pile experts at Conte Company today