Drilled Shaft Foundations

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What are Drilled Shafts:

Drilled Shafts are deep foundation systems that are commonly used for structural support, slope stabilization, or retaining walls. In the foundation drilling industry, drilled shafts can also be known as Drilled Piers, Caissons, or Bored Piles. These Drilled shafts are called a Deep Foundation system because the augured hole will typically go much deeper than other systems. As a result,  drilled shafts are usually used to accommodate large buildings or structures that require heavier axial and lateral loads.

Drilled Pier Foundation installation process:

The process of installing a Drilled Pier Foundation begins with excavating a deep hole usually a diameter of anywhere between 12-240 inches. After the hole has been drilled and inspected for continuity and debris, a special steel shaft is lowered down. One of the most distinctive features of the drilled shaft is this special cylindrical steel shaft. After the Cylindrical Steel Structure is inserted into the hole, the final step is to add Concrete. Adding Concrete to the Drilled hole is done by using the freefall method or by using the tremie method depending on the conditions of your project.

Advantages and Disadvantages of Drilled Shaft Foundations:

Advantages:

1.  Supports a Strong Foundation with High Capacity with both axial and lateral loads.

2.  Machinery/Tools required for construction can vary according even in low clearance situations.

3.  Great Solution for a variety of ground conditions including wet or dry ground

Disadvantages:

1.  Time

2.  Cost

The time it takes for a fully prepped and installed Drilled Pier Foundations depends on a lot of factors, but for most Pier Drilling this option usually takes the longest. First of all, the drilling depth is usually required to be much deeper than other solutions. Secondly, additional time is spent building the special cylindrical steel shafts. This can be done on-site, or beforehand but either way this is an arduous and labor-intensive process. Installing the Steel shaft for the Drilled Pier Foundation requires a flawless hole to be drilled with perfect continuity so that the large steel support can fit in seamlessly. That means the hole needs to be inspected from top to bottom looking for all large rocks, debris, or imperfections. Depending on the drill depth requirements the inspection process can be done just by a careful line of site inspection, or with deeper holes a special camera is lowered down to ensure the integrity of the hole. After the inspection process is complete and the imperfections are removed or reformed we are ready to slide the cylindrical frame in. Lastly, the cement pouring can also slow down as the drying process on such a deep hole can cause delays.  

As you can imagine, after you apply the additional time and supplies for this process you can bet the expenses add up quickly. Although it is a more complex pier drilling process, the extra load capacity is a great foundation solution for certain projects.  

Why Specialty Foundation Services:

Luckily, at Specialty Foundation Systems we have all the right people, processes, and equipment to get your Foundation Drilling done the right way and at the right time.  So if you need a Drilled Pier Foundation you can call us for a quote as well as other foundation systems that can fit your project requirements and budget.