Soil sampling is a crucial first step in a construction project. Before work begins, you need to study the ground the structure will be built on. The information about the chemical and physical condition of the soil directly impacts decisions for the project’s next phases, including design and construction timeline.
Developers and civil engineers often outsource soil sampling, but what if you want to take soil core sampling for land development into your own hands? Collecting your own soil samples can save time and help accelerate project timelines, but it’s important to have a full understanding of how to do so properly.
We’re here to help you make sure you have the right soil sampling equipment and know the proper tips to conduct in-house soil sampling. Here’s what you need to get started.
Choose the Right Soil Sampling Drill
First, you need to choose the right soil sampling drill. Jobsite considerations such as soil type, location, local requirements and drilling depth are important when it’s time to determine the proper soil sampling equipment. While all our soil sampling rigs are highly portable, if the site is remote and more difficult to access, you might want to consider drills with a higher level of maneuverability. If you’re drilling in areas with more challenging soil, a soil sampling rig with more power may suit you better.
- For portability and light-duty sampling: LST1A+
- For remote or limited-access sites and an optional manual hammer: LST1G+
- For denser soils and more power: LST1G+HD
- For SPT consistency and automatic hammer needs: LST1G+HDA
- For delicate or difficult terrain: the tracked and remote-controlled LSGT+HDA
You’ll also need to determine which auger to use, based on the type of soil you’re sampling. For cohesive soil with a high clay content that stays intact when disturbed, turn to a solid-stem auger. A hollow-stem auger excels when you’re drilling into noncohesive soil such as sand or gravel. Learn more about when to use each type of auger in this blog.
Set Up Your Soil Sampling Process Before Drilling
Before heading to the soil sampling site, it’s important to establish a recording system. Accurate data recording is critical. Set up a sampling log and prelabeled containers to streamline the process.
Start by assigning the overall sample area a unique identifier, like SA-1 (Sample Area One). Sample areas can be broken down further into sample sites, like SS-1, SS-2 and so on.
Handle and Record Soil Samples Correctly
After you have everything labeled, your logbook set up and the right soil sampling equipment, it’s time to start sampling. Note weather conditions, and the date and time you arrive at each sample area and for every boring within a sample site.
Developers and civil engineers establish their own standard operating procedures for handling and storing samples; however, an airtight container for storage in the field is essential. To ensure accurate soil representation, once sealed, place the samples in the shade, preferably in a cooler, until they can be refrigerated or sent to a lab.
These are a few examples of how to establish soil core sampling accuracy. Check out our full list of data recording tips here.
Avoid Soil Sampling Mistakes That Can Delay Development
Soil sampling requires great accuracy and attention to detail to avoid crucial mistakes. Steer clear of these common errors to ensure success.
- Incorrect depth and sample size: Testing at the incorrect depth or over too large of an area can provide inaccurate soil representation.
- Cross contamination: Avoid soil cross contamination by thoroughly wiping down and inspecting the auger and sampling tools between each sample.
- Not accounting for site history: A site that has been mostly untouched may have more consistent soil attributes than one that has been home to various construction projects or agricultural applications.
- Neglecting site restoration: At a minimum, holes must be refilled and compacted, asphalt patched, if necessary, and the surrounding area cleared of debris.
Should Your Team Bring Soil Sampling In-House?
Soil sampling will always be an important early-stage task for a construction or development project. If you want to accelerate the timeline by taking on sampling yourself, developing the right processes from before you start can help ensure the job is done right. We’re here to help you find the right soil sampling rig and any needed accessories. Reach out to us to get started.