Understanding the Basics of Field Exploration

The first step of any construction project, be it large or small, is field investigation or field exploration. The engineers and construction team must know the composition and layout of what lies beneath the soil before they start drilling, digging or building.

If you’ve ever wondered, “What is field exploration?” or “What does field exploration consist of?” then this article is for you. Below, we’ll cover what is done during field exploration so you can begin to understand its likely role in your project.

What is field exploration in civil engineering?

Field exploration is the process of determining the condition and composition of the ground in the “field” of any construction project. This is a fully involved, complex and crucial process that must precede any type of construction. Readings and data must be noted and logged, and the process requires knowledge in the fields of geology, geophysics, hydrology and advanced math, in addition to engineering.

What type of information is being logged during field exploration?

In short, almost everything. Basically, every single detail about the prospective field is being logged. This includes soil composition (complete with samples taken), the ground’s slope and run, where any underground utilities are located, the depth and breadth of any rock layers underneath the surface and much, much more. The type of project will slightly influence what measures are taken, but when it comes to gathering information, generally speaking, the more you have, the better.

How is the information about rock formations under the surface gathered?

To know what lies beneath and makes up the field’s foundation, engineers must oversee a boring or drilling process. The tricky part here is balancing the costs versus the information gathered. Drilling an 8-inch hole will cost more than a 3-inch hole, but the 8-inch hole might offer more actionable and valuable data, which could lead to cost savings down the line.

What specific information is the boring process trying to discern?

The boring process tries to gather the following information:

  • Stratigraphy
    • A detailed description of each layer or stratum
    • Thickness, elevation and upper and lower bounds of each layer
  • Cohesive soil layers
    • Moisture contents
    • Atterberg limits
    • The presence of all organic materials
    • Evidence of soil disturbances, dehydration, shearing or swelling
    • Shear strength
    • Compressibility
  • Granular soil layers
    • Using standard penetration and/or cone tests, calculating the average and range of the soil’s in situ density
    • Gradation
    • Presence of any organic materials
  • Ground
    • Over time and at different times, observe the piezometric surface of the field, noting its past and current measurements while also projecting its future range
    • Level of the water table
  • Bedrock
    • Depth over the entire field
    • Type of rock and composition
    • Type and amount of weathering that’s occurred
    • Detailed description of joints noting their spacing, distribution and any infilling
  • Faults
    • Note how solutions affect limestone and any other permeable types of rock
    • Soundness and core recovery

Call for your field exploration today

Now that you know the basics of field exploration in geotechnical engineering, give us a call at Emc2 Inc. We’re a premier civil engineering firm, and our 25 years of experience provide us with the requisite knowledge to help you plan and execute your next construction project. Reach out today to arrange a consultation.