Shreveport sits at roughly 160 feet above sea level on the Red River’s alluvial plain, where subsurface conditions can shift from stiff Pleistocene clays to loose Holocene sands within a single block. With over 180,000 residents and aging infrastructure from the oil boom era, many commercial and residential projects require a direct look at what lies beneath the surface before committing to a foundation design. An exploratory test pit provides that visual confirmation, allowing our team to log stratigraphy, collect undisturbed block samples, and observe groundwater seepage in real time—something no borehole alone can offer. When we excavated a series of exploratory test pits near Cross Lake for a new medical office, the visual evidence of relic oxbow deposits completely changed the geotechnical assumptions and saved the owner from a costly undercut. For deeper verification beyond 15 feet, we often pair our exploratory test pit program with SPT drilling to correlate blow counts with the exposed soil profile.
In the Red River floodplain, a 12-foot test pit gives more defensible data for shallow foundation design than a 50-foot borehole with no visual context.
Process and scope
Site-specific factors
In Shreveport, the transition zone between the Red River terrace deposits and the Eocene-age upland formations creates a perched groundwater condition that many designers miss until excavation begins. We have arrived on sites in the Ellerbe Road area where a supposedly dry profile turned into a flowing sand seam at just eight feet deep, requiring immediate dewatering and a revised foundation plan. Without an exploratory test pit to expose this condition early, the contractor would have been dealing with a flooded excavation and a potential slope failure at the property line. The greatest risk isn’t just the soil itself—it’s the unknown water that moves through relic channels and sand lenses, destabilizing trench walls and compromising bearing capacity in ways no desk study can predict.
Standards used
ASTM D2487 – Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), ASTM D1586 – Standard Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of Soils (for correlation boreholes), IBC 2021 – International Building Code, Chapter 18 (Soils and Foundations), OSHA 29 CFR 1926 Subpart P – Excavation Safety Standards (shoring and benching requirements)
Complementary services
Standard Test Pit Logging and Sampling
Excavation with rubber-tire backhoe or mini-excavator, continuous logging of the exposed face, and collection of bulk and block samples for laboratory index testing. We document groundwater ingress, soil structure, and fill boundaries with high-resolution photography.
Combined Test Pit and In-Situ Density Program
After logging the pit, we perform in-place density testing on the pit floor or adjacent compacted fill using a nuclear gauge, providing immediate feedback on compaction quality and bearing capacity for shallow foundations.
Typical parameters
FAQ
How much does an exploratory test pit cost in Shreveport?
The total cost for an exploratory test pit in the Shreveport area typically ranges from US$500 to US$880 per pit, which includes mobilization of a small excavator, a full day of geotechnical logging by our field engineer, sampling, and a factual report. The final price depends on access constraints, depth, and whether traffic control or utility locating is required.
How deep can you go with a test pit in Louisiana?
With a standard excavator, we can reach 15 feet below grade. Using a trench box or stepped benching, we can extend to 20 feet in stable soils. Beyond that depth, OSHA shoring requirements become complex, and we typically recommend transitioning to CPT soundings or mud-rotary borings for deeper exploration.
What’s the advantage of a test pit over a boring for shallow foundations?
A test pit exposes a continuous vertical face, so we can see thin sand seams, relic root casts, and fissures in the clay that a split-spoon sample from a boring would miss entirely. For evaluating the stiff crust of the Porters Creek formation, visual inspection of the test pit wall gives us confidence in the bearing stratum continuity that no SPT number alone can deliver.
Do you handle the excavation permit and utility locating?
Yes. We coordinate with Louisiana One Call (811) for utility locating before any excavation, and we manage the permitting process through the City of Shreveport Department of Engineering and Environmental works when work is within the public right-of-way. Our safety plan covers all OSHA Subpart P requirements for excavation and trenching.