30 years of Cone Penetration Testing with GEI
We’re proud of the relationship we have with our long time customers. We succeed together. One of these groups is GEI Consultants, which has been delivering engineering services around the globe since 1970. Sean Brady, Senior Instrumentation Specialist with GEI, provided CPT University with background on their operation as it pertains to their CPT efforts.
Briefly describe GEI’s engineering focus. What do you do for whom?
GEI is a medium-size engineering firm with around 700 employees in the United States. Our business line within GEI is Geotechnical, non-destructive testing, and geophysics.
Our engineering team has designed over 75% of downtown Chicago’s foundations and most of the tallest buildings in the world. We often are part of the design team when difficult and challenging soils are encountered.
We perform CPT’s on earthen dams/embankments, river sediment depths, USCOE projects from Ft. Peck Montana to New York, RR alignments, bridge embankments, and Power plants.
A little of everything you can imagine from Water, RR bridges, Landfills, the stability of tail basins for the mines. We also oversee other companies performing CPT. We just worked in Asantana, Kazahkstan overseeing a new energy exposition 2016 project for both SPT’s and CPT. Also have overseen CPT testing in Doha, Qatar.
When did CPT first become of interest and why?
We have over 30 years of CPT testing experience. In the late 80’s we purchased a 30T CPT truck and traveled around the US performing CPT on challenging geotechnical projects. In the mid-90’s we sold our truck and started to perform CPT testing behind drill rigs. At the time we had a fleet of 18 drill rigs from track-mounted, ATV, truck-mounted, Barge mounted, etc. We get involved with delicate soils all the time.
In some cases even when continuous SPT sampling you can’t always detect small seams that we’re interested in. This is where CPT comes into the picture on a lot of projects. One larger failure project was the TVA tailing basin project in Kingston, TN. We used CPT with continuous sampling for the root cause investigation.
What is the primary type of equipment GEI has outfitted with CPT capabilities and what has been the result?
We have two complete Vertek Hogentogler systems with 5T, 10T tension cones, conductivity module, seismic, pore pressure, and temp. We have had great success pushing through challenging soils throughout the United States. We’ve worked with MN DOT helping them complete backlog when their equipment was fully utilized.
Our typical production behind a drill rig is ~500 linear feet per day pushing 20’ soundings, and ~600 linear feet per day pushing 100’ soundings. We have had great seismic data and have compared it with both Downhole and Crosshole seismic data collected at the same location at Nuclear and Coal plants. We’ve performed CPT on any type of soil or location imaginable. The Key is to know the gear and the limitations.
What do you see as the future of CPT within your business?
Keep doing what we’re good at. Difficult projects that require in-situ sampling with correlation to SPTs. We are currently trying to grow our business model in the mid-Atlantic. We have seen some more potential clients looking for more of an expert than just an operator of the testing.