Within weeks of joining the Applied Geotechnical Engineering Consultants (AGEC) drill rig lineup, they tested the limits of the Geoprobe® 3230DT on several deep exploratory borings utilizing the 4-in. direct push casing. “We were impressed that we could advance the exploratory holes through dense sedimentary soil deposits to depths of up to 120 feet with the GH70 hammer while obtaining SPT samples every 5 feet,” said Benjamin Coray, P.E. with AGEC in Sandy, UT. “For us, one of the significant advantages of the direct push system is the pull-out and clean-up time. Not having to clean augers and dispose of cuttings saves us significant time and effort.”
“The 3230DT has proven to be an extremely versatile machine. Within a matter of a few months we were able to use it on a wide range of projects utilizing hollow stem auger, rotary wash, wireline rock coring and CPT methods. Geoprobe® has both the ability and the willingness to think outside the box with respect to customizing their products to fit our unique needs in the geotechnical drilling arena. It’s a pleasure to work with a company that is passionately committed to our satisfaction with their products.”
Benjamin Coray, P.E. • Exploration Manager
Applied GeoTech • Sandy, UT
Using the 3230DT for cone penetrometer testing has also been a major success for the company. Using the Geoprobe® Nova Cone CPT with the addition of the seismic geophone, “We’ve easily pushed to depths in excess of 100 feet (most likely deeper if we hadn’t run out of rod),” Ben added. “The efficiency with which we are now able to obtain seismic shear wave profiles on our projects has given us a unique advantage over our competition. What used to take several days at a significant cost can now be done in an afternoon,” he said.
Mud rotary being used to evaluate liquefaction potential in a lowland area of the Salt Lake Valley being considered for development.
AGEC has also found that the 3230DT is excellent for mud rotary and coring work and is “a joy” to operate. Being able to separately adjust weight on bit, rotation speed and pump flow allows for excellent operator control while drilling in Utah’s varied soil and rock formations. They have explored to depths of up to 170 feet in Salt Lake City lakebed sediments and gravels using rotary wash methods.
They also tested the rig’s abilities on the slopes of a local ski resort east of the city. The project required rock coring to a depth of 50 feet in hard quartzite sandstone halfway up a ski run with grades of 35 to 40 percent. According to Ben, “The rig, fully loaded with heavy tooling, climbed the slope with ease. The low center of gravity of the 3230DT gave us confidence while traversing slopes that we would not have tried with our other rigs. The mast oscillation allowed us to stay plumb despite the uneven terrain.”