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GeoTest Services collected approximately 30-in. long concrete cores with a 420M as part of the project for five limited access borings at the University of Houston inside the main auditorium of the Hofheinz Pavilion. The concrete coring was through hard rock aggregate concrete found in the older structures in Houston.

GeoTest Services collected approximately 30-in. long concrete cores with a 420M as part of the project for five limited access borings at the University of Houston inside the main auditorium of the Hofheinz Pavilion. The concrete coring was through hard rock aggregate concrete found in the older structures in Houston.

GeoTest Services in San Antonio, TX, completed five limited access interior borings to +/- 20 feet at the University of Houston Cougars Hofheinz Pavilion/Guy V. Lewis Court Basketball Arena in Houston.  Alex Forhetz, Andrew Cardenas, and Angel Hernandez, the field team for GeoTest, used the 420MT in the arena while a PortaCo hydraulic pump and their unique 200-ft. auxiliary hose system was set up outside to power the machine inside.

According to Paul Wolf, President of GeoTest Services, the scope of work required that borings be taken at four locations on the riser steps in the main auditorium, and at one location in the service concourse under the seating. “We cored about 30 inches of concrete on the riser steps,” Paul explained, “to gain access to the soils below the structure.”

The borings were taken about halfway down the riser steps from the arena’s main concourse to the playing court. The steps alternated in width from 12 inches to 22 inches on every other step. The 420M was brought in and anchored to the steps. “We anchored the 420M to the 22-in. wide steps,” Paul added, “and were able to complete all of the borings. The geotechnical engineer and the University of Houston were extremely pleased that we were able to obtain the soil samples they needed in the redesign of the Hofheinz Pavilion.”

The project took two days to complete due to the spread out logistics and the extreme amount of concrete coring …. not to mention that the concrete coring was through the famous ‘hard rock aggregate concrete’ found in the older structures of Houston!

GeoTest Services has paired their Geoprobe® 420M with a 54LT (far right) to provide shallow sampling and limited access work for their customer base.

Contact Us

1835 Wall Street
Salina, Kansas 67401
Phone: (785) 825-1842

420M can be manually lifted to hard-to-reach job sites

420M Drill Rig

Manually lift and carry the 420M portable drill rig into hard-to-reach job sites with a mast weight less than 450 lbs.

Photo Gallery


GeoTest Services collected approximately 30-in. long concrete cores with a 420M as part of the project for five limited access borings at the University of Houston inside the main auditorium of the Hofheinz Pavilion. The concrete coring was through hard rock aggregate concrete found in the older structures in Houston.
GeoTest Services collected approximately 30-in. long concrete cores with a 420M as part of the project for five limited access borings at the University of Houston inside the main auditorium of the Hofheinz Pavilion. The concrete coring was through hard rock aggregate concrete found in the older structures in Houston.
GeoTest Services collected approximately 30-in. long concrete cores with a 420M as part of the project for five limited access borings at the University of Houston inside the main auditorium of the Hofheinz Pavilion. The concrete coring was through hard rock aggregate concrete found in the older structures in Houston.
GeoTest Services collected approximately 30-in. long concrete cores with a 420M as part of the project for five limited access borings at the University of Houston inside the main auditorium of the Hofheinz Pavilion. The concrete coring was through hard rock aggregate concrete found in the older structures in Houston.
Ray Meinhardt (right) and Bill Seymour set up the GeoTest 54LT for shallow sampling work inside an office building.  At 34.5-in. wide, the 54LT fits through most doorways.
The GeoTest team operates their 420M inside an historical building in San Antonio after a fire severly damaged the structure. The 420M was used in the building’s basement to obtain geotechnical samples as part of the structural design requirements for a new elevator shaft.

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