GEO-Instruments Products

The bonded strain gauge load cell comprises a set of up to eight strain gauge rosettes mounted parallel and perpendicular to the cell axis and equally spaced in a ring around the steel alloy cylindrical housing. This method of construction results in a very robust instrument suitable for use where high performance, longevity and mechanical strength are important. All cells are manufactured with a center hole to accommodate rock-bolts, tendons or anchor cables. For use as a solid center cell the instrument can be supplied with top and bottom bearing a heavy gauge multicore, PVC sheathed cable connects the load cell to the read-out unit. Bonded SG load cells are used on support of excavation applications, and provide an excellent choice when an intrinsically temperature corrected, robust waterproof load measurement in harsh environments is needed.

Vibrating Wire Load Cells are ideally suited for measuring loads in rock bolts, cable anchors and tendons, structural beams, piles, loads between tunnel supports and loads in pull-out tests on trial anchors. Vibrating Wire Load Cell consists of a high strength steel alloy cylindrical housing with three to six vibrating wire gauges for measuring the compression of the cylinder under load. The readings of all gauges are averaged thus minimizing the detrimental effects of eccentric or uneven loading. Furthermore, the cells are fitted with thermistors for correcting the effects of temperature variations on load readings.

Strain Gauge Load Cells are ideally suited for measuring loads in rock bolts, cable anchors and tendons, structural beams, piles, loads between tunnel supports and loads in pull-out tests on trial anchors. The Strain Gauge Load Cell consists of a stainless steel cylindrical housing with up to sixteen resistance strain gauges to minimise the sensitivity to eccentric loading. When the cell is subjected to load the strain gauges will change their resistance value. The load cell output signal is directly proportional to the applied load.

Vibrating Wire Pressure Cells measure total stresses in soils and is a combination of effective stress and pore-water pressures. They are normally used to validate design assumptions and to give adequate warning of soil pressures in excess of those designed to be exerted by a structure. VW Pressure Cells are installed within fills to determine the distribution, magnitude and directions of total stresses. They can also be installed with one surface against a structure to measure total stresses acting on retaining walls, against piles, pipes, and slurry trench walls.

The Vibrating Wire Push-In Pressure Cell is normally installed in vertical boreholes and measures total horizontal stresses. They are often installed in stiff clay behind and in front of retaining walls, in soft puddle clay cores of old embankment dams and in glacial till adjacent to sea cliffs. The cells can also be installed in horizontally drilled boreholes for example from tunnels and cliff faces. In these situations both horizontal and vertical stresses can be measured by the appropriate orientation of a number of cells. The cells may be used as a site investigation tool to measure the in situ stresses in the ground prior to any disturbance.

The Vibrating Wire Concrete Stress Cell is used for measuring total stresses in tunneling process, mass concreting and rock walls in underground works. The cell is installed either prior to shotcreting, concrete pour or within a slotted hole in the rock and incorporates a repressurization tube to enable the cell face to be placed into intimate contact with the concrete should shrinkage occur during hydration, or with the rock face to take account of the slight overslotting needed to fit the cell in rock.