Rock Shear Box Apparatus

The apparatus consists of a shear box designed to accept samples not larger than 115x125 mm, or alternatively cores up to 102 mm dia. The shear box consists of two halves, the upper being connected to two rams for reversible shearing action and the lower connected to a ram for normal load application. It is a simple and practical method of determining the strength and slope stability of rock, both in the field and in the laboratory. The normal loading system is complete with an adjustable low friction pressure maintainer to absorb volume changes of the specimen during the shearing action and to ensure a constant vertical stress. The loads are recorded by Bourdon tube load gauges or by pressure transducers (in this case external datalogger is needed).

Two versions are available:

Electronic model. The pump for vertical load is fitted with a pressure maintainer to assure uniform load during the test. It is supplied complete with; 5 potentiometric transducers with 25mm travel (4 vertical and 1 horizontal); 2 mould formers; 2 hand operated pumps for lateral and vertical load fitted with Bourdon gauges; 2 pressure transducers for the direct acquisition of the load values.

Basic model. The pump for vertical load is fitted with a pressure maintainer to assure uniform load during the test. It is supplied complete with: 5 digital gauges 25x0.001 mm (4 vertical and 1 horizontal); 2 mould formers; 2 hand operated pumps for lateral and vertical load fitted with Bourdon gauges.

Technical Specifications:

Max. axial and shear load capacity (for both models): 50 kN

Displacement reading (for Electronic model): 5 potentiometric transducers with 25mm travel 

Manometers range (for both models): 50 kN x 1 kN

Displacement reading (for Basic model): 5 digital gauges 25x0.001 mm 

Max. sample dimensions: up to dia. 102 mm (for core specimens) and 115 mm x 125 mm (for prism specimens)

Overall dimensions (loading frame only): 460x250x600 mm

Weight approx.: 45 kg.