The Ring Shear apparatus tests an annular soil sample 5 mm thick with inner and outer diameters of 70 and 100 mm respectively and confine it radially between concentric rings.
It is compressed vertically between porous bronze loading platens by means of a counter balanced 10:1 ratio lever loading system. A rotation is imparted to the base plate and lower platen by means of a variable speed motor and gearbox driving through a worm drive.
This causes the sample to shear, forming a shear surface close to the upper platen, which is artificially roughened to prevent slip at the platensoil interface.
The settlement of the upper platen during consolidation or shear can be monitored by means of a sensitive dial gauge or linear transducer bearing on the top of the load hanger.
Torque transmitted through the sample is reacted by a pair of matched load measuring proving rings or load cells bearing on a cross arm.

The Ring Shear apparatus tests an annular soil sample 5 mm thick with inner and outer diameters of 70 and 100 mm respectively and confine it radially between concentric rings.
It is compressed vertically between porous bronze loading platens by means of a counter balanced 10:1 ratio lever loading system. A rotation is imparted to the base plate and lower platen by means of a variable speed motor and gearbox driving through a worm drive.
This causes the sample to shear, forming a shear surface close to the upper platen, which is artificially roughened to prevent slip at the platensoil interface.
The settlement of the upper platen during consolidation or shear can be monitored by means of a sensitive dial gauge or linear transducer bearing on the top of the load hanger.
Torque transmitted through the sample is reacted by a pair of matched load measuring proving rings or load cells bearing on a cross arm.