A SIMPLE RING SHEAR APPARATUS

A simple, robust, inexpensive ring shear apparatus which has a fairly large potential through-put of tests has been developed. Tests on both remoulded and undisturbed samples can be made rapidly and the results are comparable with those obtained from much more sophisticated equipment. The use of the apparatus involves an annular soil sample 5mm thick with inner and outer diameters of 70mm and 100mm respectively confined radially between concentric rings. It is compressed vertically between porous bronze loading platens by means of a lever loading system and dead weights. Details of sample preparation are outlined. The prototype apparatus and developments from the prototype are described. Comments are made on the interpretation of results. The sources of error that can arise from the use of the apparatus are listed. Practical experience in the use of the apparatus is described and is compared with that of an earlier ring shear machine.