Development of the University College Dublin hollow cylinder apparatus

Abstract

The principal mechanical components, instrumentation and operation of a new hollow cylinder apparatus for generalised stress path testing of soil are presented. Using the apparatus, axial and torsional loads are applied to the ends of the hollow cylindrical specimen that is subjected to lateral confining pressures inside a pressure cell. The automated apparatus is capable of regulating the induced sample stresses to 0.5kPa during testing. Accurate measurement of the mechanical and pore pressure responses of the test specimen from the pseudo-elastic domain to sample failure is facilitated. Control programs continually regulate the induced stresses, based on the updated sample geometry, to accurately follow the prescribed stress paths. Proving test results are presented to demonstrate the capability of the new apparatus to accurately follow complex stress paths.