Modeling of a Multiply Jointed Voussoir Beam in the Centrifuge

Summary The mechanics and kinematics of a multiply jointed Voussoir beam have been studied based on the response of small scale beams tested in the centrifuge. The model beams were made up of six blocks, confined between fixed abutments. The tests included monitoring of beam deflection, development of axial thrust and distribution of strain within the beam. The models were subjected to accelerations of up to 90 g, depending upon the beam geometry. Two different beam geometries were considered. The test data were analysed in the light of pseudo analytical algorithms accepted in the analysis of singly jointed Voussoir beams. The data show that small translations and rotations of the block at the beam-abutment interface are required for a stable compression arch to set up in the beam. The computations and physical models indicate that the development of thrust is in linear proportion with the applied acceleration and is independent of beam thickness. The distribution of strains along the beam leads to the conclusion that the depth of the compression arch varies from the total beam thickness, to approximately one half of the beam thickness, under stable conditions. The data should be of considerable use to researchers looking to calibrate/validate numerical techniques used in describing the response of discontinuous rock masses.