BIDIRECTIONAL PSEUDODYNAMIC TECHNIQUE FOR TESTING A THREE-STOREY REINFORCED CONCRETE BUILDING

Within the project SPEAR, a full-size three-storey non-symmetric RC building has been seismically tested at the ELSA laboratory by means of the PsD method. Since the induced torsion was one of the major concerns about the response of this structure, the tests included bidirectional excitation and allowed for three in-plane DoFs per floor: two displacements plus one rotation. The equation of motion is formulated and integrated in generalised DoFs, which are those displacements and rotation defined at the CM of each floor. At every step of integration the experimental restoring forces are statically transformed into generalised forces and, once the new generalised displacements are computed, the target displacement for the transducers on the structure are obtained by a cinematic transformation. The implemented PsD technique allows for the use of more than three actuators per floor in order improve the load distribution and avoid possible saturation of the actuators. The first series of test on the un-retrofitted structure was successfully performed giving most profitable information about the seismic behaviour of such structure