STATIC AND DYNAMIC PROPERTIES OF THE SHAKING TABLE RECENTLY BUILT AT THE EUCENTRE, PAVIA

This paper reports on the first test performed in order to characterize the static and dynamic properties of the shaking table facility recently built at the at the EUCENTRE (European Center for Training and Research in Earthquake Engineering) in Pavia, Italy. The shaking table (characterized by a single degree of freedom) is hydraulically powered through a single actuator, and is characterized by a rectangular platten of about 6.8 by 3.5 meters in plan. The total dynamic stroke of the actuator is equal to 1000 mm ( +/- 500 mm), the maximum table velocity is 1.80 m/sec (for bare table condition) and the maximum table acceleration (for bare table conditions) is about 5.0 g. The table shows an innovative design which is characterized by hydraulic cushions (sized for 85 t of total mass: table + specimen) capable of providing both vertical support and clamping against overturning and jaw motion. The test performed allowed to characterize and verify: (a) the effective horizontal mass of the table platten, (b) the forces necessary to move the table when no inertia effects are to be accounted for (frictional and dissipative forces), and (c) the maximum performances (maximum displacement, velocity and acceleration) obtained for the table. The results experimentally obtained are compared with the theoretical predictions and show a good agreement.