Assessment of the seismic design of precast frames with pinned connections from shaking table tests

摘要

The research reported in this paper concerns the experimental investigation of the seismic performance of single-storey frames with pinned beam—column connections for the assessment of current design procedures. The examined frames were made of various types of columns: flexible and weak (under-reinforced), in which large rotations were induced at the joints; flexible and strong (over-reinforced), in which significant rotations and shear forces were induced at the joints; stiff and strong (over-reinforced), in which small rotations and large shear forces were induced at the joints; and flexible and normally reinforced designed according to Eurocodes 2 and 8. The base motions were applied in the plane of the frame and were piece-wise increasing up to the point that significant damage was observed, either at the beam—column connection or at the column’s base. The results are compared with those of connections of the same geometry subjected to pure shear, cyclic loading. This comparison shows similar behaviour, with small differences in the attained shear resistance and, generally, less damage occurring in the dynamic tests than in the cyclic ones. It was proved that pinned connections can accommodate large rotations, more than 0.10 rad, without significant loss of their strength; however, if they are damaged, large joint rotations and the repetition of the ground shaking might increase the damage. Also, it was found that the vertical component of the earthquake does not seem to be important.