C V R Murty

The paper reviews seismic behaviour and performance of reinforced concrete (RC) deep vertical members, particularly bridge piers and structural walls. The provisions of the relevant Indian codes of practice, concerning shear strength and shear demand in these members, are reviewed in light of the provisions of international codes of practice. The deficiencies are identified in the seismic shear design philosophy, prescribed by Indian codes.

This paper presents an externally reinforced I-beam-to-box-column seismic connection. An inclined rib-plated collar-plated configuration with web plates is used to ensure planar continuity between I-beam and box-column webs; the rib plates, inclined in plan between the beam web and the two column web planes, along with collar-plates encircling the box-column at beam flange levels and web plates in plane with the rib plates at the beam web level constitute the new configuration. This connection configuration relieves stresses on box-column flanges and helps in force transfer to the box-column webs. Performance evaluation of the proposed connection configuration shows that sufficient inelasticity is mobilized in the beam away from the column face with connection elements and welds remaining elastic. The seismic performance of the proposed connection is also found to be better than two state-of-the-art connection schemes in terms of higher strength, stiffness, and higher reserve strength of the welds under cyclic displacement loading. © 2010 ASCE.

Based on the review of seismic shear design provisions of Indian codes for reinforced concrete (RC) deep vertical members (i.e., bridge piers and structural walls) in a companion paper, basic provisions are identified for shear resistance of RC sections. Draft provisions are presented for the consideration of the relevant Indian design code committees on bridge and building. The best seismic design practices seem to suggest that these provisions will be beneficial for the seismic performance of deep RC vertical members.