Tarantino, Angelo

Seismic Damaged Chinese RC Bridges Repaired and Retrofitted By Rapid Intervention To Improve Plastic Dissipation and Shear Strength

Abstract eng:
In this paper, Chinese rc (reinforced concrete) bridges piers damaged after a strong earthquake, were repaired and retrofitted by means of some innovative interventions which guarantee the proper plastic dissipation in plastic hinge only and the shear strength improvement according to capacity design criteria. In particular, the repair and retrofitting techniques proposed and tested with very good results during previous experimental researches on Italian [4] or Chinese bridges [5], which were designed without proper seismic details (i.e. very modest shear strength), are upgraded. The upgrades consist in: new shaped rebar parts to substitute the damaged rebar parts, new strong connection systems to connect the new rebar parts to the undamaged original rebar parts and new concrete jacket built by means of Ultra High performance concrete (UHPC) with fibers which replace the damaged concrete parts and can guarantee the necessary pier shear strength improvement. The new shaped rebar parts are designed to assure the plastic dissipation along the new rebar parts only. The rebar connection systems are realized by strong steel couplers and welding chords to simplify the connection in situ. The concrete jacket was built by UHPC considering different fiber contents (1, 2 or 3%). The experimental results about these materials confirm that a concrete jacket with fibers can provide the necessary shear strength according to CNR-DT 204/2006 formulations [21]. Some rc pier specimens (scale 1:6) were repaired and retrofitted by means of the proposed interventions with and without new stirrups in the repaired zone and external wrapping (CFRP or steel). Cyclic tests will be carried out on these scaled specimens at Fuzhou University SIBERC lab (China) to evaluate the effectiveness of the proposed technique. In particular, the experimental tests on the pier specimens repaired by using the UHPC jacket with fiber without new stirrups and external wrapping could confirm if the concrete jacket only can assure the necessary shear strength increment to obtain time and cost saving.

Contributors:

Huang, Yufan

Conference Title:

Proceedings of the 16th World Conference on Earthquake Engineering

Conference Title:

16th World Conference on Earthquake Engineering

Conference Venue:

Santiago (CL)

Conference Dates:

2017-01-09 / 2017-01-13

Rights:

Text je chráněný podle autorského zákona č. 121/2000 Sb.