A. Palermo
Department of Structural Engineering,
Technical University of Milan, Milan,
Italy
S. Pampanin and A. Amaris
Department of Civil Engineering, University of Canterbury,
Christchurch, New Zealand
Presented at New Zealand
Society for Earthquake Engineering Annual Conference (NZSEE06),
New Zealand,
2006.
Recent developments on high
performance seismic resisting precast concrete frame systems, based on the use
of unbonded post-tensioned tendons with selfcentring capabilities in
combination with additional sources of energy dissipation, are herein
presented. Alternative arrangements for jointed ductile connections to accommodate
different structural or architectural needs have been implemented and validated
through quasi-static cyclic tests on a series of 2/3 scaled beam-column
subassemblies under uni- or bi-directional loading regime. The satisfactory
results confirmed the unique flexibility and potentiality of the proposed
solutions for the development of the next generation of seismic resisting
buildings.
Several alternative solutions to
provide moment-resisting connections between precast elements for seismic
resistance have been studied in the past and developed in literature (Watanabe
et al 2000, Park 2002, fib Bulletin No. 27 2003) mostly relying on
cast-in-place techniques to provide equivalent “monolithic” connections (i.e.
equivalent strength and toughness to their cast-in-place counterparts). As
implicit in a traditionally accepted seismic design approach, based on the
development of a desired inelastic mechanism through the formation of plastic
hinge regions in the discrete and controlled locations within the structure
(i.e. weak beam, strong column mechanism), different levels of structural
damage and, consequently, repair cost, will be expected and, depending on the
seismic intensity, typically accepted as unavoidable results of the inelastic
behaviour itself.
In the last decade, a revolutionary
alternative approach in seismic design, has been introduced in the solutions
developed under the U.S. PRESSS (PREcast
Seismic Structural System) program coordinated by the University of
California, San Diego (Priestley 1991, Priestley 1996, Priestley et al. 1999)
for precast concrete buildings in seismic regions with the introduction of
“dry” jointed ductile systems, as an alternative to the traditional emulation
of cast-in-place solutions and based on the use of unbonded post-tensioning
techniques.
A comprehensive overview of
developments on high-performance seismic resisting
precast/prestressed systems based
on jointed ductile connections has been recently given by Pampanin (Pampanin,
2005).
References
Priestley MJN. (1991). “Overview of
the PRESSS Research Programme.” PCI Journal. 36(4), 50-57.
Priestley MJN, Sritharan S, Conley
JR, Pampanin S. (1999). “Preliminary Results and Conclusions from the PRESSS
Five-Storey Precast Concrete Test-Building.” PCI Journal, 44(6), 42-67.
Priestley MJN. (1996). “The PRESSS
Program Current Status and Proposed Plans for Phase III.” PCI Journal, 41(2),
22-40.
Stanton JF, Stone WC and Cheok GS. (1997). “A
Hybrid Reinforced Precast Frame for Seismic Region.” PCI Journal, 42 (2),
20-32.
ACI T1.1-01 & ACI T1.1R-01
2001. (2001). “Acceptance Criteria for Moment Frames Based on Structural
Testing (T1.1-01) and Commentary (T1.1R-01).” ACI Innovation Task Group 1 and
Collaborators.
Watanabe F. (2000). “Seismic Design
for Prefabricated and Prestressed Concrete Moment Resisting Frames.”
Proceedings of the 46th PCI Annual Convention, Orlando, Florida.
fib (2003), “International
Federation for Structural Concrete. Seismic Design of Precast Concrete Building
Structures.” Bulletin No. 27, Lausanne,
254 pp.
Pagani C. (2001). “Four is better
than two – The principle of cable-stayed bridges applied to building beams.”
Elite International Journal on the Art of Prefabrication, 4, 50-69.
SNZ (2005) DRAFT NZS3101:2005.
(2005). "Appendix B: Special Provisions for the Seismic Design of Ductile
Jointed Precast Concrete Structural Systems." Standards New Zealand, Wellington, New Zealand.
Pampanin S, Pagani C, Zambelli S.
(2004). “Cable-stayed and Suspended Post-tensioned Solutions for Precast
Concrete Frames:the Brooklyn System.” Proceedings of New
Zealand Concrete Industry Conference, Queenstown, New Zealand.
Pampanin S, Palermo A, Amaris A. (2006). “Implementation
and Testing of Advanced Solutions for Jointed Ductile Seismic Resisting
Frames.” Proceedings of the 2nd International fib Congress. Naples, Italy.
Pampanin S. (2005). “Emerging
Solutions for High Seismic Performance of Precast/Prestressed Concrete
Buildings.” Journal of Advanced Concrete Technology (ACT), invited paper for
Special Issue on “High performance systems”, 3(2), 202-223.
Park R. (2002). “Seismic Design and
Construction of Precast Concrete Buildings in New Zealand.” PCI Journal, 47(5),
60-75.
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