Shaking table tests of a reinforced concrete waffle-flat plate structure designed following modern codes: seismic performance and damage evaluation

2015 ◽  
Vol 45 (2) ◽  
pp. 315-336 ◽  
Author(s):  
Amadeo Benavent-Climent ◽  
Jesús Donaire-Avila ◽  
Elena Oliver-Saiz
2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Zhenying Wang ◽  
Chenxi Mao ◽  
Lili Xie

This paper presents an experimental study on the seismic performance of a bidirectional self-centering reinforced concrete (RC) frame structure. In the structure, the column-base joints, which were installed with external mild steel (MS) dampers, could uplift freely and the beam-column joints could open effectively under earthquake excitations. Angle steels and MS dampers were installed at the beam-column joints in the structural X and Y directions, respectively. During the gap opening of the joints, unbonded posttensioned (PT) steel wires, which passed through the plastic ducts inserted in the RC beams and columns, provided the structure with the ability to return to pre-earthquake positions, and the yielding MS dampers and angle steels dissipated the seismic energy. A 1/2-scale two-story model structure was designed and constructed. Shaking table tests were performed on the structure under four different types of earthquake excitations with increasing seismic hazard levels. The test results indicated that the self-centering RC frames installed in both the directions showed satisfactory seismic performance, with only slight damage to the main structure after extreme earthquakes. The natural frequencies of the self-centering frames installed in both the directions degraded progressively, mainly because of the prestress loss of the PT steel wires and the yielding of the MS dampers. The structure showed desirable self-centering ability with very small residual deformation under ground motions of all hazard levels. The structural deformation was mainly concentrated at the column-base and beam-column joints, and hence, damage to the concrete beams and columns was considerably alleviated. In addition, the residual gap opening of the joints was minimal.


2021 ◽  
Vol 1 (2) ◽  

The need to satisfy high seismic performance of structures and to comply with the latest worldwide policies of environmental sustainability is leading engineers and researchers to higher interest in timber buildings. A post-tensioned timber frame specimen was tested at the structural laboratory of the University of Basilicata in Italy, in three different configurations: i) without dissipation (post-tensioning only-F configuration); ii) with dissipative angles (DF- dissipative rocking configuration) and iii) with dissipative bracing systems (BF - braced frame configuration). The shaking table tests were performed considering a set of spectra-compatible seismic inputs at different seismic intensities. This paper describes the experimental estimation of energy dissipated by multistorey post-tensioned timber prototype frame with different anti-seismic hysteretic dissipative devices used in the DF and BF testing configurations. The main experimental seismic key parameters have also been investigated in all testing configurations.


2018 ◽  
Vol 12 (1) ◽  
pp. 9-33
Author(s):  
Nicholas Kyriakides ◽  
Ahmad Sohaib ◽  
Kypros Pilakoutas ◽  
Kyriakos Neocleous ◽  
Christis Chrysostomou ◽  
...  

Background: Reinforced Concrete (RC) buildings with no seismic design exhibit degrading behaviour under severe seismic loading due to non-ductile brittle failure modes. The seismic performance of such substandard structures can be predicted using existing capacity demand diagram methods through the idealization of the non-linear capacity curve of the degrading system, and its comparison with a reduced earthquake demand spectrum. Objective: Modern non-linear static methods for derivation of capacity curves incorporate idealization assumptions that are too simplistic and do not apply for sub-standard buildings. The conventional idealisation procedures cannot maintain the true strength degradation behaviour of such structures in the post-peak part, and thus may lead to significant errors in seismic performance prediction especially in the cases of brittle failure modes dominating the response. Method: In order to increase the accuracy of the prediction, an alternative idealisation procedure using equivalent elastic perfectly plastic systems is proposed herein that can be used in conjunction with any capacity demand diagram method. Results: Moreover, the performance of this improved equivalent linearization procedure in predicting the response of an RC frame is assessed herein. Conclusion: This improved idealization procedure has been proven to reduce the error in the seismic performance prediction as compared to seismic shaking table test results [1] and will be further investigated probabilistically herein.


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