Simplified Predictive Expressions of Drift Limit States for Reinforced Concrete Circular Bridge Columns

2022 ◽  
Vol 148 (3) ◽  
Author(s):  
Saif Aldabagh ◽  
Faroque Hossain ◽  
M. Shahria Alam
2016 ◽  
Vol 32 (3) ◽  
pp. 1627-1652 ◽  
Author(s):  
Jason C. Goodnight ◽  
Mervyn J. Kowalsky ◽  
James M. Nau

Described in this paper are strain limit states for reinforced concrete bridge columns. A total of 30 large scale reinforced concrete bridge columns were subjected to either reversed cyclic loading or real seismic load histories as part of this research program. Through the use of a non-contact three-dimensional (3-D) position measurement system, accurate strain measurements that are not possible with conventional instrumentation were made, which allowed for development of strain limits for serviceability, spiral yielding, and reinforcing bar buckling limit states. The proposed bar buckling strain limit was compared to an existing drift-based approach and one formulated using finite element analysis for columns in the data set and the literature.


Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 295
Author(s):  
Amirhossein Orumiyehei ◽  
Timothy J. Sullivan

To strengthen the resilience of our built environment, a good understanding of seismic risk is required. Probabilistic performance-based assessment is able to rigorously compute seismic risk and the advent of numerical computer-based analyses has helped with this. However, it is still a challenging process and as such, this study presents a simplified probabilistic displacement-based assessment approach for reinforced concrete wall buildings. The proposed approach is trialed by applying the methodology to 4-, 8-, and 12-story case study buildings, and results are compared with those obtained via multi-stripe analyses, with allowance for uncertainty in demand and capacity, including some allowance for modeling uncertainty. The results indicate that the proposed approach enables practitioners to practically estimate the median intensity associated with exceeding a given mechanism and the annual probability of exceeding assessment limit states. Further research to extend the simplified approach to other structural systems is recommended. Moreover, the research highlights the need for more information on the uncertainty in our strength and deformation estimates, to improve the accuracy of risk assessment procedures.


2016 ◽  
Vol 691 ◽  
pp. 51-60 ◽  
Author(s):  
Martin Krizma ◽  
Lubomir Bolha

The issue of strengthening the damaged linear reinforced concrete elements have been engaged since 2008. We focused on the analysis of resistance and the characteristics of limit states of serviceability in the damaged and subsequently strengthened elements at a short-term loading. In the introduction phase, the strengthening of the elements was carried out with the following procedures – installation of an overlayer on the coupling board or a combination of the board and use of glass – fiber fabric (GFRP). The strengthening was also affected by the type of contact (reinforced/non-reinforced) – the deformed element/coupling board and its effect on resistance, type of deformation and serviceability. In the non-reinforced contact, we applied some of the types of adjustments to the surface of the strengthened element. At the moment, we are dealing with the effects of time and repeated load on the strengthened elements. The results correspond to the reinforced contact. The values are compared with the short-term results of the strengthened beams and with the long-term results of the beams prepared for strengthening.


2021 ◽  
Vol 93 (1) ◽  
pp. 16-25
Author(s):  
P.D. DEMINOV ◽  

The estimate of failure probability on the inclined section from the action of transverse forces, as well as the total probability of the limit States of reinforced concrete beams with probabilistic strength parameters lying on an elastic Foundation model V.Z. Vlasov-P.L. Pasternak, possessing stochastic properties. Probabilistic characteristics of the transverse force and its distribution density are constructed for a Foundation beam resting on an elastic base with two random characteristics, loaded with a quasi-stationary random load, taking into account the probabilistic nature of the strength properties of concrete and reinforcement. It is shown that if the spectral densities of the bed and load coefficients are fractional rational functions, the deflection correlation functions and, accordingly, the deflection variance are calculated using the residue theory.


2012 ◽  
Vol 268-270 ◽  
pp. 646-655
Author(s):  
Fabio de Angelis ◽  
Donato Cancellara

In the present work we discuss on the seismic vulnerability of reinforced concrete existing buildings. In particular we consider a reinforced concrete building originally designed for only gravitational loads and located in a zone recently defined at seismic risk. According to the Italian seismic code NTC 2008 a displacement based approach is adopted and the N2-method is considered for the nonlinear seismic analysis. In the analysis all the masonry infill panels in effective interaction with the structural frame are considered for the nonlinear modeling of the structure. The influence of the effective masonry infills on the seismic response of the structure is analyzed and it is discussed how the effect of the masonry infills irregularly located within the building can give rise to a worsening of the seismic performance of the structure. It is shown that in the present case a not uniform positioning of the masonry infills within the building can give rise to a fragile structural behavior in the collapse mechanism. Furthermore a comparative analysis is performed by considering both the structure with the effective masonry infills and the bare structural frame. For these two structures a pushover analysis is performed, the relative capacity curves are derived and it is shown that fragile collapse mechanisms can occur depending on the irregular positioning of the effective masonry infills. Accordingly it is discussed how in the present case a decoupling of the effective masonry infills from the structural frame can give rise to a smoother response of the capacity curves. For the examined case of an obsolete building with irregular positioning of the masonry panels, the choice of decoupling the effective masonry panels from the structural frame may facilitate the retrofitting strategies for the achievement of the proper safety factors at the examined limit states.


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