Performance-Based Evaluation of Reinforced Concrete Building Exterior Joints for Seismic Excitation

2002 ◽  
Vol 18 (3) ◽  
pp. 449-480 ◽  
Author(s):  
Chris P. Pantelides ◽  
Chandra Clyde ◽  
Lawrence D. Reaveley
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Load Reduction ◽  
Limit States ◽  
Joint Shear Strength ◽  
Seismic Rehabilitation ◽  
Specific Performance ◽  
Concrete Building ◽  
Current Design ◽  
Performance Based Evaluation

Beam-column joints of nonductile reinforced concrete buildings that were built prior to the current seismic code provisions have been investigated using several performance-based criteria. Four half-scale reinforced concrete exterior joints were tested to investigate their behavior in a shear-critical failure mode. The joints were subjected to quasi-static cyclic loading, and their performance was examined in terms of lateral load capacity, drift ratio, axial load reduction in the column at high drift ratios, joint shear strength, ductility, shear deformation angle of the joint, and residual strength. Two levels of axial compressive column load were investigated to determine how this variable might influence the performance of the joint. Specific performance levels for this type of reinforced concrete joint were established and a comparison was made to current design and rehabilitation standards. A limit states model was established, which could be used for performance evaluation or seismic rehabilitation.

scholarly journals Jacketing of existing reinforced concrete structures with composites in view of seismic rehabilitation

2018 ◽  
Vol 191 ◽  
pp. 00006
Author(s):  
Siham Bouras ◽  
Abdellatif Khamlichi ◽  
Sabri Attajkani
Keyword(s):  
Reinforced Concrete ◽  
Pushover Analysis ◽  
Nonlinear Static Analysis ◽  
Initial State ◽  
Seismic Rehabilitation ◽  
Lateral Resistance ◽  
Concrete Building ◽  
Nonlinear Static ◽  
Static Pushover Analysis

Seismic rehabilitation of pre-code existing buildings requires the choice of the method of strengthening and the determination of the amount of materials to be used optimally. Accurate evaluation of the building response in terms of its capacity at the initial state and that obtained after application of some reinforcement should be performed. For regular buildings, the nonlinear static analysis procedure constitutes a powerful tool that is used to estimate seismic performance. This procedure is characterised by its high effectiveness to account for the non-linear characteristics of the materials involved and provides a direct mean to shape the capacity curve of the construction; enabling then to make the correct decision about rehabilitation task with regards to a desired performance state. In this work, the nonlinear static pushover analysis was performed by means of ZeusNL software. Use was made of the Moroccan seismic regulations RPS2000 version 2011to determine the targeted seismic demand. Considering a four floor reinforced concrete building which is undersized with regards to actual seismic regulation, jacketing with fiber reinforced composites at different reinforcement rates was analyzed. The obtained results were expressed in terms of the lateral resistance capacity and the building tip displacement. Optimal jacketing of columns was then determined.

Implications of Experiments on the Seismic Behavior of Gravity Load Designed RC Beam-to-Column Connections

1996 ◽  
Vol 12 (2) ◽  
pp. 185-198 ◽  
Author(s):  
Attila Beres ◽  
Stephen P. Pessiki ◽  
Richard N. White ◽  
Peter Gergely
Keyword(s):  
Reinforced Concrete ◽  
Seismic Behavior ◽  
Test Results ◽  
Joint Shear Strength ◽  
Cornell University ◽  
Gravity Load ◽  
Concrete Building ◽  
Load Effects ◽  
Definition Of ◽  
Reversed Cyclic

This paper summarizes recent experimental research at Cornell University conducted on the behavior of gravity load designed reinforced concrete building frame components subjected to reversing cyclic loads (simulated seismic effects). Reinforced concrete framing systems, designed primarily for gravity loads, with little or no attention given to lateral load effects, are typically characterized by non-ductile reinforcing details in the joint regions and in the members. The seismic response of connection regions for gravity load design (GLD) frames has received relatively little attention in earlier studies, thus making it difficult to reliably evaluate GLD frames and to properly plan repair or retrofit strategies. Thirty-four full scale bare interior and exterior beam-to-column joints have been tested under reversed cyclic bending to identify the different damage mechanisms and to study the effect of critical details on strength and deformations. The discussion of test results focuses on the definition of joint shear strength factors for GLD frames to complement those provided by ACI-ASCE Committee 352 for frames designed with better details.

scholarly journals Flexibility modeling of reinforced concrete concentric frame joints

2013 ◽  
Vol 6 (3) ◽  
pp. 360-374 ◽  
Author(s):  
S. J. P. J. Marques Filho ◽  
B. Horowitz
Keyword(s):  
Reinforced Concrete ◽  
Lateral Displacement ◽  
Shear Stresses ◽  
Building Structures ◽  
Concrete Frames ◽  
Limit States ◽  
Joint Flexibility ◽  
Proposed Model ◽  
Concrete Building ◽  
Ultimate Limit

The intersections between beams and columns in a reinforced concrete building structure are called frame joints. It is a region with significant bending stiffness but subjected to large shear stresses. Appropriate modeling of the flexibility of reinforced concrete frames is essential to its design, in service limit states as well as in ultimate limit states. It has been shown, theoretically as well as experimentally, that the influence of joint flexibility may account for 20% of total structural lateral displacement. Models using only bar elements and rotational springs are proposed to consider the joint flexibility in linear analyses of building structures. In order to validate the proposed model, comparisons with experimental results found in the literature are made. Finally, the results of second order analyses using the proposed model are compared with those obtained by finite elements.

Experimental and analytical investigations of reinforced concrete beam-column joints retrofitted by single haunch

2020 ◽  
Vol 23 (15) ◽  
pp. 3171-3184
Author(s):  
Ebrahim Emami ◽  
Ali Kheyroddin ◽  
Mohhamad Kazem Sharbatdar
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Peak Load ◽  
Vulnerability Index ◽  
Reinforced Concrete Beam ◽  
Stiffness Ratio ◽  
Limit States ◽  
Joint Shear Strength ◽  
Analytical Results ◽  
Joint Shear

Recently, the single haunch with specifications such as less invasive and architectural consistency, and easy to practice have been adopted as one of the considered retrofitting options for deficient reinforced concrete beam-column joints. In this article, by analytical evaluation, the influence parameters such as haunch to beam stiffness ratio, haunch inclination angles, and mounted position were investigated. Analytical equations were also proposed for haunch to beam stiffness ratio in terms of both shear interaction between haunch and beam-column members and reduction of joint shear demand. Moreover, five exterior beam-column joint sub-assemblies were fabricated afterwards four of those retrofitted by various cross-sectional area of single steel haunch. Then, all of these beam-column joints and remaining one (as-built joint) were experimentally subjected to cyclic loading. To validate the analytical results, the experimental responses in four limit states including first diagonal core crack in as-built joint, drift ratio 2%, the first diagonal core crack in all the joints, and ultimate state (peak load) were provided for comparison. Also, by definition of an index as vulnerability index in fraction ratio of available joint shear force to joint shear strength predicted by international codes, the obtained vulnerability index of experimental responses were compared to analytical results.

scholarly journals Seismic Performance Assessment of a Moment-Frame Reinforced Concrete Building Typology

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Marsed Leti
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Analysis ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Seismic Performance Assessment ◽  
Moment Frame ◽  
Limit States ◽  
Reinforced Concrete Building ◽  
Concrete Building ◽  
Building Typology

This study covers the application of Static and Dynamic nonlinear analysis to an old moment-frame reinforced concrete building. The case study selected is a template one designed in 1982 without shear walls and built throughout Albanian region in the communism era using old standards (KTP 2-78). For the capacity calculation, Pushover analysis is performed using an inverse triangular load pattern. The demand calculation is conducted using Incremental Dynamic Analysis (IDA) as a method which provides the response behavior of the structure from the elastic range until collapse. For the dynamic analysis is used a set of 18 earthquakes with no marks of directivity. Limit states are defined for both Pushover and IDA based on the FEMA 356 guidelines. The mathematical model is prepared in the environment of Zeus-NL, a software developed especially for earthquake applications. The parameters defined for the IDA analysis are 5% damped first mode spectral acceleration (Sa(T1,5%)) for the intensity measure (IM) and maximum global drift ratio (ϴmax) for the damage measure (DM). In addition, limit states are selected for the pushover curve as Immediate Occupancy (IO), Life Safety (LS) and Collapse Prevention (CP). Similarly, for the IDA curve the limit states are selected as IO, CP and Global Instability (GI) based on FEMA guidelines. Furthermore, IDA curves are summarized into 16%, 50% and 84% fractiles as suggested in the literature. Additionally, a comparison between Pushover and IDA median (50% fractile) is shown from the same graph to illustrate the correlations between performance levels. Finally, structural performance is interpreted based on the outcomes.

The Live Load Capacity of Rectangular Precast Reinforced Concrete Stick Plates

2018 ◽  
Vol 9 (5) ◽  
pp. 174
Author(s):  
Agus Maryoto ◽  
Han Ay Lie ◽  
Nanang Gunawan Wariyatno
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Live Load

scholarly journals Displacement-Based Seismic Assessment of the Likelihood of Failure of Reinforced Concrete Wall Buildings

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 295
Author(s):  
Amirhossein Orumiyehei ◽  
Timothy J. Sullivan
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Concrete Wall ◽  
Limit States ◽  
Simplified Approach ◽  
Performance Based Assessment ◽  
Assessment Approach ◽  
Reinforced Concrete Wall ◽  
Displacement Based ◽  
Assessment Procedures

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.

scholarly journals Finite element analysis of reinforced concrete deep beam with large opening

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elsayed Ismail ◽  
Mohamed S. Issa ◽  
Khaled Elbadry
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
The Other ◽  
Deep Beam ◽  
Web Openings ◽  
Design Load ◽  
Large Opening

Abstract Background A series of nonlinear finite element (FE) analyses was performed to evaluate the different design approaches available in the literature for design of reinforced concrete deep beam with large opening. Three finite element models were developed and analyzed using the computer software ATENA. The three FE models of the deep beams were made for details based on three different design approaches: (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978), (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006), and Strut and Tie method (STM) as per ACI 318-14 (ACI318 Committee, Building Code Requirements for Structural Concrete (ACI318-14), 2014). Results from the FE analyses were compared with the three approaches to evaluate the effect of different reinforcement details on the structural behavior of transfer deep beam with large opening. Results The service load deflection is the same for the three models. The stiffnesses of the designs of (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and STM reduce at a load higher than the ultimate design load while the (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) reduces stiffness at a load close to the ultimate design load. The deep beam designed according to (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) model starts cracking at load higher than the beam designed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) method. The deep beam detailed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) and (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) failed due to extensive shear cracks. The specimen detailed according to STM restores its capacity after initial failure. The three models satisfy the deflection limit. Conclusion It is found that the three design approaches give sufficient ultimate load capacity. The amount of reinforcement given by both (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) is the same. The reinforcement used by the STM method is higher than the other two methods. Additional reinforcement is needed to limit the crack widths. (Mansur, M. A., Design of reinforced concrete beams with web openings, (2006)) method gives lesser steel reinforcement requirement and higher failure load compared to the other two methods.

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