Seismic response of structural walls: recent developments

2001 ◽  
Vol 28 (6) ◽  
pp. 922-937 ◽  
Author(s):  
T Paulay
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Seismic Design ◽  
Limit State ◽  
Lateral Force ◽  
Structural Walls ◽  
Structural Class ◽  
Response Component ◽  
Displacement Ductility ◽  
Ductility Capacity

It is postulated that for purposes of seismic design, the ductile behaviour of lateral force-resisting wall components, elements, and indeed the entire system can be satisfactorily simulated by bilinear force–displacement modeling. This enables displacement relationships between the system and its constituent components at a particular limit state to be readily established. To this end, some widely used fallacies, relevant to the transition from the elastic to the plastic domain of behaviour, are exposed. A redefinition of stiffness and yield displacement allows more realistic predictions of the important feature of seismic response, component displacements, to be made. The concepts are rational, yet very simple. Their applications are interwoven with the designer's intentions. Contrary to current design practice, whereby a specific global displacement ductility capacity is prescribed for a particular structural class, the designer can determine the acceptable displacement demand to be imposed on the system. This should protect critical components against excessive displacements. Specific intended displacement demands and capacities of systems comprising reinforced concrete cantilever and coupled walls can be estimated.Key words: ductility, displacements, reinforced concrete, seismic design, stiffness, structural walls.

scholarly journals A review of code provisions for torsional seismic effects in buildings

1997 ◽  
Vol 30 (3) ◽  
pp. 252-263 ◽  
Author(s):  
T. Paulay
Keyword(s):  
Seismic Design ◽  
Limit State ◽  
Ultimate Limit State ◽  
Deformation Pattern ◽  
Displacement Ductility ◽  
Torsional Response ◽  
Yield Displacement ◽  
Design Requirements ◽  
Ductility Capacity ◽  
Ultimate Limit

A series of recent studies of the seismic torsional response of ductile buildings is condensed and extended to serve as a basis for recommendations for possible amendments of the relevant clauses of the current New Zealand loadings standard [1]. It is postulated that the primary seismic design aim, associated with criteria of the ultimate limit state, should address displacement ductility demands and supply, as affected by twisting of the system, rather than torsional strength. Some well-established parameters, such as yield displacement, element and system stiffness, are redefined to enable the inelastic deformation pattern of rigid diaphragms to be simply quantified. The presentation concludes with specific recommendations and corresponding commentaries in a form suitable, with editorial modifications, for possible adoption as codified design requirements. To illustrate both the relevance of the recommendations and their simplicity, two numerical examples, showing the evaluation of the displacement ductility capacity of a model structure, are appended.

New Seismic Design Specifications of Highway Bridges in Japan

1994 ◽  
Vol 10 (2) ◽  
pp. 333-356 ◽  
Author(s):  
Kazuhiko Kawashima ◽  
Kinji Hasegawa
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Response ◽  
Seismic Design ◽  
Structural Response ◽  
Highway Bridges ◽  
Lateral Force ◽  
Inertia Force ◽  
Response Analysis ◽  
Design Specifications ◽  
Recent Earthquakes

This paper presents the new seismic design specifications for highway bridges issued by the Ministry of Construction in February 1990. Revisions of the previous specifications were based on the damage characteristics of highway bridges that were developed after the recent earthquakes. The primary revised items include the seismic lateral force, evaluation of inertia force for design of substructures considering structural response, checking the bearing capacity of reinforced concrete piers for lateral load, and dynamic response analysis. Emphasis is placed on the background of the revisions introduced in the new seismic design specifications.

scholarly journals Investigating the effects of structural pounding on the seismic performance of adjacent RC and steel MRFs

2020 ◽  
Vol 19 (1) ◽  
pp. 317-343
Author(s):  
F. Kazemi ◽  
M. Miari ◽  
R. Jankowski
Keyword(s):  
Reinforced Concrete ◽  
Near Field ◽  
Limit State ◽  
Steel Structures ◽  
Lateral Force ◽  
Separation Distance ◽  
Natural Period ◽  
Performance Levels ◽  
Structural Pounding ◽  
Adjacent Structures

AbstractAn insufficient separation distance between adjacent buildings is the main reason for structural pounding during severe earthquakes. The lateral load resistance system, fundamental natural period, mass, and stiffness are important factors having the influence on collisions between two adjacent structures. In this study, 3-, 5- and 9-story adjacent reinforced concrete and steel moment resisting frames (MRFs) were considered to investigate the collision effects and to determine modification factors for new and already existing buildings. For this purpose, incremental dynamic analysis was used to assess the seismic limit state capacity of the structures using a developed algorithm in OpenSees software including two near-field record subsets suggested by FEMA-P695. The results of this paper can help engineers to approximately estimate the performance levels of MRFs due to pounding phenomenon. The results confirm that collisions can lead to the changes in performance levels, which are difficult to be considered during the design process. In addition, the results of the analyses illustrate that providing a fluid viscous damper between adjacent reinforced concrete and steel structures can be effective to eliminate the sudden changes in the lateral force during collision. This approach can be successfully used for retrofitting adjacent structures with insufficient in-between separation distances.

scholarly journals Simplified Data-Driven Model for the Moment Curvature of T-Shaped RC Shear Walls

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Wang ◽  
Wenzhe Cai ◽  
Qingxuan Shi
Keyword(s):  
Cross Sections ◽  
Limit State ◽  
Shear Walls ◽  
Load Ratio ◽  
Ultimate Limit State ◽  
Limit States ◽  
Displacement Ductility ◽  
And Performance ◽  
Displacement Based ◽  
Ductility Capacity

Sectional deformation quantities, such as curvature and ductility, are of prime significance in the displacement-based seismic design and performance evaluation of structural members. However, few studies on the estimates of curvatures at different limit states have been performed on asymmetric flanged walls. In this paper, a parametric study was performed for a series of T-shaped wall cross-sections based on moment-curvature analyses. By investigating the effects of the axial load ratio, reinforcement content, material properties, and geometric parameters on curvatures at the yield and ultimate limit state, we interpret the variation in curvature with different influencing factors in detail according to the changes of the neutral axis depth. Based on the regression analyses of the numerical results of 4941 T-shaped cross-sections, simple expressions to estimate the yield curvature and ultimate curvature for asymmetric flanged walls are developed, and simplified estimates of the ductility capacity including curvature ductility and displacement ductility are further deduced. By comparing with the experimental results, we verify the accuracy of the proposed formulas. Such simple expressions will be valuable for the determination of the displacement response of asymmetric flanged reinforced concrete walls.

scholarly journals Influence of Superior Vibration Modes on the Seismic Response of Reinforced Concrete Structures with Eigen-Periods Near Code Control Periods

2020 ◽  
Vol 9 (1) ◽  
pp. 108-122
Author(s):  
Savu Adrian-Alexandru
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Seismic Design ◽  
Structural Design ◽  
Control Period ◽  
Three Dimensional ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Base Shear ◽  
Seismic Design Code

Abstract The current paper studies the effect of superior eigen-modes on the seismic response for a series of reinforced concrete structures having eigen-periods near code control periods. Although the structural design is based on Romanian seismic design codes (“P100-1/2013 - Seismic design code - Part 1 - Design provisions for buildings” and “SR-EN 1998/2004 - Design of structures for earthquake resistance”), it carries some importance for other countries with similar seismic design spectra. A total of twenty-four models for structures were considered by varying their location (through control period values), three-dimensional regularity, overall dimensions and height regime. Results were compared and conclusions were drawn based on percentage values of relative displacements (storey drifts) and base shear forces.

scholarly journals Aspects of drift and ductility capacity of rectangular cantilever structural walls

1998 ◽  
Vol 31 (2) ◽  
pp. 73-85 ◽  
Author(s):  
M. J. N. Priestley ◽  
M. J. Kowalsky
Keyword(s):  
Damage Control ◽  
Shear Walls ◽  
Load Ratio ◽  
Longitudinal Reinforcement ◽  
Structural Walls ◽  
Displacement Ductility ◽  
Drift Capacity ◽  
Aspect Ratios ◽  
Axial Load Ratio ◽  
Ductility Capacity

Moment-curvature analyses of cantilever shear walls are used to show that yield curvature, serviceability curvature, and ultimate (damage-control) curvature are insensitive to variations of axial load ratio, longitudinal reinforcement ratio, and distribution of longitudinal reinforcement. The results are used to determine available displacement ductility factors for walls of different aspect ratios and drift limits. It is shown that drift capacity will generally exceed code levels of permissible drift, and that code drift limits will normally restrict, sometimes severely, the design displacement ductility factor.

Seismic design and assessment of risk-targeted reduction factor for a reinforced concrete pipe rack – piping system

2020 ◽  
Author(s):  
George Karagiannakis
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Structural Parameters ◽  
Limit State ◽  
Input Parameter ◽  
Reduction Factor ◽  
Eurocode 8 ◽  
Piping System ◽  
Seismic Action ◽  
Concrete Pipe

The procedure for estimating a target risk for adverse consequences of earthquakes should be developed in close cooperation with stakeholders and decision-makers who understand the high impact of the potential failure of industrial facilities on society and business state. However, the conventional procedures for earthquake-resistant design of critical infrastructures are not developed to such a level that would make it possible to use a target risk as an input parameter for designing the structures. This issue can be overcome by introducing the risk-based formulation for the evaluation of seismic design action for force-based design. In such an approach, the reduction factor depends on a target probability of exceedance of a designated limit state and takes into account the ground-motion randomness and uncertainty. In general, the formulation of the risk-targeted reduction factor depends on the code format for the reduction of seismic action. In this paper, the Eurocode’s format of force-based design is used. Therefore, the reduction of seismic action is accounted for by the behaviour factor.Several structural parameters have to be assumed in order to estimate the risk-targeted behaviour as discussed in the paper. In virtue of poor knowledge concerning the nonlinear response of pipe rack – piping systems, it is very challenging to appropriately assume these parameters. Thus, a reinforced concrete pipe rack, which represents a part of a liquified natural gas terminal, was firstly modelled and designed according to Eurocode 8 accounting for the low and high probability of earthquake recurrence aimed at designing the system for damage and life safety objective, respectively. The pipe rack, the piping system and the interaction of the pipe rack – piping system with the adjacent storage tank were explicitly considered in the 3D model, which provided full dynamic coupling of the three components of the analysed system.The seismic performance assessment of the pipe rack and piping system was performed by the incremental dynamic analysis using a set of 11 spectrum compatible ground motions. Based on the results of IDA analysis, the design of pipe rack was evaluated on the safe side, however, the pipelines presented higher vulnerability due to a number of assumptions that are discussed. For the presented example, it was shown that the behaviour factor for the design of the pipe rack – piping system is controlled by the performance of the pipes and not the structure supporting the pipes.

Investigating Influencing Factors on the Ductility Capacity of a Fixed-Head Reinforced Concrete Pile in Homogeneous Clay

2012 ◽  
Vol 28 (3) ◽  
pp. 489-498 ◽  
Author(s):  
J.-S. Chiou ◽  
Y.-C. Tsai ◽  
C.-H. Chen
Keyword(s):  
Reinforced Concrete ◽  
Tensile Force ◽  
Plastic Region ◽  
Quantitative Relationship ◽  
Model Parameters ◽  
Strength Ratio ◽  
Head Region ◽  
Displacement Ductility ◽  
Concrete Pile ◽  
Ductility Capacity

AbstractThis study performs parametric analyses on the displacement ductility capacity of a fixed-head reinforced concrete pile in homogeneous clay, considering the spread of plasticity in the pile. The parametric study regards the pile as a limited ductility structure, which conditionally allows the pile to have inelastic response during large loading. The variables considered include the pile section parameters and p-y model parameters. A large number of pushover analyses are conducted to examine the displacement ductility capacity of the pile. The results show that the plastic hinging will occur at the pile head region for a fixed-head pile, and the displacement ductility capacity of the pile is mainly influenced by the over-strength ratio of the pile section. Furthermore, the second plastic region may occur in ground when the axial force is in high tension. Based on the design concept of limited ductility structures, the high tensile force in pile should be avoided in pile design. A quantitative relationship between the displacement ductility capacity and over-strength ratio is suggested for engineering applications.

Displacement-based seismic design of regular reinforced concrete shear wall buildings

2011 ◽  
Vol 38 (6) ◽  
pp. 616-626 ◽  
Author(s):  
JagMohan Humar ◽  
Farrokh Fazileh ◽  
Mohammad Ghorbanie-Asl ◽  
Freddy E. Pina
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Pushover Analysis ◽  
Shear Wall ◽  
Base Shear ◽  
Ductility Demand ◽  
Inelastic Demand ◽  
Displacement Based ◽  
Ductility Capacity ◽  
Shear Demand

A displacement based method for the seismic design of reinforced concrete shear wall buildings of regular shape is presented. For preliminary design, approximate estimates of the yield and ultimate displacements are obtained, the former from simple empirical relations, and the latter to keep the ductility demand within ductility capacity and to limit the maximum storey drift to that specified by the codes. For a multi-storey building, the structure is converted to an equivalent single-degree-of-freedom system using an assumed deformation shape that is representative of the first mode. The required base shear strength of the system is determined from the inelastic demand spectrum corresponding to the ductility demand. In subsequent iterations a pushover analysis for the force distribution based on the first mode is used to obtain better estimates of yield and ultimate displacements taking into account stability under P–Δ effect. A multi-mode pushover analysis is carried out to find more accurate estimates of the shear demand.

scholarly journals Model of seismic design lateral force levels for the existing reinforced concrete European building stock

2021 ◽  
Vol 19 (7) ◽  
pp. 2839-2865
Author(s):  
Helen Crowley ◽  
Venetia Despotaki ◽  
Vitor Silva ◽  
Jamal Dabbeek ◽  
Xavier Romão ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Lateral Force ◽  
Building Stock
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