scholarly journals Floor Acceleration Demands in a Twelve-Storey RC Shear Wall Building

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 38
Author(s):  
Vladimir Vukobratović ◽  
Sergio Ruggieri
Keyword(s):  
Direct Determination ◽  
Shear Walls ◽  
Eurocode 8 ◽  
Structural Components ◽  
Linear Elastic ◽  
History Analysis ◽  
Response History Analysis ◽  
Rc Shear Wall ◽  
New Generation ◽  
Floor Acceleration

The seismic response of acceleration-sensitive non-structural components in buildings has attracted the attention of a significant number of researchers over the past decade. This paper provides the results which improve the state-of-knowledge of the influences that higher vibration modes of structures and nonlinearity of non-structural components have on floor acceleration demands. In order to study these influences, a response-history analysis of a code-designed twelve-storey reinforced concrete building consisting of uncoupled ductile cantilever shear walls was conducted. The obtained absolute floor accelerations were used as a seismic input for linear elastic and nonlinear non-structural components represented by simple single-degree-of-freedom systems, and the main observations and findings related to the studied influences along the building height are presented and discussed. Additionally, the accuracy of the method for the direct determination of peak floor accelerations and floor response (acceleration) spectra recently co-developed by the first author was once again investigated and validated. A brief summary of the method is provided in the paper, along with the main steps in its application. Being relatively simple and sufficiently accurate, the method (in its simplified form) has been recently incorporated into the draft of the new generation of Eurocode 8.

Compression failure of thin concrete walls during 2010 Chile earthquake: lessons for Canadian design practice

2013 ◽  
Vol 40 (8) ◽  
pp. 711-721 ◽  
Author(s):  
P. Adebar
Keyword(s):  
Axial Compression ◽  
Shear Walls ◽  
Concrete Wall ◽  
Element Analysis ◽  
Uniform Compression ◽  
Concrete Walls ◽  
Compression Strain ◽  
History Analysis ◽  
Chile Earthquake ◽  
Response History Analysis

Numerous thin concrete walls failed in compression during the 2010 Chile earthquake. Experiments on small wall elements indicate that thin concrete walls without tied vertical reinforcement may fail very suddenly at uniform compression strains as low as 0.001 due to the thin layer of concrete between two layers of reinforcement becoming unstable. A test on a wall subjected to axial compression and strong-axis bending demonstrated that unlike a tied column, a thin concrete wall can suddenly lose all axial load-carrying capacity. Nonlinear response history analysis of a typical Chilean high-rise shear wall building indicates small global drift demands and correspondingly small curvature and compression strain demands when subjected to the ground motions measured in Santiago, which explains why most buildings were not damaged. Nonlinear finite element analysis of a typical wall step-back irregularity indicates the increase in maximum compression strains due to a reduction in wall length is much larger than predicted by a sectional analysis. Based on all the results of the current study, a number of significant changes are proposed for the 2014 edition of CSA A23.3 to avoid compression failures of thin concrete walls, including limiting the axial compression force applied to thin bearing walls, accounting for unexpected strong-axis bending of thin bearing walls, and limiting the compression strain demands on thin concrete shear walls.

A subset of CyberShake ground-motion time series for response-history analysis

2021 ◽  
pp. 875529302098197
Author(s):  
Jack W Baker ◽  
Sanaz Rezaeian ◽  
Christine A Goulet ◽  
Nicolas Luco ◽  
Ganyu Teng
Keyword(s):  
Time Series ◽  
Los Angeles ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Motion Time ◽  
History Analysis ◽  
Response History Analysis ◽  
Simulated Ground Motions

This manuscript describes a subset of CyberShake numerically simulated ground motions that were selected and vetted for use in engineering response-history analyses. Ground motions were selected that have seismological properties and response spectra representative of conditions in the Los Angeles area, based on disaggregation of seismic hazard. Ground motions were selected from millions of available time series and were reviewed to confirm their suitability for response-history analysis. The processes used to select the time series, the characteristics of the resulting data, and the provided documentation are described in this article. The resulting data and documentation are available electronically.

Lateral Force Resisting Systems Made of Cold-Formed Steel Material: Proposal of Seismic Design Criteria for 2nd Generation of Eurocode 8

2021 ◽  
Vol 885 ◽  
pp. 127-132
Author(s):  
Sarmad Shakeel ◽  
Alessia Campiche
Keyword(s):  
Seismic Design ◽  
Shear Walls ◽  
Lateral Force ◽  
Background Information ◽  
Design Criteria ◽  
Eurocode 8 ◽  
Building Structures ◽  
Design Standards ◽  
Design Strength ◽  
Cold Formed Steel

The current edition of Eurocode 8 does not cover the design of the Cold-Formed steel (CFS) building structures under the seismic design condition. As part of the revision process of Euro-code 8 to reflect the outcomes of extensive research carried out in the past decade, University of Naples “Federico II” is involved in the validation of existing seismic design criteria and development of new rules for the design of CFS systems. In particular, different types of Lateral Force Resisting System (LFRS) are analyzed that can be listed in the second generation of Eurocode 8. The investigated LFRS’s include CFS strap braced walls and CFS shear walls with steel sheets, wood, or gypsum sheathing. This paper provides the background information on the research works and the reference design standards, already being used in some parts of the world, which formed the basis of design criteria for these LFRS systems. The design criteria for the LFRS-s common to CFS buildings would include rules necessary for ensuring the dissipative behavior, appropriate values of the behavior factor, guidelines to predict the design strength, geometrical and mechanical limitations.

scholarly journals Evaluation of a Modified MPA Procedure Assuming Higher Modes as Elastic to Estimate Seismic Demands

2004 ◽  
Vol 20 (3) ◽  
pp. 757-778 ◽  
Author(s):  
Anil K. Chopra ◽  
Rakesh K. Goel ◽  
Chatpan Chintanapakdee
Keyword(s):  
Structural Engineering ◽  
Pushover Analysis ◽  
Computational Effort ◽  
Attractive Alternative ◽  
Engineering Practice ◽  
Seismic Demands ◽  
History Analysis ◽  
Modes Of Vibration ◽  
Response History Analysis ◽  
Damped Systems

The modal pushover analysis (MPA) procedure, which includes the contributions of all significant modes of vibration, estimates seismic demands much more accurately than current pushover procedures used in structural engineering practice. Outlined in this paper is a modified MPA (MMPA) procedure wherein the response contributions of higher vibration modes are computed by assuming the building to be linearly elastic, thus reducing the computational effort. After outlining such a modified procedure, its accuracy is evaluated for a variety of frame buildings and ground motion ensembles. Although it is not necessarily more accurate than the MPA procedure, the MMPA procedure is an attractive alternative for practical application because it leads to a larger estimate of seismic demands, improving the accuracy of the MPA results in some cases (relative to nonlinear response history analysis) and increasing their conservatism in others. However, such conservatism is unacceptably large for lightly damped systems, with damping significantly less than 5%. Thus the MMPA procedure is not recommended for such systems.

scholarly journals Analisis Pengaruh Lokasi Dinding Geser Terhadap Pergeseran Lateral Bangunan Bertingkat Beton Bertulang 5 Lantai

2021 ◽  
Vol 4 (1) ◽  
pp. 16
Author(s):  
Leonardus Setia Budi Wibowo ◽  
Dermawan Zebua
Keyword(s):  
Lateral Displacement ◽  
Shear Walls ◽  
Seismic Loading ◽  
Shear Wall ◽  
Structural System ◽  
Earthquake Force ◽  
Earthquake Resistant ◽  
Story Drift ◽  
Frame System ◽  
Rc Shear Wall

Indonesia is one of the countries in the earthquake region. Therefore, it is necessary to build earthquake-resistant buildings to reduce the risk of material and life losses. Reinforced Concrete (RC) shear walls is one of effective structure element to resist earthquake forces. Applying RC shear wall can effectively reduce the displacement and story-drift of the structure. This research aims to study the effect of shear wall location in symmetric medium-rise building due to seismic loading. The symmetric medium rise-building is analyzed for earthquake force by considering two types of structural system. i.e. Frame system and Dual system. First model is open frame structural system and other three models are dual type structural system. The frame with shear walls at core and centrally placed at exterior frames showed significant reduction more than 80% lateral displacement at the top of structure.

scholarly journals Shear and Flexural Stiffnesses of Reinforced Concrete Shear Walls Subjected to Cyclic Loading

2014 ◽  
Vol 8 (1) ◽  
pp. 104-121 ◽  
Author(s):  
T. O. Tang ◽  
R. K.L. Su
Keyword(s):  
Seismic Analysis ◽  
Classical Mechanics ◽  
Shear Walls ◽  
Shear Stiffness ◽  
Eurocode 8 ◽  
Design Codes ◽  
Structural Walls ◽  
Load Distributions ◽  
Classical Models ◽  
Ductility Capacity

Seismic analyses of concrete structures under maximum-considered earthquakes require the use of reduced stiffness accounting for cracks and degraded materials. Structural walls, different to other flexural dominated components, are sensitive to both shear and flexural stiffness degradations. Adoption of the gross shear stiffness for walls in seismic analysis prevails particularly for the design codes in the US. Yet available experimental results indicate that this could overstate the shear stiffness by more than double, which would hamper the actual predictions of building periods and shear load distributions among columns and walls. In addition, the deformation capacity could be drastically understated if the stipulated constant ductility capacity is adopted. This paper reviews the available simplified shear and flexural models, which stem from classical mechanics, empirical formulations and/or parametric studies, suitable for structural walls at the state-of-the-art. Reviews on the recommended flexural and shear stiffnesses by prominent design codes such as ACI318-11, Eurocode 8 and CSA are included. A database comprised of walls subjected to reverse-cyclic loads is formed to evaluate the performance of each model. It is found that there exist classical models that could outweigh overconservative codified values with comparable simplicity for practical uses.

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