Spectral matching RotD100 target spectra: Effect on records characteristics and seismic response

2021 ◽  
pp. 875529302110492
Author(s):  
Alan Rivera-Figueroa ◽  
Luis A Montejo
Keyword(s):  
Seismic Response ◽  
Strong Motion ◽  
Bridge Piers ◽  
Spectral Variability ◽  
Reinforced Concrete Bridge ◽  
Energy Demands ◽  
Target Spectrum ◽  
Single Column ◽  
Scaling Down ◽  
Motion Characteristics

This article investigates three different approaches to generate seismic input compatible with RotD100 design spectra: (1) separately matching each horizontal component to the target spectrum, (2) separately matching and then scaling-down the records to improve the match and (3) directly pursuing the match of RotD100 by simultaneously modifying both horizontal components. We examine the strong motion characteristics of the resulting records individually and their variability as suites of input records. The records generated, along with a set of amplitude-scaled records, are used as input for bi-directional non-linear response history analyses of idealized single column reinforced concrete bridge piers with different geometric and reinforcement characteristics. It is shown that the records generated pursuing a direct match of the target spectrum attain the closest match, retain better the strong motion characteristics of the seed records and their horizontal components exhibit a spectral variability comparable to suites of amplitude-scaled records. Regarding the effect on seismic response, the suites constructed separately matching each component consistently imposed larger peak inelastic and total energy demands than all other suites. Directly pursuing the match of RotD100 generated responses close but consistently below the expected from amplitude-scaled suites. The best results were obtained using the direct match methodology but using as target 110% the RotD100 spectrum as required in ASCE 7-16.

Spectrum-Compatible Earthquake Records and Their Influence on the Seismic Response of Reinforced Concrete Structures

2016 ◽  
Vol 32 (1) ◽  
pp. 101-123 ◽  
Author(s):  
Ramon L. Gascot ◽  
Luis A. Montejo
Keyword(s):  
Frequency Domain ◽  
Structural Response ◽  
Strong Motion ◽  
Continuous Wavelet ◽  
Earthquake Records ◽  
Inelastic Demand ◽  
Target Spectrum ◽  
Motion Characteristics ◽  
Frequency Domain Approach ◽  
Original Characteristic

Three different methodologies for the generation of spectrum-compatible records are evaluated: wavelet-based modification of seed records, seed record adjustment based on the continuous wavelet transform, and synthetic record generation in the frequency domain. It was found that the three methodologies are capable of generating compatible records with an acceptable level of match. However, the records generated using the frequency domain approach exhibit unrealistic strong motion characteristics and a tendency to induce less inelastic demand in the structures. In the case of methodologies based on modification of actual earthquake records, it was found that when the seed records are selected based on their initial compatibility with the target spectrum, the resultant compatible records not only better retain the original characteristic of the records but the variability in the structural response is reduced.

Optimal Trends in Seismic Design of Single Column Circular Reinforced Concrete Bridge Piers

1994 ◽  
Vol 10 (3) ◽  
pp. 589-614
Author(s):  
Ravindra Verma ◽  
M. J. Nigel Priestley
Keyword(s):  
Axial Load ◽  
Load Ratio ◽  
Bridge Piers ◽  
Column Height ◽  
Column Diameter ◽  
Displacement Ductility ◽  
Reinforced Concrete Bridge ◽  
Axial Load Ratio ◽  
Single Column ◽  
Ductility Capacity

An algorithm is developed to incorporate seismic capacity design philosophy in a computer program for the optimal design of single column circular reinforced concrete bridge piers for seismic loading. The program designs the circular column as a single degree of freedom system under the combined effect of axial and lateral seismic loads over a broad range of axial load ratio, column height and design displacement ductility capacity. Flexural, confinement and shear reinforcement requirements are then assessed for the entire range of parameters and cost calculations performed. For a given column height, design displacement ductility and axial load level, results indicate the existence of an optimal column diameter and ductility level. As the column diameter is reduced, cost savings are effected by reduced volume of concrete, but tend to be offset by P-Δ effects, increased longitudinal reinforcement for flexure, and increased transverse reinforcement for confinement and shear. Based on common trends, solutions are provided for the most economical range of the axial load ratio and design displacement ductility capacity for a given column height.

scholarly journals Seismic response of bridge piers on pile groups for different soil damping models and lumped parameter representations of the foundation

2018 ◽  
Vol 48 (3) ◽  
pp. 306-327 ◽  
Author(s):  
Francisco González ◽  
Luis A. Padrón ◽  
Sandro Carbonari ◽  
Michele Morici ◽  
Juan J. Aznárez ◽  
...  
Keyword(s):  
Seismic Response ◽  
Bridge Piers ◽  
Pile Groups ◽  
Lumped Parameter ◽  
Soil Damping

Seismic response and retrofit of industrial brick masonry chimneys

1992 ◽  
Vol 19 (1) ◽  
pp. 117-128 ◽  
Author(s):  
A. Ghobarah ◽  
T. Baumber
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Strong Motion ◽  
Brick Masonry ◽  
Wind Loading ◽  
Earthquake Ground Motion ◽  
Lumped Mass ◽  
Mass System ◽  
Higher Modes ◽  
Recent Earthquakes

During recent earthquakes, the documented cases of collapsed unreinforced brick masonry industrial chimneys are numerous. Observed modes of structural failure are either total collapse or sometimes collapse or damage of the top third of the structure. The objective of this study is to analyze and explain the modes of observed failure of masonry chimneys during earthquake events, and to evaluate two retrofit systems for existing chimneys in areas of high seismicity. The behaviour of the masonry chimney, when subjected to earthquake ground motion, was modelled using a lumped mass system. Several actual strong motion records were used as input to the model. The shear, moment, and displacement responses to the earthquake ground motion were evaluated for various chimney configurations. It was found that the failure of the chimney at its base is the result of the fundamental mode of vibration. Failure at the top third of the structure due to the higher modes of vibration is possible when the chimney is subjected to high frequency content earthquakes. Higher modes, which are normally not of concern under wind loading, were shown to be critical in seismic design. Post-tensioning and the reinforcing steel cage were found to be effective retrofit systems. Key words: masonry, chimneys, behaviour, analysis, design, retrofit, dynamic, earthquakes, seismic response.

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