scholarly journals Evaluation of earthquake response of low-rise structures using design codes and local specifications

1983 ◽  
Vol 16 (4) ◽  
pp. 331-344
Author(s):  
G. L. Hutchinson ◽  
A. Navidi
Keyword(s):  
Earthquake Engineering ◽  
Structural Response ◽  
Response Spectra ◽  
Building Code ◽  
Earthquake Response ◽  
Engineering Research ◽  
Analysis And Design ◽  
High Rise ◽  
Time Histories ◽  
Local Specifications

Most earthquake engineering research projects are concerned with the analysis and design of high-rise buildings. Comparisons of
actual earthquake forces with pseudo-static design forces recommended
by various building codes indicate that in actual earthquakes the forces in low-rise buildings can be up to three to five times the pseudo-static design forces. This paper is concerned with evaluating and comparing the earthquake response of low-rise buildings calculated using local response spectra and real time-histories with various Building Code Recommendations. It is shown that Building Code Recommendations underestimate the
structural response.

The SMART I Accelerograph Array (1980-1987): A Review

1987 ◽  
Vol 3 (2) ◽  
pp. 263-287 ◽  
Author(s):  
N. A. Abrahamson ◽  
B. A. Bolt ◽  
R. B. Darragh ◽  
J. Penzien ◽  
Y. B. Tsai
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Near Field ◽  
Strong Motion ◽  
Response Spectra ◽  
Transform Faults ◽  
Engineering Research ◽  
Motion Data ◽  
Time Histories

SMART 1 is the first large digital array of strong-motion seismographs specially designed for engineering and seismological studies of the generation and near-field properties of earthquakes. Since the array began operation in September 1980, it has recorded over 3000 accelerogram traces from 48 earthquakes ranging in local magnitude ( ML) from 3.6 to 7.0. Peak ground accelerations have been recorded up to 0.33g and 0.34g on the horizontal and vertical components, respectively. Epicentral distances have ranged from 3 km 200 km from the array center, and focal depths have ranged from shallow to 100 km. The recorded earthquakes had both reverse and strike-slip focal mechanisms associated with the subduction zone and transform faults. These high quality, digital, ground motions provide a varied resource for earthquake engineering research. Earthquake engineering studies of the SMART 1 ground motion data have led to advances in knowledge in several cases: for example, on frequency-dependent incoherency of free-surface ground motions over short distances, on response of linear systems to multiple support excitations, on attenuation of peak ground-motion parameters and response spectra, on site torsion and phasing effects, and on the identification of wave types. Accelerograms from individual strong-motion seismographs do not, in general, provide such information. This review describes the SMART 1 array and the recorded earthquakes with special engineering applications. Also, it tabulates the unfiltered peak array accelerations, displays some of the recorded ground motion time histories, and summarizes the main engineering research that has made use of SMART 1 data.

Behavior of CFST-RC Pier under Different Ground Motions

2018 ◽  
Vol 1145 ◽  
pp. 134-139
Author(s):  
Raghabendra Yadav ◽  
Bao Chun Chen ◽  
Hui Hui Yuan ◽  
Zhi Bin Lian
Keyword(s):  
Earthquake Engineering ◽  
Large Scale ◽  
Dynamic Testing ◽  
Ground Motions ◽  
Dynamic Test ◽  
Longitudinal Direction ◽  
Steel Tube ◽  
Engineering Research ◽  
Magnification Factors ◽  
Time Histories

The dynamic testing of large-scale structures continues to play a significant role in earthquake engineering research. The pseudo- dynamic test (PDT) is an experimental technique for simulating the earthquake response of structures and structural components in time domain. A CFST-RC pier is a modified form of CFST laced column in which CFST members are connected with RC web in longitudinal direction and with steel tube in transverse direction. For this study, a CFST -RC pier is tested under three different earthquake time histories having scaled PGA of 0.05g. From the experiment acceleration, velocity, displacement and load time histories are observed. The dynamic magnification factors for acceleration due to Chamoli, Gorkha and Wenchuan ground motions are observed as 12, 10 and 10 respectively. The frequency of the pier is found to be 1.42 Hz. The result shows that this type of pier has excellent static and earthquake resistant properties.

NGA-West2 Research Project

2014 ◽  
Vol 30 (3) ◽  
pp. 973-987 ◽  
Author(s):  
Yousef Bozorgnia ◽  
Norman A. Abrahamson ◽  
Linda Al Atik ◽  
Timothy D. Ancheta ◽  
Gail M. Atkinson ◽  
...  
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Research Program ◽  
Epistemic Uncertainty ◽  
Response Spectra ◽  
Site Amplification ◽  
Earthquake Hazards ◽  
Research Project ◽  
Engineering Research ◽  
Crustal Earthquakes

The NGA-West2 project is a large multidisciplinary, multi-year research program on the Next Generation Attenuation (NGA) models for shallow crustal earthquakes in active tectonic regions. The research project has been coordinated by the Pacific Earthquake Engineering Research Center (PEER), with extensive technical interactions among many individuals and organizations. NGA-West2 addresses several key issues in ground-motion seismic hazard, including updating the NGA database for a magnitude range of 3.0–7.9; updating NGA ground-motion prediction equations (GMPEs) for the “average” horizontal component; scaling response spectra for damping values other than 5%; quantifying the effects of directivity and directionality for horizontal ground motion; resolving discrepancies between the NGA and the National Earthquake Hazards Reduction Program (NEHRP) site amplification factors; analysis of epistemic uncertainty for NGA GMPEs; and developing GMPEs for vertical ground motion. This paper presents an overview of the NGA-West2 research program and its subprojects.

Gaseous Deflagration in Piping: Part 1 — Experimental Observations

2017 ◽  
Author(s):  
Thomas C. Ligon ◽  
David J. Gross ◽  
John C. Minichiello
Keyword(s):  
High Speed ◽  
Structural Response ◽  
Analysis And Design ◽  
Flame Acceleration ◽  
Pressure Time ◽  
Piping Systems ◽  
Time Histories ◽  
Short Test ◽  
Semi Empirical ◽  
Measured Pressure

The focus of this paper is on gaseous deflagration in piping systems and the corresponding implications on piping analysis and design. Unlike stable detonations that propagate at a constant speed and whose pressure-time histories can in some cases be predicted analytically, deflagration flame speeds and pressure-time histories are transient and depend on both the gas mixture and geometry of the pipe. This paper presents pressure and pipe strain data from gaseous deflagration experiments in long and short test apparatuses fabricated from either 2-inch or 4-inch diameter pipes. These data are used to demonstrate a spectrum of measured pressure-time histories and corresponding pipe response. It is concluded that deflagrations can be categorized as either “high” or “slow” speed with respect to pipe response. Slow deflagrations can be treated as quasi-static pressurizations, but high speed deflagrations can generate shock waves that dynamically excite the pipe. The existence of a transition from quasi-static to dynamic response has ramifications in regards to piping structural analysis and design, and a method for predicting the expected deflagration structural response using a semi-empirical flame acceleration model is proposed.

DAMAGE EVOLUTION SPECTRA FOR SEISMIC ANALYSIS OF HIGH-RISE BUILDINGS

2012 ◽  
Vol 06 (03) ◽  
pp. 1250021
Author(s):  
Y. B. HO ◽  
J. S. KUANG
Keyword(s):  
Damage Evolution ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Time History ◽  
Tall Buildings ◽  
Response Spectra ◽  
Seismic Damage ◽  
Analysis And Design ◽  
High Rise ◽  
Earthquake Ground Motions

Seismic response spectra are amongst one of the most important tools for characterizing earthquake ground motions. In design practice, the response spectra are presented without including any load history, hence the nonlinear analysis of structures based solely on conventional earthquake response spectra is theoretically unsound, particularly for long-period or vertically irregular high-rise buildings. In this paper, a concept of seismic damage evolution is introduced and the method of analysis for characterizing the process of seismic damage to structures under earthquakes is presented. Seismic damage evolution spectra for analysis and design of high-rise buildings are then developed as an effective means of describing and simplifying earthquake ground motions. These spectra are shown to be very useful in selecting the ground motion-time history and, particularly, validating the equivalent static-load analysis and design of high-rise buildings under near-fault pulse-like ground motions. Case studies of the seismic inelastic performance of two vertically irregular, tall buildings are presented considering the seismic damage evolution spectra.

Implementing Nepal's National Building Code: A Case Study in Patience and Persistence

2017 ◽  
Vol 33 (1_suppl) ◽  
pp. 167-183 ◽  
Author(s):  
Lucy Arendt ◽  
Ayse Hortacsu ◽  
Kishor Jaiswal ◽  
John Bevington ◽  
Surya Shrestha ◽  
...  
Keyword(s):  
Earthquake Engineering ◽  
Relative Effectiveness ◽  
Building Code ◽  
National Society ◽  
Gorkha Earthquake ◽  
Engineering Research ◽  
2015 Gorkha Earthquake ◽  
Code Compliance ◽  
And Training

The April 2015 Gorkha earthquake in Nepal revealed the relative effectiveness of the Nepal Standard or the national building code (NBC), and irregular compliance with it in different parts of Nepal. Much of the damage to more than half a million residential structures in Nepal may be attributed to the prevalence of owner-built or owner-supervised construction and the lack of owner and builder responsiveness to seismic risk and training in the appropriate means of complying with the NBC. To explain these circumstances, we review the protracted implementation of the NBC and the role played by one organization, the National Society for Earthquake Technology—Nepal (NSET), in the implementation of the NBC. We also share observations on building code compliance made by individuals in Nepal participating in workshops led by the Earthquake Engineering Research Institute's 2014 class of Housner Fellows.

Use of RVT for Computation of In-Structure Response Spectra and Peak Responses and Comparison to Time History and Response Spectrum Analysis

2018 ◽  
Vol 34 (4) ◽  
pp. 1913-1930 ◽  
Author(s):  
Irmela Zentner
Keyword(s):  
Response Spectrum ◽  
Structural Response ◽  
Time History ◽  
Strong Motion ◽  
Response Spectra ◽  
Combination Rules ◽  
Floor Response Spectra ◽  
Power Spectral ◽  
Time Histories ◽  
Definition Of

The random vibration theory offers a framework for the conversion of response spectra into power spectral densities (PSDs) and vice versa. The PSD is a mathematically more suitable quantity for structural dynamics analysis and can be straightforwardly used to compute structural response in the frequency domain. This allows for the computation of in-structure floor response spectra and peak responses by conducting only one structural analysis. In particular, there is no need to select or generate spectrum-compatible time histories to conduct the analysis. Peak response quantities and confidence intervals can be computed without any further simplifications such as currently used in the response spectrum method, where modal combination rules have to be derived. In contrast to many former studies, the Arias intensity-based definition of strong-motion duration is adopted here. This paper shows that, if the same definitions of strong-motion duration and modeling assumptions are used for time history and RVT computations, then the same result can be expected. This is illustrated by application to a simplified model of a reactor building.

Drift Spectrum vs. Modal Analysis of Structural Response to Near-Fault Ground Motions

2001 ◽  
Vol 17 (2) ◽  
pp. 221-234 ◽  
Author(s):  
Anil K. Chopra ◽  
Chatpan Chintanapakdee
Keyword(s):  
Earthquake Engineering ◽  
Response Spectrum ◽  
Ground Motions ◽  
Structural Response ◽  
Response Spectra ◽  
Engineering Practice ◽  
Drift Spectrum ◽  
Combination Rules ◽  
Near Fault ◽  
Far Fault

A new measure of earthquake demand, the drift spectrum has been developed as an adjunct to the response spectrum, a central concept in earthquake engineering, in calculating the internal deformations of a structure due to near-fault ground motions with pronounced coherent pulses in the velocity and displacement histories. Compared in this paper are certain aspects of the elastic structural response to near-fault and far-fault ground motions. It is demonstrated that (1) the difference between drift and response spectra are not unique to near-fault ground motions; these differences simply reflect higher-mode response, which is larger due to near-fault ground motions; (2) response spectrum analysis (RSA) using existing modal combination rules can provide an estimate of structural response that is accurate to a useful degree; (3) these modal combination rules are similarly accurate for near-fault and far-fault ground motions although the underlying assumptions are not satisfied by near-fault excitations; and (4) RSA is preferable over the drift spectrum in computing structural response because it represents standard engineering practice and is applicable to a wide variety of structures.

Increasing Student Understanding of Response Spectra: An Argument for the Inductive Learning Approach

2018 ◽  
Vol 34 (2) ◽  
pp. 459-469 ◽  
Author(s):  
H. Benjamin Mason ◽  
David S. Hurwitz ◽  
Rachel K. Adams ◽  
Kamilah Buker ◽  
Richard K. Slocum ◽  
...  
Keyword(s):  
Engineering Education ◽  
Earthquake Engineering ◽  
Inductive Learning ◽  
Response Spectra ◽  
Earthquake Response ◽  
Learning Approach ◽  
Learning Modules ◽  
Earthquake Response Spectra ◽  
Post Class ◽  
Interactive Classroom

Creating and interpreting earthquake response spectra are important fundamentals in earthquake engineering education. We argue that an effective approach for teaching the fundamentals of earthquake response spectra is to use an inductive learning approach in an interactive classroom, which is well supported by engineering education literature. To demonstrate this approach we use desktop learning modules that exhibit response spectra concepts. Preliminary data based on post-class interviews with instructors support our opinion. Notably, all interviewed instructors have chosen to adopt the inductive learning approach when teaching response spectra concepts in future iterations of their classes.

scholarly journals Testing of Passive Energy Dissipation Systems

1993 ◽  
Vol 9 (3) ◽  
pp. 335-370 ◽  
Author(s):  
Ian D. Aiken ◽  
Douglas K. Nims ◽  
Andrew S. Whittaker ◽  
James M. Kelly
Keyword(s):  
Energy Dissipation ◽  
Earthquake Engineering ◽  
Structural Response ◽  
Phase Changes ◽  
Acrylic Copolymer ◽  
Friction Resistance ◽  
Engineering Research ◽  
Passive Energy Dissipation ◽  
Energy Dissipators ◽  
Shake Table Experiments

Over the period 1986 to 1991, seven different passive energy dissipation systems were studied in experimental research programs at the Earthquake Engineering Research Center of the University of California at Berkeley. This paper presents an overview of these studies, describing the different types of devices, the results of the shake table experiments, and associated analytical work. Four of the systems studied are friction systems, and of these, three (Sumitomo, Pall, and Friction-Slip) are based on Coulomb friction. The fourth is the Fluor-Daniel Energy Dissipating Restraint, which is a device capable of providing self-centering friction resistance that is proportional to displacement. The three other systems all have different energy dissipation mechanisms: ADAS elements, which utilize the yielding of mild-steel X-plates; viscoelastic shear dampers using a 3M acrylic copolymer as the dissipative element; and Nickel-Titanium alloy shape-memory devices that take advantage of reversible, stress-induced phase changes in the alloy to dissipate energy. The effectiveness of the various systems is evaluated by comparing the response of the test structures without and with the energy dissipators. In some cases, where devices were studied using the same test structure, they are compared directly. All of the systems investigated exhibited characteristics beneficial to improved structural response to earthquake loading.

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