Ductility-dependent intensity measure that accounts for ground-motion spectral shape and duration

2015 ◽  
Vol 45 (4) ◽  
pp. 653-672 ◽  
Author(s):  
Nasser A. Marafi ◽  
Jeffrey W. Berman ◽  
Marc O. Eberhard
Keyword(s):  
Ground Motion ◽  
Spectral Shape ◽  
Intensity Measure

Proposal of orientation-independent measure of intensity for earthquake-resistant design

2021 ◽  
pp. 875529302110382
Author(s):  
Alan Poulos ◽  
Eduardo Miranda
Keyword(s):  
United States ◽  
Ground Motion ◽  
The United States ◽  
Design Codes ◽  
Intensity Measure ◽  
Independent Measure ◽  
Earthquake Resistant Design ◽  
Earthquake Resistant ◽  
Ground Motion Records ◽  
Structural Engineers

A new measure of ground motion intensity in the horizontal direction is proposed. Similarly to other recently proposed measures of intensity, the proposed intensity measure is also independent of the as-installed orientation of horizontal sensors at recording stations. This new measure of horizontal intensity, referred to as MaxRotD50, is defined using the maximum 5%-damped response spectral ordinate of two orthogonal horizontal directions and then computing the 50th percentile for all non-redundant rotation angles, that is, the median of the set of spectral ordinates in a range of 90°. This proposed measure of intensity is always between the median and maximum spectral ordinate for all non-redundant orientations, commonly referred to as RotD50 and RotD100, respectively. A set of 5065 ground motion records is used to show that MaxRotD50 is, on average, approximately 13%–16% higher than Rot50 and 6% lower than RotD100. The new measure of intensity is particularly well suited for earthquake-resistant design where a major concern for structural engineers is the probability that the design ground motion intensity is exceeded in at least one of the two principal horizontal components of the structure, which for most structures are orthogonal to each other. Currently, design codes in the United States are based on RotD100, and hence using MaxRotD50 for structures with two orthogonal principal horizontal components would result in a reduction of the ground motion intensities used for design purposes.

A spectral-acceleration-based combination-type earthquake intensity measure for high-rise stack-like structures

2019 ◽  
Vol 23 (7) ◽  
pp. 1350-1366 ◽  
Author(s):  
Yikun Qiu ◽  
Changdong Zhou ◽  
Siha A ◽  
Guangwei Zhang
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Spectral Acceleration ◽  
Intensity Measure ◽  
Earthquake Intensity ◽  
Intensity Measures ◽  
Higher Modes ◽  
High Rise ◽  
Near Fault ◽  
Period Elongation

Ground motion intensity measures are of great importance for the seismic design of structures. A well-chosen intensity measure will reduce the detailed ground motion record selection effort for the nonlinear dynamic structural analyses. In this article, a spectral-acceleration-based combination-type earthquake intensity measure is presented. This intensity measure considers the higher modes effect and period elongation effect due to nonlinear deformation at the same time. The modal mass participation factors are determined to take weighting coefficients and the product of elastic first-mode period T1 and a constant C is expressed to represent the elongated period. Therefore, the proposed intensity measure is a combination of earthquake ground motion characteristics, elastic structural responses, higher modes participation, and the period elongation effect due to inelastic structural behaviors. Four three-dimensional models of reinforced concrete stack-like structures including a 240 m-high chimney, a 180 m-high chimney, a 120 m-high chimney, and a 42.3 m-high water tower are established and analyzed in ABAQUS to investigate the correlation between the intensity measure and the maximum curvatures under 44 far-field ground motions and 28 near-fault ground motions with a pulse-like effect. With the optimal vibration modes and the proper period elongation coefficient, the efficiency of the introduced intensity measure is compared with the other 15 intensity measures. The results indicate that the proposed intensity measure is believed to be a good choice for high-rise stack-like structures, especially under the near-fault ground motions with pulse-like effect.

A new ground motion intensity measure I B

2017 ◽  
Vol 99 ◽  
pp. 97-107 ◽  
Author(s):  
Edén Bojórquez ◽  
Robespierre Chávez ◽  
Alfredo Reyes-Salazar ◽  
Sonia E. Ruiz ◽  
Juan Bojórquez
Keyword(s):  
Ground Motion ◽  
Intensity Measure ◽  
Ground Motion Intensity Measure
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