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.

Site-dependent spectra for earthquake-resistant design

1976 ◽  
Vol 66 (1) ◽  
pp. 221-243 ◽  
Author(s):  
H. Bolton Seed ◽  
Celso Ugas ◽  
John Lysmer
Keyword(s):  
United States ◽  
Statistical Analysis ◽  
Ground Motion ◽  
The United States ◽  
Design Criteria ◽  
Earthquake Resistant Design ◽  
Geological Conditions ◽  
Earthquake Resistant ◽  
Ground Motion Records ◽  
Spectral Shapes

abstract The paper presents the results of a statistical analysis of the spectral shapes of 104 ground-motion records obtained from 23 earthquakes, mostly in the western part of the United States. The analysis shows clear differences in spectral shapes for different soil and geological conditions, indicating the need for consideration of these effects in selecting earthquake-resistant design criteria.

scholarly journals The measurement of ground motion of destructive earthquakes

1963 ◽  
Vol 53 (2) ◽  
pp. 419-437
Author(s):  
D. E. Hudson
Keyword(s):  
United States ◽  
Transient Response ◽  
Strong Motion ◽  
The United States ◽  
Geodetic Survey ◽  
Natural Period ◽  
Earthquake Resistant Design ◽  
Earthquake Resistant ◽  
The World ◽  
Structural Engineers

abstract The need for a greatly expanded network of strong-motion accelerographs throughout the seismic regions of the world is stressed. A summary of the characteristics of currently available strong-motion accelerographs is presented, and the design details are given for an instrument suitable for acquiring the basic data needed by structural engineers for earthquake resistant design. It is shown that for such an instrument, the natural period must be less than 0.1 seconds, and that the recording speed must be at least 1 cm/sec. The critical nature of the inertia starting device is discussed, and some information is given on the transient response of the standard pendulum starter used in the United States Coast and Geodetic Survey Strong-Motion Accelerograph. The use of simpler, non-time-recording instruments such as the U.S.C.G.S. Seismoscope to supplement the accelerograph network is described.

Calibration of the Ground Motion Model Using a Simplified Stochastic Model in the Case of the Central Exhibition Pavilion ROMEXPO

2013 ◽  
Vol 430 ◽  
pp. 335-341
Author(s):  
Patricia-Florina Murzea
Keyword(s):  
Stochastic Model ◽  
Ground Motion ◽  
Design Codes ◽  
Motion Model ◽  
Ambient Vibrations ◽  
Ground Motion Model ◽  
Earthquake Resistant Design ◽  
Earthquake Resistant ◽  
Induced Motion ◽  
Macroscopic Parameters

The aim of the paper is to present the results of applying the formulae of a simplified stochastic model for the calibration of some macroscopic parameters of the ground motion, on the basis of rather rough estimates. For this purpose the basic records combinations results obtained with the aid of computer programs (DaisyLab and LABView) are used, after digital recordings on the large span and rather isolated structure of the ROMEXPO Pavilion in Bucharest were performed. A stochastic model of stationary, low intensity, ground motion (referred to in literature as microtremors or ambient vibrations) was proposed by H. Sandi (1982, 2005). This lay at the basis of the specification of input for a consistent analysis of 3D earthquake induced motion of structures, adopted in the Romanian earthquake resistant design codes.

A comparison of earthquake damage areas as a function of magnitude across the United States

1993 ◽  
Vol 83 (4) ◽  
pp. 1064-1080 ◽  
Author(s):  
G. A. Bollinger ◽  
M. C. Chapman ◽  
M. S. Sibol
Keyword(s):  
United States ◽  
North America ◽  
Ground Motion ◽  
Epicentral Distance ◽  
The United States ◽  
Western United States ◽  
Eastern North America ◽  
Similar Response ◽  
Eastern United States ◽  
The West

Abstract This study investigates the relationship between earthquake magnitude and the size of damage areas in the eastern and western United States. To quantify damage area as a function of moment magnitude (M), 149 MMI VI and VII areas for 109 earthquakes (88 in the western United States, 21 in the eastern United States and Canada) were measured. Regression of isoseismal areas versus M indicated that areas in the East were larger than those in the West, at both intensity levels, by an average 5 × in the M 4.5 to 7.5 range. In terms of radii for circles of equivalent area, these results indicate that damaging ground motion from shocks of the same magnitude extend 2 × the epicentral distance in eastern North America compared to the West. To determine source and site parameters consistent with the above results, response spectral levels for eastern North America were stochastically simulated and compared with response spectral ordinates derived from recorded strong ground motion data in the western United States. Stress-drop values of 200 bars, combined with a surficial 2-km-thick low velocity “sedimentary” layer over rock basement, produced results that are compatible with the intensity observations, i.e., similar response spectral levels in the east at approximately twice their epicentral distance in the western U.S. distance. These results suggest that ground motion modeling in eastern North America may need to incorporate source and site parameters different from those presently in general use. The results are also of importance to eastern U.S. hazard assessments as they require allowance for the larger damage areas in preparedness and mitigation programs.

scholarly journals Seismic Response of Large span slab in Horizontal Setback Building

2021 ◽  
Vol 9 (11) ◽  
pp. 1353-1360
Author(s):  
Manish Kumar Pandey
Keyword(s):  
Structural Elements ◽  
Commercial Building ◽  
Flat Slab ◽  
Large Span ◽  
Earthquake Resistant Design ◽  
Earthquake Resistant ◽  
Different Types ◽  
Waffle Slab ◽  
Earthquake Zone ◽  
Structural Engineers

Abstract: The demand for multi-storey buildings is increasing day by day. Residential plus commercial building is mainly used for wide span needs. Wide span required for Flat slab, Waffle slab and ribbed slab stands An excellent option for architects when larger openings in a building need to be covered with as few columns as possible. The use of different types of plates is developing as a new trend and is becoming a major challenge for structural engineers. Therefore, it is necessary to study about its structural behavior. The project is carried out under earthquake zone III under the earthquake analysis of G+9 storey building. For this study, four different types of large span slab structure are modelled in C-shape (Horizontal Setback Building) having 10-stories i.e. G+9 storied buildings with 3.50 meters height for each story is modelled and analysed. The plan area of all four buildings is same i.e. 2859 square meters (49.50 m x 82.50 m) each. These buildings were designed in compliance with the Indian Code of Practices for earthquake resistant design of buildings. Base of the building were fixed. The square sections are used for structural elements. The height of the buildings is considered constant throughout the structure. The buildings are modelled using ETABSvr.2016. Keywords: large span slab, ETABSvr.2016, Horizontal Setback Building, Flat slab, Waffle slab and ribbed slab

scholarly journals Site investigation of masonry buildings damaged during the 23 October and 9 November 2011 Van Earthquakes in Turkey

2013 ◽  
Vol 13 (3) ◽  
pp. 689-708 ◽  
Author(s):  
F. Piroglu ◽  
K. Ozakgul
Keyword(s):  
Site Investigation ◽  
Masonry Buildings ◽  
Design Codes ◽  
Confined Masonry ◽  
Earthquake Resistant Design ◽  
Richter Scale ◽  
Earthquake Resistant ◽  
Van Earthquakes ◽  
The City ◽  
Extensive Damage

Abstract. The purpose of this study is to scrutinize and interpret the damages to masonry buildings after a series of earthquakes that occurred in Van, which is an eastern city of Turkey, within 17 days in 2011, i.e., the first earthquake hit on 23 October having the magnitude 7.1, and the second on 9 November with the magnitude 5.6 on the Richter scale. These consecutive earthquakes and their aftershocks caused extensive damage and the collapse of buildings in the city of Van and its villages and especially its near town, namely Ercis. For the investigation of masonry buildings, Hacibekir district, which is one of the regions comprising the highest density of masonry buildings in the city of Van, was selected and the seismic performance of these buildings was observed, tested in the field, and interpreted according to the Turkish earthquake-resistant design codes. In this region, masonry buildings were classified as adobe, unreinforced and confined masonry buildings. As a result of this field study, it was observed that whereas the confined masonry buildings had usually shown good performance during the earthquakes, the adobe and the unreinforced masonry buildings were seriously damaged and some of them were partially collapsed.

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