RECENT EARTHQUAKES AND NEW CONCEPTS FOR EARTHQUAKE RESISTANT DESIGN

Author(s):  
Akira Wada
Author(s):  
Ms. Sayali Ambatkar

The field of Earthquake Engineering has existed in our country for over 35 years now. Indian earthquake engineers have made significant contributions to the seismic safety of several important structures in the country. However, as the recent earthquakes have shown, the performance of normal structures during past Indian earthquakes has been less satisfactory. This is mainly due to the lack of awareness amongst most practising engineers of the special provisions that need to be followed in earthquake resistant design and thereafter in construction. In India, the multi-storied building is constructed due to high cost and scarcity of land. In order to utilize maximum land area, builders and architects generally proposed asymmetrical plan configuration. These asymmetrical plan buildings, which are constructed in seismic prone areas, are likely to be damaged during earthquake. Earthquake is a natural phenomenon which can be generate the most destructive forces on structure. Buildings should be made Safe for lives by proper design and detailing of structural member in order to have a ductile form of failure. The concept of earthquake resistant design is that the building should be designed to resist the forces, which arises due to Design Basic Earthquake, with only minor damages and the forces which arises due to Maximum Considered Earthquake, with some accepted structural damages but no collapse. This paper studies the Earthquake Resisting Building.


1986 ◽  
Vol 2 (4) ◽  
pp. 825-858 ◽  
Author(s):  
Vitelmo V. Bertero

Following an overview of the special problems inherent in the design and construction of earthquake-resistant buildings in regions of high seismic risk, the techniques that will be required to solve these problems in the U.S. are discussed. Some lessons learned from recent earthquakes, particularly those in Chile and Mexico in 1985, are discussed as are some results of integrated analytical and experimental research at the University of California, Berkeley. The implications of the ground motions recorded during the 1985 Mexican and Chilean earthquakes, the performance of buildings during the Mexican earthquake, and the research results previously discussed are then assessed with respect to seismic-resistant design regulations presently in force (UBC) as well as those formulated by ATC 3-06 and the Tentative Lateral Force Requirements recently developed by the Seismology Committee of SEAOC. The rationale for and reliability of the values suggested by the ATC for the “Response Modification Factor R” and by the SEAOC Seismology Committee for the “Structural Quality Factor Rw” are reviewed in detail. In the conclusion to the paper, two solutions for improving the earthquake-resistant design of building structures are proposed: an ideal (rational) method to be implemented in the future, and a compromise solution that can be implemented immediately.


1983 ◽  
Vol 1983 (339) ◽  
pp. 127-136 ◽  
Author(s):  
Yoshio OHNE ◽  
Hidehiro TATEBE ◽  
Kunitomo NARITA ◽  
Tetsuo OKUMURA

Author(s):  
GENE F. SIRCA ◽  
HOJJAT ADELI

In earthquake-resistant design of structures, for certain structural configurations and conditions, it is necessary to use accelerograms for dynamic analysis. Accelerograms are also needed to simulate the effects of earthquakes on a building structure in the laboratory. A new method of generating artificial earthquake accelerograms is presented through adroit integration of neural networks and wavelets. A counterpropagation (CPN) neural network model is developed for generating artificial accelerograms from any given design spectrum such as the International Building Code (IBC) design spectrum. Using the IBC design spectrum as network input means an accelerogram may be generated for any geographic location regardless of whether earthquake records exist for that particular location or not. In order to improve the efficiency of the model, the CPN network is modified with the addition of the wavelet transform as a data compression tool to create a new CPN-wavelet network. The proposed CPN-wavelet model is trained using 20 sets of accelerograms and tested with additional five sets of accelerograms available from the U.S. Geological Survey. Given the limited set of training data, the result is quite remarkable.


1975 ◽  
Vol 101 (7) ◽  
pp. 1349-1366
Author(s):  
Anil K. Chopra ◽  
C-Y. Liaw

2021 ◽  
pp. 875529302110382
Author(s):  
Alan Poulos ◽  
Eduardo Miranda

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.


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