Evaluation of Damage Potential of Ground Motions during Great Earthquakes

2003 ◽  
Vol 19 (3) ◽  
pp. 713-730 ◽  
Author(s):  
Y. Sunasaka ◽  
K. Toki ◽  
A. S. Kiremidjian

In order to select appropriate input ground motions for earthquake-resistant design or estimation of seismic safety of structures, their characteristics should be identified. In this paper, damage potential is defined as a spectrum of strength demand required to maintain a damage index less than or equal to a tolerable damage index value. The damage index proposed by Park and Ang (1985) and a bilinear model are used to calculate the strength demand spectrum. The damage index describes the state of the concrete structure from slight damage to severe damage or collapse. Studies of the damage potential of ground motions during the recent great earthquakes, including the 1995 Hyogoken-Nanbu earthquake in Japan and the 1999 Chi-Chi earthquake in Taiwan, show that damage potential may be greatly affected by the location of the fault, the geological structure of the site, and the fault rupture mechanism. Furthermore, an estimation of damage potential of ground motions over a large area, Kawasaki City in Japan, is described.

1998 ◽  
Vol 25 (6) ◽  
pp. 1078-1090 ◽  
Author(s):  
R Tremblay

There is now growing evidence that large-magnitude earthquakes have occurred and could occur again along the Cascadia subduction zone located west of Vancouver Island, Bristish Columbia. Numerical simulations indicate that these earthquakes would produce long-duration ground motions and would thus be capable of inducing a large number of reversals of inelastic deformations in engineered structures. Efforts have now been undertaken to account for this damage potential in building codes. In this paper, inelastic design spectra are developed for Cascadia subduction earthquakes for four sites in British Columbia. These spectra are compared with elastic design spectra that have been developed recently for the same sites based on empirical attenuation relationships for Cascadia events. The approach used to develop the inelastic spectra aims at providing the same level of protection against structural failure for both subduction events and crustal or subcrustal earthquakes. Force modification factors are first determined for structures exhibiting various failure modes and ductility levels when subjected to representative crustal and subcrustal earthquake ground motions. Thereafter, design spectra are developed for the same structures to prevent structural collapse under simulated Cascadia subduction ground motions. The study reveals that the elastic spectra do not reflect adequately the damage potential of Cascadia earthquakes. These elastic spectra generally are unconservative for Tofino and Victoria. For Vancouver and Prince George, the elastic spectra overestimate the demand, especially for short-period structures.Key words: collapse, crustal earthquakes, damage index, design spectrum, ductility, duration, ground motion, subduction zone.


2018 ◽  
Vol 34 (2) ◽  
pp. 773-793 ◽  
Author(s):  
Mario E. Rodriguez

This study quantifies the damage index previously proposed by the writer ( Rodriguez 2015 ) for different structural systems subjected to a set of earthquake ground motions recorded during 12 strong earthquakes in different countries. Damage spectra were also computed using this seismic damage index. This study revisits the previously proposed index and shows that this index can also be interpreted as a ratio of velocities in the structural system responding to the earthquake demand. In addition, this study gives a more general damage analysis interpretation than that of the previous study since damage spectra were computed to assess the damage potential of a given recorded earthquake ground motion for different types of earthquake-resisting systems. The results from the damage analysis are consistent with the findings from previous research: most structural wall buildings show satisfactory earthquake performance, whereas frame buildings frequently show severe damage and collapse.


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 (3) ◽  
pp. 653-667
Author(s):  
Walter W. Hays

Data and technical knowledge gained from postearthquake investigations of a dozen earthquakes since the 1964 Prince William Sound, Alaska, earthquake have significantly advanced the state-of-knowledge about earthquakes. These advances have motivated new and (or) improved programs, applications, and changes in public policy, including (1) the 1977 National Earthquake Hazards Reduction Program and its extensions, (2) earthquake prediction research, (3) deterministic and probabilistic hazards assessments, (4) design criteria for critical facilities, (5) earthquake-resistant design provisions of building codes, (6) seismic safety elements, (7) seismic microzoning, (8) lifeline engineering, and (9) seismic safety organizations. To date, the 1971 San Fernando, California, earthquake has triggered more rapid advances in knowledge and applications than any other earthquake.


2013 ◽  
Vol 330 ◽  
pp. 878-883 ◽  
Author(s):  
Salimi Firoozabad Ehsan ◽  
K. Rama Mohan Rao ◽  
Bagheri Bahador

Most seismic codes specify empirical formulas to obtain the fundamental period of buildings. The equations specified in present IS codes, are according to the available data on the time period of buildings measured from their recorded accelerograms. Shear-wall dominant reinforced concrete buildings, constructed, using codes specification are commonly built in different countries, facing a substantial seismic risk, in spite of their high resistance against ground motions. Current seismic code provisions including the Uniform Building Code (International Conference of Building Officials, Whittier, CA, 1997) and the Indian Seismic Code (Criteria for earthquake resistant design of buildings, fifth revision, 2002) are considered to evaluate the effect of time period on seismic behavior of building.In this study, time period obtained by code formulas are compared with those obtained by modal analysis in SAP2000. Also the top story displacement (as an adequate parameter of determination the seismic performance of building) correspond to the values of mentioned time period are estimated using uniform building code and software respectively. It is observed that current empirical equation for calculating the time period of RCC buildings is rather inaccurate. Also it is shown that the time period has very effective influence on seismic performance of building.


2020 ◽  
Vol 6 (10) ◽  
pp. 1906-1921
Author(s):  
Manish Bhutani ◽  
Sanjeev Naval

Stability of infrastructure during earthquakes demands ground response analysis to be carried out for a particular region as the ground surface may suffer from amplified Peak Ground Acceleration (PGA) as compared to bedrock PGA causing instability. Many studies have been carried out the world over using different techniques but very few studies have been carried out for the northern part of India, Punjab situated at latitude of 31.326° N and longitude of 75.576° E, which is highly seismic and lies in seismic zone IV as per IS:1893-2016. In this paper 1-D equivalent non-linear ground response analysis has been conducted for sixteen sites of Jalandhar region, Punjab (India) by using five earthquake motions. Input ground motions are selected from the worldwide-recorded database based on the seismicity of the region. Based on the average SPT-N values, all the sites have been classified as per the guidelines of National Earthquake Hazard Reduction program (NEHRP). Shear modulus (G) was calculated using correlation between G and SPT–N Value. The ground surface PGA varies from 0.128 to 0.292 g for the sites of Jalandhar region with Amplification Factor values varying from 1.08 to 2.01. Hence the present study will be useful to the structural designers as an input towards suitable earthquake resistant design of structures for similar sites.


2006 ◽  
Vol 22 (2) ◽  
pp. 367-390 ◽  
Author(s):  
Erol Kalkan ◽  
Sashi K. Kunnath

This paper investigates the consequences of well-known characteristics of near-fault ground motions on the seismic response of steel moment frames. Additionally, idealized pulses are utilized in a separate study to gain further insight into the effects of high-amplitude pulses on structural demands. Simple input pulses were also synthesized to simulate artificial fling-step effects in ground motions originally having forward directivity. Findings from the study reveal that median maximum demands and the dispersion in the peak values were higher for near-fault records than far-fault motions. The arrival of the velocity pulse in a near-fault record causes the structure to dissipate considerable input energy in relatively few plastic cycles, whereas cumulative effects from increased cyclic demands are more pronounced in far-fault records. For pulse-type input, the maximum demand is a function of the ratio of the pulse period to the fundamental period of the structure. Records with fling effects were found to excite systems primarily in their fundamental mode while waveforms with forward directivity in the absence of fling caused higher modes to be activated. It is concluded that the acceleration and velocity spectra, when examined collectively, can be utilized to reasonably assess the damage potential of near-fault records.


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

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