scholarly journals Vertical Seismic Effect on the Seismic Fragility of Large-Space Underground Structures

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Zhiming He ◽  
Qingjun Chen
Keyword(s):  
Peak Ground Acceleration ◽  
Fragility Curves ◽  
Underground Structure ◽  
Seismic Effect ◽  
Peak Ground Velocity ◽  
Seismic Fragility ◽  
Vertical Acceleration ◽  
Underground Structures ◽  
Ground Acceleration ◽  
Large Space

The measured vertical peak ground acceleration was larger than the horizontal peak ground acceleration. It is essential to consider the vertical seismic effect in seismic fragility evaluation of large-space underground structures. In this research, an approach is presented to construct fragility curves of large-space underground structures considering the vertical seismic effect. In seismic capacity, the soil-underground structure pushover analysis method which considers the vertical seismic loading is used to obtain the capacity curve of central columns. The thresholds of performance levels are quantified through a load-drift backbone curve model. In seismic demand, it is evaluated through incremental dynamic analysis (IDA) method under the excitation of horizontal and vertical acceleration, and the soil-structure-interaction and ground motion characteristics are also considered. The IDA results are compared in terms of peak ground acceleration and peak ground velocity. To construct the fragility curves, the evolutions of performance index versus the increasing earthquake intensity are performed, considering related uncertainties. The result indicates that if we ignore the vertical seismic effect to the fragility assessment of large-space underground structures, the exceedance probabilities of damage of large-space underground structures will be underestimated, which will result in an unfavorable assessment result.

Mobile home fragility curves

2021 ◽  
pp. 875529302110575
Author(s):  
Bruce Maison ◽  
John Eidinger
Keyword(s):  
Peak Ground Acceleration ◽  
Fragility Curves ◽  
Seismic Fragility ◽  
Risk Modeling ◽  
Mobile Home ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Modeling Methodology ◽  
Manufactured Homes ◽  
Support Conditions

Seismic fragility of mobile (manufactured) homes is investigated. Compiled is a catalog of home performance in past earthquakes. Intensity measures causing damage are characterized by peak ground acceleration and velocity. Damage is defined as when the home is knocked out of position necessitating repairs and re-installation. Four categories of support conditions are identified: unanchored, tie-downs, proprietary systems, and perimeter wall foundations. Suggested fragility curves for unanchored homes and homes with tie-downs are derived from computer simulations. As a benchmark, a fragility curve for proprietary and perimeter wall systems is taken as the same as that for conventional wood homes. Shortcomings of using tie-down and proprietary systems in high seismic zones are discussed. The suggested fragility curves account for the different categories of support conditions thereby representing advancement to those in the Hazus national standardized risk modeling methodology.

Seismic Fragility Analysis of Hill Buildings with Uneven Ground Column Heights

2014 ◽  
Vol 638-640 ◽  
pp. 1848-1853
Author(s):  
Lin Qing Huang ◽  
Li Ping Wang ◽  
Chao Lie Ning
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Slope Angle ◽  
Seismic Fragility ◽  
Exceedance Probability ◽  
Considerable Influence ◽  
Analysis Method ◽  
Ground Acceleration ◽  
Mountainous Regions ◽  
The Hill

The hill buildings sited on slopes have been widely constructed in mountainous regions. In order to estimate the seismic vulnerability of the hill buildings with uneven ground column heights under the effect of potential earthquakes, the exceedance probabilities of the hill buildings sited on different angle slopes in peak ground acceleration (PGA) are calculated and compared by using the incremental dynamic analysis method. The fragility curves show the slope angle has considerable influence on the seismic performance. Specifically, the exceedance probability increases with the increasing of the slope angle at the same performance level.

Seismic Hazard Analysis for an NPP Site

2004 ◽  
Author(s):  
A. K. Ghosh ◽  
H. S. Kushwaha
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Hazard Analysis ◽  
Structural Response ◽  
Response Spectra ◽  
Seismic Fragility ◽  
Material Strength ◽  
Ground Acceleration ◽  
Hazard Response

The various uncertainties and randomness associated with the occurrence of earthquakes and the consequences of their effects on the NPP components and structures call for a probabilistic seismic risk assessment (PSRA). However, traditionally, the seismic design basis ground motion has been specified by normalised response spectral shapes and peak ground acceleration (PGA). The mean recurrence interval (MRI) used to be computed for PGA only. The present work develops uniform hazard response spectra i.e. spectra having the same MRI at all frequencies for Kakrapar Atomic Power Station site. Sensitivity of the results to the changes in various parameters has also been presented. These results determine the seismic hazard at the given site and the associated uncertainties. The paper also presents some results of the seismic fragility for an existing containment structure. The various parameters that could affect the seismic structural response include material strength of concrete, structural damping available within the structure and the normalized ground motion response spectral shape. Based on this limited case study the seismic fragility of the structure is developed. The results are presented as families of conditional probability curves plotted against the peak ground acceleration (PGA). The procedure adopted incorporates the various randomness and uncertainty associated with the parameters under consideration.

Earthquake-induced site effect in the oil field deposit of Absheron peninsula (Azerbaijan)

2020 ◽  
Author(s):  
Gulam Babayev ◽  
Fakhraddin Kadirov (Gadirov)
Keyword(s):  
Shear Wave ◽  
Peak Ground Acceleration ◽  
Empirical Relationship ◽  
Seismic Effect ◽  
Oil Field ◽  
Second Phase ◽  
Soil Amplification ◽  
Ground Acceleration ◽  
Scenario Earthquake ◽  
Design Earthquake

<p>Absheron peninsula (Azerbaijan) area was hit by the strong Caspian earthquakes on November 25, 2000 with Mw6.1 and 6.2 magnitudes. The seismic networks successfully recorded the foreshock, main shock and many aftershocks at respective locations. By using probabilistic analysis, magnitude of design earthquake for the current study in the oilfield was taken as 6.3. From this concept design (scenario) earthquake, accelerations were estimated for the distance of 35 km. In the second phase of the study, soil amplification factors and site characteristics data from boreholes were determined and estimated. In the next phase, the study uses synthesized accelerograms formed on the basis of simulation of the seismic wave propagation processes through ground layer aiming to determine the quantitative characteristics of seismic effect on the oilfield region. Soil amplification values estimated by empirical relationships in terms of shear wave velocities are in the range of 0.7 and 1.9 values. Shear wave velocity (Vs, 30) values are 100 and 110 (m/s). The PGA values for the study area were evaluated by considering the local site effects. Peak ground acceleration varies between 100 – 380 gal. On the basis of the empirical relationship between MSK-64 and peak ground acceleration, the special distribution of intensity of the design earthquake with intensity of >8 is represented. Finally, the study presents possible relationship between seismic effect and daily oil recovery which states the direct proportional characteristics.</p><p><strong>Keywords: </strong>ground classification, oilfield, scenario earthquake, Vs30, amplification factor, peak ground acceleration</p>

Relationships between ground motion parameters and damaged buildings for 2016 Mw 6.4 Meinong, Taiwan Earthquake

2020 ◽  
Author(s):  
Guan-Yi Song ◽  
Yih-Min Wu
Keyword(s):  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Hazard Analysis ◽  
Assessment System ◽  
Peak Ground Velocity ◽  
Current Status ◽  
Ground Acceleration ◽  
Ground Motion Parameters ◽  
Motion Parameters ◽  
Seismic Damage Assessment

<p>The relationships between ground motion parameters (including peak ground acceleration, PGA; peak ground velocity, PGV) and building damages are crucial to estimate the possible seismic losses for future destructive earthquakes. One such relationship had been established based on the 1999 Chi-Chi earthquake (Mw=7.6). Since 2010, a new assessment system of seismic damaged buildings had been adopted in Taiwan. Damaged buildings are now classified into two categories, yellow-tagged buildings are amendable and red-tagged buildings may need to rebuild. Our main goal is to renew the relationship to better reflect the current status in Taiwan, both in the buildings and assessment system. 2016 Meinong earthquake (Mw=6.4) caused the most damaging buildings in Taiwan since 1999 Chi-Chi earthquake. It’s an opportunity to combine ground motion data with building assessments for the new regression relationship. From the results, we find out that in the Meinong earthquake, the PGA seems to possess a higher correlation to the building damages, contrary to the previous studies. Further investigation suggests that it may be due to the biased sample size to the damaged buildings, that is, most of the damaged buildings tend to be lower.</p><p>Keywords: Hazard analysis, Peak ground acceleration, Peak ground velocity, Seismic damage assessment</p>

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