Seismic Site Classification and Site Period Determination of NIT Silchar Using MASW

2020 ◽  
pp. 507-522
Author(s):  
Arindam Saha ◽  
Kallol Saha ◽  
Ashim Kanti Dey
Keyword(s):  
Site Classification ◽  
Site Period

Determination of seismic site classification of seismic recording stations in the Himalayan region using HVSR method

2019 ◽  
Vol 116 ◽  
pp. 304-316 ◽  
Author(s):  
P. Anbazhagan ◽  
K.N. Srilakshmi ◽  
Ketan Bajaj ◽  
Sayed S.R. Moustafa ◽  
Nassir S.N. Al-Arifi
Keyword(s):  
Himalayan Region ◽  
Site Classification ◽  
Seismic Recording ◽  
Hvsr Method

Determination of site period for NZS1170.5:2004

2014 ◽  
Vol 47 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Tam Larkin ◽  
Chris Van Houtte
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Closed Form Solution ◽  
Form Solution ◽  
Site Classification ◽  
Lumped Mass ◽  
Mass System ◽  
Site Classes ◽  
Site Period

The fundamental site period, T, is a key parameter for site classification in NZS 1170.5:2004. Many sites in New Zealand will fall into site classes C and D, where the boundary between the site classes is T = 0.6 seconds. NZS 1170.5 offers several methods of determining site classification. The intent of this paper is to expand on NZS 1170.5 and guide practising engineers towards more accurate and efficient methods for determining site period. We review methods to calculate the shear-wave velocity, then give specific examples for calculating the site period for five types of soil profile (uniform layer, shear-wave velocity increasing as a power of depth, shear modulus increasing linearly with depth, two-layer profile and three-layer profile). We find that NZS 1170.5 clause 3.1.3.7 for calculating site period at layered sites is unconservative and inconsistent with two other well-accepted methods for calculating site period. We consider the most accurate and efficient method of calculating site period for layered sites is to represent the profile as a lumped mass system, then calculate the fundamental frequency from the eigenvalues of the system. The successive application of the two-layer closed form solution is also considered an acceptable method.

Rapid Post-Earthquake Microtremor Measurements for Site Amplification and Shear Wave Velocity Profiling in Kathmandu, Nepal

2017 ◽  
Vol 33 (1_suppl) ◽  
pp. 55-72 ◽  
Author(s):  
Sheri Molnar ◽  
John Onwuemeka ◽  
Sujan Raj Adhikari
Keyword(s):  
Surface Wave ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Joint Inversion ◽  
Ambient Vibration ◽  
Site Classification ◽  
Source Surface ◽  
Individual Measurement ◽  
Site Period

This paper presents application of microtremor (ambient vibration) and surface wave field techniques for post-earthquake geotechnical reconnaissance purposes in Kathmandu, Nepal. Horizontal-to-vertical spectral ratios (HVSR) are computed from microtremor recordings at 16 individual measurement locations to obtain an estimate of fundamental frequency (site period) of the subsurface soils. A combination of active- and passive-source surface wave array testing was accomplished at five key sites including Kathmandu's Durbar Square and Airport. Joint inversion of each site's higher frequency dispersion and lower frequency HVSR data sets provides an estimate of subsurface material stiffness [i.e., shear wave velocity ( V S) depth profiles]. Direct comparison of our V S profiling at Kathmandu Durbar Square and that accomplished by downhole V S and/or standard penetration testing (SPT) profiling yield similar results. Classification of the five sites based on average V S, site period, and/or basin depth is presented. There is little differentiation in these site classification designations amongst the five sites, which does not capture significant differences in observed earthquake damage.

A Study on Elastic Input Energy Spectra Based on the Compound Intensity Indicator

2012 ◽  
Vol 446-449 ◽  
pp. 140-145
Author(s):  
Li He ◽  
Xian Guo Ye
Keyword(s):  
Ground Motion ◽  
Damping Ratio ◽  
Energy Spectra ◽  
Site Classification ◽  
Input Energy ◽  
Damage Potential ◽  
Normalization Methods ◽  
Seismic Records ◽  
Energy Based Design

Determination of a SDOFS elastic input energy is the primary problem to solve for energy-based design approach. The effect of ground motion and damping ratio were analyzed on the input energy spectra. is selected as the compound ground motion intensity indicator to represent the damage potential of strong ground motion. Through inputting of 188 seismic records according to the site classification of Chinese seismic code, three-segment elastic energy spectra are proposed based on normalization methods. The calculation formula of the peak and the value of long-period section of the input energy spectra are presented for four categories of site conditions by statistical analysis. Moreover, calculation procedure of the total energy input is given in the paper.

scholarly journals Seismic site classification and site period mapping in the Ottawa area using geophysical methods

2010 ◽  
Author(s):  
J A Hunter ◽  
H L Crow ◽  
G R Brooks ◽  
M Pyne ◽  
D Motazedian ◽  
...  
Keyword(s):  
Geophysical Methods ◽  
Site Classification ◽  
Period Mapping ◽  
Site Period

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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