Ground Motion Synthesis and Seismic Scenario in Guwahati City--A Stochastic Approach

2009 ◽  
Vol 80 (2) ◽  
pp. 233-242 ◽  
Author(s):  
S. K. Nath ◽  
A. Raj ◽  
K. K. S. Thingbaijam ◽  
A. Kumar
Keyword(s):  
Ground Motion ◽  
Stochastic Approach ◽  
Motion Synthesis ◽  
Guwahati City

Ground motion estimation at Guwahati city for an Mw 8.1 earthquake in the Shillong plateau

2008 ◽  
Vol 448 (1-4) ◽  
pp. 98-114 ◽  
Author(s):  
S.T.G. Raghu Kanth ◽  
S. Sreelatha ◽  
Sujit Kumar Dash
Keyword(s):  
Motion Estimation ◽  
Ground Motion ◽  
Shillong Plateau ◽  
Guwahati City

Seismic Ground Response Analysis of Some Typical Sites of Guwahati City

2013 ◽  
Vol 4 (1) ◽  
pp. 83-101 ◽  
Author(s):  
Shiv Shankar Kumar ◽  
A. Murali Krishna
Keyword(s):  
Ground Motion ◽  
Amplitude Ratio ◽  
Response Spectrum ◽  
Strong Motion ◽  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Ground Acceleration ◽  
Surface Level ◽  
Guwahati City

In this study, one dimensional equivalent–linear ground response analyses were performed for some typical sites in the Guwahati city, India. Six bore locations covering about 250 km2 area of the city were considered for the analyses. As the strong motion significantly influences the ground response, seven different recorded ground motions, varying in magnitude (6.1 to 8.1) and other ground motion parameters, were adopted. Seismic site analyses were carried out for all layers of borelogs using all the seven earthquakes. Results are presented in terms of surface acceleration histories, strain and shear stress ratio variation, response spectrum, Fourier amplitude ratio versus frequency. The results indicate that accelerations were amplified the most at the surface level. The range of peak ground acceleration (PGA) values obtained at the ground surface is about 0.2 g to 0.79 for a range of PGA considered at bedrock level (rigid half space at bottom of borelog) of 0.1 g to 0.34 g. The Fourier amplifications of ground motion at surface are in the range of 4.14 – 8.99 for a frequency band of 1.75 Hz to 3.13 Hz. The maximum spectral acceleration at six locations varies in the range of 1.0 g – 4.71 g for all the seven earthquakes. The study clearly demonstrated the role for site effect and the type of ground motion on the ground response. For a given earthquake motion, amplification factors at surface level change by almost about 20% to 70% depending on local site conditions.

A Stochastic Approach to Nonlinear Seismic Design Spectra

2010 ◽  
Author(s):  
Malek Brahimi
Keyword(s):  
Yield Strength ◽  
Ground Motion ◽  
Nonlinear Response ◽  
Moving Average ◽  
Response Spectra ◽  
Stochastic Approach ◽  
Earthquake Ground Motion ◽  
Autoregressive Moving Average ◽  
Design Spectra ◽  
Nonlinear Design

The purpose of this study is to examine the effects of yield strength ratios and damping values on the nonlinear response of Single Degree of Freedom Systems (S.D.F.S) subjected to earthquake ground motion. A stochastic approach to constructing design response spectra and period dependent strength reduction factors for current existing nonlinear design spectra is then proposed. Non-stationary stochastic models are adopted to characterize earthquake ground motion. Twenty simulated earthquakes accelerograms are generated for each of eight historical events using Autoregressive Moving Average (ARMA) techniques. The average of nonlinear response spectra for a given Structural period from a sample of twenty records for each event are calculated to obtain the response spectra. These response spectra are used to examine the effects of structural strength factors such as the yield strength ratio and damping value, and the effects of nonlinear stiffness models including the elastoplasic model, a stiffness degrading model and a stiffness softening model.

scholarly journals Analysis of the variability in ground-motion synthesis and inversion

2017 ◽  
Author(s):  
Paul A. Spudich ◽  
Antonella Cirella ◽  
Laura Scognamiglio ◽  
Elisa Tinti
Keyword(s):  
Ground Motion ◽  
Motion Synthesis ◽  
And Inversion

A Stochastic Approach in Estimating the Pseudo-Relative Spectral Velocity

1998 ◽  
Vol 14 (2) ◽  
pp. 301-317 ◽  
Author(s):  
Li Jun Liu ◽  
Shahram Pezeshk
Keyword(s):  
Ground Motion ◽  
Gaussian White Noise ◽  
Stochastic Approach ◽  
Gaussian Stationary Process ◽  
Spectral Velocity ◽  
Seismological Model ◽  
Pseudo Spectral ◽  
Amplitude Level ◽  
Motion Amplitude ◽  
Good Agreement

In the prediction of ground motion from seismological model by random vibration theory, the basic assumption as that the ground motion process is a bandlimited Gaussian white noise (BGWN). For pseudo-response spectral values, the estimation is based on the response of a single-degree-of-freedom (SDOF) system due to the input of BGWN. The function of an SDOF is a narrowband filter. Therefore, the response of an SDOF is a narrowband process that no longer satisfies the assumption of bandlimited random process. The property of a narrowband process is significantly different from that of a bandlimited process and should be incorporated into the estimation of pseudo-spectral values. A stochastic methodology is proposed to estimate the spectral values on the basis of narrowband Gaussian stationary process. A key feature of the method is the use of envelope crossings in lieu of press crossings of the ground motion amplitude level. This substitution makes the estimation of spectral values more accurate. Comparing our results with those of previous research studies, we will illustrate that our proposed approach is in a good agreement with that of the simulation of time domain.

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