Taxonomy for evaluating the site-specific applicability of one-dimensional ground response analysis

2020 ◽  
Vol 128 ◽  
pp. 105865 ◽  
Author(s):  
Yumeng Tao ◽  
Ellen Rathje
Keyword(s):  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Site Specific ◽  
One Dimensional

Site-Specific Ground Motion Studies for a Deep Soil Site Near Ahmedabad, Gujarat

2018 ◽  
pp. 31-65
Author(s):  
A. Boominathan ◽  
Krishna Kumar ◽  
R. Vijaya
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Site Specific ◽  
Linear Approach ◽  
Specific Analysis ◽  
Soil Site ◽  
A Site

Design ground motions are usually developed by one of two approaches: by performing site-specific analyses or from provisions of building codes. Although contemporary codes consider the site effects to an extent, they provide more conservative estimates. Hence, site-specific analysis, which involves both the seismic hazard analysis and ground response analysis, is a preferred approach to obtain design ground motions. This chapter presents a site-specific analysis for a site near Ahmedabad, Gujarat. The seismic hazard analysis was carried out by DSHA approach. The site is predominantly characterized by deep stiff sandy clay deposits. Extensive shear wave velocity measurement is used for site classification and ground response analysis. The ground response analysis was carried out by using two approaches: the equivalent linear approach using SHAKE2000 and the non-linear approach using FLAC2D. The deep-stiff-soil site is found to amplify the ground motion. The response from nonlinear analysis is found to be considerably higher than those obtained from the equivalent linear approach.

One-Dimensional Effective Stress Non-Masing Nonlinear Ground Response Analysis of IIT Guwahati

2017 ◽  
Vol 8 (1) ◽  
pp. 1-27 ◽  
Author(s):  
Devdeep Basu ◽  
Arindam Dey ◽  
Shiv Shankar Kumar
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Response Analysis ◽  
Eastern Region ◽  
Seismic Zone ◽  
Ground Response ◽  
Accurate Identification ◽  
Ground Response Analysis ◽  
Soil Medium ◽  
One Dimensional

Ground response analysis (GRA) helps to assess the influence of the soil medium on the propagating shear waves and indicates about the characteristics of the waves reaching the ground surface from the bedrock level. Such a study becomes imperative for the urbanized alluvial banks of North-Eastern region of India, which is located in the highest seismic zone of the country. Conventionally, GRA is carried out based equivalent linear approach, which being a simplistic approach is unable to capture the nonlinear characteristics of saturated silty sands subjected to seismic shaking. This article presents the outcome of seismic one-dimensional nonlinear GRA of IIT Guwahati (located on a varying geology in the saturated alluvial banks of River Brahmaputra) considering pore-water pressure dissipation characteristics and non-Masing unload-reload criteria. Various ground response parameters obtained from the study helps in the accurate identification of the earthquake intensity based site amplification of the region expressed through a 2-D mapping.

A Site Specific Study on Evaluation of Design Ground Motion Parameters

2010 ◽  
Vol 1 (1) ◽  
pp. 1-24 ◽  
Author(s):  
A. Boominathan ◽  
S. Krishna Kumar
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Analysis ◽  
Seismic Hazard Analysis ◽  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Site Specific ◽  
Specific Analysis ◽  
A Site

Design ground motions are usually developed by one of the two approaches: site-specific analyses or from provisions of building codes. Although contemporary codes do consider approximately the site effects, they provide more conservative estimates. Hence it is preferred to carry out site specific analysis which involves both the seismic hazard analysis and ground response analysis. This article presents a site specific analysis for a seismically vulnerable site near Ahmedabad, Gujarat. The seismic hazard analysis was carried out by DSHA approach considering seismicity and seismotectonics within 250km radius. The site is predominantly characterized by deep stiff sandy clay deposits. Extensive shear wave velocity measurement by cross hole test is used for site classification and ground response analysis. The ground response analysis was carried out by equivalent linear approach using SHAKE2000. It is found that the deep stiff soil site considered is found to amplify the ground motion. The site specific response spectra obtained from RRS analysis is compared with the codal provision which reveals high spectral acceleration in site specific spectra for mid period range.

Integration of Viscoplastic Effects in a One-Dimensional Constitutive Model for Ground Response Analysis

2020 ◽  
Author(s):  
Samuel Yniesta ◽  
Mallak Janati-Idrissi
Keyword(s):  
Strain Rate ◽  
Stress Component ◽  
Response Analysis ◽  
Shear Strain Rate ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Strain Rate Effects ◽  
One Dimensional ◽  
Rate Effects ◽  
Modulus Reduction

During an earthquake, strain-rate effects affect both the stiffness and damping behaviour of soils, yet existing constitutive models for ground response analysis are typically formulated within a rate-independent framework. In this paper, a one-dimensional viscoplastic stress-strain model is presented to introduce strain rate effects in ground response analysis. Its constitutive equations are based on a model that uses a cubic spline fit of the modulus reduction curve and a coordinate transformation technique to match any input modulus reduction and damping curve. A viscous stress component is added to model the effect of strain rate on the mechanical behaviour of soils using a single input parameter. The model is able to reproduce the linear increase in shear strength with the logarithm of shear strain rate, and allows to introduce viscous effects in 1D ground response analysis with control over damping and modulus reduction behaviour. The model is implemented in a software for ground response analysis and used to predict the results of a centrifuge test modeling one-dimensional wave propagation. The results show that the model predicts accurately the amplification and attenuation of shear waves, in a context where strain rates impact significantly the response of the model.

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