scholarly journals Impact of Local Site Conditions on Simulation of Non-stationary Spatial Variable Seismic Motions

2021 ◽  
Author(s):  
Nassima Benmansour ◽  
Rachid Derbal ◽  
Mustapha Djafour ◽  
Salvador Ivorra ◽  
Mohammed Matallah
Keyword(s):  
Spatial Variability ◽  
Site Conditions ◽  
Seismic Excitations ◽  
Multi Scale ◽  
Seismic Motion ◽  
Local Site ◽  
Scale Structures ◽  
Wave Passage ◽  
Coherency Loss ◽  
Local Site Conditions

It is commonly accepted that multi-scale structures are subject to spatially variable seismic motions. This spatial variability of seismic motions is described by different intensities at different locations due to the coherency loss effect, wave passage effect and local site conditions. For multi-scale structures, the estimation of seismic excitations must consider these factors. Often, the influence of the spatial variability of seismic motion on the dynamic response of structures is performed by neglecting the site effect. In several cases, it has been observed that the high intensities of seismic motion are caused by the site amplification besides coherency loss and wave passage effects. This study aims to analyze the impact of local site conditions on seismic motions. For this purpose, a method of simulation of spatially variable seismic motions is performed. The seismic signals on the bedrock are defined by considering a target power spectral density and a coherency loss model. According to the seismic wave propagation theory, the projection of these seismic motions on the surface is realized. The results of this study show that neglecting the local site conditions induces an undervaluation of spatially variable seismic excitations.

scholarly journals Anomalous transients in GPS measurements due to induced changes in local site conditions

2019 ◽  
Vol 128 (7) ◽  
Author(s):  
Sandeep Gupta ◽  
Paresh Nath Singharoy ◽  
Rajeev Kumar Yadav ◽  
Joshi K Catherine ◽  
Roland Burgmann ◽  
...  
Keyword(s):  
Site Conditions ◽  
Gps Measurements ◽  
Local Site ◽  
Induced Changes ◽  
Local Site Conditions

Effects of Local Site Conditions on Seismic Responses of a Reactor Containment Structure

2006 ◽  
Author(s):  
Jian-Chu Chen
Keyword(s):  
Shear Wave ◽  
Half Space ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Response Spectra ◽  
Site Conditions ◽  
Pressurized Water ◽  
Soil Thickness ◽  
Local Site ◽  
Local Site Conditions

The effect of local site conditions on soil-structure interaction (SSI) responses of a pressurized water reactor (PWR) containment building founded on different site conditions was investigated using substructure SSI analysis procedure. The structure was analyzed for both surface and embedded foundation conditions for each site with an exception for one half-space site with shear wave velocity 5000 fps. Only the surface foundation was analyzed for this very stiff half-space site. A total of 23 analyses are presented in this paper. Responses including peak ground accelerations and response spectra at selected locations were compared. The results indicate that the local site conditions have a significant influence on SSI response particularly for the structure founded on the surface of shallow soil deposit overlying competent rock. For thick soil sites having shear wave velocity larger than 1000 fps and having soil thickness greater than 3.5 times the radius of the structure, the effect of the soil thickness is not important.

scholarly journals A Parametric Study of Nonlinear Seismic Response Analysis of Transmission Line Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Li Tian ◽  
Yanming Wang ◽  
Zhenhua Yi ◽  
Hui Qian
Keyword(s):  
Transmission Line ◽  
Seismic Response ◽  
Parametric Study ◽  
Ground Motions ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Nonlinear Seismic Response ◽  
Local Site ◽  
Wave Passage ◽  
Coherency Loss

A parametric study of nonlinear seismic response analysis of transmission line structures subjected to earthquake loading is studied in this paper. The transmission lines are modeled by cable element which accounts for the nonlinearity of the cable based on a real project. Nonuniform ground motions are generated using a stochastic approach based on random vibration analysis. The effects of multicomponent ground motions, correlations among multicomponent ground motions, wave travel, coherency loss, and local site on the responses of the cables are investigated using nonlinear time history analysis method, respectively. The results show the multicomponent seismic excitations should be considered, but the correlations among multicomponent ground motions could be neglected. The wave passage effect has a significant influence on the responses of the cables. The change of the degree of coherency loss has little influence on the response of the cables, but the responses of the cables are affected significantly by the effect of coherency loss. The responses of the cables change little with the degree of the difference of site condition changing. The effect of multicomponent ground motions, wave passage, coherency loss, and local site should be considered for the seismic design of the transmission line structures.

Driveability Analysis Techniques for Offshore Pile Installations

2013 ◽  
Author(s):  
Scott Webster ◽  
Brent Robinson
Keyword(s):  
American Petroleum Institute ◽  
Site Conditions ◽  
Offshore Platforms ◽  
Soil Resistance ◽  
Analysis Techniques ◽  
Pile Installation ◽  
Local Site ◽  
Methods Of Calculation ◽  
The World ◽  
Local Site Conditions

Pile driveability analyses for offshore platforms require a unique set of criteria, which may not normally be associated with other pile foundation installations. The selected hammers, pile makeup details and soil profile must be carefully reviewed, as these factors will determine if pile installations will be successful. The most important of the variables to establish is the expected Soil Resistance to Driving (SRD). Common practice is to relate the SRD to the Static Soil Resistance (SSR) which is normally provided based upon the American Petroleum Institute (API) methods of calculation or some variance based upon local site conditions and experience. In addition, due to the substantial use of hydraulic hammers hammer operating energies must be selected such that pile driving can be accomplished while avoiding pile damage. Current procedures used for driveability analysis will be provided and the methods of parameter selection discussed in detail. These procedures, which have been used on several offshore projects in various offshore fields around the world, will be presented with the original driveability analysis and the recorded pile installation records. A method to determine the expected SRD will be discussed based upon the experience collected from these sites which are in numerous offshore fields worldwide. Four Case Studies are shown to validate the described methodology.

scholarly journals Influence of Local Site Effects on the Typological Fragility Curves for Class-Oriented Masonry Buildings in Aggregate Condition

2021 ◽  
Vol 15 (1) ◽  
pp. 149-164
Author(s):  
Antonio Formisano ◽  
Nicola Chieffo ◽  
Francesco Clementi ◽  
Marius Mosoarca
Keyword(s):  
Site Effects ◽  
Fragility Curves ◽  
Stone Masonry ◽  
Reference Scenario ◽  
Masonry Building ◽  
Site Conditions ◽  
Local Site Effects ◽  
Local Site ◽  
Starting Point ◽  
Local Site Conditions

Background: The Municipality of Baranello, located in the province of Campobasso, is considered as a reference case study for implementing a systematic procedure for the assessment of local site effects. The territory is characterised by a heterogeneous soil, made of a basal interval formed in large part by outcrops found along with the middle-basal bands of the local slopes, which is particularly sensitive to geo-hazard effects. Aims: The present work aims to investigate the influence of local site effects on the seismic vulnerability of an oriented- class of masonry building compounds. The historical buildings surveyed are mainly made up of rough stone masonry, particularly vulnerable to seismic phenomena. The buildings are appropriately grouped in typological classes based on the CARTIS form and then subdivided into different categories according to the EMS-98 scale based on their geometrical and structural characteristics. Methods: The performed vulnerability analysis is based on a vulnerability-index method conceived for buildings grouped in aggregate condition. Moreover, the expected damage scenario is properly evaluated based on a specific attenuation law to take into consideration the effect produced by a reference scenario event. Furthermore, the local site conditions have been evaluated based on a 1D half space approach in order to predict the possible increment of the expected damage due to the soil stratigraphy. Results: The local site conditions provide a global increment of the expected vulnerability of 33% with respect to the case in which the geo-hazard effects are neglected. In this activity framework, typological fragility curves are derived for comparing the exceeding probability thresholds for the examined building classes. Conclusion: The proposed research represents an important starting point for large-scale vulnerability assessment since it provides a simplified and comprehensive method for predicting seismic damage scenarios of historic center considering local site effects.

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