Influence of ground motion spatial variations and local soil conditions on the seismic responses of buried segmented pipelines

2012 ◽  
Vol 44 (5) ◽  
pp. 663-680 ◽  
Author(s):  
Kaiming Bi ◽  
Hong Hao
Keyword(s):  
Ground Motion ◽  
Spatial Variations ◽  
Soil Conditions ◽  
Seismic Responses ◽  
Local Soil ◽  
Local Soil Conditions

scholarly journals Investigating the influence of topographic irregularities and two-dimensional effects on surface ground motion intensity with one- and two-dimensional analyses

2014 ◽  
Vol 14 (7) ◽  
pp. 1773-1788 ◽  
Author(s):  
G. Ç. İnce ◽  
L. Yılmazoğlu
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Soil Conditions ◽  
Response Analysis ◽  
Two Dimensional ◽  
Ground Acceleration ◽  
Equivalent Linear ◽  
Local Soil ◽  
Different Depths ◽  
Earthquake Response Analysis

Abstract. In this work, the surface ground motion that occurs during an earthquake in ground sections having different topographic forms has been examined with one and two dynamic site response analyses. One-dimensional analyses were undertaken using the Equivalent-Linear Earthquake Response Analysis (EERA) program based on the equivalent linear analysis principle and the Deepsoil program which is able to make both equivalent linear and nonlinear analyses and two-dimensional analyses using the Plaxis 8.2 software. The viscous damping parameters used in the dynamic site response analyses undertaken with the Plaxis 8.2 software were obtained using the DeepSoil program. In the dynamic site response analyses, the synthetic acceleration over a 475-year return period representing the earthquakes in Istanbul was used as the basis of the bedrock ground motion. The peak ground acceleration obtained different depths of soils and acceleration spectrum values have been compared. The surface topography and layer boundaries in the 5-5' cross section which cuts across the study area west to east were selected in order to examine the effect of the land topography and layer boundaries on the analysis results, and were flattened and compared with the actual status. The analysis results showed that the characteristics of the surface ground motion change in relation to the varying local soil conditions and land topography.

scholarly journals Realistic modelling of observed seismic motion in compIex sedimentary basins

1994 ◽  
Vol 37 (6) ◽  
Author(s):  
D. Fah ◽  
G. F. Panza
Keyword(s):  
Ground Motion ◽  
Mexico City ◽  
Sedimentary Basin ◽  
Numerical Technique ◽  
Sedimentary Basins ◽  
Space Distribution ◽  
Soil Conditions ◽  
Macroseismic Data ◽  
Resonance Effects ◽  
Local Soil

Three applications of a numerical technique are illustrated to model realistically the seismic ground motion for complex two-dimensional structures. First we consider a sedimentary basin in the Friuli region, and we model strong motion records from an aftershock of the 1976 earthquake. Then we simulate the ground motion caused in Rome by the 1915, Fucino (Italy) earthquake, and we compare our modelling with the damage distribution observed in the town. Finally we deal with the interpretation of ground motion recorded in Mexico City, as a consequence of earthquakes in the Mexican subduction zone. The synthetic signals explain the major characteristics (relative amplitudes, spectral amplification, frequency content) of the considered seismograms, and the space distribution of the available macroseismic data. For the sedimentary basin in the Friuli area, parametric studies demonstrate the relevant sensitivity of the computed ground motion to small changes in the subsurface topography of the sedimentary basin, and in the velocity and quality factor of the sediments. The relative Arias Intensity, determined from our numerical simulation in Rome, is in very good agreoment with the distribution of damage observed during the Fucino earthquake. For epicentral distances in the range 50 km-100 km, the source location and not only the local soil conditions control the local effects. For Mexico City, the observed ground motion can be explained as resonance effects and as excitation of local surface waves, and the theoretical and the observed maximum spectral amplifications are very similar. In general, our numerical simulations estimate the maximum and average spectral amplification for specific sites, i.e. they are a very powerful tool for accurate micro-zonation

Modification of seismograph records for effects of local soil conditions

1972 ◽  
Vol 62 (6) ◽  
pp. 1649-1664 ◽  
Author(s):  
P. Schnabel ◽  
H. Bolton Seed ◽  
J. Lysmer
Keyword(s):  
San Francisco ◽  
Ground Surface ◽  
Soil Conditions ◽  
Local Soil ◽  
Geological Conditions ◽  
Soil Deposits ◽  
Time Histories ◽  
Seismic Records ◽  
Local Soil Conditions ◽  
Good Agreement

abstract A procedure for modifying the time histories of seismic records for the effect of local soil conditions is presented. The method is based on a conventional one-dimensional wave-propagation approach with equivalent linear soil properties, extended to practical use for transient motions through the Fast Fourier technique. The validity of the approach is tested against the motions recorded at four soil sites and one rock site during the 1957 San Francisco earthquake. The good agreement between the computed and recorded values indicates that rock motions can be computed from motions recorded on soil deposits, and that the computed rock motions in turn can be used to predict the motion that would have been recorded under different soil and geological conditions. The method is also used to evaluate the probable rock motions in the vicinity of El Centro in the earthquake of 1940 and the ground surface motions that could have been developed on various soil conditions in the same general area.

scholarly journals Permafrost Thaw with Thermokarst Wetland-Lake and Societal-Health Risks: Dependence on Local Soil Conditions under Large-Scale Warming

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 574 ◽  
Author(s):  
Jan-Olof Selroos ◽  
Hua Cheng ◽  
Patrik Vidstrand ◽  
Georgia Destouni
Keyword(s):  
Large Scale ◽  
Mineral Soil ◽  
Soil Conditions ◽  
Lake Ecosystems ◽  
Surface Warming ◽  
Permafrost Thaw ◽  
Rock Formations ◽  
Local Soil ◽  
Local Soil Conditions ◽  
Mineral Soils

A key question for the evolution of thermokarst wetlands and lakes in Arctic and sub-Arctic permafrost regions is how large-scale warming interacts with local landscape conditions in driving permafrost thaw and its spatial variability. To answer this question, which also relates to risks for ecology, society, and health, we perform systematic model simulations of various soil-permafrost cases combined with different surface-warming trends. Results show that both the prevalence and the thaw of permafrost depended strongly on local soil conditions and varied greatly with these for the same temperature conditions at the surface. Greater ice contents and depth extents, but also greater subsurface volumes thawing at depth under warming, are found for peat soils than other studied soil/rock formations. As such, more thaw-driven regime shifts in wetland/lake ecosystems, and associated releases of previously frozen carbon and pathogens, may be expected under the same surface warming for peatlands than other soil conditions. Such risks may also increase in fast permafrost thaw in mineral soils, with only small thaw-protection effects indicated in the present simulations for possible desertification enhancement of mineral soil covers.

Analysis of Earthing System Cabinet of Telekom Malaysia

2015 ◽  
Vol 799-800 ◽  
pp. 1249-1256
Author(s):  
David Caulker ◽  
Mohd Annuar Ramli
Keyword(s):  
Computer Simulation ◽  
Simulation Software ◽  
Current Injection ◽  
Soil Conditions ◽  
Soil Resistivity ◽  
Specific Location ◽  
Local Soil ◽  
Local Soil Conditions ◽  
Earthing Systems ◽  
The Impact

This paper investigated the impact on the earthing systems of cabinets of Telekom Malaysia (TM) when subjected to dangerous voltages due to current injection from remote sources. TM have received numerous cases regarding the failures of their cabinets due to power related issues (PRI) as well as lightning. These failures may have occurred partly due to the existing earthing systems installations. This research aims to determine earthing impedance of 5 ohms or less of TM cabinets with respect to local soil conditions. Low impedance earthing is not easy to realize mainly due to the local soil resistivity, layering and structures. To achieve a low impedance of below 5 ohms as per Telekom Malaysia's requirement, three types of earthing electrodes were modelled and simulated using CDEGS computer simulation software. Results have demonstrated that the existing earthing system of 3 rods practice by TM is sufficient for areas of resistivity less than 500ٹ-m. Combination of rectangular and vertical rods for resistivity of 500ٹ-m above is the preferred choice of earthing. Analysis and discussions presented in this study can be used as a guide for TM for their cabinet installations. Results also highlighted that achieving less than 5ٹ does not constitute a safe earthing system. Other parameters have to be taken into account before ascertain which type of earthing to be used in a specific location of a TM installation.

scholarly journals SEISMIC DAMAGE SCENARIOS IN KALAMATA (S. GREECE)

2017 ◽  
Vol 50 (3) ◽  
pp. 1495
Author(s):  
D. Kazantzidou-Firtinidou ◽  
I. Kassaras ◽  
A. Ganas ◽  
C. Tsimi ◽  
N. Sakellariou ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Fragility Curves ◽  
Site Amplification ◽  
Soil Conditions ◽  
Damage Scenarios ◽  
Local Soil ◽  
Protection Strategies ◽  
The Impact ◽  
The City

Damage scenarios are necessary tools for stakeholders, in order to prepare protection strategies and a total emergency post-earthquake plan. To this aim, four seismic hazard models were developed for the city of Kalamata, according to stochastic simulation of the ground motion, using site amplification functions derived from ambient noise HVSR measurements. The structural vulnerability of the city was assessed following an empirical macroseismic model, developed for the European urban environment (EMS-98). The impact of the vulnerability due to the seismic hazard potential is also investigated by means of synthetic response spectral ratios at 108 sites of the city. The expected damage grade per building block, is calculated by combining vulnerability with the respective seismic intensities, derived for the four seismic sources. The importance of the followed methodology for implementing microzonation studies is emphasized, since the expected influence of the ground motion amplification due to local soil conditions has been approximated in detail. Moreover, new fragility curves for the main structural types in Kalamata are proposed for each seismic scenario.

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