Relevance Vector Machine for Evaluating Seismic Liquefaction Potential Using Shear Wave Velocity

2010 ◽  
Author(s):  
Pijush Samui ◽  
T. G. Sitharam
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Relevance Vector Machine ◽  
Liquefaction Potential ◽  
Seismic Liquefaction

Probabilistic neural network for evaluating seismic liquefaction potential

2002 ◽  
Vol 39 (1) ◽  
pp. 219-232 ◽  
Author(s):  
Anthony TC Goh
Keyword(s):  
Neural Network ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Probabilistic Neural Network ◽  
Penetration Test ◽  
Cone Penetration ◽  
Liquefaction Potential ◽  
Seismic Liquefaction ◽  
The Relationship

Simplified techniques based on in situ testing methods are commonly used to assess seismic liquefaction potential. Many of these simplified methods are based on finding the liquefaction boundary separating two categories (the occurrence or non-occurrence of liquefaction) through the analysis of liquefaction case histories. As the liquefaction classification problem is highly nonlinear in nature, it is difficult to develop a comprehensive model taking into account all the independent variables, such as the seismic and soil properties, using conventional modeling techniques. Hence, in many of the conventional methods that have been proposed, simplified assumptions have been made. In this study, a probabilistic neural network (PNN) approach based on the Bayesian classifier method is used to evaluate seismic liquefaction potential based on actual field records. Two separate analyses are performed, one based on cone penetration test data and one based on shear wave velocity data. The PNN model effectively explores the relationship between the independent and dependent variables without any assumptions about the relationship between the various variables. Through the iterative presentation of the data (the learning phase), this study serves to demonstrate that the PNN can "discover" the intrinsic relationship between the seismic and soil parameters and the liquefaction potential. Comparisons indicate that the PNN models perform far better than the conventional methods in predicting the occurrence or non-occurrence of liquefaction.Key words: cone penetration test, neural networks, prediction, probabilistic neural network, sand, seismic liquefaction, shear wave velocity.

Soil Liquefaction Evaluation of Offshore Site Based on In Situ Shear Wave Velocity Measurements

2013 ◽  
Vol 405-408 ◽  
pp. 470-473
Author(s):  
Sheng Jie Di ◽  
Ming Yuan Wang ◽  
Zhi Gang Shan ◽  
Hai Bo Jia
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Wind Farm ◽  
Soil Liquefaction ◽  
Offshore Wind ◽  
Velocity Measurements ◽  
Liquefaction Resistance ◽  
Liquefaction Potential

A procedure for evaluating liquefaction resistance of soils based on the shear wave velocity measurements is outlined in the paper. The procedure follows the general formal of the Seed-Idriss simplified procedure. In addition, it was developed following suggestions from industry, researchers, and practitioners. The procedure correctly predicts moderate to high liquefaction potential for over 95% of the liquefaction case histories. The case study for the site of offshore wind farm in Jiangsu province is provided to illustrate the application of the proposed procedure. The feature of the soils and the shear wave velocity in-situ tested in site are discussed and the liquefaction potential of the layer is evaluated. The application shows that the layers of the non-cohesive soils in the depths 3-11m may be liquefiable according to the procedure.

scholarly journals Evaluation of liquefaction potentials based on shear wave velocities in Pohang City, South Korea

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yumin Ji ◽  
Byungmin Kim ◽  
Kiseog Kim
Keyword(s):  
South Korea ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Surface ◽  
Velocity Profiles ◽  
Liquefaction Potential ◽  
Attenuation Relationships ◽  
Cyclic Resistance ◽  
Sand Boils

AbstractThis study evaluates the potentials of liquefaction caused by the 2017 moment magnitude 5.4 earthquake in Pohang City, South Korea. We obtain shear wave velocity profiles measured by suspension PS logging tests at the five sites near the epicenter. We also perform downhole tests at three of the five sites. Among the five sites, the surface manifestations (i.e., sand boils) were observed at the three sites, and not at the other two sites. The maximum accelerations on the ground surface at the five sites are estimated using the Next Generation Attenuation relationships for Western United State ground motion prediction equations. The shear wave velocity profiles from the two tests are slightly different, resulting in varying cyclic resistance ratios, factors of safety against liquefaction, and liquefaction potential indices. Nevertheless, we found that both test approaches can be used to evaluate liquefaction potentials. The liquefaction potential indices at the liquefied sites are approximately 1.5–13.9, whereas those at the non-liquefied sites are approximately 0–0.3.

scholarly journals Liquefaction hazard zonation mapping of the Saitama City, Japan

2010 ◽  
Vol 40 ◽  
pp. 69-76 ◽  
Author(s):  
Rama Mohan Pokhrel ◽  
Jiro Kuwano ◽  
Shinya Tachibana
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Hazard Zonation ◽  
Liquefaction Potential ◽  
Amplification Ratio ◽  
Liquefaction Hazard ◽  
Clayey Silt ◽  
The City ◽  
Very High

Liquefaction hazard zonation mapping of the Saitama City targeted on the Kanto Plain NW Edge Fault is described in this paper. The study involves the geotechnical properties of the alluvial soil of the city including Standard Penetration Test (SPT), shear wave velocity and other geological data analysis. The city being highly urbanized is situated on the soft soil (alluvial deposits) at the proximity of an active seismic fault that has increased the possibility of liquefaction hazard in the area. Kanto Plain NW Edge Fault is an active fault that lies very near to the Saitama City having the estimated possible earthquake magnitude of 7.4. The possible peak horizontal ground acceleration (amax) from this earthquake is calculated as from 0.15 g to 0.30 g. By considering all possible acceleration values the liquefaction potential maps were prepared and presented in this paper. Additionally, the shear wave velocity is very low and amplification ratio is very high at the marshy deposit but it has comparatively high velocity and low amplification ratio at the marine loam deposit area of the Omiya Plateau. In this paper the liquefaction potential of the area is expressed in terms of liquefaction potential index (PL). The PL value for the clayey silt deposit in the marshy area with shallow water table is very high. In addition, the PL value in the marine loam deposit of the Omiya Plateau is less which indicates that loam deposit has less liquefaction potential than marshy deposit. The map obtained from this study was validated with the field condition of the study area. Hence, it is expected that this study will assist in characterizing the seismic hazards and its mitigation and will provide valuable information for urban planning in the study area in future.

Seismic cone penetration test for evaluating liquefaction potential under cyclic loading

1992 ◽  
Vol 29 (4) ◽  
pp. 686-695 ◽  
Author(s):  
P. K. Robertson ◽  
D. J. Woeller ◽  
W. D. L. Finn
Keyword(s):  
Cyclic Loading ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Penetration Resistance ◽  
Penetration Test ◽  
Cone Penetration ◽  
Liquefaction Potential ◽  
A Site ◽  
Seismic Cone Penetration Test

Impressive progress has been made in the last 25 years in recognizing liquefaction hazards, understanding liquefaction phenomena, and analyzing and evaluating the potential for liquefaction at a site. Recent findings related to the application of the seismic cone penetration test (SCPT) for the evaluation of liquefaction potential under cyclic loading are presented and discussed. The SCPT provides independent measurements of penetration resistance, pore pressures, and shear-wave velocity in a fast, continuous, and economic manner. The current methods available for evaluating liquefaction using penetration resistance are presented and discussed. Recent developments in the application of shear-wave velocity to evaluate liquefaction potential are discussed, and a new method based on normalized shear-wave velocity is proposed. Limited case-history data are used to evaluate and support the proposed correlation. A worked example is presented to illustrate the potential usefulness of the SCPT for evaluating liquefaction potential at a site. Key words : liquefaction, in situ tests, seismic.

Guide for Shear-Wave-Based Liquefaction Potential Evaluation

2004 ◽  
Vol 20 (2) ◽  
pp. 285-308 ◽  
Author(s):  
Ronald D. Andrus ◽  
Kenneth H. Stokoe ◽  
C. Hsein Juang
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Evaluation Method ◽  
Field Performance ◽  
Small Strain ◽  
Liquefaction Resistance ◽  
Liquefaction Potential ◽  
Soil Aging ◽  
Potential Evaluation

Small-strain shear-wave velocity measurements provide a promising approach to liquefaction potential evaluation. In some cases, where only seismic measurements are possible, it may be the only alternative to the penetration-based approach. Various investigators have developed relationships between shear wave velocity and liquefaction resistance. Successful application of any liquefaction evaluation method requires that procedures used in their development also be used in their application. This paper presents detailed guidelines for applying the procedure described in Andrus and Stokoe that was developed using suggestions from two workshops and following the general format of the Seed-Idriss simplified procedure. Correction factors to velocity and liquefaction resistance for soil aging are suggested. Based on the work by Juang et. al., factors of safety of 1.0, 1.2, and 1.5 correspond to probabilities of liquefaction of about 0.26, 0.16, and 0.08, respectively. Additional field performance data are needed from all soil types, particularly denser and older soil deposits shaken by stronger ground motions, to further validate the recommended procedure.

Study on Critical Shear Wave Velocity of Saturated Loess Foundation Soil Liquefaction under Different Seismic Magnitudes Action

2012 ◽  
Vol 594-597 ◽  
pp. 1720-1726 ◽  
Author(s):  
Ping Wang ◽  
Lan Min Wang ◽  
Qian Wang ◽  
Jun Wang
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Evaluation Method ◽  
Soil Liquefaction ◽  
Test Results ◽  
Foundation Soil ◽  
Liquefaction Potential ◽  
Potential Evaluation ◽  
Loess Region

Use of Seed’s simplified liquefaction evaluation method, combined with the dynamic triaxial test results, and the wave velocity of site liquefaction, to evaluate liquefaction potential of the three typical loess sites under the action of different seismic magnitudes, and calculate the boundary depth of the liquefaction site. Moreover, give the corresponding relationship between the typical loess site liquefaction boundary depth and shear wave velocity, and get the critical shear wave velocity of typical loess liquefaction site. The results of the study show that, (1) saturated loess site could be liquefied under the action of a certain intensity earthquake. (2) saturated soil layers which do not produce liquefied under the action of 6.5 degree earthquake，its critical shear wave velocity is about 200 m/s, and under the action of 7 degree earthquake its critical shear wave velocity is about 303 m/s, under the action of 8 degree earthquake its critical shear wave velocity is about 368 m/s. This conclusion enriches and develops the basis of liquefaction potential evaluation in the loess region.

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