Regression model for evaluating liquefaction potential by discriminant analysis of the SPT N value

2005 ◽  
Vol 42 (3) ◽  
pp. 856-875 ◽  
Author(s):  
Sheng-Yao Lai ◽  
Ping-Sien Lin ◽  
Ming-Jyh Hsieh ◽  
Hoi-Fung Jim
Keyword(s):  
Discriminant Analysis ◽  
Standard Penetration Test ◽  
Cyclic Stress ◽  
Soil Liquefaction ◽  
Liquefaction Resistance ◽  
Multivariate Statistical ◽  
Liquefaction Potential ◽  
Cyclic Stress Ratio ◽  
N Value ◽  
Spt N Value

Discriminant models are developed for evaluating soil liquefaction potential, using standard penetration test (SPT) data for 592 occurrences of liquefaction and nonliquefaction. The discriminant model used is a multivariate statistical method. The square root of the SPT N value, (N1)601/2, and the logarithm of the cyclic stress ratio, ln CSR7.5, are adopted as the major parameters for analyses. Two models measuring liquefaction resistance through the SPT N value are also established in this study, which allows calculated results to be compared with the empirical curves. Key words: liquefaction, discriminant analysis, misclassified probability.

scholarly journals Evaluation Of Bucharest Soil Liquefaction Potential

2015 ◽  
Vol 11 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Arion Cristian ◽  
Calarasu Elena ◽  
Neagu Cristian
Keyword(s):  
Surface Wave ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Penetration Test ◽  
Borehole Data ◽  
Liquefaction Resistance ◽  
Liquefaction Potential ◽  
Data Standard ◽  
Wave Methods ◽  
Surface Wave Method

Abstract The paper contains the experimental research performed in Bucharest like the borehole data (Standard Penetration Test) and the data obtained from seismic investigations (down-hole prospecting and surface-wave methods). The evaluation of the soils liquefaction resistance based on the results of the SPT, down-hole prospecting and surface-wave method tests and the use of the earthquake records will be presented.

scholarly journals A Liquefaction Study Using ENN, CA, and Biogeography Optimized-Based ANFIS Technique

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Construction Projects ◽  
Fuzzy Inference ◽  
Model Development ◽  
Standard Penetration Test ◽  
Cyclic Stress ◽  
Cultural Algorithm ◽  
Liquefaction Potential ◽  
Cyclic Stress Ratio ◽  
Inference System ◽  
Reliable Technique

In any construction projects,assessment of liquefaction potential induced due to seismic excitation during earthquake is a critical concern.The objective of present model development is to classify and assess liquefaction potential of soil.This paper addresses Emotional Neural Network(ENN), Cultural Algorithm(CA) and biogeography optimized(BBO) based adaptive neuro-fuzzy inference system (ANFIS) for liquefaction study.The performance of neural emotional network and cultural algorithm has been also discussed. BBO-ANFIS combines the biogeography features to optimize the ANFIS parameters to achieve higher prediction accuracy.The model is trained with case history of liquefaction databases.Two parameters are used as input such as the cyclic stress ratio and standard penetration test (SPT) value.The performance of these models was assessed using different indexes i.e. sensitivity, specificity, FNR, FPR and accuracy rate.The performance of all models is compared.Among the models, the BBO-ANFIS model has been outperformed and can be adopted as new reliable technique for liquefaction study.

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.

Prediction of liquefaction potential and pore water pressure beneath machine foundations

2014 ◽  
Vol 4 (3) ◽  
Author(s):  
Mohammed Fattah ◽  
Mohammed Al-Neami ◽  
Nora Jajjawi
Keyword(s):  
Pore Water ◽  
Sandy Soil ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Liquefaction ◽  
Elastic Model ◽  
Liquefaction Resistance ◽  
Overburden Pressure ◽  
Liquefaction Potential ◽  
Frequency Changes

AbstractThe present research is concerned with predicting liquefaction potential and pore water pressure under the dynamic loading on fully saturated sandy soil using the finite element method by QUAKE/W computer program. As a case study, machine foundations on fully saturated sandy soil in different cases of soil densification (loose, medium and dense sand) are analyzed. Harmonic loading is used in a parametric study to investigate the effect of several parameters including: the amplitude frequency of the dynamic load. The equivalent linear elastic model is adopted to model the soil behaviour and eight node isoparametric elements are used to model the soil. Emphasis was made on zones at which liquefaction takes place, the pore water pressure and vertical displacements develop during liquefaction. The results showed that liquefaction and deformation develop fast with the increase of loading amplitude and frequency. Liquefaction zones increase with the increase of load frequency and amplitude. Tracing the propagation of liquefaction zones, one can notice that, liquefaction occurs first near the loading end and then develops faraway. The soil overburden pressure affects the soil liquefaction resistance at large depths. The liquefaction resistance and time for initial liquefaction increase with increasing depths. When the frequency changes from 5 to 10 rad/sec. (approximately from static to dynamic), the response in displacement and pore water pressure is very pronounced. This can be attributed to inertia effects. Further increase of frequency leads to smaller effect on displacement and pore water pressure. When the frequency is low; 5, 10 and 25 rad/sec., the oscillation of the displacement ends within the period of load application 60 sec., while when ω = 50 rad/sec., oscillation continues after this period.

scholarly journals The effect of confinement in liquefaction tests carried out in a cyclic simple shear apparatus

2019 ◽  
Vol 92 ◽  
pp. 08002 ◽  
Author(s):  
Lucia Mele ◽  
Stefania Lirer ◽  
Alessandro Flora
Keyword(s):  
Simple Shear ◽  
Initial Conditions ◽  
Confining Pressure ◽  
Cyclic Stress ◽  
Shear Tests ◽  
Liquefaction Resistance ◽  
Pressurized Water ◽  
Cyclic Stress Ratio ◽  
Complex Behaviour ◽  
Continuous Rotation

The cyclic simple shear tests can be used to reproduce in laboratory the complex behaviour of the soil during an earthquake, simulating the continuous rotation of the principal stress axes. In this research a comparison of results between cyclic simple shear tests carried out with confining pressure or confining rings is reported. A cyclic simple shear apparatus is used to carry out tests with confining rings (the conventional way to carry out cyclic simple shear tests) and with a confining pressure applied to the specimen through pressurized water, where the K0 condition during consolidation is guaranteed by a sophisticated control system. The apparatus, in both the configurations, is described in detail. All tests were carried out on reconstituted specimens of an Italian sand with similar initial conditions, such as low relative density and confining pressure. All experimental results are reported in the plane cyclic stress ratio (CSR) and number of cycles where liquefaction occurs (Nliq) in order to evaluate the effect of confinement on the liquefaction resistance of the studied sand.

Evaluating cyclic liquefaction potential using the cone penetration test

1998 ◽  
Vol 35 (3) ◽  
pp. 442-459 ◽  
Author(s):  
P K Robertson ◽  
CE (Fear) Wride
Keyword(s):  
Earthquake Engineering ◽  
Sandy Soils ◽  
Cone Penetration Test ◽  
Soil Liquefaction ◽  
Penetration Test ◽  
Cone Penetration ◽  
Liquefaction Resistance ◽  
Liquefaction Potential ◽  
Engineering Research ◽  
Research Workshop

Soil liquefaction is a major concern for structures constructed with or on sandy soils. This paper describes the phenomena of soil liquefaction, reviews suitable definitions, and provides an update on methods to evaluate cyclic liquefaction using the cone penetration test (CPT). A method is described to estimate grain characteristics directly from the CPT and to incorporate this into one of the methods for evaluating resistance to cyclic loading. A worked example is also provided, illustrating how the continuous nature of the CPT can provide a good evaluation of cyclic liquefaction potential, on an overall profile basis. This paper forms part of the final submission by the authors to the proceedings of the 1996 National Center for Earthquake Engineering Research workshop on evaluation of liquefaction resistance of soils.Key words: cyclic liquefaction, sandy soils, cone penetration test

scholarly journals LPI Based Earthquake Induced Soil Liquefaction Susceptibility Assessment at Probashi Palli Abasan Project Area, Tongi, Gazipur, Bangladesh

2018 ◽  
Vol 10 (2) ◽  
pp. 105-116
Author(s):  
A. H. Farazi ◽  
N. Ferdous ◽  
A. S. M. M. Kamal
Keyword(s):  
Threshold Value ◽  
Flood Plain ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Cumulative Frequency ◽  
Liquefaction Potential ◽  
Project Area ◽  
Potential Index ◽  
Liquefaction Hazard ◽  
Simplified Procedure

This study aims at evaluation of seismic soil liquefaction hazard potential at Probashi Palli Abasan Project area of Tongi, Gazipur, exploiting standard penetration test (SPT) data of 15 boreholes, following Simplified Procedure. Liquefaction potential index (LPI) of each borehole was determined and then cumulative frequency distribution of clustered LPI values of each surface geology unit was determined assuming cumulative frequency at LPI = 5 as the threshold value for liquefaction initiation. By means of geotechnical investigation two surface geological units—Holocene flood plain deposits, and Pleistocene terrace deposits were identified in the study area. We predicted that 14% and 24% area of zones topped by Pleistocene terrace deposits and zones topped by Holocene flood plain deposits, respectively, would exhibit surface manifestation of liquefaction as a result of 7 magnitude earthquake. The engendered hazard map also depicts site specific liquefaction intensity through LPI values of respective boreholes, and color index, which was delineated by mapping with ArcGIS software. Very low to low, and low to high liquefaction potential, respectively, was found in the areas covered by Pleistocene terrace deposits and Holocene flood plain deposits. LPI values of both units are such that sand boils could be generated where LPI > 5.

The Effect of Cyclic Loading of Liquefaction on Palu Sands 

2021 ◽  
Author(s):  
Muhammad Firas Andanawarih ◽  
Widjojo Adi Prakoso
Keyword(s):  
Relative Density ◽  
Cyclic Load ◽  
Stress Ratio ◽  
Cyclic Stress ◽  
Cyclic Triaxial ◽  
Liquefaction Resistance ◽  
Cyclic Stress Ratio ◽  
Factors Affecting ◽  
Earthquake Load ◽  
Central Sulawesi

<p>Liquefaction is a phenomenon where soil loses its strength. The phenomenon of liquefaction occurs on non-cohesive soils with medium to fine grains. The phenomenon of liquefaction occurs during an earthquake, the ground experiences shaking vibrations. Palu, Central Sulawesi, Indonesia is one of the areas affected by the liquefaction phenomenon which causes damage to infrastructure in the area. The Palu earthquake that occurred on September 28, 2018, at 18:02:44 WITA with a magnitude of M<sub>w</sub> = 7.4, centered on 26 km north of Donggala, Central Sulawesi. One aspect of the assessment for soil susceptibility to potential liquefaction is laboratory tests. One common laboratory test that can be performed is the cyclic triaxial test. The factors affecting the liquefaction resistance of saturated sand are the relative density and cyclic stress ratio (CSR). The susceptibility of each relative density (30%, 50% and 70%) of the soil experiencing liquefaction and the cyclic stress ratio (0.15, 0.20 and 0.25) will be varied to see the amount of cyclic load needed until the soil experiences liquefaction, the load frequency to represent the earthquake load is 1 Hz with sinusoidal waves. This study will test the fine sands from Palu, Central Sulawesi, Indonesia, to determine their respective behavior when the soil is given a cyclic load.</p><p>Keywords: Cyclic Triaxial, Liquefaction, Cyclic Stress Ratio, Relative Density, Fine Sands.</p>

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