scholarly journals Performance of liquefaction assessment method based on combined use of cone penetration testing and shear wave velocity measurement

ce/papers ◽  
2018 ◽  
Vol 2 (2-3) ◽  
pp. 193-198
Author(s):  
Zoltán BÁN ◽  
András MAHLER ◽  
Erzsébet GYŐRI
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Measurement ◽  
Assessment Method ◽  
Cone Penetration ◽  
Penetration Testing ◽  
Cone Penetration Testing ◽  
Combined Use ◽  
Liquefaction Assessment

scholarly journals Towards consideration of epistemic uncertainty in shear-wave velocity measurements obtained via seismic cone penetration testing (SCPT)

2020 ◽  
Vol 57 (1) ◽  
pp. 48-60 ◽  
Author(s):  
Andrew C. Stolte ◽  
Brady R. Cox
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Epistemic Uncertainty ◽  
Velocity Analysis ◽  
Travel Times ◽  
Cone Penetration ◽  
Penetration Testing ◽  
Cone Penetration Testing ◽  
Analysis Methods

Seismic cone penetration testing (SCPT) is a powerful geotechnical site characterization tool, allowing for simultaneous collection of routine cone penetration testing data and rapid downhole-type measurements of shear-wave velocity (VS). However, the uncertainties associated with developing VS profiles from SCPT measurements are rarely considered or communicated to the end-user. One important source of VS uncertainty is related to how the shear wave travel times are interpreted from the recorded waveforms, while another critical source of uncertainty is related to the analysis method used to transform the travel times to velocities. In this study, four common ways of obtaining travel times were considered: (i) first arrival picks, (ii) peaks and troughs picks, (iii) crossover picks, and (iv) the peak response of the cross-correlation function. Using these different travel times, a number of VS profiles were developed using four different velocity analysis methods: (i) pseudo-interval, (ii) true-interval, (iii) corrected vertical travel time slope-based, and (iv) raytracing. Through consideration of multiple wave arrival time and velocity analysis methods, a robust and meaningful quantification of the intramethod, depth-dependent epistemic uncertainty in VS obtained from several example SCPT datasets has been developed. VS uncertainty is further examined through consideration of the intermethod variability and bias between SCPT and direct-push crosshole testing.

Consolidation characteristics of hydraulically deposited tailings obtained from shear wave velocity (Vs) measurements in triaxial and oedometric cells with piezoelectric ring-actuator technique (P-RAT)

2020 ◽  
pp. 1-14 ◽  
Author(s):  
Louis-Philippe Grimard ◽  
Mourad Karray ◽  
Michael James ◽  
Michel Aubertin
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Void Ratio ◽  
Cone Penetration ◽  
Confining Stress ◽  
Overconsolidation Ratio ◽  
Cone Penetration Testing ◽  
Tailings Impoundment ◽  
P Rat

This paper presents the main results of a laboratory study of the use of shear wave velocity, Vs, to characterize hydraulically deposited tailings on the basis of density (void ratio), mean effective stress, and overconsolidation ratio. Tailings specimens from a gold mine in western Quebec were prepared in triaxial and oedometric cells in a manner that simulates hydraulic deposition. The specimens were consolidated isotropically and anisotropically (stress ratio, K of 0.38). Vs measurements were performed at each load increment using the piezoelectric ring-actuator technique (P-RAT). Correlations relating shear wave velocity to the void ratio, confining stress, and overconsolidation ratio of the tailings are presented. These laboratory correlations can be used for the characterization of the tailings by in situ Vs measurement. The application of these correlations to seismic cone penetration testing in an actual tailings impoundment is also presented.

Continuous-interval shear wave velocity profiling by auto-source and seismic piezocone tests

2013 ◽  
Vol 50 (4) ◽  
pp. 382-390 ◽  
Author(s):  
Taeseo Ku ◽  
Paul W. Mayne ◽  
Ethan Cargill
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Test Site ◽  
Cone Penetration ◽  
Cone Penetration Testing ◽  
Large Numbers ◽  
Tip Resistance ◽  
A Site ◽  
Exploratory Procedure

A new exploratory procedure for collecting continuous shear wave velocity measurements via cone penetration testing using a special autoseis source is presented whereby wavelets can be generated and recorded every 1 to 10 s. The continuous-interval seismic piezocone test (CiSCPTu) offers a fast, productive, and reliable means to expedite the collection of downhole shear wave velocity profiles, as well as additional readings on cone tip resistance, sleeve friction, and penetration porewater pressures with depth. A site in Windsor, Virginia, is utilized for illustrating the collection of data, calibration, and post-processing issues arising from large numbers of wavelets that require filtering, windowing, and selection in both time and frequency domain analyses. At the test site, the geology consists of shallow Holocene deposits of clays and sands to 8 m that are underlain by much stiffer calcareous sandy marine clay soils of Miocene age, which extend beyond the termination depths of the soundings at 30 m.

Multifunctional Piezocone Penetration Testing in Geotechnical Practice

2011 ◽  
Vol 90-93 ◽  
pp. 250-254
Author(s):  
Yan Yong An ◽  
Bao Tian Wang
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Sensor Technology ◽  
Soil Parameters ◽  
Cone Penetration ◽  
Empirical Formulas ◽  
Test Technique ◽  
Penetration Testing ◽  
Porewater Pressure

Cone penetration test is a fast and efficient in-situ test technique. With the development of sensor technology and the use of new probes, such test is employed in more fields and reveals more soil parameters. Based on advanced CPTU equipment, soil types were classified. As CPTU has the function of porewater pressure test, the value of porewater pressure varies a lot when the soil changes, which is shown clearly in the CPTU feature map. So it can be easier to judge soil boundaries and its result is in good agreement with the borehole. Multi-function CPTU system is equip with SCPTU module, which enable to measure shear wave velocity of the soil easily. To meet the needs of conventional CPT equipment, the relationships between shear wave velocity measured by SCPTU and other CPT indexes were analyzed; then, two empirical formulas which suitable for kinds of soils are proved more consistent with the measured results, so it is a good method to estimate shear wave velocity without seismic wave test. With a view to get greater economic and technical benefits, more cone penetration testing experience in different regions should be accumulated for geotechnical engineering investigation and design.

scholarly journals Evaluating simplified methods for liquefaction assessment for loss estimation

2017 ◽  
Vol 17 (5) ◽  
pp. 781-800 ◽  
Author(s):  
Indranil Kongar ◽  
Tiziana Rossetto ◽  
Sonia Giovinazzi
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Deformation ◽  
Insurance Industry ◽  
Binary Classification ◽  
Remote Sensing Data ◽  
Velocity Profiles ◽  
Loss Estimation ◽  
Liquefaction Assessment

Abstract. Currently, some catastrophe models used by the insurance industry account for liquefaction by applying a simple factor to shaking-induced losses. The factor is based only on local liquefaction susceptibility and this highlights the need for a more sophisticated approach to incorporating the effects of liquefaction in loss models. This study compares 11 unique models, each based on one of three principal simplified liquefaction assessment methods: liquefaction potential index (LPI) calculated from shear-wave velocity, the HAZUS software method and a method created specifically to make use of USGS remote sensing data. Data from the September 2010 Darfield and February 2011 Christchurch earthquakes in New Zealand are used to compare observed liquefaction occurrences to forecasts from these models using binary classification performance measures. The analysis shows that the best-performing model is the LPI calculated using known shear-wave velocity profiles, which correctly forecasts 78 % of sites where liquefaction occurred and 80 % of sites where liquefaction did not occur, when the threshold is set at 7. However, these data may not always be available to insurers. The next best model is also based on LPI but uses shear-wave velocity profiles simulated from the combination of USGS VS30 data and empirical functions that relate VS30 to average shear-wave velocities at shallower depths. This model correctly forecasts 58 % of sites where liquefaction occurred and 84 % of sites where liquefaction did not occur, when the threshold is set at 4. These scores increase to 78 and 86 %, respectively, when forecasts are based on liquefaction probabilities that are empirically related to the same values of LPI. This model is potentially more useful for insurance since the input data are publicly available. HAZUS models, which are commonly used in studies where no local model is available, perform poorly and incorrectly forecast 87 % of sites where liquefaction occurred, even at optimal thresholds. This paper also considers two models (HAZUS and EPOLLS) for estimation of the scale of liquefaction in terms of permanent ground deformation but finds that both models perform poorly, with correlations between observations and forecasts lower than 0.4 in all cases. Therefore these models potentially provide negligible additional value to loss estimation analysis outside of the regions for which they have been developed.

Development of an empirical correlation for predicting shear wave velocity of Christchurch soils from cone penetration test data

2015 ◽  
Vol 75 ◽  
pp. 66-75 ◽  
Author(s):  
Christopher R. McGann ◽  
Brendon A. Bradley ◽  
Merrick L. Taylor ◽  
Liam M. Wotherspoon ◽  
Misko Cubrinovski
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Test Data ◽  
Shear Wave Velocity ◽  
Cone Penetration Test ◽  
Empirical Correlation ◽  
Penetration Test ◽  
Cone Penetration

Development Of a Bottom-Hole Device For Offshore Shear Wave Velocity Measurement

1978 ◽  
Author(s):  
K.H. Stokoe ◽  
E.J. Arnold ◽  
R.J. Hoar ◽  
D.J. Shirley ◽  
D.G. Anderson
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Measurement ◽  
Bottom Hole

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.

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