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.

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.

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

scholarly journals Characterization of Norwegian marine clays with combined shear wave velocity and piezocone cone penetration test (CPTU) data

2010 ◽  
Vol 47 (7) ◽  
pp. 709-718 ◽  
Author(s):  
Michael Long ◽  
Shane Donohue
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Small Strain ◽  
Cone Penetration Test ◽  
Research Quality ◽  
Penetration Test ◽  
Cone Penetration ◽  
Tip Resistance ◽  
Marine Clays

A database of research-quality piezocone cone penetration test (CPTU) and shear wave velocity, Vs, information for Norwegian marine clays has been assembled to study the small-strain stiffness relationships for these materials and to examine the potential use of CPTU and Vs data in combination for the purposes of characterizing these soils. Data for sites where high-quality block sampling was carried out have mostly been used. Improvements have been suggested to existing correlations between the small-strain shear modulus, Gmax, or Vs and index properties for these soils. Recent research has shown that CPTU corrected cone tip resistance, qt, and especially the pore pressure measured during CPTUs, u2, and Vs can be measured reliably and repeatably and are not operator or equipment dependant. Therefore, a new soil classification chart involving the normalized cone resistance, Qt, and normalized shear wave velocity, Vs1, or Vs1 and Δu/[Formula: see text] (where u is the pore-water pressure and [Formula: see text] is the in situ vertical effective stress) is presented. Using this chart it is possible to clearly distinguish between clays of different overconsolidation ratios (OCRs).

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.

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