Cone penetration test (CPT)-based stratigraphic profiling using the wavelet transform modulus maxima method

2015 ◽  
Vol 52 (12) ◽  
pp. 1993-2007 ◽  
Author(s):  
Jianye Ching ◽  
Jiun-Shiang Wang ◽  
C. Hsein Juang ◽  
Chih-Sheng Ku
Keyword(s):  
Fourier Transform ◽  
Wavelet Transform ◽  
Cone Penetration Test ◽  
Change Points ◽  
Penetration Test ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Soil Layers ◽  
Wavelet Transform Modulus Maxima ◽  
Modulus Maxima

In this paper, a stratigraphic profiling approach is proposed based on the soil behavior type index, Ic, obtained from the cone penetration test (CPT). The basic idea of this approach is simple: the layer boundaries can be identified as the points at which a change occurs in the Ic profile. It is shown that these change points can be easily identified using the wavelet transform modulus maxima (WTMM) method. This method is able to accurately pinpoint the locations of change points in the Ic profile and to produce graphs and plots that fit well with engineers’ methods of visualization and intuition. Moreover, by virtue of the fast Fourier transform, the computation is very fast. Case studies show that the WTMM method is effective for the detection of change points in the Ic profile. It is also capable of detecting thin soil layers.

scholarly journals Study of mining tailings geotechnical parameters obtained from SCPTu tests carried on dry and saturated layers

2021 ◽  
Vol 337 ◽  
pp. 04010
Author(s):  
Helena P. Nierwinski ◽  
Marcelo Heidemann ◽  
Laura A. Lavalle ◽  
Bruna Sell
Keyword(s):  
Laboratory Tests ◽  
Cone Penetration Test ◽  
Test Results ◽  
Penetration Test ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Geotechnical Parameters ◽  
Saturated Layer ◽  
Laboratory Test Results

The correct interpretation of in situ and laboratory test results is an important step in the design of mining tailing containment structures. This study aims to analyze the Seismic Cone Penetration Test (SCPTu) results obtained into a mining tailing reservoir composed of two material layers: a thick-dry and a tick-saturated. It is possible to observe that in a same tailing reservoir, the CPTu test interpretation can lead to a classification of each layer as a different soil with specific behavior and properties. This condition demonstrates that tailings with intermediate permeability (10-5 m/s < k < 10-8 m/s) may present partial drainage conditions during a standard cone penetration test (CPTu) (v=20 mm/s), if saturated conditions are verified. The effects of partial drainage can affect test results, and can induce to errors in the prediction of soil behavior and geotechnical parameters. To evaluate the possible effects of partial drainage, in situ test results were compared to laboratory tests results. It was possible to verify that estimated behavior of dry layers, obtained from in situ tests results, present more similarity to the results from laboratory tests. Probably, the partial drainage effects verified through the interpretation of dissipation tests, distorted the estimated behavior of the saturated layer material.

Seismic cone penetration test and seismic tomography in permafrost

2004 ◽  
Vol 41 (5) ◽  
pp. 796-813 ◽  
Author(s):  
Anne-Marie LeBlanc ◽  
Richard Fortier ◽  
Michel Allard ◽  
Calin Cosma ◽  
Sylvie Buteau
Keyword(s):  
Seismic Tomography ◽  
Dynamic Properties ◽  
Cone Penetration Test ◽  
The Body ◽  
Body Waves ◽  
Reconstruction Technique ◽  
Seismic Velocities ◽  
Penetration Test ◽  
Cone Penetration ◽  
Seismic Cone Penetration Test

Two high-resolution multi-offset vertical seismic profile (VSP) surveys were carried out in a permafrost mound near Umiujaq in northern Quebec, Canada, while performing seismic cone penetration tests (SCPT) to study the cryostratigraphy and assess the body waves velocities and the dynamic properties of warm permafrost. Penetrometer-mounted triaxial accelerometers were used as the VSP receivers, and a swept impact seismic technique (SIST) source generating both compressional and shear waves was moved near the surface following a cross configuration of 40 seismic shot-point locations surrounding each of the two SCPTs. The inversion of travel times based on a simultaneous iterative reconstruction technique (SIRT) provided tomographic images of the distribution of seismic velocities in permafrost. The Young's and shear moduli at low strains were then calculated from the seismic velocities and the permafrost density measured on core samples. The combination of multi-offset VSP survey, SCPT, SIST, and SIRT for tomographic imaging led to new insights in the dynamic properties of permafrost at temperatures close to 0 °C. The P- and S-wave velocities in permafrost vary from 2400 to 3200 m/s and from 900 to 1750 m/s, respectively, for a temperature range between –0.2 and –2.0 °C. The Young's modulus varies from 2.15 to 13.65 GPa, and the shear modulus varies from 1.00 to 4.75 GPa over the same range of temperature.Key words: permafrost, seismic cone penetration test, vertical seismic profiling, seismic tomography, dynamic properties.

A Bayesian unsupervised learning approach for identifying soil stratification using cone penetration data

2019 ◽  
Vol 56 (8) ◽  
pp. 1184-1205 ◽  
Author(s):  
Hui Wang ◽  
Xiangrong Wang ◽  
J. Florian Wellmann ◽  
Robert Y. Liang
Keyword(s):  
Computational Cost ◽  
Physical Space ◽  
Soil Classification ◽  
Feature Space ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Soil Layers ◽  
Tip Resistance ◽  
Input Dataset ◽  
Spatial Configurations

This paper presents a novel perspective to understanding the spatial and statistical patterns of a cone penetration dataset and identifying soil stratification using these patterns. Both local consistency in physical space (i.e., along depth) and statistical similarity in feature space (i.e., logQt–logFrspace, where Qtis the normalized tip resistance and Fris the normalized friction ratio, or the Robertson chart) between data points are considered simultaneously. The proposed approach, in essence, consists of two parts: (i) a pattern detection approach using the Bayesian inferential framework and (ii) a pattern interpretation protocol using the Robertson chart. The first part is the mathematical core of the proposed approach, which infers both spatial pattern in physical space and statistical pattern in feature space from the input dataset; the second part converts the abstract patterns into intuitive spatial configurations of multiple soil layers having different soil behavior types. The advantages of the proposed approach include probabilistic soil classification and identification of soil stratification in an automatic and fully unsupervised manner. The proposed approach has been implemented in MATLAB R2015b and Python 3.6, and tested using various datasets including both synthetic and real-world cone penetration test soundings. The results show that the proposed approach can accurately and automatically detect soil layers with quantified uncertainty and reasonable computational cost.

Sign in / Sign up

Export Citation Format

Share Document