Methods for evaluating overconsolidation ratio from piezocone sounding results

Chanmee, Nachanok; Chai, Jinchun; Hino, Takenori; Wang, Jun

doi:10.1016/j.undsp.2017.05.004

Cited by 9 publications

(3 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To validate the methods proposed in this paper, the predictions of equations (43) and (44) were compared with the results of in situ CPTU tests for marine soft clay in two coastal areas [23,24]. Moreover, the predictions of Wayne's method [12] and Chanmee's method [14] were also included in comparison with further interpretation of the reliability and superiority of the methods proposed in this paper. Table 2 lists the model input parameters used in the analyses.…”

Section: Comparisons Of Ocr Obtained From Two Methods Proposed In Is mentioning

confidence: 99%

“…Based on the solution of a spherical cavity expansion described with the modified cam clay, a modified approach to determine the OCR from CPTU was proposed. Chanmee et al [14] combined the undrained shear strength of the modified Cambridge model with the undrained shear strength based on the net cone tip resistance to determine the OCR of soil by the iteration convergence method, which is expressed as follows:…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Prediction Method for Overconsolidation Ratio of Marine SoftSoil Based on the Piezocone Penetration Tests

Zhang

et al. 2019

Advances in Civil Engineering

View full text Add to dashboard Cite

Because of the strong structural and sensitive behavior, the properties of marine soft soil change greatly when subjected to external disturbances, which leads to great difficulty in reflecting its real mechanical properties in the laboratory soil tests. The piezocone penetration test (CPTU) is one of the main technologies for in situ testing of geotechnical engineering. CPTU has the advantages of being fast and convenient, no sampling, low disturbance to soil, large amount of data, and reliable testing. The determination of the overconsolidation ratio (OCR) based on the CPTU results can solve the problems of soil disturbance and stress release, which occur during the consolidation test in the laboratory. However, there are still some problems such as lack of strict theoretical analysis of penetration mechanism and incomplete interpretation theory of in situ test parameters of CPTU. In this paper, the CPTU cone head is assumed to be hemispherical considering the penetration mechanism of CPTU. Moreover, the compaction modes of the CPTU probe penetrating into soil are adopted as spherical and cylindrical cavity expansion modes, respectively. The ultimate expansion pressures of the probe penetrating into soil under the spherical and cylindrical cavity expansion modes are first obtained by virtue of the theory of cavity expansion. Then, two prediction methods for OCR considering the roughness and penetration rate of the cone are proposed by combining the ultimate expansion pressures of the probe penetrating the approximate closed solution of cavity expansion in the modified Cambridge model, which is suitable for predicting the OCR of marine soft clay. Finally, to verify the reliability of the two proposed prediction methods, comparisons with the in situ CPTU tests of marine soft clay in two coastal areas and two existing prediction methods are made. The comparison results show that predictions of OCR of marine soft clay in this paper are close to Wayne’s method and more accurate than Chanmee’s method since the factors such as cone roughness and penetration rate are considered in the new proposed prediction methods. In order to improve the applicability in different cases of the OCR predictions, the average values of the two proposed methods are recommended as the reference value for the OCR of marine soft soil.

show abstract

Section: Comparisons Of Ocr Obtained From Two Methods Proposed In Is mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Prediction Method for Overconsolidation Ratio of Marine SoftSoil Based on the Piezocone Penetration Tests

Zhang

et al. 2019

Advances in Civil Engineering

View full text Add to dashboard Cite

show abstract

“…uCPT provides nearly continuous measurements of tip resistance (q t ), sleeve friction (f s ) and pore water pressure (u 2 ) at the shoulder of a cone (standard cone). These measurements can be used to estimate the undrained shear strength of a deposit (s u ) (Campanella and Robertson 1988; Teh and Houlsby 1991;Lu et al 2004), overconsolidation ratio (OCR) (Wroth 1984;Mayne and Kemper 1988;Robertson 1990;Chanmee et al 2017) and permeability of soil in the horizontal direction (k h ) (Robertson et al 1992;Lunne et al 1997;Sully et al 1999;Elsworth and Lee 2005;Robertson 2010;Chai et al 2011). The cone can be held at a predetermined depth to measure the pore pressure dissipation process, and these dissipation results can be used to estimate the coefficient of consolidation of the soil at that depth (Teh and Houlsby 1991;Robertson et al 1992;Burns and Mayne 1998;Chai et al 2012a;Chai et al 2015).…”

Section: Introductionmentioning

confidence: 99%

A modified method for estimating permeability of clayey soils based on piezocone sounding results

Chai

Chanmee

2018

Can. Geotech. J.

Self Cite

View full text Add to dashboard Cite

A modified method for estimating permeability of clayey deposits in the horizontal direction (kh) based on piezocone sounding (uCPT) results is proposed. Most of the currently available methods relate the value of kh with the Δu/[Formula: see text] ratio (Δu is the measured excess pore pressure from uCPT at the shoulder of the cone and [Formula: see text] is the initial vertical effective stress at the measurement location). However, it has been understood that the effect of the overconsolidation ratio (OCR) on the Δu/[Formula: see text] ratio is more significant than that on the value of kh. As a result, for an overconsolidated deposit, there is no suitable method for estimating the value of kh based on uCPT results. Based on the results of laboratory model uCPT, an empirical equation for considering the effect of the OCR on Δu/[Formula: see text] and then kh corresponding to the yield vertical effective stress ([Formula: see text]) and initial vertical effective stress ([Formula: see text]) for OCR > 1.0 is established. The modified method for kh corresponding to [Formula: see text] requires two parameters: OCR and a model parameter (α). In addition, for kh corresponding to [Formula: see text], two more soil parameters are needed: the swelling index (Cs) and the initial void ratio (e0). The methods for estimating these parameters are also proposed. Finally, the modified method is applied to three field case histories to show its usefulness.

show abstract

On possibilities of using global monitoring in effective prevention of tailings storage facilities failures

Stefaniak

Wróżyńska

2017

Environ Sci Pollut Res

View full text Add to dashboard Cite

Protection of common natural goods is one of the greatest challenges man faces every day. Extracting and processing natural resources such as mineral deposits contributes to the transformation of the natural environment. The number of activities designed to keep balance are undertaken in accordance with the concept of integrated order. One of them is the use of comprehensive systems of tailings storage facility monitoring. Despite the monitoring, system failures still occur. The quantitative aspect of the failures illustrates both the scale of the problem and the quantitative aspect of the consequences of tailings storage facility failures. The paper presents vast possibilities provided by the global monitoring in the effective prevention of these failures. Particular attention is drawn to the potential of using multidirectional monitoring, including technical and environmental monitoring by the example of one of the world's biggest hydrotechnical constructions-Żelazny Most Tailings Storage Facility (TSF), Poland. Analysis of monitoring data allows to take preventive action against construction failures of facility dams, which can have devastating effects on human life and the natural environment.

show abstract

Methods for evaluating overconsolidation ratio from piezocone sounding results

Cited by 9 publications

References 21 publications

Prediction Method for Overconsolidation Ratio of Marine SoftSoil Based on the Piezocone Penetration Tests

Prediction Method for Overconsolidation Ratio of Marine SoftSoil Based on the Piezocone Penetration Tests

A modified method for estimating permeability of clayey soils based on piezocone sounding results

On possibilities of using global monitoring in effective prevention of tailings storage facilities failures

Contact Info

Product

Resources

About