Effective Friction Angle Of Deltaic Soils In The Vistula Marshlands

Open access

Abstract

This article presents the results of laboratory tests on soft, normally consolidated soils from the Vistula Marshlands. Samples of high-plasticity organic soils (muds) taken from 3.2–4.0 m and 9.5–10.0 m depth, as well as peat deposit at 14.0 m, are analysed. Presented case study confirms the applicability of the Norwegian Institute of Technology (NTH) method based on Cone Penetration Tests (CPTU) and allows for a conservative estimation of effective friction angle for muds. The plastification angle equal to 14.5° for organic silt, applied in the modified NTH method, fits well the triaxial test (TX) results. Moreover, the dilative-contractive behaviour according to the CPTU soil classification based on the Robertson’s proposal from 2016 corresponds well with volumetric changes observed in the consolidated drained triaxial compression tests. The internal friction angles of the Vistula Marshlands’ muds and peats are lower in comparison with the database of similar soft soils.

1 Introduction

1.1 Aim of research

This research is focused on effective angle of internal friction and compares the results for the Vistula Marshlands muds and peats with similar soft soils. Effective shear strength parameters of the deltaic soils near Gdańsk are measured in drained and undrained triaxial compression tests and estimated with the Norwegian Institute of Technology (NTH) method using the Cone Penetration Tests (CPTU) sounding. The observed dilative-contractive soil behaviour is discussed taking into account the CPTU classification chart proposed by Robertson (2016). The aim of the research presented herein is to verify the applicability of the NTH method for the estimation of effective friction angle of soft soils in the Vistula Marshlands.

1.2 Testing site description

The testing field is located near the Jazowa village, in the Vistula Marshlands, Northern Poland. Intensive geotechnical investigations related with the construction of S-7 expressway were carried out in the studied area. Fifteen CPTU soundings, performed at every 2 m spacing, proved the regularity of the subsoil. Soil layers, distinguished according to the Unified Soil Classification System (USCS), are presented in Figure 1 along with the results of the CPTU soundings. The soil profile at the site contains the following layers:

Figure 1
Figure 1

Soil profile and CPTU sounding results.

Citation: Studia Geotechnica et Mechanica 41, 3; 10.2478/sgem-2019-0016

  1. 0.00–0.70 m– silty sand (working platform)
  2. 0.70–1.80 m – low-plasticity silt
  3. 1.80–2.70 m – organic silty clay (mud) of high-plasticity
  4. 2.70–4.05 m – mixture of organic silty clay (mud) and peat
  5. 4.00–7.05 m – silty sand (loose to medium dense)
  6. 7.05–12.15 m - organic silt (mud) of high plasticity intersected with thin sand layer
  7. 12.15–14.45 m – peat with organic silt inclusions
  8. below 14.45 m – well-graded sand

In this paper, the study is focused on the samples taken from 1.8–4.0 m (organic silty clay), 7.80–12.15 m (organic silt), and 12.15–14.45 m (peat). Selected index properties of these soils are presented in Table 1.

Table 1

Selected index properties of the Vistula Marshlands soft soils.

Soil layerSampling depthwcγGsPLLLIPLOI

[m][%][kN/m3][g/cm3][%][%][%][%]
Organic silty clay (OH)3.2÷4.0554.4 ÷75.914.22 ÷14.522.54 ÷2.6140.7 ÷55.390.4 ÷119.049.7 ÷63.711.4 ÷16.2
Organic silt (OH)9.5÷10.545.4 ÷57.315.6÷16.62.54 ÷2.67228.3 ÷38.053.7÷57.115.7 ÷27.554.2÷7.1
Peat (Pt)13.0÷14..0179.210.51.57N/AN/AN/A87.2

2 Testing Methodology

2.1 Triaxial tests

The consolidated undrained (CU) triaxial compression test (ASTM D4767, 2011) was conducted on muds (organic silty clay and organic silt) taken from 3.2–4.0 m and 9.5–10.0 m and on peat from approximately 14 m. The specimens were sheared at the rate of 0.011 mm/min. The three CU tests on mud samples were made at different level of cell pressure. However, only two samples of peat have been sheared due to limited amount of material. The consolidated drained (CD) triaxial compression test (ASTM D7181, 2011) was conducted only on organic silt samples, sheared at the rate of 0.002 mm/min. Standard triaxial device was used. The angle of internal friction has been determined using the stress ratio M in the p’-q (p’ = effective mean stress; q = deviatoric stress) plane defined as:

M=6sinϕ3sinϕ

where: ϕ’ = effective angle of internal friction.

2.2 CPTU soundings

The CPTU estimation of internal friction angle using the NHT method was calculated with the following equations (Mayne, 2007):

ϕ=29.5Bq0.1210.256+0.336Bq+logQt

where:

Qt=qtσv0σv0
Bq=u2u0qtσv0

qt = corrected cone resistance, σv0 = in-situ vertical total stress, σ’v0 = in-situ vertical effective stress, Qt = normalized cone resistance, Bq = normalized pore-water pressure, u0 = hydrostatic pressure based on the water table level.

The values of effective angle of internal friction based on CPTU results were adjusted with those determined from the triaxial tests using the modified NTH method (Ouyang & Mayne, 2017) with the angle of plastification β being fitting parameter:

ϕ=29.5100.0035βBq0.1210.256+0.336Bq+logQt

The modified NTH method can be applied for soils ranging from sands to clays, where the angle of plastification β = (-20°; 20°). The modified NTH method should not be adopted to peats.

The dilative-contractive soil behaviour type parameters required in the Robertson (2016) classification are:

  • – normalized sleeve friction:
F=fsσv0
  • - normalized cone resistance:
Qtn=qtσv0papaσv0n

and:

n=0.38Ic+0.05σv0pa0.15
Ic=3.47logQt2+logFr+1.2220.5
Fr=fs/qtσv0100%

where: fs = sleeve friction, pa = atmospheric reference pressure equal to 100 kPa, n = variable stress exponent; n ≤ 1.0, Ic = soil behaviour type index, Fr = friction ratio.

3 Results And Interpretation

Frictional strength of soil in terms of effective angle of internal friction ϕ’ depends on soil particles interference and interlocking (Terzaghi et al., 1996). For normally consolidated soils, the critical value of effective angle of internal friction (ϕ’c) is equal to the maximum value (ϕ’max). The determination of ϕ’max in TX tests is related to the choice of failure criterion. There are three standard criterions: (i) maximum deviatoric stress qmax = max(σ13), (ii) maximum obliquity: max(σ13), (iii) max(σ13) or max(σ13) at predefined value of axial strain (usually 15%). The choice of failure criterion for organic soils is not obvious as soft soils, and peats in particular, could exhibit plastic flow phenomenon, see Figure 3. For some soils (mostly peats), the qmax can even increase up to Rankine’s surface. To interpret such behaviour, the procedure adopted after Hendry et al. (2012), and schematically presented in Figure 2, was applied. The plastic flow is usually characterized by almost linear increase of qmax with axial strain (εa). The qmax is assumed as a point of intersection between non-linear and linear part of q-εa plot (see Figure 2). The Authors believe that this interpretation can be satisfactorily applied for non-standard q-εa curves when considerable plastic flow occurs.

Figure 2
Figure 2

Determination of qmax for non-standard q-εa curves. Procedure adopted after Hendry et al. (2012).

Citation: Studia Geotechnica et Mechanica 41, 3; 10.2478/sgem-2019-0016

Figure 3
Figure 3

The CU tests results for (a) organic silty clay, (b) organic silt and (c) peat.

Citation: Studia Geotechnica et Mechanica 41, 3; 10.2478/sgem-2019-0016

The results of CU triaxial compression tests are presented in Figure 3 in terms of the plots in q-εa and p’-q planes. Strength mobilization in the organic silty clay progresses slowly (Figure 3a) and the failure is achieved at the axial strain between 6% and 8%. The achieved M = 0.904 corresponds to the effective angle of internal friction of 23.1°.

For organic silt (Figure 3b), the maximum deviatoric stress is reached at the axial strains of 3-4%. The samples exhibit plastic flow phenomenon and the failure point has been adopted after the procedure described above. The assumed stress ratio M = 1.255, which results in the angle of internal friction equal to 31.3°. The results of CU tests on organic silt have been verified by CD triaxial compression tests, see Figure 4. Almost the same failure envelope has been achieved in CD and CU tests. However, large axial strains are required at the failure in CD tests and the response of specimens during shearing is clearly contractive (Figure 4). This observation confirms the CPTU soil classification based on soil behaviour type (SBT) proposed by Robertson (2016) (Figure 5). The organic silt and peat layers are classified as clay-like contractive, while the silty clay layer is mostly dilative.

Figure 4
Figure 4

The results of CD tests on organic silt.

Citation: Studia Geotechnica et Mechanica 41, 3; 10.2478/sgem-2019-0016

Figure 5
Figure 5

SBTn chart based on Qtn-F (Robertson, 2016).

Citation: Studia Geotechnica et Mechanica 41, 3; 10.2478/sgem-2019-0016

The angle of internal friction equal to 55.7° was obtained in CU tests for peat taken from 14 m. High value of ϕ’ is typical for fibrous peat (Mesri and Ajlouni, 2007) due to its microstructure (Cheng et al., 2007). The assumed qmax for peats is achieved at approximately 10% of axial strain.

Using CPTU results, the ϕ’ was determined with Equations 2 and 5. Only the results for organic silt and peat layers from 7.80–14.45 m depth could be taken into consideration. In the shallow layers (up to 4.05 m), negative u2 readings were obtained, which results in Bq < 0. The ϕ’ according to the Equation 2 almost perfectly fits the TX value for organic silts. However, the CPTU based ϕ’ underestimates the TX value of ϕ’ for peats.

In organic silt, the angle of plastification equal to 14.5° provides a fitting match between the modified NHT and the TX tests. The effective internal friction angles obtained in the laboratory tests and mean value derived from the fifteen CPTU tests are summarized in Table 2.

Table 2

Values of effective friction angle of soft soils in Jazowa.

Soil typeType of the test
CUCDCPTU
NHT method (Mayne, 2007)NTH modified method (Ouyang & Mayne, 2017)
Organic silty clay (3.2–4.0 m depth)23.1°23.4° *N/AN/A
Organic silt (9.5–10.0 m depth)31.3°31.0°27.9°±1.231.3°±1.4
Peat (~14.0 m depth)55.7°N/A29.0°±2.4N/A
*Value obtained from lab tests, conducted by an external company, and summarized in geotechnical documentation for the S-7 expressway.

The effective friction angels for soft soil deposits in the Jazowa site are compared with the other soft soils in Table 3. As one can see, the organic soft soil in the Jazowa are characterized by similar frictional parameters as observed for other sites. However, the angles of the internal friction of organic silty clay and organic silt form the lower bound of the reported database.

Table 3

Effective friction angle of soft soils deposits.

Soilϕ’Reference
CLAYSBothkennar clay34°(Hight et al., 1992)
Osaka bay clay25–40°(Tanaka and Locat, 1999)
Omono clay50–60°(Yasuhara and Takenaka, 1977)
Muck clay52–60°(Tsushima et al., 1977)
Juturnaiba organic clay23–57°(Coutinho and Lacerda, 1989)
Soft organic clay32.0°(Danziger, 2007)
Organic clay30.0°(Larsson et al., 2007)
Organic clay38–46°(Cheng et al., 2007)
Organic clay from Cubzac-les-Ponts28–34°(Shahanguian, 1981)
Various organic clays44–74°(Krieg, 2000)
Alluvial clay31.5°(Sandroni et al., 2015)
Soft alluvial clay36°(Takemura et al., 2006)
Soft alluvial Atchafalaya clay20.2°(Donaghe and Townsend, 1978)
Soft deltaic clay36.0°(Sultan et al., 2004; Dan et al., 2007)
SILTSAlluvial clayey silt28°(Lambson et al., 1993; Powell and Lunne, 2005)
Organic silt38–56°(Cheng et al., 2007)
PEATSwedish clayey gyttja60–90°(Larsson, 1990)
Eemian gyttja29–44°(Pietrzykowski, 2004)
peat63–65°(Cheng et al., 2007)
Middleton peat60°(Ajlouni, 2000)
Ohmiya peat51–55°(Yamaguchi et al., 1985)
Edson peat28.8–50.1°(Hendry et al., 2012)
THISJazowa silty clay23°
STUDYJazowa organic silt31°
Jazowa peat56°

4 Conclusions

The high values of effective angle of internal friction are obtained for organic silts, organic silty clays and peats. However, the full shear strength is achieved at relatively large strains (εa = 10% in most cases). The angles of internal friction are lower in comparison with database. The ϕ’ according to NTH (Mayne, 2007) almost fits the value of effective friction angle for silty layers, but significantly underestimates the ϕ’ for peats. However, the good estimation of ϕ’ requires reliable measurement of u2 reading, which was not be fulfilled for shallow layers of soft soils in the reported testing site. The presented research shows that the NTH method can be treated as a conservative estimation of effective friction angle for soft soils. In case of organic silt, perfect agreement between the CPTU and the modified NTH method is achieved for the angle of plastification β = 14.5°. The CD triaxial tests on organic silt confirmed the updated Robertson’s (2016) classification as a practical tool for qualitative description of soil behaviour type (SBT).

Acknowledgements

The research is supported by the National Centre for Research and Development grant PBS3/B2/18/2015. Some of the geotechnical data was provided by the General Directorate for National Roads and Motorways in Poland.

References

  • [1]

    Ajlouni M.A. 2000. Geotechnical properties of peat and related engineering problems. Ph.D. thesis Univ. of Illinois at Urbana-Champaign Urbana Ill.

  • [2]

    ASTM D4767 2011. Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils. ASTM International West Conshohocken PA.

  • [3]

    ASTM D7181 2011. Method for Consolidated Drained Triaxial Compression Test for Soils. ASTM International West Conshohocken PA.

  • [4]

    Cheng X.H. Ngan-Tillard D.J.M. Den Haan E.J. 2007. The causes of the high friction angle of Dutch organic soils. Engineering Geology 93 31–44. https://doi.org/10.1016/j.enggeo.2007.03.009

    • Crossref
    • Export Citation
  • [5]

    Coutinho R.Q. Lacerda W.A. 1989. Strength characteristics of Juturnaiba organic clays. Presented at the 12th International conference on Soil Mechanics and Foundation Engineering Balkema Rio de Janeiro pp. 1731–1734.

  • [6]

    Dan G. Sultan N. Savoye B. 2007. The 1979 Nice harbor catastrophe revisited: trigger mechanism inferred from Geotechnical measurements and numerical modelling. Marine Geology 245(1–4): 40–64. doi:10.1016/j.margeo. 2007.06.011.

    • Crossref
    • Export Citation
  • [7]

    Danziger F.A.B. 2007. In-situ testing of soft Brazilian soils. Studia Geotechnica et Mechanica 29(1–2): 5–22.

  • [8]

    Donaghe R.T. and Townsend F.C. 1978. Effects of anisotropic versus isotropic consolidation in consolidated undrained triaxial compression tests of cohesive soils. Geotechnical Testing Journal 1(4): 173–189. doi:10.1520/GTJ10868J.

    • Crossref
    • Export Citation
  • [9]

    Hendry M.T. Sharma J.S. Martin C.D. Barbour S.L. 2012. Effect of fibre content and structure on anisotropic elastic stiffness and shear strength of peat. Canadian Geotechnical Journal 49 403–415. https://doi.org/10.1139/t2012-003

    • Crossref
    • Export Citation
  • [10]

    Hight D.W. Bond A.J. Legge J.D. 1992. Characterization of the Bothkennar clay: an overview. Geotechnique 42 303–347.

    • Crossref
    • Export Citation
  • [11]

    Krieg S. 2000. Viskoses Bodenverhalten von Mudden Seeton und Klei. Veroff. Inst. Boden-u. Felsm. 150.

  • [12]

    Lambson M.D. Clare D.G. Senner D.W.F. and Semple R.M. 1993. Investigation and interpretation of Pentre and Tilbrook Grange soil conditions. In Large scale pile tests in clay. Thomas Telford Publishing London pp. 134–196.

  • [13]

    Larsson R. Westerberg B. Albing D. Knutsson S. and Carlsson E. 2007. Sulfidjord–geoteknisk klassificering och odranerad skjuvhallfasthet. [Sulphide soil—geotechnical classification and undrained shear strength.] Report No. 69 Swedish Geotechnical Institute SGI Linkoping. 135 pp.

  • [14]

    Larsson R. 1990. Behaviour of Organic Clay and Gyttja (No. Report vol.38). Swedish Geotechnical Institute.

  • [15]

    Mayne P.W. 2007. In-situ test calibrations for evaluating soil parameters. In Characterization & Engineering Properties of Natural Soils Vol. 3 Proc. Singapore 2006 Taylor & Francis Group London pp. 1602–1652.

  • [16]

    Mesri G. Ajlouni M. 2007. Engineering properties of fibrous peats. Journal of Geotechnical and Geoenvironmental Engineering 133 850–866.

    • Crossref
    • Export Citation
  • [17]

    Ouyang Z. & Mayne P.W. 2017. Effective Friction Angle of Clays and Silts from Piezocone Penetration Tests. Canadian Geotechnical Journal (ja).

  • [18]

    Pietrzykowski P. 2004. Charakterystyka geologiczno-inżynierska eemskich gytii i kredy jeziornej z terenu Warszawy PhD Thesis. ed. University of Warsaw Warsaw. (in Polish)

  • [19]

    Powell J.J.M. and Lunne T. 2005. Use of CPTU data in clays/ fine grained soils. Studia Geotechnica et Mechanica 27(3–4): 29–66.

  • [20]

    Robertson P.K. 2016. Cone penetration test (CPT)-based soil behaviour type (SBT) classification system — an update. Canadian Geotechnical Journal 53 1910–1927.

    • Crossref
    • Export Citation
  • [21]

    Sandroni S. Barreto E. and Leroueil S. 2015. The Santana Port accident: Could it be a sensitive clay flowslide under the Equator? In Proceedings GeoQuebec 2015 (68th Canadian Geotechnical Conference) Canadian Geotechnical Society Ottawa.

  • [22]

    Shahanguian S. 1981. Détermination expérimentale des courbes d’état limite de l’argile organique de Cubzac-les-Ponts. Rapport de recherche LCPC vol. 106.

  • [23]

    Sultan N. Voisset M. Marsset B. Marsset T. Cauquil E. and Colliat J.L. 2007. Potential role of compressional structures in generating submarine slope failures in the Niger Delta. Marine Geology 237(3): 169–190. doi:10.1016/j.margeo.2006.11.002.

    • Crossref
    • Export Citation
  • [24]

    Takemura J. Watabe Y. and Tanaka M. 2006. Characterization of alluvial deposits in Mekong Delta. In Characterisation and Engineering Properties of Natural Soils II Singapore. Vol. 3 Taylor & Francis Group London pp. 1805–1829.

  • [25]

    Tanaka H. Locat J. 1999. A microstructural investigation of Osaka Bay clay: the impact of microfossils on its mechanical behaviour. Canadian Geotechnical Journal 36 493–508. https://doi.org/10.1139/t99-009

    • Crossref
    • Export Citation
  • [26]

    Terzaghi K. Peck R.B. Mesri G. 1996. Soil mechanics in engineering practice Third Edition. ed. John Wiley & Sons Inc. New York. https://doi.org/10.1139/cgj-2016-0044

  • [27]

    Tsushima M. Miyakawa I. and Iwasaki T. 1977. Some investigations on shear strength of organic soil. Tsuchi-to-Kiso J. Soil Mech. Found. Eng. 235 13–18 (in Japanese).

  • [28]

    Yamaguchi H. Ohira Y. Kogure K. Mori S. 1985. Undrained shear characteristics of normally consolidated peat under triaxial compression and extension conditions. Soils and Foundations 25 1–18.

    • Crossref
    • Export Citation
  • [29]

    Yasuhara K. & Takenaka H. 1977. Physical and mechanical properties 2. Engineering Problems of Organic Soils in Japan Japanese Society of Soil Mechanics and Foundation Engineering 35–48.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • [1]

    Ajlouni M.A. 2000. Geotechnical properties of peat and related engineering problems. Ph.D. thesis Univ. of Illinois at Urbana-Champaign Urbana Ill.

  • [2]

    ASTM D4767 2011. Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils. ASTM International West Conshohocken PA.

  • [3]

    ASTM D7181 2011. Method for Consolidated Drained Triaxial Compression Test for Soils. ASTM International West Conshohocken PA.

  • [4]

    Cheng X.H. Ngan-Tillard D.J.M. Den Haan E.J. 2007. The causes of the high friction angle of Dutch organic soils. Engineering Geology 93 31–44. https://doi.org/10.1016/j.enggeo.2007.03.009

    • Crossref
    • Export Citation
  • [5]

    Coutinho R.Q. Lacerda W.A. 1989. Strength characteristics of Juturnaiba organic clays. Presented at the 12th International conference on Soil Mechanics and Foundation Engineering Balkema Rio de Janeiro pp. 1731–1734.

  • [6]

    Dan G. Sultan N. Savoye B. 2007. The 1979 Nice harbor catastrophe revisited: trigger mechanism inferred from Geotechnical measurements and numerical modelling. Marine Geology 245(1–4): 40–64. doi:10.1016/j.margeo. 2007.06.011.

    • Crossref
    • Export Citation
  • [7]

    Danziger F.A.B. 2007. In-situ testing of soft Brazilian soils. Studia Geotechnica et Mechanica 29(1–2): 5–22.

  • [8]

    Donaghe R.T. and Townsend F.C. 1978. Effects of anisotropic versus isotropic consolidation in consolidated undrained triaxial compression tests of cohesive soils. Geotechnical Testing Journal 1(4): 173–189. doi:10.1520/GTJ10868J.

    • Crossref
    • Export Citation
  • [9]

    Hendry M.T. Sharma J.S. Martin C.D. Barbour S.L. 2012. Effect of fibre content and structure on anisotropic elastic stiffness and shear strength of peat. Canadian Geotechnical Journal 49 403–415. https://doi.org/10.1139/t2012-003

    • Crossref
    • Export Citation
  • [10]

    Hight D.W. Bond A.J. Legge J.D. 1992. Characterization of the Bothkennar clay: an overview. Geotechnique 42 303–347.

    • Crossref
    • Export Citation
  • [11]

    Krieg S. 2000. Viskoses Bodenverhalten von Mudden Seeton und Klei. Veroff. Inst. Boden-u. Felsm. 150.

  • [12]

    Lambson M.D. Clare D.G. Senner D.W.F. and Semple R.M. 1993. Investigation and interpretation of Pentre and Tilbrook Grange soil conditions. In Large scale pile tests in clay. Thomas Telford Publishing London pp. 134–196.

  • [13]

    Larsson R. Westerberg B. Albing D. Knutsson S. and Carlsson E. 2007. Sulfidjord–geoteknisk klassificering och odranerad skjuvhallfasthet. [Sulphide soil—geotechnical classification and undrained shear strength.] Report No. 69 Swedish Geotechnical Institute SGI Linkoping. 135 pp.

  • [14]

    Larsson R. 1990. Behaviour of Organic Clay and Gyttja (No. Report vol.38). Swedish Geotechnical Institute.

  • [15]

    Mayne P.W. 2007. In-situ test calibrations for evaluating soil parameters. In Characterization & Engineering Properties of Natural Soils Vol. 3 Proc. Singapore 2006 Taylor & Francis Group London pp. 1602–1652.

  • [16]

    Mesri G. Ajlouni M. 2007. Engineering properties of fibrous peats. Journal of Geotechnical and Geoenvironmental Engineering 133 850–866.

    • Crossref
    • Export Citation
  • [17]

    Ouyang Z. & Mayne P.W. 2017. Effective Friction Angle of Clays and Silts from Piezocone Penetration Tests. Canadian Geotechnical Journal (ja).

  • [18]

    Pietrzykowski P. 2004. Charakterystyka geologiczno-inżynierska eemskich gytii i kredy jeziornej z terenu Warszawy PhD Thesis. ed. University of Warsaw Warsaw. (in Polish)

  • [19]

    Powell J.J.M. and Lunne T. 2005. Use of CPTU data in clays/ fine grained soils. Studia Geotechnica et Mechanica 27(3–4): 29–66.

  • [20]

    Robertson P.K. 2016. Cone penetration test (CPT)-based soil behaviour type (SBT) classification system — an update. Canadian Geotechnical Journal 53 1910–1927.

    • Crossref
    • Export Citation
  • [21]

    Sandroni S. Barreto E. and Leroueil S. 2015. The Santana Port accident: Could it be a sensitive clay flowslide under the Equator? In Proceedings GeoQuebec 2015 (68th Canadian Geotechnical Conference) Canadian Geotechnical Society Ottawa.

  • [22]

    Shahanguian S. 1981. Détermination expérimentale des courbes d’état limite de l’argile organique de Cubzac-les-Ponts. Rapport de recherche LCPC vol. 106.

  • [23]

    Sultan N. Voisset M. Marsset B. Marsset T. Cauquil E. and Colliat J.L. 2007. Potential role of compressional structures in generating submarine slope failures in the Niger Delta. Marine Geology 237(3): 169–190. doi:10.1016/j.margeo.2006.11.002.

    • Crossref
    • Export Citation
  • [24]

    Takemura J. Watabe Y. and Tanaka M. 2006. Characterization of alluvial deposits in Mekong Delta. In Characterisation and Engineering Properties of Natural Soils II Singapore. Vol. 3 Taylor & Francis Group London pp. 1805–1829.

  • [25]

    Tanaka H. Locat J. 1999. A microstructural investigation of Osaka Bay clay: the impact of microfossils on its mechanical behaviour. Canadian Geotechnical Journal 36 493–508. https://doi.org/10.1139/t99-009

    • Crossref
    • Export Citation
  • [26]

    Terzaghi K. Peck R.B. Mesri G. 1996. Soil mechanics in engineering practice Third Edition. ed. John Wiley & Sons Inc. New York. https://doi.org/10.1139/cgj-2016-0044

  • [27]

    Tsushima M. Miyakawa I. and Iwasaki T. 1977. Some investigations on shear strength of organic soil. Tsuchi-to-Kiso J. Soil Mech. Found. Eng. 235 13–18 (in Japanese).

  • [28]

    Yamaguchi H. Ohira Y. Kogure K. Mori S. 1985. Undrained shear characteristics of normally consolidated peat under triaxial compression and extension conditions. Soils and Foundations 25 1–18.

    • Crossref
    • Export Citation
  • [29]

    Yasuhara K. & Takenaka H. 1977. Physical and mechanical properties 2. Engineering Problems of Organic Soils in Japan Japanese Society of Soil Mechanics and Foundation Engineering 35–48.

Search
Journal information
Impact Factor


CiteScore 2018: 1.03

SCImago Journal Rank (SJR) 2018: 0.213
Source Normalized Impact per Paper (SNIP) 2018: 1.106

Figures
Metrics
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 38 38 38
PDF Downloads 10 10 10