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The Canadian Geotechnical Society La Société Canadienne de Géotechnique CROSS CANADA LECTURE TOUR SPRING 2009 Characteristics of organic soils and construction.

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Presentation on theme: "The Canadian Geotechnical Society La Société Canadienne de Géotechnique CROSS CANADA LECTURE TOUR SPRING 2009 Characteristics of organic soils and construction."— Presentation transcript:

1 The Canadian Geotechnical Society La Société Canadienne de Géotechnique CROSS CANADA LECTURE TOUR SPRING 2009 Characteristics of organic soils and construction on organic terrain Arvid Landva, Dr.Ing.*, PhD.**, PEng, FEIC * Norwegian Institute of Technology **Université Laval

2 Sponsors For Cross Canada Lecture Tour, Spring 2009

3 The Canadian Foundation for Geotechnique La Fondation canadienne de géotechnique The Canadian Geotechnical Society La Société canadienne de géotechnique Sponsors For Cross Canada Lecture Tour, Spring 2009 Organization: Funding:

4 Geotechnical Engineering Hydrogeology Environmental Engineering 515 Beaverbrook Court Fredericton, New Brunswick Canada, E3B 1X6 Tel: (506) Fax: (506) The following presentation is available on our website.

5 FIGURE 4.14 AND TABLE 4.2 FROM MUSKEG ENGINEERING HANDBOOK 1969 AND FIGURE 9(b) FROM Hobbs 1986 ORGANIC CONTENT (%) ASH CONTENT (%)

6 Fine-grained soils (F>50%, O c ≤10%) Non organic soils (O c <3%) Slightly organic soils [fO] (3%80%) Peaty organic soil with -amorphous [PtO-a] -semi-fibrous [PtO-sf] -fibrous [PtO-f] organic matter Peaty soils and peats with -amorphous [Pt-a]←”dy” -semi-fibrous [Pt-sf] -fibrous [Pt-f] organic matter Symbols: O c – organic content, F – content of particles finer than #200 sieve, C – clay, M - silt The classification of organic matter is based on the von Post index: H1 to H3: fibrous organic matter, H4 to H6: semi-fibrous organic matter, H7 to H10: amorphous organic matter PROPOSED CLASSIFICATION SYSTEM FOR ORGANIC SOILS Based on von Post 1922, Casagrande 1948, Perrin 1974, Magnan 1980, Landva et al. 1983

7 ESCUMINAC PEAT BOG, NB (Landva and Pheeney 1980)

8 ESCUMINAC RAISED PEAT BOG, NB (DRIVING ON WATER?) V A = 0.05 Water Organic solids Gas V S = 0.04 V w = 0.91 V v = 0.96 V = 1 n = VvVv V = V v if V = 1 S r = VwVw VvVv = 0.95 = VwVw n e = VvVv VSVS = 24 n = = 0.96 V W = nS r = 0.96 x 0.95 = 0.91 PHASE DIAGRAM

9 !

10 PEAT UNDER A MICROSCOPE 500 m m100 m m50 m m 25 m m5 m m50 m m SH 1 leaf SH 1 stem SH 1 leavesSH 1 leaf SH 1 apical bundle

11 100 m m 200 m m 100 m m SH 3 peat SH 3 compressed under 7000 kPa SH 4 stem Classified as SH 8. Alternating layers/lenses of SH 9-10 and SH 3-5 ErH 8 sedge sheathErH 8 sedge sheaths PEAT UNDER A MICROSCOPE

12 HALL’S CREEK ORGANIC SOIL BORELOG FROM TEST FILL AREA (Keenan et al. 1986) (σ c at p’ a ) σ c = p’ 0

13 MIRAMICHI CHANNEL STUDY (ADI 1976) w OcOc

14 SUMMARY OF SOIL PROPERTIES AT THE VÄSBY TEST FIELDS (Chang 1981)

15 CONSOLIDATION TESTS ON UNDISTURBED AND REMOULDED PEAT VERTICAL STRAIN, ε v APPLIED PRESSURE, kPa

16 ALTERNATIVE PLOTS OF STRAIN OR VOID RATIO VS STRESS OR LOG STRESS Void ratio, e Effective consolidation stress, σ’ vc (kPa) Void ratio, e Effective consolidation stress, σ’ vc (kPa) Vertical Strain, ε v S=Hm v Δσ=HΔε S=HC cε log σ o ’+Δσ σo’σo’ CcεCcε CcCc (e o, σ o ’) S=H avav 1+e o Δσ S=H CcCc 1+e o log σ o ’+Δσ σo’σo’

17 “THE LOG TRAP” Effective consolidation stress σ’ (kPa) ε v (%) σ’=30-34 kPa

18 “THE LOG TRAP” Effective consolidation stress σ’ (kPa) ε v (%) σ’=30-34 kPa Effective consolidation stress σ’ (kPa) ε v (%)

19 INSTANT/DELAYED VS PRIMARY/SECONDARY MODES OF COMPRESSION (BJERRUM 1967)

20 COMPRESSIBIITY OF A CLAY EXHIBITING DELAYED CONSOLIDATION (BJERRUM 1967)

21 LABORATORY CONSOLIDATION, SH 3 PEAT (Landva 1980) VERTICAL STRAIN ε v

22 CONSOLIDATION TESTS ON UNDISTURBED SH 3 PEAT VERTICAL STRAIN ε v C α =0.025 C α =0.024 C α =0.025 C α =0.020 C α =0.022 C α =0.025 C α =0.105 C α =0.043 C α =0.015 C α =0.004 C α =0.005

23 SETTLEMENT OF ESCUMINAC TEST FILLS

24 COEFFICIENT OF SECONDARY COMPRESSION C αε VERSUS COMPRESSION INDEX C c (Lefebvre et al. 1984) C αε C αε /C c = 0.11 C αε /C c = 0.06 C αε /C c = 0.033

25 EMBANKMENTS ON PEAT (Weber 1969, Hobbs 1986) CαCα

26 STRAIN VS LOG TIME FOR TWO DIFFERENT THICKNESSES OF PEAT UNDER THE SAME LOAD (From Hobbs 1986) Strain (ε)

27 COEFFICIENT OF SECONDARY COMPRESSION VERSUS WATER CONTENT FOR MIRES AND CLAY (Hobbs 1986)

28 SETTLEMENT BENEATH EMBANKMENTS ON PEAT Vertical strain, ε v

29 ESCUMINAC TEST FILLS

30 SECTIONS THROUGH LARGE TEST FILL (Landva 1980)

31 SUMMARY OF SETTLEMENT DATA (Scotton, 1981) “In common use by many geotechnical engineers on the west coast”

32 SURCHARGE ON PEAT (Samson 1985, Samson and La Rochelle 1972) VERTICAL STRAIN, ε v

33 PRECONSOLIDATION DEFINED IN TERMS OF VOID RATIO (From Lefebvre 1986) logσ v ’ C α OC C α NC

34 EXPRESSWAY “AUTOROUTE DE LA RIVE NORD” P.Q. V A = 0.04 Water Organic solids Gas V S = 0.16 V w = 0.80 V v = 0.84 V = 1 n = VvVv V = V v if V = 1 S r = VwVw VvVv = 0.96 = VwVw n e = VvVv VSVS = 5.1 n = = 0.84 V W = nS r = 0.84 x 0.96 = 0.80 PHASE DIAGRAM

35 JAMES BAY, P.Q. NBR-2 PEAT (Lefebvre et al. 1984) Several dams & dikes are founded on peat in Alberta and B.C.

36 MIRAMICHI LAGOON BERM ON DIATOMACEOUS ORGANIC SILT Δu max ≈75 kPa Δσ max ≈80 kPa

37 CONSOLIDATION MODEL I

38 CONSOLIDATION MODEL II Springs displaying plastic behaviour

39 CONSOLIDATION MODEL III

40 PEAT CLIFF FAILURES, ESCUMINAC, NB (Landva 2007)

41 PLATE LOAD TESTS IN INTACT AND IN PRECUT PEAT, ESCUMINAC, NB SETTLEMENT δ (cm) MAX δ = 10cm (failure)

42 SHEAR FAILURE PATTERNS RECORDED ON OUTER SURFACE IN RING SHEAR TESTS σ va Τ

43 RING SHEAR TEST OF FIBROUS SOIL Circle 1 = consolidation under s va and K o s va = (1-sin f ) s va Circle 2 = initial attempted failure along yz at end of pure shear Circle 3 = final failure in simple shear along st σ va Τ ΤyΤy ΤsΤs c=3 kPa, Ф=30 o σ (kPa) σ va Τ (kPa) δhδh Τ ΤsΤs ΤyΤy

44 “TENSILE” TEST OF FIBROUS SOIL – CONSOLIDATION STAGE Equipment designed for measurement of tensile strength Τ (kPa) σ (kPa) σ va σ ha σ fr σ va σ fr σ ha σ va = applied vertical stress in confined compression σ fr = fibre resistance during consolidation σ ha =0.2σ va = applied lateral confinement stress (at ε h =0) Circle 1 = consolidation under σ va and σ ha +σ fr where σ ha +σ fr = K o σ va = (1-sinФ)σ va (as before) Circle 4 = externally applied stresses (i.e. apparent consolidation circle)

45 “TENSILE” TEST OF FIBROUS SOIL -σ ta = externally applied tensile stress σ frf = fibre resistance at failure Τ (kPa) σ (kPa) σ va σ ta σ frf α α=45 o + Ф α=60 o -σ ta σ frf c=3 kPa, Ф=30 o Circle 1: consolidation (as before) Circle 5: usually - but mistakenly - assumed to represent tensile failure on vertical plane ab Circle 6: shear failure on planes at 45 + Ф/2 to horizontal Circle 7: apparent failure circle (externally applied stresses σ va and -σ ta ) α

46 DIRECT AND SIMPLE SHEAR TESTS ON FIBROUS PEAT (From Rowe et al. 1984) σn’σn’ σn’σn’

47 DIRECT SIMPLE SHEAR, SH 3 PEAT STAGE 1-2, PURE SHEAR FAILURE PLANE FP 1-2 c=2.5 kPa, Ф=30 o Τ (kPa) ε (%) ε s = δhδh H σvσv δhδh Τ σ (kPa)

48 DIRECT SIMPLE SHEAR, SH 3 PEAT FINAL STAGE 4-5 FAILURE PLANE FP 4-5 (horizontal) Τ (kPa) σ (kPa) Τ (kPa) ε (%) σvσv Τ c=2.5 kPa, Ф=30 o

49 MIRAMICHI BAY MUD, NB, TRIAXIAL AND SIMPLE SHEAR RESULTS CAU - anisotropically consolidated, undrained triaxial test CCV - anisotropically consolidated, constant volume simple shear test CD – anisotropically consolidated, drained simple shear test C≈3-10 kPa Ф≈40 o -53 o Shear stress Τ (kPa) Effective stress σ’ (kPa) Ф=18 o Ф=23 o

50 TRIAXIAL AND SIMPLE SHEAR TESTS DIATOMACEOUS ORGANIC CLAYEY SILT σ Τ σ va σ ha σ fr c=6 kPa,Ф=40 o c=6 kPa,Ф=23 o c t =0,Ф=12 o σ σ

51 100 m m MIRAMICHI BAY MUD Scanning Electron Microscope (UNB 1997)

52 MEXICO CITY SOIL (Mesri et al. 1975) Composition of Mexico City Clay consists of about 5-10% sand-sized concretionary particles of ooliths composed of calcium carbonate; 55-65% silt-sized siliceous diatoms; 20-30% clay sized particles of which probably 10% is interlayered smectite and the remaining is biogenic or volcanogenic silica; and 5-10% organic material. The basic characteristics of the siliceous diatoms, interlayered smectite and organic matter combine to give Mexico City clay its unusual physical properties.

53 RELATIONSHIP BETWEEN S u / s ’ p AND PLASTICITY INDEX (modified from Tavenas & Leroueil 1987) σ’ vo

54 CORRECTION FACTOR VERSUS PLASTICITY INDEX FOR UNDRAINED SHEAR STRENGTH FROM VANE SHEAR TEST (modified from Ladd et al. 1977) Halls Creek test fill failure: F=2.5 based on vane strength*, *Keenan et al i.e. m ≈0.25 μ μ

55 POTENTIAL FAILURE MECHANISM DUE TO LATERAL THRUST AND SLIDING ON A DEEPER LOW STRENGTH LAYER (after Rowe 2001)

56 POSSIBLE SEVERING OF MAT AT LEFT EDGE OF RIGID BASE (CORDUROY) REINFORCEMENT

57 EMBANKMENT ON PEAT BEFORE AND AFTER WIDENING (b) additional pressure on peat at end of construction (after widening) (a) settlement and cracking after widening

58 CUSH ROAD (IRELAND) SECTION BEFORE AND AFTER WIDENING (after Hanrahan 1964)

59 OLD ROAD (CA. 1870), ESCUMINAC, NB

60 OLD ROAD (CA. 1870) AT ESCUMINAC, NB ERODED BY WAVES

61

62

63 CONSOLIDATION OF CLAY SOIL BY MEANS OF ATMOSPHERIC PRESSURE (W. Kjellman, 1948) “The cost of using the vacuum method is nearly independent of the desired intensity of the surcharge. Therefore, the vacuum method can best compete with the sand layer method when the desired surcharge is great. This occurs when time is scarce, and also when the structure is heavy. It may also occur when a deep excavation is to be made. A great surcharge of sand on a soft clay must be applied slowly, lest the ground fail. If vacuum is used instead of sand, ground failure is impossible, and many months may be saved. A surcharge of sand cannot be used at all for stabilizing an existing slope or shaft, because it would cause a slide. Vacuum, on the contrary, can well be applied in such cases.”

64 MASS STABILIZATION OF PEAT (Jelisic and Lepp ä nen 1999)

65 MIRAMICHI CHANNEL FULLY LOADED COAL FREIGHTER OBSERVED PLOWING THROUGH “MUD” OUTSIDE DREDGED CHANNEL

66 Geotechnical Engineering Hydrogeology Environmental Engineering 515 Beaverbrook Court Fredericton, New Brunswick Canada, E3B 1X6 Tel: (506) Fax: (506) This presentation is available on our website.

67 Sponsors For Cross Canada Lecture Tour, Spring 2009

68 The Canadian Foundation for Geotechnique La Fondation canadienne de géotechnique The Canadian Geotechnical Society La Société canadienne de géotechnique Sponsors For Cross Canada Lecture Tour, Spring 2009 Organization: Funding:

69 Bibliography and Supplementary Slides

70 BIBLIOGRAPHY Adams, J.I The engineering behaviour of a Canadian muskeg. Proc. 6th Int. Conf. SMFE, vol. I. Adams, J.I The engineering behaviour of a Canadian muskeg. Proc. 6th Int. Conf. SMFE, vol. I. ADI Limited Miramichi Channel Study report. ADI Limited Miramichi Channel Study report. Berry, P.L. and Poskitt, T.J The consolidation of peat. Géotechnique, 22, 1. Berry, P.L. and Poskitt, T.J The consolidation of peat. Géotechnique, 22, 1. Bjerrum, L. and Landva, A Direct simple-shear tests on a Norwegian quick clay. Géotechnique 16, 1. Bjerrum, L. and Landva, A Direct simple-shear tests on a Norwegian quick clay. Géotechnique 16, 1. Bjerrum, L Engineering geology of Norwegian normally-consolidated marine clays as related to settlement of buildings. 7th Rankine Lecture, NGI Publ. No. 71, Oslo. Bjerrum, L Engineering geology of Norwegian normally-consolidated marine clays as related to settlement of buildings. 7th Rankine Lecture, NGI Publ. No. 71, Oslo. Bjerrum, L Embankments on soft ground. ASCE Spec. Conf. on Performance of Earth and Earth- supported Structures. Purdue University, Lafayette, Ind. Proc., vol. 2. Bjerrum, L Embankments on soft ground. ASCE Spec. Conf. on Performance of Earth and Earth- supported Structures. Purdue University, Lafayette, Ind. Proc., vol. 2. Bjerrum, L General report to: Session 4. Problems of soil mechanics and construction on soft clays and structurally unstable soil. Proc. 8th Int. Conf. SMFE, Moscow. Vol. 3, pp. 111 – 159. Bjerrum, L General report to: Session 4. Problems of soil mechanics and construction on soft clays and structurally unstable soil. Proc. 8th Int. Conf. SMFE, Moscow. Vol. 3, pp. 111 – 159. Brawner, C Classification, laboratory testing and highway construction procedure for organic terrain. Technical Bulletin No. 2, Department of Highways, BC. Brawner, C Classification, laboratory testing and highway construction procedure for organic terrain. Technical Bulletin No. 2, Department of Highways, BC. Briaud, J.-L Development of peat mechanics at UNB ( ). M.Sc.Eng. thesis, Department of Civil Engineering, University of New Brunswick. Briaud, J.-L Development of peat mechanics at UNB ( ). M.Sc.Eng. thesis, Department of Civil Engineering, University of New Brunswick. Buisman, A.S.K Resiults of long-duration settlement tests. Proc., 1st Int. Conf. SMFE, vol. 1, Cambridge, Mass. Buisman, A.S.K Resiults of long-duration settlement tests. Proc., 1st Int. Conf. SMFE, vol. 1, Cambridge, Mass. Casagrande, A Classification and identification of soils. Trans. ASCE, vol.113. Casagrande, A Classification and identification of soils. Trans. ASCE, vol.113. Chai, J.-C., Carter, J.P. and Hayashi, S Vacuum consolidation and its combination with embankment loading. Can. Geot. J., 43. Chai, J.-C., Carter, J.P. and Hayashi, S Vacuum consolidation and its combination with embankment loading. Can. Geot. J., 43. Chang, Y.C.E., Broms, B.B. and Peck R.B Relationship between the settlement of soft clays and excess pore pressures due to imposed loads. Proc. 8th Int. Conf. SMFE, Moscow. Vol. 1:1. Chang, Y.C.E., Broms, B.B. and Peck R.B Relationship between the settlement of soft clays and excess pore pressures due to imposed loads. Proc. 8th Int. Conf. SMFE, Moscow. Vol. 1:1. Chang, Y.C.E Long term consolidation beneath the test fills at Väsby, Sweden. Swedish Geot. Inst., Report No. 13. Chang, Y.C.E Long term consolidation beneath the test fills at Väsby, Sweden. Swedish Geot. Inst., Report No. 13. Crawford, C.B. and Burn, K.N Long-term settlements on sensitive clay. Laurits Bjerrum Memorial Volume, Norw. Geot. Inst., Oslo. Crawford, C.B. and Burn, K.N Long-term settlements on sensitive clay. Laurits Bjerrum Memorial Volume, Norw. Geot. Inst., Oslo. Crawford, C.B., Fannin, R.J. and Kern, C.B Embankment failures at Vernon, British Columbia. Can. Geot. J., 32, No.2. Crawford, C.B., Fannin, R.J. and Kern, C.B Embankment failures at Vernon, British Columbia. Can. Geot. J., 32, No.2. Dewar, S The oldest roads in Britain. The Countryman, vol. 59 (3). Dewar, S The oldest roads in Britain. The Countryman, vol. 59 (3). Eggestad, Å. and Føyn, T Settlement observations beneath a test fill on peat. Väg- og vatten-byggaren (Journ. Swedish Soc. of Civil Engineers), 23, No Eggestad, Å. and Føyn, T Settlement observations beneath a test fill on peat. Väg- og vatten-byggaren (Journ. Swedish Soc. of Civil Engineers), 23, No Feyling-Hanssen, R.W Micropaleontology applied to soil mechanics in Norway. Norw. Geot. Inst. Publ. No. 20. Feyling-Hanssen, R.W Micropaleontology applied to soil mechanics in Norway. Norw. Geot. Inst. Publ. No. 20. Foote, R. and Ladd, C.C Undrained settlement of plastic and organic clays. J. Geot. Eng. Div., Proc., ASCE 107, No. GT8. Foote, R. and Ladd, C.C Undrained settlement of plastic and organic clays. J. Geot. Eng. Div., Proc., ASCE 107, No. GT8. Gautschi, M.A Torf als baugrund (peat as foundation soil). Research summary report, Norw. Geot. Inst., Oslo. (In German) Gautschi, M.A Torf als baugrund (peat as foundation soil). Research summary report, Norw. Geot. Inst., Oslo. (In German)

71 BIBLIOGRAPHY Hanrahan, E.T A road failure on peat. Géotechnique, 14, No. 3. Hanrahan, E.T A road failure on peat. Géotechnique, 14, No. 3. Hobbs, N.B Mire morphology and the properties and behaviour of some British and foreign peats. Quarterly J. Eng. Geology, London, vol. 19, pp Hobbs, N.B Mire morphology and the properties and behaviour of some British and foreign peats. Quarterly J. Eng. Geology, London, vol. 19, pp Hobbs, N.B A note on the classification of peat. Géotechnique 37, No. 3, p Hobbs, N.B A note on the classification of peat. Géotechnique 37, No. 3, p Horn, H.M. and Deere, D.U Frictional characteristics of minerals. Géotechnique 12. Horn, H.M. and Deere, D.U Frictional characteristics of minerals. Géotechnique 12. Hungr. O. and Evans, S.G An example of a peat flow near Prince Rupert, British Columbia. Can. Geot. Journal, vol. 22, No. 2. Hungr. O. and Evans, S.G An example of a peat flow near Prince Rupert, British Columbia. Can. Geot. Journal, vol. 22, No. 2. Hutchinson, J.N The record of peat wastage in the East Anglian fenlands at Holme Post, A.D. J. Ecol., vol. 68, Blackwell Scientific Publ. Hutchinson, J.N The record of peat wastage in the East Anglian fenlands at Holme Post, A.D. J. Ecol., vol. 68, Blackwell Scientific Publ. Jelisic, N. and Leppänen, M Mass stabilization of peat in road and railway construction. In Proc. Int. Conf. on Dry Mix Methods for Deep Soil Stabilization, Stockholm. Edited by H. Bredenberg. G. Holm and B. Broms. Rotterdam; Brookfield, VT: Balkema, pp Jelisic, N. and Leppänen, M Mass stabilization of peat in road and railway construction. In Proc. Int. Conf. on Dry Mix Methods for Deep Soil Stabilization, Stockholm. Edited by H. Bredenberg. G. Holm and B. Broms. Rotterdam; Brookfield, VT: Balkema, pp Keenan, G.H., Landva, A.O., Valsangkar, A.J. and Cormier, R.J Performance and failure of test embankment on organic silty clay. Proc. Building on Marginal and Derelict Land. Inst. of Civil Engineering (U.K.), Glasgow, Scotland. Keenan, G.H., Landva, A.O., Valsangkar, A.J. and Cormier, R.J Performance and failure of test embankment on organic silty clay. Proc. Building on Marginal and Derelict Land. Inst. of Civil Engineering (U.K.), Glasgow, Scotland. Kjellman, W Consolidation of clay soil by means of atmospheric pressure. Proc. Conf. on Soil Stabilization, MIT, pp Kjellman, W Consolidation of clay soil by means of atmospheric pressure. Proc. Conf. on Soil Stabilization, MIT, pp Koda,, E., Szymanski, A. and Wolski, W Field and laboratory experience with the use of strip drains in organic soils. Can. Geot. Journal, vol. 30, No. 2. Koda,, E., Szymanski, A. and Wolski, W Field and laboratory experience with the use of strip drains in organic soils. Can. Geot. Journal, vol. 30, No. 2. Ladd, C.C., Foote, R., Ishikara, K., Schlosser, F. and Poulos, H.G Stress-deformation and strength characteristics. State-of-the-art Report, Proc. 9th Int. Conf. SMFE, Tokyo, vol. 2. Ladd, C.C., Foote, R., Ishikara, K., Schlosser, F. and Poulos, H.G Stress-deformation and strength characteristics. State-of-the-art Report, Proc. 9th Int. Conf. SMFE, Tokyo, vol. 2. Lagrange, M., Perrin, J. & Magnan, J.P Classification géotechnique des sols: 2 – Mécanisation du test de von Post pour les sols organiques. Bulletin de liaison des Laboratoires des Ponts et Chaussées, Paris, 105: Lagrange, M., Perrin, J. & Magnan, J.P Classification géotechnique des sols: 2 – Mécanisation du test de von Post pour les sols organiques. Bulletin de liaison des Laboratoires des Ponts et Chaussées, Paris, 105: Landva, A.O. 1980a. Vane testing in peat. Can. Geot. Journal, vol. 17, No. 1. Landva, A.O. 1980a. Vane testing in peat. Can. Geot. Journal, vol. 17, No. 1. Landva, A.O. 1980b. Geotechnical behaviour and testing of peat. PhD thesis, Université Laval Quebec. Landva, A.O. 1980b. Geotechnical behaviour and testing of peat. PhD thesis, Université Laval Quebec. Landva, A.O. and Pheeney, P.E Peat fabric and structure. Can. Geot. Journal, vol. 17, No. 3. Landva, A.O. and Pheeney, P.E Peat fabric and structure. Can. Geot. Journal, vol. 17, No. 3. Landva, A.O., Korpijaakko, E.O. and Pheeney, P.E Geotechnical classification of peats and organic soils. In STP 820, P.M. Jarrett (Ed.), ASTM Committee D-18 Symposium, Toronto, Canada, pp Landva, A.O., Korpijaakko, E.O. and Pheeney, P.E Geotechnical classification of peats and organic soils. In STP 820, P.M. Jarrett (Ed.), ASTM Committee D-18 Symposium, Toronto, Canada, pp Landva, A.O. and La Rochelle, P Compressibility and shear characteristics of Radforth peats. In STP 820, P.M. Jarrett (Ed.), ASTM Committee D-18 Symposium, Toronto, Canada, pp Landva, A.O. and La Rochelle, P Compressibility and shear characteristics of Radforth peats. In STP 820, P.M. Jarrett (Ed.), ASTM Committee D-18 Symposium, Toronto, Canada, pp Landva, A.O., Korpijaakko, E.O. and Pheeney, P.E Notes on the original von Post peat and peatland classification system. Proc. Advances in Peatlands Engineering, Carleton University, Ottawa, pp Landva, A.O., Korpijaakko, E.O. and Pheeney, P.E Notes on the original von Post peat and peatland classification system. Proc. Advances in Peatlands Engineering, Carleton University, Ottawa, pp Landva, A.O., Pheeney, P.E., La Rochelle, P. and Briaud, J.-L Structures on peatland – geotechnical investigations. Proc. Advances in Peatlands Engineering, Carleton University, pp Landva, A.O., Pheeney, P.E., La Rochelle, P. and Briaud, J.-L Structures on peatland – geotechnical investigations. Proc. Advances in Peatlands Engineering, Carleton University, pp

72 BIBLIOGRAPHY Landva, A.O., Clark, J.I., Crooks, J.H.A. and Burwash, W.J Degradation of peats and organic soils under engineered structures – a preliminary study. Proc. Advances in Peatlands Engineering, Carleton University, pp Landva, A.O., Clark, J.I., Crooks, J.H.A. and Burwash, W.J Degradation of peats and organic soils under engineered structures – a preliminary study. Proc. Advances in Peatlands Engineering, Carleton University, pp Landva, A.O., Valsangkar, A.J. and Charalambous, P Performance of a raft foundation supporting a multi storey structure. Can. Geot. Journal, vol. 25, No. 1. Landva, A.O., Valsangkar, A.J. and Charalambous, P Performance of a raft foundation supporting a multi storey structure. Can. Geot. Journal, vol. 25, No. 1. Landva, A.O., Valsangkar, A.J. and Wroblevicz, Z Long-term performance of raft and footing foundations above clayey silt. ASCE Spec. Geot. Publ. No. 40, Settlement 1994 Conference, vol. 1. Texas A & M. University, pp Landva, A.O., Valsangkar, A.J. and Wroblevicz, Z Long-term performance of raft and footing foundations above clayey silt. ASCE Spec. Geot. Publ. No. 40, Settlement 1994 Conference, vol. 1. Texas A & M. University, pp Landva, A.O Characterization of Escuminac peat and construction on peatland. In Characterization and Engineering Properties of Natural Soils. Edited by T.S Tan, K.K. Phoon, D.W. Hight and S. Leroueil. Taylor and Francis Group, London, pp Landva, A.O Characterization of Escuminac peat and construction on peatland. In Characterization and Engineering Properties of Natural Soils. Edited by T.S Tan, K.K. Phoon, D.W. Hight and S. Leroueil. Taylor and Francis Group, London, pp Larsson, R Behaviour of organic clay and gyttja. Swed. Geot. Inst. Report No. 38, Linköping, Sweden. Larsson, R Behaviour of organic clay and gyttja. Swed. Geot. Inst. Report No. 38, Linköping, Sweden. Lea, N.D. and Brawner, C.O Highway design and construction over peat deposits in lower British Columbia. Highway Res. Bd., Rec. 7: 1-33 Washington, DC. Lea, N.D. and Brawner, C.O Highway design and construction over peat deposits in lower British Columbia. Highway Res. Bd., Rec. 7: 1-33 Washington, DC. Lefebvre, G., Langlois, P., Lupien, C. and Lavallée, J.-G Laboratory testing and in situ behaviour of peat as embankment foundation. Can. Geot. Journal, vol. 21, No. 2. Lefebvre, G., Langlois, P., Lupien, C. and Lavallée, J.-G Laboratory testing and in situ behaviour of peat as embankment foundation. Can. Geot. Journal, vol. 21, No. 2. Lo, K.Y Shear strength properties of a sample of volcanic material of the Valley of Mexico. Géotechnique 12. Lo, K.Y Shear strength properties of a sample of volcanic material of the Valley of Mexico. Géotechnique 12. Lupien, C., Lefebvre, G., Rosenberg, P. and Lavallée, J.G Observations during construction of till embankments on peat foundation. Proc. 34th Can. Geot. Conf., Fredericton, NB. Lupien, C., Lefebvre, G., Rosenberg, P. and Lavallée, J.G Observations during construction of till embankments on peat foundation. Proc. 34th Can. Geot. Conf., Fredericton, NB. Lupien, C., Lefebvre, G., Rosenberg, P., Paré, J.J. and Lavallée, J.G The use of fabrics for improving the placement of till on peat foundation. 62nd Annual Meeting of the Transportation Research Board, Washington, DC. Lupien, C., Lefebvre, G., Rosenberg, P., Paré, J.J. and Lavallée, J.G The use of fabrics for improving the placement of till on peat foundation. 62nd Annual Meeting of the Transportation Research Board, Washington, DC. MacKenzie, W.B Notes on railway work. Lecture given to the Engineering Society of the University of New Brunswick, October Constitution and Lectures MacKenzie, W.B Notes on railway work. Lecture given to the Engineering Society of the University of New Brunswick, October Constitution and Lectures MacFarlane, I.C. and Rutka, A An evaluation of pavement performance over muskeg in Northern Ontario. Highway Research Board Bulletin 316, Washington, DC. MacFarlane, I.C. and Rutka, A An evaluation of pavement performance over muskeg in Northern Ontario. Highway Research Board Bulletin 316, Washington, DC. Magnan, J.P Classification géotechnique des sols: 1 – A propos de la classification LPC. Bulletin de liaison des Laboratoires des Ponts et Chaussées, Paris, 105: Magnan, J.P Classification géotechnique des sols: 1 – A propos de la classification LPC. Bulletin de liaison des Laboratoires des Ponts et Chaussées, Paris, 105: Mesri, G Discussion on ‘New design procedure for stability of soft clays’. J. Geotech. Div., ASCE, Reston, VA. 101(4): Mesri, G Discussion on ‘New design procedure for stability of soft clays’. J. Geotech. Div., ASCE, Reston, VA. 101(4): Mesri, G., Rokhsar, A. and Bohor, B.F Composition and compressibility of typical samples of Mexico City clay. Géotechnique 25, No. 3, p Mesri, G., Rokhsar, A. and Bohor, B.F Composition and compressibility of typical samples of Mexico City clay. Géotechnique 25, No. 3, p Mesri, G. and Ajlouni, M Engineering properties of fibrous peats. J. Geot. and Geoenv. Eng., vol. 133, No. 7, pp Mesri, G. and Ajlouni, M Engineering properties of fibrous peats. J. Geot. and Geoenv. Eng., vol. 133, No. 7, pp Miyakawa, I Some aspects of road construction in peaty or marshy areas in Hokkaido, with particular reference to filling methods. Civil Eng. Research Inst., Hokkaido Development Bureau, Sapporo. Miyakawa, I Some aspects of road construction in peaty or marshy areas in Hokkaido, with particular reference to filling methods. Civil Eng. Research Inst., Hokkaido Development Bureau, Sapporo.

73 BIBLIOGRAPHY Mullins, B. and Mullins, M.B On the origin and reclamation of peat bog, with some observations on the construction of roads, railways and canals in bog. Trans. Inst. of Civil Eng. of Ireland, vol. II, pp plates I-V. Presented to the Institution on February 10th, Mullins, B. and Mullins, M.B On the origin and reclamation of peat bog, with some observations on the construction of roads, railways and canals in bog. Trans. Inst. of Civil Eng. of Ireland, vol. II, pp plates I-V. Presented to the Institution on February 10th, Muskeg Engineering Handbook Muskeg Subcommittee of the NRC Associate Committee on Geotechnical Research. Edited by I.C. MacFarlane. University of Toronto Press, 297 pp. Muskeg Engineering Handbook Muskeg Subcommittee of the NRC Associate Committee on Geotechnical Research. Edited by I.C. MacFarlane. University of Toronto Press, 297 pp. Nichol, D Construction over peat in Greater Vancouver, British Columbia. Proc. Inst. of Civil Eng.: Municipal Engineer, 127: Nichol, D Construction over peat in Greater Vancouver, British Columbia. Proc. Inst. of Civil Eng.: Municipal Engineer, 127: Perrin, J Classification des sols organiques. Bulletin de liaison des Laboratoires des Ponts et Chaussées, Paris, 69: Perrin, J Classification des sols organiques. Bulletin de liaison des Laboratoires des Ponts et Chaussées, Paris, 69: Pheeney, P.E Fabric and geotechnical behaviour of sphagnum peats. M.Sc.Eng. thesis, Department of Civil Engineering, University of New Brunswick. Pheeney, P.E Fabric and geotechnical behaviour of sphagnum peats. M.Sc.Eng. thesis, Department of Civil Engineering, University of New Brunswick. Radforth, N.W Muskeg as an engineering problem. In Muskeg Engineering Handbook, University of Toronto Press. Ed. I.C. MacFarlane. Radforth, N.W Muskeg as an engineering problem. In Muskeg Engineering Handbook, University of Toronto Press. Ed. I.C. MacFarlane. Ripley, C.F. and Leonoff, C.E Embankment settlement behaviour on deep peat. Proc. 7th Muskeg Res. Conf., NRC of Canada, Assoc. Ctee. on Soil and Snow Mech., Tech. Mem. 71. Ripley, C.F. and Leonoff, C.E Embankment settlement behaviour on deep peat. Proc. 7th Muskeg Res. Conf., NRC of Canada, Assoc. Ctee. on Soil and Snow Mech., Tech. Mem. 71. Reid, A.G Construction over peat. Vancouver Soils Group, Peat Symposium February Reid, A.G Construction over peat. Vancouver Soils Group, Peat Symposium February Root, A.W California experience in construction of highway across marsh deposits. Highwau Research Board, Bull. 173, Washington, DC. Root, A.W California experience in construction of highway across marsh deposits. Highwau Research Board, Bull. 173, Washington, DC. Rowe, R.K Recommendations for the use of geotextile reinforcement in the design of low embankments on very soft/weak soils. In Geotextiles in Filtration & Drainage, Corbet, S. and King, J. (Eds.), Thomas Telford, London, England, pp Rowe, R.K Recommendations for the use of geotextile reinforcement in the design of low embankments on very soft/weak soils. In Geotextiles in Filtration & Drainage, Corbet, S. and King, J. (Eds.), Thomas Telford, London, England, pp Rowe, R.K., MacLean, M.D. and Barsvary, A.K The observed behaviour of a geotextile-reinforced embankment constructed on peat. Can. Geot. J., 21, 2. Rowe, R.K., MacLean, M.D. and Barsvary, A.K The observed behaviour of a geotextile-reinforced embankment constructed on peat. Can. Geot. J., 21, 2. Rowe, R.K., MacLean, M.D. and Soderman, K.L Analysis of a geotextile-reinforced embankment constructed on peat. Can. Geot. J., 21, 3. Rowe, R.K., MacLean, M.D. and Soderman, K.L Analysis of a geotextile-reinforced embankment constructed on peat. Can. Geot. J., 21, 3. Rowe, R.K. and Soderman, K.L. 1985a. An approximate method for estimating the stability of geotextile- reinforced embankments. Can. Geot. J., 22, 3. Rowe, R.K. and Soderman, K.L. 1985a. An approximate method for estimating the stability of geotextile- reinforced embankments. Can. Geot. J., 22, 3. Rowe, R.K. and Soderman, K.L. 1985b. Reinforced embankments on very poor foundations. Geotextiles and Geomembranes, 4: Rowe, R.K. and Soderman, K.L. 1985b. Reinforced embankments on very poor foundations. Geotextiles and Geomembranes, 4: Rowe, R.K. and Soderman, K.L Reinforced embankments on very poor foundations. Geotextiles and Geomembranes, 2: Rowe, R.K. and Soderman, K.L Reinforced embankments on very poor foundations. Geotextiles and Geomembranes, 2: Rowe, R.K. and Mylleville, B.L.J A geogrid reinforced embankment on peat over organic silt: a case history. Can. Geot. J., 33, 1. Rowe, R.K. and Mylleville, B.L.J A geogrid reinforced embankment on peat over organic silt: a case history. Can. Geot. J., 33, 1. Rowe, R.K. (ed.) Geotechnical and Geoenvironmental Engineering Handbook. Kluwer Academic Publishers, Boston, 1088 pp. Rowe, R.K. (ed.) Geotechnical and Geoenvironmental Engineering Handbook. Kluwer Academic Publishers, Boston, 1088 pp. Rowe, R.K., Gnanendran, C.T., Valsangkar, A.J. and Landva, A.O Performance of a test embankment constructed on an organic clayey silt deposit. Can. Geot. J., 38, Rowe, R.K., Gnanendran, C.T., Valsangkar, A.J. and Landva, A.O Performance of a test embankment constructed on an organic clayey silt deposit. Can. Geot. J., 38,

74 BIBLIOGRAPHY Royer, J.A Experimental road for heavy traffic on a very compressible soil (peat bog ground). Proc. 1st Int. Conf SMFE, vol. I. Royer, J.A Experimental road for heavy traffic on a very compressible soil (peat bog ground). Proc. 1st Int. Conf SMFE, vol. I. Samson, L. and La Rochelle, P Design and performance of an expressway constructed over peat by preloading. Can. Geot. J., 9, 4. Samson, L. and La Rochelle, P Design and performance of an expressway constructed over peat by preloading. Can. Geot. J., 9, 4. Samson, L Postconstruction settlement of an expressway built on peat by precompression. Can. Geot. J., 22, 3. Samson, L Postconstruction settlement of an expressway built on peat by precompression. Can. Geot. J., 22, 3. Scotton, S Experiences with organic soils in the Greater Vancouver area of south-western British Columbia. Proc. 34th Can. Geot. Conf., Fredericton, NB. Scotton, S Experiences with organic soils in the Greater Vancouver area of south-western British Columbia. Proc. 34th Can. Geot. Conf., Fredericton, NB. Silburn, J.D Peat as the impermeable membrane in an earth dam. Symp. on Peat Moss in Canada, Univ. of Sherbrooke. Silburn, J.D Peat as the impermeable membrane in an earth dam. Symp. on Peat Moss in Canada, Univ. of Sherbrooke. Skempton, A.W Discussion: The planning and design of the new Hong Kong airport. Proc. Inst. Civil Engrs., London, 7, pp Skempton, A.W Discussion: The planning and design of the new Hong Kong airport. Proc. Inst. Civil Engrs., London, 7, pp Spence, R.A Consolidation of fibrous peat. Vancouver Soils Group, Peat Symposium February Spence, R.A Consolidation of fibrous peat. Vancouver Soils Group, Peat Symposium February Tavenas, F.A. and Leroueil, S State-of-the-art on laboratory and in-situ stress-strain-time behaviour of soft clays. In Proc. Int. Symp. on Geot. Eng. of Soft Soils, Mexico City, pp Tavenas, F.A. and Leroueil, S State-of-the-art on laboratory and in-situ stress-strain-time behaviour of soft clays. In Proc. Int. Symp. on Geot. Eng. of Soft Soils, Mexico City, pp Terzaghi, K Report concerning the subsoil conditions at the site of the proposed flying field at Väsby. Appendix I in Swedish Geot. Inst. Report No. 13, Linköping Terzaghi, K Report concerning the subsoil conditions at the site of the proposed flying field at Väsby. Appendix I in Swedish Geot. Inst. Report No. 13, Linköping Terzaghi, K. and Peck, R.B Soil mechanics in engineering practice. 2nd ed., Wiley, New York. Terzaghi, K. and Peck, R.B Soil mechanics in engineering practice. 2nd ed., Wiley, New York. Tresidder, J.O A review of existing methods of road construction over peat. Dept. of Scientific and Industrial Research. Road Res. Tech. Paper No. 40, London. Her Majesty’s Stationery Office. Tresidder, J.O A review of existing methods of road construction over peat. Dept. of Scientific and Industrial Research. Road Res. Tech. Paper No. 40, London. Her Majesty’s Stationery Office. UNB Microscopy and Microanalysis Facility, UNB Campus, Fredericton, NB. UNB Microscopy and Microanalysis Facility, UNB Campus, Fredericton, NB. van der Burght, J.H Long duration consolidation tests. 1st Int. Conf. SMFE, vol. 1, p.51, Cambridge, Mass. van der Burght, J.H Long duration consolidation tests. 1st Int. Conf. SMFE, vol. 1, p.51, Cambridge, Mass. Vidal, H The principle of reinforced earth. Hwy. Res. Rec. No. 282, Highway Res. Board, National Academy of Sciences, NRC, National Academy of Engineering. Vidal, H The principle of reinforced earth. Hwy. Res. Rec. No. 282, Highway Res. Board, National Academy of Sciences, NRC, National Academy of Engineering. von Post L Sveriges Geologiska Undersöknings torvinventering och nogra av dess hittils vunna resultat (SGU’s peat inventory and some preliminary results). Svenska Mosskulturföreningens Tidsskrift (J. Swedish Moss Culture Society), vol. 36, Jönköping, Sweden. von Post L Sveriges Geologiska Undersöknings torvinventering och nogra av dess hittils vunna resultat (SGU’s peat inventory and some preliminary results). Svenska Mosskulturföreningens Tidsskrift (J. Swedish Moss Culture Society), vol. 36, Jönköping, Sweden. Warnock, T.A Construction of roads on peat foundations using lightweight rafts. J. Inst. of Highway Engineers, vol. 14, (4). Warnock, T.A Construction of roads on peat foundations using lightweight rafts. J. Inst. of Highway Engineers, vol. 14, (4). Weber, W.G Performance of embankments constructed over peat. Proc. Amer. Soc. of Civil Engr., J. SMFE, vol. 95, SM1. Weber, W.G Performance of embankments constructed over peat. Proc. Amer. Soc. of Civil Engr., J. SMFE, vol. 95, SM1. Wiesner, W.R. and Hardy, R.M Design and construction experiences with fluid retaining embankments on peat. Proc. 17th Muskeg Res. Conf., NRC of Canada, Tech. Memo Wiesner, W.R. and Hardy, R.M Design and construction experiences with fluid retaining embankments on peat. Proc. 17th Muskeg Res. Conf., NRC of Canada, Tech. Memo. 122.

75 TOTAL LAND AREA IN CANADA Peatland area Forested area where surface organics dominate Forested area 45% 12.5% 8.5% - Total land area in Canada 1,000,000,000 ha - 660,000,000 ha or 2/3 of the total land area is peatland and forestry country: "an enormous area" (1975 Muskeg Research Conference) Other 34%

76 PEAT originates from plants and denotes the various stages in the humification process where the plant structure can still be discerned. Peat is a sedentary soil which has been formed in situ from the original material. DY, which has a somewhat sticky consistency and is generally brown-black in colour, denotes the various stages in the humification process where the plant structure is completely destroyed. Some types of dy are formed in situ, where they constitute the highest degree of humification of the peat. Other types of dy have been transported by water and precipitated in a colloidal form in environments with low contents of calcium. GYTTJA, which has a more or less elastic consistency and is generally greenish in colour, originates from remains of plants and animals rich in fats and proteins, in contrast to peat which is formed from remains of plants rich in carbohydrates. Dead microscopic aquatic animals are dissolved and decomposed with the aid of bacteria to a flocculent substance, in which mineral particles and less decomposed remains of plants and animals are embedded. Further decomposition occurs with the aid of organisms living in the substance, such as worms and larvae. Fermentation processes generating sulphuretted hydrogen and methane complete the formation of gyttja. BEHAVIOUR OF ORGANIC CLAY AND GYTTJA (Larsson 1990)

77 “RAILWAY ON PEAT BOGS OR SWAMPS: Should your line cross a morass, peat-bog or swamp, (1)Drain and side ditch where possible, and thus make bog firm enough to carry, in preference to cross logging. Ditches may be 5 feet deep, and, if possible, 20 to 50 feet from the centre line. (2)Do not cross-log where bank is high and settlement likely to be considerable, only where bog is nearly but not quite sufficient to sustain the bank. The cross-logs broaden the base and form a light material for part of the bank; used in any other way, they are more harm than good. (3)Keep grade low. (4)Make banks as light as possible, using turf, peat, sawdust or cinders. (5)If sides bulge up much, leave only 5 ft. berm* between toe of bank and edge of ditch; but, if no bulging, make berm as wide as possible.” *= space “In places where piles are not desirable, the ground may be consolidated in the following manner: Prepare a piece of hard wood 4 in. diameter 6 feet long, pointed at one end, and having an iron ring on the other end. Drive this down about five feet with a hand maul, pull it out again with a lever and chain, pour sand or gravel into the hole and pack it down with an iron bar. Begin at the outside and work towards the centre, putting the holes about 18 inches apart. By the time you reach the centre, the ground will be almost as hard as rock. I have used this very successfully under bridge abutments and turn-table centres. In Paris, the ground under the Exhibition Buildings was consolidated in this manner, though on a larger scale. There, a cone-shaped casting or punch was used which weighed 2,000 lbs. This was exactly like the hammer of a pile-driver, being allowed to fall from the top of a pair of leaders about 20 feet high. The punch, on falling, buried itself in the soft ground, and was pulled out by the wire rope attached to the drum of the engine. Sand or gravel was then shovelled into the hole and the punch allowed to fall again into the same hole; and so on until the hole was filled. The leaders were then moved 4 or 5 feet away, and the same thing repeated until the whole area was consolidated – in some cases to a depth fifteen feet below the surface. Two shapes of punches were used. A testing hammer, was also first used to test the carrying capacity of the natural ground, so that the degree of additional consolidation required might be estimated.” 107 YEARS AGO LITTLE N.B. WAS A PIONEER ! ( Notes on Railway Work by Wm. B. MacKenzie, C.E.

78 250 m m 50 m m 25 m m10 m m Comparison between filter paper and sphagnum peat leaves (a) Whatman filter paper (65X) (b) Ditto (330X) (c) Ditto (600X) (d) SH 1 leaves (65X) (e) SH 3 leaf (330X) (f) SH 1 leaf (1600X)

79 SETTLEMENT OF DIKES ON PEAT FROM (van der Burght 1936)

80 SETTLEMENT OF DIKES ON PEAT, (van der Burght 1936, Buisman 1936) Initial load (1841) Δp = 33 kPa Maximum load (1924) S = 1.67 m ( ) Δp = 45 kPa

81 MIRAMICHI WASTEWATER TREATMENT BERM ON ORGANIC DIATOMACEOUS SILT (1997)

82

83 VÄSBY TEST FILL GENERAL THEORY OF CONSOLIDATION (Terzaghi 1946)

84 VÄSBY TEST FILL PRIMARY CONSOLIDATION UNDER SURCHARGE q 1 AND UNDER PERMANENT FILL q 2 (Terzaghi 1946)

85 VÄSBY TEST FILL – PRIMARY AND SECONDARY CONSOLIDATION UNDER SURCHARGE (Terzaghi 1946)

86 SURCHARGE ON PEAT (Brawner 1969) TIME-SETTLEMENT CURVES ILLUSTRATING PRECONSOLIDATION PRINCIPLE CHART ILLUSTRATING PROCEDURE USED TO DETERMINE PRECONSOLIDATION SURCHARGE LOAD

87 DIRECT SIMPLE SHEAR, SH 3 PEAT VERTICAL CONSOLIDATION STRESS = 20 kPa LATERAL CONSOLIDATION STRESS ≈ 8 kPa Τ (kPa) σ (kPa) σvσv

88 DIRECT SIMPLE SHEAR, SH 3 PEAT STAGE 1-2, PURE SHEAR FAILURE PLANE FP 1-2 c=2.5 kPa, Ф=30 o Τ (kPa) ε (%) ε s = δhδh H σvσv δhδh Τ σ (kPa)

89 DIRECT SIMPLE SHEAR, SH 3 PEAT STAGE 2-3, END OF PURE SHEAR FAILURE PLANE FP 2-3 Τ (kPa) σ (kPa) σvσv Τ Τ (kPa) ε (%) c=2.5 kPa, Ф=30 o c=4.7 kPa, Ф=30 o

90 DIRECT SIMPLE SHEAR, SH 3 PEAT STAGE 3-4 FAILURE PLANE FP 3-4 Τ (kPa) σ (kPa) σvσv Τ Τ (kPa) ε (%) c=6.0 kPa, Ф=30 o c=2.5 kPa, Ф=30 o

91 DIRECT SIMPLE SHEAR, SH 3 PEAT FINAL STAGE 4-5 FAILURE PLANE FP 4-5 (horizontal) Τ (kPa) σ (kPa) Τ (kPa) ε (%) σvσv Τ c=2.5 kPa, Ф=30 o

92 DESIGN CHART FOR PEAT UNDERLAIN BY A FIRM BASE (after Rowe & Soderman 1985) TF = test fills at Escuminac (peat thickness 7.4m, w=1200 to 1800%) gfgf gfgf


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