seismic flat dilatometer (sdmt) 4. 2015/4...29 may 2015 eng. diego marchetti seismic flat...
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Eng. Diego Marchetti29 May 2015www.marchetti-dmt.it
Seismic Flat Dilatometer (SDMT)Working Principle, Equipment, Test Procedure, Results
MiddelfartDenmark
Lab Testing In Situ Testing: SCPT & SDMT
In situ testing : simple, fast, economical,repeatable, provides continuous soil profile,results real time, ..
In Sand :recovering undisturbed samples very difficultand in situ testing is the state-of-practice.
Caution : laboratory is the basis for research
TOO SLOW !
Mayne et al: State-of-the-Art Lecture (Alexandria Egypt 2009)17th Int. Conference on Soil Mechanics and Geotechnical Engineering
SCPT & SDMT fast and convenient tools for everyday investigations
SDMT Equipment
DMT(static)
Seismic(dynamic)
DMT equipment
DMT Flat Dilatometer equipment
BLADE
FLEXIBLEMEMBRANE(D = 60mm)
DMT Test Layout
blade
rods
penetrationmachine
pneumatic-electric cable control box
gas tank(air, nitrogen,etc)
Test Procedure
stop every 20 cm
P0: Lift-off pressure
P1: Pressure for1.1 mm expansion
DMT Equipment (mechanical)
Machines for advancing the DMT andSDMT equipment
Truck Penetrometer (most efficient)
cable exitsfrom rods
Light Penetrometer (most common)
Role of penetration for CPT and DMT
CPT – measurements performed during penetration
at a fix speed of 2 cm / sec (with some tolerance)
DMT – penetration necessary to arrive at next test
depth, without constraint on penetration speed.
Measurements when blade is not moving
High flexibility to advance DMT in the soil
Many ways of advancing the blade
Driven by Spt tripod
Driven by drill rig
Pushed by drill rig Driven or pushed bylight penetrometer
Pushed by a fixed platformPushed from a barge
Drill Rig – downhole Torpedo method
• TORPEDO pre-assembled before test and joined to drill rods
• Cable exits from slot of adaptor and is taped to drill rods
• Drill rods + torpedo inserted at bottom of borehole (then advance 20 cm)
DMT test from Jack-up
Venice lagoon, Italy (MO.SE.) Roskilde Fjord,Frederikssund - Denmark
Seafloor DMT
WATERDEPTH 0 to 100 m - PUSH CAPACITY 5 ton
Max test depth is the depth penetrable with 5 ton push.
6-7 ton ballast(built locally)
Shipped byair (50 Kg)
4 bolts
First Seafloor DMT test: 13 June 2014
First Seafloor DMT test: 13 June 2014
First Seafloor DMT test: 13 June 2014
SEAFLOOR DILATOMETER
Shipped by air (50 Kg)
Seafloor
ballast built locally ballast built locally
Supportanchoredto ballast
SeismicDilatometer
SEAFLOOR DMT (2015 USA – river bed)
2015 April 30th
6.5 ton ballast (steel plate)
5 ton push (max)
Field data and Interpretation of the Results
Field Data
Z(m)
P0
(kPa)P1
(kPa)
0.200.400.600.801.001.20…
220210305310285290…
300310420450380390…
DMT Intermediate parameters
Intermediate ParametersDMT Field Readings
P0
P1
Kd: Horizontal Stress Index
Ed: Dilatometer Modulus
Id: Material Index
DMT Formulae – Interpreted parameters
Intermediate
Parameters
Id
Kd
Ed
Interpreted Geotechnical Parameters
Cu: Undrained Shear Strength
Ko: Earth Pressure Coeff (clay)
OCR: Overconsolidation ratio (clay)
Φ: Safe floor friction angle (sand)
γ : Unit weight and description
M: Constrained Modulus
ID contains information on soil type
Performing DMT, immediately notice that:
p1
CLAY
pp0
SAND
p0
p1
p
SILT falls in between
ID=(p0 -u0)
(p1 -p0)
ID contains information on soil type
SAND
CLAY
KD contains information on stress history
KD is an ‘amplified’ K0, because (p0 - u0)is an ‘amplified’ σ’h, due to penetration
KD =σ’v
(p0 - u0)
p0
DMT
Definition of KD similar to K0:
Very roughly Kd ≈ 4 KoE.g. in NC : Ko ≈ 0.5 and Kd ≈ 2
KD reflects ‘stress history’ (OCR)
Depth
Z
Kd
KD contains information on stress history
2
KD = 2 in NC clay (OCR = 1)
NC
OC
KD > 2 in OC clay (OCR > 1)
KD contains information on stress history
OC Kd > 2
NC Kd͌ 2
Taranto 1987
KD correlated to OCR (clay)
ExperimentalKamei & Iwasaki 1995
TheoreticalFinno 1993
TheoreticalYu 2004
OCR = Kd
1.56
Marchetti 1980 (experimental)0.5
KD correlated to K0 (clay)
Theoretical2004 Yu
ExperimentalMarchetti (1980)
K0 =Kd 0.47
Marchetti 1980 (experimental)1.5
0.6
ED contains information on deformation
Theory of elasticity:
ED = elastic modulus of the horizontal load test performed
by the DMT membrane (D = 60mm, 1.1 mm expansion)
1.1 mm
DMT
ED= 34.7 (P1 -P0)
Gravesen S. "Elastic Semi-Infinite Medium bounded by a Rigid Wall with a CircularHole", Danmarks Tekniske Højskole, No. 11, Copenhagen, 1960, p. 110.
ED not directly usable corrections(penetration,etc)
M obtained from Ed using information onstress history (Kd) and soil type (Id)
ED (DMT modulus)
MConstrained
Modulus
KD (stress history)
ID (soil type)
Definition of M (no ambiguity)
Vertical drained confinedtangent modulus (at σ'vo)
M = Eoed = 1/mv = ∆σ'v / ∆εv (at σ'vo)
M Comparison from DMT and from Oedometer
Norwegian Geotechnical Institute (1986)."In Situ Site Investigation Techniques andinterpretation for offshore practice".Report 40019-28 by S. Lacasse, Fig. 16a,8 Sept 86
ONSOY Clay – NORWAY
Constrained Modulus M (Mpa)
Constrained Modulus M (Mpa)
Tokyo Bay Clay - JAPAN
Iwasaki K, Tsuchiya H., Sakai Y.,Yamamoto Y. (1991) "Applicability of theMarchetti Dilatometer Test to SoftGround in Japan", GEOCOAST '91,Sept. 1991, Yokohama 1/6
Virginia - U.S.A.
Failmezger, 1999
Cu from OCRLadd SHANSEP 77 (SOA TOKYO)
Ladd: best Cu measurement not from TRX UU !!
Using m ≈ 0.8 (Ladd 1977) and (Cu/σ’v)NC ≈ 0.22 (Mesri 1975)
Cu
σ’v OC
=Cu
σ’vNC
OCR m OCR = 0.5 Kd
1.56
Cu = σ’v 0.5 Kd
1.250.22
best Cu from oed OCR Shansep
A.G.I., 10th ECSMFE Firenze 1991Vol. 1, p. 37
Cu at National Site FUCINO – ITALY
different CPT profileaccording to Nc value
(Nc 14-22)
Cu comparisons from DMT and from other tests
Recife - Brazil
Coutinho et al., Atlanta ISC'98 Mekechuk J. (1983). "DMT Use on C.N.Rail Line British Columbia",First Int.Conf. on the Flat Dilatometer,Edmonton, Canada, Feb 83, 50
Skeena Ontario – Canada Tokyo Bay Clay - JAPAN
Iwasaki K, Tsuchiya H., Sakai Y.,Yamamoto Y. (1991) "Applicability of theMarchetti Dilatometer Test to SoftGround in Japan", GEOCOAST '91,Sept. 1991, Yokohama 1/6
Interpretation of Soil Description & Unit weight
I )EQUATION OF THE LINES:
SOIL DESCRIPTION
0.6
Material Index
If PI>50, reduce by 0.1
D
Dil
atom
ete r
Mod
ulus
0.1
and/or
PEAT5
MUD12
10
20
50
( )1.5
0.2 0.5
MUD
A
B
C
0.33
1.6
1.8
1.7
1000
(bar
)E
100
200
D
500
2000
D
0.585
0.6570.694
CLAY
2.05
DC
AB 0.621
m
1.9
SILTY
2.0132.2892.564
1.737
n
E =10(n+m log
3.3
1.7
γ
1
I
2
D
0.8 1.2
1.6
1.7
1.8
5
SAND
2
1.8
1.9
2.15
1.95
1.8
2.1
SILT
CL
AY
EY
SILTY
SA
ND
Y
D
and ESTIMATED γ/γwChart for evaluating:
ɣ unit weight ( σ'vo profile)
Soil description
as f (ID, ED)
Material Index ID
Dila
tom
ete
rM
od
ulu
sE
D(b
ar)
Marchetti & Crapps 1981
Example red dot:
ID = 1.6, Ed = 200 bar
Ɣ = 1.8 Ɣw
Soil description: sandy silt
C-reading
Readings:
ON OFF ON (OFF) ON
P0 P1 C (P2)
Audio signal:
C readings (in sand): pore water pressure
Schmertmann 1988 (DMT Digest No. 10, May 1988, Fig. 3)
SAND: C ≈ Uodrainage (≈ piezometer)
CLAY: C > Uono drainage (≈ highlights ∆u)
Du≈0
Du≈0
Du>0
UD=(p0 -u0)
(p2 -u0)
Example of C readings
Catania Harbour - 2012
Example of C readings
Catania Harbour - 2012
Example of C readings
wedge vs cone (dissipation)
Dissipation test in cohesive soilsestimate coefficient consolidation & permeability
Time (min)
h(k
Pa
)
Totani et al. (1998)
wedgeFrom a ≈ miniembankmentLarger volumein a lessdisturbed zone
coneFrom u(t) ina singularhighlydisturbedpoint
Acquisition DMT Dissipation (T, A)
DMT Dissipation Interpretation (Ch, Kh)
Validation of consolidation coefficientDMT vs. other dissipation tests
Totani et al. ISC '98 - Atlanta, Georgia (USA)
Seismic Dilatometer (2004)
SDMT – Test Layout
Acquisition Board
DM
TS
eis
mic
pro
be
Top Sensor
Bottom Sensor
Shear wave velocity measurement
Hammer generating shear wave
Data Acquisition is rapid (7-8 sec)
Vs interpretation real time
Automatic delay evaluation
Cross-correlation algorithm
shift red signal back
towards blu signal, until
best superimposition is
obtained
Δt = wave delay
SDMT main features
Accuracy of delay (Δt) calculation
• true-interval (2 receivers instead of 1)
• Trigger offset no influence on Δt calculation
• Same wave to both receivers
• Signals are amplified and digitized in depthclean waves delay Δt very clear
• Vs interpretation
• Automatic
• operator independent
• real time
• Test execution is rapid
• no hole
• no wait for cementation (e.g. crosshole, downhole)
SDMT
Fucino-TelespazioNational Research Site
(Italy) 2004
SDMT(2004)
SCPTCross HoleSASW
AGI (1991)
Vs at National Site FUCINO – ITALY
Vs validations
Bothkennar(UK)
Treporti-Venezia(Italia)
Zelazny Most(Polonia)
0
5
10
15
20
25
30
35
40
0 100 200 300 400Vs (m/s)
Z(m
)
SDMT P.I.
SDMT T.I.
SCPT P.I.
SDMT pseudo-intervalSDMT true-intervalSCPTU pseudo-interval
Młynarek et al.(2006)
McGillivray &Mayne (2004)
Hepton(1988)
Soils testable by DMT/SDMT
DMT• ALL SANDS, SILTS, CLAYS• Very soft soils (Cu = 2-4 kPa, M=0.5 MPa)
• Hard soils/Soft Rock (Cu = 1 MPa, M=400 MPa)
• Blade robust (safe push 25 ton)
SDMT• All penetrable soils
• Non penetrable soils (gravel, rock, ..):
inside a backfilled borehole
Max depth: 135 m in L’Aquila (2009)
Vs in non-penetrable soils
Totani (2009)
Method (downhole):
Drill borehole
careful backfill of borehole with
gravel (grains D = 5-15 mm)
Vs in borehole
the sand
travelpath
is similar
Travelpath includes short path in the
sand backfill similar for both receivers
delay Δt does not change
SDMT validation in non-penetrable soils
(only Vs in sandfilled borehole - no DMT !!!)
In penetrable soils both
procedures are possible
results ≈ same
SDMT in borehole (140m) – Aquila (ITALY)
SHEAR WAVE VELOCITY (m/s)Aquila (Earthquake – 2009)Fill Material
Calcareous Breccia
LACUSTRINE DEPOSITS:
SILTY SAND and
CLAYEY-SANDY SILT
De
pth
(m)
Main Applications using SDMT results
SDMT main graph
DMT Seismic DMT
GO= ρ Vs2
grain size stress historycompressibility strength Vs and G0
SDMT repeatability
repeatability ≈ 1-2%
Other SDMT results
OCR (clay)
K0 (clay)
Soil description
Unit weight ɣ (kN/m3)
Friction angle (sand)
Pore water pressure (sand)
Ch and Kh (clay & silt)
Vp (compression wave)
KD indicator of Stress History
KD indicator of stress history
Calibration chamber tests with prestraining cycles
Jamiolkowski & Lo Presti ISC'98 Atlanta
CC TEST N. 216 IN TICINO SAND
Kd increased 7 times the increaseof penetration resistance
Stress History: effects on CPT and DMT
Effect of SH onnormalized Qc (CPT)
Lee 2011, Eng. Geology – CC in sand
Effect of SHon KD (DMT)
Kd more reactive than Qc to Stress History
Stress History may have a very strong impacton settlement and liquefaction huge costsavings, especially in medium-big projects
KD leads to a more economical design
Two sites: same Qc, different OCR. Site 2 much ‘stronger’
Main SDMT applications
Settlements of shallow foundations
In situ G-γ decay curves
Compaction control
Liquefaction risk analysis
Slip surface detection in OC clay
Seismic design (Eurocode 8)
Laterally loaded piles (P-y curves)
Diaphragm walls (springs model)
FEM input parameters (es. Plaxis)
DMT for Settlements
Main DMT Application: Settlement prediction
LOAD
Boussinesq
Δσv
SOIL
DMT
M
ƩS =Δσv
MΔz
1-D approach (classic Terzaghi)
Many publications & case histories ofgood agreement between measured andDMT-predicted settlements / moduli:
• Vargas (2009)
• Bullock (2008)
• Monaco (2006)
• Lehane & Fahey (2004)
• Mayne (2001, 2004)
• Failmezger (1999, 2000, 2001)
• Crapps & Law Engineering (2001)
• Tice & Knott (2000)
• Woodward (1993)
• Iwasaki et al. (1991)
• Hayes (1990)
• Mayne & Frost (1988)
• Schmertmann 1986,1988)
• Steiner (1994)
• Leonards (1988)
• Lacasse (1986)
…
…
Observed vs. predicted by DMTSilos on Danube Bank (Belgrade )
DMT Settlement prediction: 77 cmMeasured Settlement: 63 cmDMT +22%
D. Berisavijevic, 2013
Observed vs. predicted by DMTDormitory Building 13 storeys (Atlanta - USA)
DMT
observed
Settlements profile: Measured vs DMT predicted
(Piedmont residual soil)
Mayne, 2005
SPT Settlement prediction: 460 mm
DMT Settlement prediction: 250 mm
Observed Settlement: 250 mm
SPT large error conservative expensive !!!
M at Sunshine Skyway BridgeTampa Bay – Florida
World record span for cablestayed post-tensioned concretebox girder concrete construction
(Schmertmann – Asce Civil Engineering – March 1988)
M from DMT ≈ 200 MPa (≈ 1000 DMT data points)M from laboratory: M ≈ 50 MPaM from observed settlements: M ≈ 240 MPa DMT good estimate of M
DMT Settlements software
Settlement prediction using DMT Settlements
software from the Constrained Modulus obtained
with the Flat Dilatometer in Bogotà two weeks
ago (May 9th) in a 30 m SDMT test lasted 4 hours
SDMT Escuela Colombiana 9 May 2015
SDMT Escuela Colombiana 9 May 2015
SDMT Escuela Colombiana 9 May 2015
SDMT Escuela Colombiana 9 May 2015
SDMT Escuela Colombiana 9 May 2015
SDMT Escuela Colombiana 9 May 2015
SDMT Escuela Colombiana 9 May 2015
Possible reasons DMT good settlement predictions
Baligh & Scott (1975)
measure zone
measurezone
Stiffness ≠ Strength
2. Modulus by mini load test relates betterto modulus than penetration resistance
1. Wedges deform soil less than cones
Possible reasons DMT predicts well settlement
Mayne(2001)
Soil is loaded at strain level for deformation analysis
Go and MDMT on the G - γ decay curve
G0 / MDMT may provide an estimate of in situ G-γ decay curve- Amoroso et al (2014, 2012)
- Marchetti et al (2008) in Schmertmann Volume
- Lehane & Fahey (2004) Porto ISC-2 – non linear settlement analysis from in situ tests
HARA (1973)
YOKOTA et al. (1981)
TATSUOKA (1977)
SEED & IDRISS (1970)
ATHANASOPOULOS (1995)
CARRUBBA & MAUGERI (1988)
0.05 to 0.1%
HARA (1973)
YOKOTA et al. (1981)
TATSUOKA (1977)
SEED & IDRISS (1970)
ATHANASOPOULOS (1995)
CARRUBBA & MAUGERI (1988)
0.05 – 0.1%
Maugeri (1995)
Mayne (2001)Ishihara (2001)
SDMT G0 - small strain modulus
MDMT - working strain modulus (γ = 0.05 – 0.1 %)two points
low GO/M
high GO/M
0
0.2
0.4
0.6
0.8
1
1.2
0.0001 0.001 0.01 0.1 1 10
no
rma
lized
sh
ea
rm
od
ulu
s,G
/G0
shear strain,g (%)
GDMT/G0 sand:gDMT ≈ 0.015 - 0.30 %
GDMT/G0 silt and clay:gDMT ≈ 0.23 - 1.75 %
G0 (Vs) from SDMT
1.2Sands (Darendeli2001)
Silts and clays with PI=0-50%(Darendeli2001)
Silts and clays with PI=50-100%Darendeli (2001)
Sands (experimentaldata)Silts and clays (experimentaldata)
"typical shape" G/G0-γcurves in different soiltypes
range of values of GDMT/G0 andcorresponding shear strain γDMT determinedby the "intersection" procedure in differentsoil types
G - γ decay curve: experimental results
(Amoroso et al. 2012, 2014)
SDMT experimental data usedto assist the construction of ahyperbolic equation
Summary of results
(Amoroso et al. 2014)
Comparison betweenhyperbolic and "measured"stiffness decay curves
DMTDMTG
GG
G
γ
γ
−+
=
11
1
00
0
0.2
0.4
0.6
0.8
1
1.2
0.0001 0.001 0.01 0.1 1 10
DSDSS - Roio Piano S3 C2
GDMT/G0 Roio Piano S3 C2
Hyperbolic curve
ROIO PIANOClayey silt(b)
no
rmal
ize
dsh
ear
mo
du
lus,
G/G
0
shear strain,g (%)
Compaction Control
DMT for Compaction Control
The high sensitivity to changes of stresses and density make the DMT particularly
suitable for detecting benefits of SOIL IMPROVEMENT
Compaction of a loose sandfillResonant vibrocompaction technique
Van Impe, De Cock, Massarsch, MengéNew Delhi (1994)
Dep
th(m
)
DMT vs CPT sensitivity to Compaction
Schmertmann (1986) DYNAMIC COMPACTION of sand site.MDMT % increase ≈ twice % increase in Qc
Jendeby (1992) monitored DEEP COMPACTION in a sand fillby VIBROWING. MDMT increase ≈ twice increase in Qc.
Pasqualini & Rosi (1993) VIBROFLOTATION job :
"DMT clearly detected improvement even in layers wherebenefits were undetected by CPT".
Ghent group (1993) before-after CPTs DMTs to evaluateeffects (±∆σh , Dr) by PILE (Atlas) INSTALLATION"DMTs before-after installation demonstrate more clearly
[than CPT] beneficial effects of Atlas installation".
Compaction Control DMT vs CPT
Jendeby 92: Qc & Mdmt before & after compaction of a loose sandfill
Before compaction
After compaction
Subgrade Compaction Control
MDMT acceptance profile(max always found at 25-26 cm)
Bangladesh Subgrade Compaction Case History90 km Road Rehabilitation Project
Acceptance MDMT profile fixed and used asalternative/fast acceptance tool for quality control ofsubgrade compaction, with only occasional verificationsby originally specified methods (Proctor, CBR, plate),(Marchetti, 1994)
DMT for Liquefaction Risk Assessment
Liquefaction risk assessment
Robertson & Wride (1998) CRR by CPT adequate for low-risk projects. For high-risk: estimate CRR by more than onemethod
Youd & Idriss (NCEER Workshops 2001) use 2 or moretests for a more reliable evaluation of CRR
Idriss & Boulanger (2004) the allure of relying on a singleapproach (e.g. CPT-only) should be avoided
Jamiolkowski (1985, 11 ICSMFE) reliable predictions ofCRR require the development of some new in situ device[other than CPT or SPT] much more sensitive to theeffects of past stress and strain histories
VERY CAUTIOUS RECOMMENDATIONS USING SPT AND CPT
Basis of the correlation CRR-KD
Research has pointed out:
KD sensitive to stress history (including aging),cementation, structure …
KD correlated with relative density and in situstate parameter
all factors known to influence liquefaction resistance
KD ≈ Stress History Index ≈"cumulative" index
parameter of liquefaction resistance
Horizontal Stress Index KD = (p0- u0) /σ'v0
Summary of CRR-KD correlations(Seed & Idriss 1971 simplified procedure)
MAGNITUDE M = 7.5 – CLEAN SAND
SDMT for LIQUEFACTION
SDMT provides 2 independent evaluations of CRR
Andrus & Stokoe (2000)Andrus et al. (2004)
CRR from VsCRR from KD
Marchetti ASCE 2013
... good to have more than one method for CRR …
SDMT for LIQUEFACTIONVittorito – L’Aquila (April 2009)
Kd
Vs
Moment magnitude MW: 6.3Distance from the epicentre: 45 kmPeak ground acceleration PGA: 0.065 g
CSR
SDMT for LIQUEFACTION
Liquefaction depth from Vs: 1-2.5 m
0
0.1
0.2
0.3
0.4
0.5
0.6
0 50 100 150 200 250
Normalized shear wave velocity, Vs1 (m/s)C
yclic
Str
ess
Ra
tio
,C
SR
or
Cyc
licR
esis
tan
ce
Ra
tio
,C
RR
Fc <=5%
Fc= 15%
Fc >= 35%
LIQUEFACTION
NOLIQUEFACTION
Monaco et al. (2009, 2010)
Liquefaction depth from KD: 2-6 m
0
0.1
0.2
0.3
0.4
0.5
0 2 4 6 8 10
Cyc
licS
tress
Ra
tioC
SR
or
Cyc
licR
esi
stance
Ratio
CR
R
KD
LIQUEFACTION
NO LIQUEFACTION
Both Kd and Vs indicated Liquefaction (red points)
Liquefaction case history in Costarica
“Just a few weeks after the SDMT execution, the cyclic wave action dueto a storm induced liquefaction of the soil deposit..” (Vargas & Coto 2012)
cofferdam
Design Earthquake (M Richter = 7,5 and PGA = 0,25 g)
LIQUEFACTION
NO LIQUEFACTION
LIQUEFACTION
NO LIQUEFACTION
Slip surface detection in OC clay slopes
(Totani et al. 1997)
DMT-KD method Verify if an OC clay slopecontains active (or old quiescent) slip surfaces
Validation of DMT-KD methodLANDSLIDE "FILIPPONE" (Chieti)
LANDSLIDE "CAVE VECCHIE" (S. Barbara)
DOCUMENTEDSLIP SURFACE
DOCUMENTEDSLIP SURFACE(inclinometers)
Slip surface detection in clay slopes
SS. N. 83 “Marsicana”Gioia dei Marsi (2006)
blocked
Mine of lignite S. Barbara(San Giovanni Valdarno)
Quantify σ'h relaxation behind a landslide
Case History:Landslide in Milazzo, Sicily
Horizontal Stress σ’h(kPa)
Z(m
)–
above
sea
leve
l 1
2
3
σ’h obtained using K0 from DMT
RAILWAY
123
clay
Design of Laterally Loaded Piles
Design of laterally loaded piles (Winkler)
Three different methods using DMTresults for evaluating P-y curves forlaterally loaded piles:
Es = constant
Deflection yS
oil
rea
ctio
n,
p
Linear P-y curve
Es = f (y)
Deflection y
So
ilre
actio
n,
p
Non Linear P-y curve
Gabr & Borden (1988)
Robertson et al. (1989)
Marchetti et al. (1991)
recommendedmethods
Robertson et al. (1989)
Marchetti et al. (1991)
Observed vs. DMT predicted pile deflections
single pile, 1st time monotonic loading In clay.L=57m, D=0.50m
Mortaiolo (Italy)
NC soft clay
Mortaiolo (Italy)
NC soft clay
Validation:2 independent methodsusing DMT results(Robertson 1989 &Marchetti 1991) providesimilar predictions, invery good agreementwith measured full-scalepile behaviour
(1989)
Design of Diaphragm Walls
DMT for DESIGN of DIAPHRAGM WALLS
Tentative correlation forderiving the Winkler modelsprings for design of multi-propped diaphragm wallsfrom MDMT
Indications on input modulifor FEM analyses (PLAXISHardening Soil model) basedon MDMT
g.l.
sH
L
g.l.g.l.
ssHH
LL
Monaco & Marchetti (2004 – ISC'2 Porto)
DMT for FEM input parameters→ PLAXIS Hardening Soil constitutive model
E50ref is a reference stiffness
modulus corresponding to thereference confining pressurepref (pref =1 bar)
E50 is the Modulus for primary loading
Eurref =4⋅Eoed
ref = 4⋅MDMT
(Vermeer, 2001)
E50ref correlated to MDMT and Eoed
ref
(Schanz & Vermeer, 1997)
literature: E50ref = 15 to 75 MPa, like
MDMT by DMT (quartz sand, loose
to very dense sand)
E50ref = Eoed
ref = MDMT
Some SDMT test sites...
Via Fori Imperiali Piazza Venezia
Underground in Rome - New Line C
Palazzo Esposizioni - Rome
This building experienced acrack in the ceiling due todifferential settlements
SDMT 1 (front) SDMT 2 (front) SDMT 3 (back)
CROSS SECTION: CONSTRAINED MODULUS M (MPa)
SDMT - NASA Cape Kennedy (USA)
SDMT at Zelazny Most – PolandTests performed for monitoring copper waste dam
DMT users community
Major diffusion: North-America, Europe, Eastern Asia
Expanding in: South America and Australia
STANDARDSEUROCODE 7 (2007). Standard Test Method, European Committee forStandardization, Part 3: Design Assisted by Field Testing, Section 9: FlatDilatometer Test (DMT), 9 pp.
ASTM (2007). Standard Test Method D6635-01, American Society for Testingand Materials. The standard test method for performing the Flat DilatometerTest (DMT), 14 pp.
TC16 (1997). “The DMT in soil Investigations”, a report by the ISSMGETechnical Committee tc16 on Ground Property, Characterization from in-situtesting, 41 pp.
ASTM (2011) – Standard Test Method D7400 – 08, “Standard Test Methods forDownhole Seismic Testing“, 11 pp.
NATIONAL STANDARDS:
• Italy: Consiglio Superiore Lavori Pubblici (2009), Protezione Civile (2008)
• Sweden: Swedish Geotechnical Society SGF report (1994)
• France: ISO/TS 22476-11:2005(F)
• China: TB10018 (2003), GB50021 (2003), DGJ08-37 (2012)• ..
Website: www.marchetti-dmt.it
3rd International Conference on theFlat Dilatometer (DMT)
Rome 14th-16th June 2015
Official web site:
www.dmt15.com
Papers:
Contact Info:
Highlights of the conference include
Prof. Roger Frank (ISSMGE president) Welcomespeech
Prof. J. Schmertmann’s dinner talk
Prof. M. Jamiolkowski: use of SDMT in theZelazny Most dam in Poland
Prof. F. Schnaid: use of DMT and SDMT in
tailings dam
120 abstracts from over 32 countries
www.dmt15.com
Conference venue in the town centerwww.dmt15.com
Rome Touristic Attractionswww.dmt15.com
St. Peters and Pope Francescowww.dmt15.com