[Geotech] SEMINAR MONDAY APRIL 29TH,2013 Georgia Tech, Atlanta
Pressuremeter testing and foundation design Roger FRANK Université Paris-Est, Navier, CERMES (ENPC-LCPC), Paris R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Contents Introduction to design rules. Why use the MPT ? Shallow foundations Axial capacity of piles Transverse capacity of piles Conclusions
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Main references
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Work of Ménard (1954-1967), Cambefort, Gambin, Cassan, etc. Work of Laboratoires des ponts et chaussées (LPCs) from 1963-… by Amar, Baguelin, Bustamante, Canépa, Frank, Garnier, Jézéquel and others 3 synthetical papers: Gambin, M., Frank, R. (2009) "Direct Design Rules For Piles Using Ménard Pressuremeter Test", Proc Int Foundation Congress and Equipment Expo’09 (IFCEE’09), Orlando, Florida, ASCE Canépa, Y., Garnier J. (2004). "Etudes expérimentales du comportement des fondations superficielles - Etat de l'art", Proc. Int Symp. Fondsup 2003 Bustamante M., Frank R. (1999) "Current French design practice for axially loaded piles". Ground Engineering (note : MPM & CPT)
Foundation engng code for public works (Fascicule 62-V, 1993) and course taught at Ecole nationale des ponts et chaussées – under rere-drafting to match Eurocode 7… 7… R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Contents Introduction
to design rules. Why use the MPM?
Shallow foundations Axial capacity of piles Transverse capacity of piles Conclusions
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
The Ménard pressuremeter test (MPT)
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
DOCUMENT APAGEO - XPRESSIO
1200
VS + 2V1 1000
800
EM = 23 MPa 600
Pl = 1,7 MPa
400
p2
200
pf
p1 0 0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6
1,8
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Pressuremeter soil profile
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Bearing capacity : the pressuremeter ‘faith’
qu = qo + kp (ple - po)
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
The pressuremeter test can be performed in all types of soils and soft rocks
It provides the soil engineer with both a failure parameter and a deformation parameter measured in situ
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Use of in situ test results
The direct method (‘semi-empirical’) should be preferred i.e direct rules for determining the bearing capacity of foundations from the test results : Rd,N,qc, etc. (and possibly the displacements)
Specific advantages of the Pressuremeter with the limit pressure pLM : bearing capacity of shallow foundations (qp) axial bearing capacity of deep foundations (qp and qs) With the pressuremeter modulus EM : settlement of shallow foundations (s) analysis of the behaviour of deep foundations under transverse loading R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Contents
Introduction to design rules. Why use the MPM ?
Shallow
foundations
Axial capacity of piles Transverse capacity of piles Conclusions
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Tests at Jossigny & La Benne (1980s)
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
LCPC Centrifuge (Nantes) 1985 -…
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Bearing factors - strip and square footings
(AFNOR, 2013) R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Design bearing capacity Reference stress qréf :
iδβ reduction factor depends on β, δ, d/Be, De/Be
With (model factor) γRD ≈ 1.2 and
γR;v = 1.4 for ULS γR;v = 2.3 for SLS R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Pressuremeter method for settlement prediction
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Ménard’s formula for settlement years)
is the volumetric settlement is the deviatoric settlement
Rheological coefficient α
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Selection of moduli Ec and Ed
Ec = E 1 and R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
LPCs 1978-1987
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Contents Introduction to design rules. Why use the MPM ? Shallow foundations
Axial
capacity of piles
Transverse capacity of piles Conclusions
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Pile load tests at Dunkirk (1985)
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Revised MPM rules for bearing capacity : kp
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Revised MPM rules for bearing capacity : qs
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Settlement of piles t-z curves from Ménard pressuremeter modulus EM (laws of Frank-Zhao, 1982)
for fine grained soils : kτ = 2.0 EM/(2ro) and kq = 11.0 EM/(2ro) for granular soils kτ = 0.8 EM/(2ro) and kq = 4.8 EM/(2ro) R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
2nd example : CFA pile in silt and clay (Northern France) B = 0.5 m ; D = 12 m pLM(MPa)
EM(MPa) 0
10
20
30
0,0
40
2
EM moyen
2
4
EM-Forage100
4
1,5
6
z (m )
z (m )
EM-Forage-10 EM-Forage20
8
1,0
0
0
6
0,5
8
10
10
12
12
14
14
16
16
pLM moyen pLM-Forage100 pLM-Forage10 pLM-Forage20
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
2,0
0
Charge en tête / vertical load (kN) 200 400 600 800 1000 1200
1400
0 5
déplacement / settlement (mm)
10 15 20 25
Pieu test/pile tested (Bustamante M. et Gianeselli L.) Antoinet et al.
30
Bahar et al.
35
Robas et Kuder Said et al.
40 45
Mecsi Monnet
50
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Contents Introduction to design rules. Why use the MPM (and CPT) ? Shallow foundations Axial capacity of piles
Transverse
capacity of piles
Conclusions
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Transverse load tests at Plancoët (1975-…)
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
P-y curves
Short duration
Accidental actions
with Kf = 2ESM EsM = EM
18 --------------------------------------------4(2,65 B/Bo)α Bo/B + 3α
18 or EM -------------------------4(2,65)α + 3α
EsM = Ménard reaction modulus R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
g(z) method
d4y EI ---- + P(y - g) = 0 dz4 R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Reaction curve for long duration loads
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Pile of Provins (1974)
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Contents Introduction to design rules. Why use the MPM (and CPT) ? Shallow foundations Axial capacity of piles Transverse capacity of piles
Conclusions
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
The pressuremeter allows the determination of the bearing capacity and of the displacement of foundations The base capacity is based on the analogy with the cavity expansion theory (sounder than limit equilibrium approaches) The shaft friction of piles is determined essentially in an empirical manner (numerous full scale load test results) MPM results yield easily p-y and t-z curves.
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Eurocode 7 issues/challenges …
All design rules compatible with Eurocode 7 should be based on pile load test results
Important role of displacement of foundations of structures (more than safety with regard to ground failure)
Are we ready of SLS checks only based on displacements? … and is the structural engineer ready himself ?
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
Thank you for your attention !
R Frank Pressuremeter testing and foundation design, GT Seminar, Georgia Tech, Atlanta, 29 April 2013
