Activities of the Geotechnical Research Group on ... · 1 GEOTECNIA Universidade de Brasília...
Transcript of Activities of the Geotechnical Research Group on ... · 1 GEOTECNIA Universidade de Brasília...
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GEOTECNIA Universidade de BrasíliaUniversidade de Brasília
Activities of the Geotechnical Research
Group on Foundations (GPFees)
University of Brasília-Brazil
Renato P. Cunha
Civil Engineer, Ph.D., Associate Professor
University of Brasília, Dept. of Civil & Env. Engineering
Geotechnical Graduation Program
University of Applied Sciences
Munich, May 2015
Special Lecture
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City and University Characteristics
Research Lines of the GPFees Group
On Going MSc & DSc Students
Recent Research Details
LAYOUT
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Central Region of Brazil
3 states + Federal Dist.
1,606,371 km²
19% Brz total area
(4.5 x Germany)
13,270,000 inhabitants
7% Brz total inhab.
Avg 8.3 inhab/km2
8.8% GNP
(3.7% for Fed. District)
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Federal District
BRASIL N
a
Area = 5822 km2
Population = 2.6 millions inhabitants
Density 443 inhab/km2
~50 km
~30 km
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Brazil x Germany
Area Brazil 24 x Area Germany
Population Brazil 2.5 x Pop. Germany
(approximate relative dimensions)
Data from: Main Indicators. Central Bureau of
Statistics homepage (2015). Wikipedia
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University of Brasília
30000 undergrad students, 5000 grad
2000 professors
Photo
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Geotechnical Graduation Program
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Statistics
12 Professors, 51 MSc
students, 57 DSc students
•MSc Program since 1989 and
DSc since 1996
•Defended +80 DSc Theses
and +200 MSc Theses
•Entrance: 16 MSc and 8 DSc
per year
• Scholarships: 37 MSc-31 DSc
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Research Lines
Foundations and In Situ Testing
• Site behavior of real scale isolated foundations as well as groups and
piled rafts;
• Design and simulation of deep foundations via in situ and laboratory
tests coupled with numerical or analytical techniques;
• Simulation of standard pile groups and piled raft foundations under
small scale model conditions (1g and centrifuged);
• Use of site investigation techniques to obtain geotechnical
parameters in tropical soils, to enhance geo-environmental designs;
• Instrumentation of foundation systems at real or small scale sizes;
• Influence of defective piles and the reinforcement system in the
behavior of foundation groups and piled rafts;
• Soil-superstructure interaction;
• Special foundations for dynamic wind power generators;
• Energy foundations for heat transfer with the geotechnical medium.
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Research Lines
Soil Stabilization via Retaining Structures
• Site behavior and design of real scale retaining structures;
• Use of field and laboratory tests to design and simulate retaining
structures founded on tropical soil;
• Assessment of numerical and analytical techniques to forecast the
behavior of retaining structures;
• Instrumentation of retaining structures in terms of loads, pressures
and displacements during and after construction;
• Influence of external and internal factors as weather seasonality,
geotechnical parameters, suction etc. on the behavior of such
structures;
• Study of soil nailing and active anchors.
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Brief Results of Recent Research
DSc Students
Juan Carlos
Osvaldo
Christian
Dasiel
Edgar
Francisco
Figueiredo
Raydel
MSc Students
Henry
Gabriela
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Juan Carlos Ruge Cardenas
Colombian Student
Analysis of the Behavior of Pile Curtain
walls executed in porous and
metastable soil through the use of a
hypoplastic constitutive model that
considers the unsaturated soil
response
DSc Thesis
192 pages
Defended May 2014
Defended DSc Thesis
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Calibration of parameters hypoplastic model
Ruge 2009/2014
FEM simulations
Computational model 17
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Defended DSc Thesis
Osvaldo de Freitas Neto
Brazilian Student
Experimental and Numerical Evaluation of
Piled Raft with Defective Piles in Brazil's
Tropical Soil
DSc Thesis
253 pages
Defended August 2013
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Instrumentação da Ponta da Estaca
ESQUEMA LONGITUDINAL DAS ESTACAS DEFEITUOSAS (E9, E13 e E26)
Instrumentação doTopo de Estaca
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0
20
40
60
80
100
120
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
Rec
alq
ue
(mm
)
Carga (kN)
CF1(NUM) R1INT (NUM) Ruptura Estrutural / GeotécnicaCF1 (EXP)
0
10
20
30
40
50
60
70
80
90
100
0 15 30 45 60 75 90 105 120 135 150
Carg
a p
or
Ele
men
to (
kN
)
Carga Total Aplicada (kN)
E13 (Defeituosa) Carga no Radier Ruptura Estrutural / Geotécnica
0,14 0,19 0,32 0,72 2,01 3,11 100,269,56,54
Recalque (mm)
% Carga na Estaca % Carga no Radier Ruptura Estrutural / Geotécnica
Fs = 1
0,0
2,0
4,0
6,0
8,0
10,0
15 30 45 60 75 90 105 120 125 131 135
Fa
tor
de
Seg
ura
nça
Carga Total Aplicada (kN)
Fs Global CF1 - EXPERIMENTAL
Fs Global (R1INT) - NUMÉRICO0 100 200 300 400 500 600 700
Dis
torç
ão
An
gu
lar
Carga Total Aplicada (kN)
CF1 CF3 CF4
1/100
1/50
1/20
1/25
1/16,6
1/14,3
1/12,5
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Defended DSc Thesis
Cristhian Camilo Mendoza Bolaños
Colombian Student
The mechanical behavior of pile
groups and piled rafts with
Alluvial Anker piles types installed
in porous clays of the Federal
District of Brazil.
DSc Thesis
234 pages
Defended September 2013
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Calibration of constitutive models
Experimental data x Numerical Parametric
Results
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On Going DSc Thesis
Dasiel Hernández Fernández
Cuban Student
Determination of laterally
loaded foundations numerical
analyses of pressuremeter tests
and computer modeling
techniques
DSc Thesis
Defense in 2017
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Edgar Rodríguez Rincón
Colombian Student
Experimental analysis of the
behavior of piled raft systems
in soft soil with consolidation
processes
DSc Thesis.
Defense in 2016
On Going DSc Thesis
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Influence of
drawndown
Centrifuge tests in small scale models
Distinct model types 28
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Load test of pile in 1/70 model.
Load test of plate in 1/70 model.
Water pressure, displacement and
load results
Modelling box and piled raft model
4x4 to 1/200 model test.
Settlement of soil, raft (up) and
piled raft (down), in 1/200
model. 29
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Francisco Javier Alva García
Mexican Student
Analysis of the Behavior of Piled
Rafts with and without defective
piles, laterally loaded into a
tropical laterized soil of Brazil
DSc Thesis
Defense in 2017
On Going DSc Thesis
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Piled Raft under laterally loaded
Damaged piles
Area
reduction
Low
resistance
zone
Fissuration
zone Top pile
damage
Defective piles examples
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Abaqus software (MEF) for modelling
Single pile Single pile results under lateral loading
soil Raft
and
piles
Assambly
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Luiz Carlos de Figueiredo
Brazilian Student
Energy Measurement of Dynamic
Light Probe Tests (DPL) on Porous
Tropical Soil
Defense in 2016
190 pages
On Going DSc Thesis
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Details of accelerometers
Test setup with DPL
Preparation
of laboratory
DPL
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Acquired and integrated signal
0 4 8 12 16 20 24
0
5
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45
50
Inte
gra
ted
en
erg
y (
Jo
ule
s)
Tempo (ms)
Integrated energy
Permanent penetration
Theoretical energy= 49,03 Joules
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18
16
14
12
10
8
6
4
2
0
Pe
rma
ne
nt p
en
etr
atio
n (
mm
)
Energy evolution for penetration of 18 mm
0 4 8 12 16 20 24 28 32
20
25
30
35
40
45
50
55
EFV
EF
V (
Jo
ule
s)
(mm)
Equation y = 14,55 +2,30*x - 0,037*x^2
R²= 0,93744
EFV versus permanent penetration
Theoretical energy =49,03 Joules
EFV - maximum energy transferred to the rods
0 5 10 15 20 25 30 35 40 45 50 55
40
50
60
70
80
90
100
nD
PL
(%
)
Blows per 0.1 meter, N10
nDPL
Efficiency of energy for DPL (nDPL)
Energy efficiency per blow
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Raydel Lorenzo Reinaldo
Cuban Student
Analysis of Displacement Piles
Using the Material Point Method
Defense in 2015
On Going DSc Thesis
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Large strain and distortion problems Simulation of Pile Installation
Idealized
exponential
curve
Typical in-situ
profile
k0
Skin friction
Pile
penetr
ation
Porosity:
Density:
Resistance: 37
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1. Modified Cam Clay
2. Subloading Cam Clay f = M 2(p2 - p0 p)+ q2
Analytical vs. Numerical
Exp. vs. Numerical
Implementation and Validation of
Constitutive Models for Soils
Professor John A. Nairn
NairnMPM Code: Material Point Method
code for Mechanics Analysis
Jardine et al. (2013)
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Henry Castillo Orozco
Colombian Student
Numerical and Parametric
Study of Energy Piles Founded
in Tropical Soil
Defense in 2016
On Going MSc Thesis
Mathieu Velle – BSc Level
Exchange French Student
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Energy pile-soil thermal interaction
System Layout – Primary and Secondary
Example of Instalation (U Pipes)
(Brandl, 2010) 40
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Modeling in a Finite Element Model (MEF) Expected Results
(Gashti, 2014)
(Bidarmaghz A., 2013)
Considerations
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Gabriela de Athayde Duboc Bahia
Brazilian Student
Evaluation of the Behavior of Deep
Foundation Groups in normal
Edifications in the Federal District
of Brazil with the Use of Soil-
Interaction Techniques
Defense in 2016
On Going MSc Thesis
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Parametric Analyses
Field Displacements
P209 P212 P218 P223 P225 P226 P233 P234 P235 P237 P238
P209 - 1/7137 1/8910 1/5093 0 0 0 0 0 1/8854 1/5563
P212 -1/
7137 - 0 0 0 -1/8931 0 0 0 0 1/9630
P218 -1/
8910 0 - 0 0 -1/3753 0 0 0 1/8859 1/5281
P223 -1/
5093 0 0 - 0 -1/4559 0 -1/7130 0 0 1/8519
P225 0 0 0 0 - 0 0 0 0 1/2946 1/4249
P226 0 1/8931 1/3753 1/4559 0 - 0 1/7822 0 1/4921 1/1564
P233 0 0 0 0 0 0 - 0 1/4980 1/3209 1/9056
P234 0 0 0 1/7130 0 -1/7822 0 - 0 1/8624 1/3163
P235 0 0 0 0 0 0 -1/
4980 0 - 0 0
P237 -1/8854 0 -1/8859 0 -1/2946 -1/4921 -1/3209 -1/8624 0 - 0
P238 -1/5563 -1/9630 -1/5281 -1/
8519 -1/4249
-1/ 1564
-1/9056 -1/3163 0 0 -
Differential Displacements
Interaction Factors for Typical Pile Diameter
Real Case
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Large Effort to form Researchers and to
Gather Knowledge
Collaborative Work is welcome!
Scholarships are available
Summary