Deep excavation for the new Central Library of Lisbon...Deep excavation for the new Central Library...
Transcript of Deep excavation for the new Central Library of Lisbon...Deep excavation for the new Central Library...
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Deep excavation for the new Central Library of LisbonExcavation profonde pour la construction de la nouvelle Bibliothèque Central de Lisbonne
A. Pinto, A. Pereira & M. Villar (Paper number 206)
Alexandre Pinto,
Ana Pereira,
43,80(floor 0)
A 40 m deep excavation was performed for the construction of the new Central Library and Municipal Archive of Lisbon.
Geology:
ZG3 - Heterogeneous fills with thickness varying between 1,5 and 20m, with the major thickness at South - West, close to Álvares Fagundes St;
ZG2 - Miocene sands and clays with fossils, with NSPT values under 60 and a maximum thickness of 19m;
ZG1 - Sands, clays and loam limestones with NSPT values over 60.
Conditions:
- The building could not support the earth pressures caused by the differences of the ground level (30m) at both longitudinal sides of the site (South-West and North-East).
- Streets, services and structures nearby the construction site
- Executive difficulties caused by the topography of the site.
Example of the displacements of the retaining wall in the direction normal to the wall obtained from inclinometer I3 (located in the South-West side).Positive displacements are those occurring towards the excavation.
Plan view of the excavation
Site before excavation
Cross section A-A
Cross section of the South-West side
Cross section of the North-West side
Example of results of staticnumerical calculation for the
South-West retaining wall
Example of results of pseudo-static numerical calculation(seismic coefficient (β) = 0.1) for the South-West retaining wall
South-West side view
Final Excavation (40m depth maximum)
Location of the monitoring equipments
Adopted solutions for the South-West side (maximum excavation depth is 40m, includind 20m of fills):
- Bored pile wall supported by 10 levels of permanent anchors. Jet-grouting columns was performed for protect the soil between the piles in the depth of ZG2 and ZG3. Reinforced shotcrete was used in ZG1.
Adopted solutions for the North-West side:
- Bored pile wall supported by 4 levels of temporary anchors bellow floor 0 with shotcrete to protect the soil between piles.
- Slope stabilization using jet-grouting columns above floor 0, in the depth of ZG3, supported by temporary anchors.
Considering the depth of the excavation (H=40m), the obtained displacements were small (∆h/H = 0.012/40 = 0.03%) and in general lesser than the design prediction.
Measurements were performed the day after each excavation phase
Displacements (mm)
Dep
th (
m)
A
D
C
F
E
36. 65
36.3 0
35.7 5
36.52
33.9 5
34.7 5
33 .43
34.7 6
33.2 2
64.5765 .36
65. 80
66.7 5
37 .02
36.8 5
37 .65
R
M
MMM M
1.00
R
R
M
MMMM
2.00
M M
R
2 xHEB22
0
2xHEB2 40
2 colun as Jet-G routing
Ø12 00 //1.0m2 colun as Jet-Grouting Ø1200 //1.0m
FA
3
2xHEB22 02 xHEB12
0
2xHEB1
20
BE1 BE2 BE3
AB
1A
B2
AB
3A
B4
A
B5
FA
3
FA
2F
A2
FA
1F
A1
Rua do Bar
Rua A
lvare
s Fag
unde
s
Rua Barao de Monte Pedral
Rua Barão M
onte Pedral
2 x 3 colun as Jet-Grouti ng Ø1200 //1.0m c/7 .5m
FA
4F
A4
EF
2 E
F3
EF
4E
F1
EF
2
EF
1
26.8
1
Pav
imen
to T
érre
o(e
=0.1
5)
Ens
olei
ram
ento
Ger
al(h
=1.6
0)
FUN
DAÇÃ
O
26.8
1
Pav
imen
to T
érre
o
(e=0
.15)
Ens
olei
ram
ento
Ger
al
(h=1
.60)
FUN
DAÇÃ
O
2xHEB2
2 0
2xHEB120
2xHEB120
B
Mín.1.00
AB
1A
B2
AB
3A
B4
AB
5
25.0
6
Cot
a de
fund
o da
esc
avaç
ão
Contrafortes(Ver proj ecto de Estabi lidade )
3 colu nas Jet-Grouting Ø120 0 //1 .2m co m 6.0m
3 colun as Jet-Grouting Ø1200 //1.2m com 6.0m
3 colun as Jet-Grouting Ø1200 //1.2m com 6.0m
3 coluna s Jet-Grouting Ø1200 //1.2m com 6.0m
3 colun as Jet-Grouting Ø1200 //1 .2m com 6.0m
Topographic Mark
Topographic Mark
Anchor Load Cells
Topographic Targets
Inclinometers
N
Topographic Mark
Topographic Mark
Anchor Load Cells
Topographic Targets
Inclinometers
I3
MZG2
ZG3
ZG1
Temporary anchors
Jet grouting columns
φ1,2m//1,2m
Concrete Beams
Bored Pile Wall φ0,8m//1,5m
25,06
43,80(floor 0)
66,08 (floor 5)
Micropiles1
2
1
2
56,00
ZG1
ZG2
Aterros
Te
ch
nic
al G
alle
ry
ZG3
BuildingÁlvares
Fagundes St.
Permanent Anchors
Bored Pile wall φ1,0m//1,3m
43,80
25,06
66,08(floor 5)
Static Horizontal Displacements [mm]
Deformed MeshDeformed Mesh
Pseudo-Static Horizontal Displacements [mm]