2014 Workshop Presentation Mong coc
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Transcript of 2014 Workshop Presentation Mong coc
Large prefabricated pile foundation,a solution for high-rise buildings in
Ha Noi and HoChiMinh city
Bao Viet NGUYENNational University of Civil Engineering, Hanoi, [email protected]
A LOT OF BUILDINGS ARE RISING IN HANOI & HOCHIMINH CITY
BORED PILE FOUNDATION
Bored piles- Very high bearing
capacity- A lot of mud &
construction trash with a swampy site
- Cost Increased because of environmental treatments
- Construction time might be extended
Prefabricated piles with large size- High bearing
capacity up to 8000kN
- No construction trash with clean site
- Properly reduce cost and construction time
APPLICABILITY OF PREFABRICATED
PILES FOUNDATION
Where: Rfea = feasibility ratioQaua = Allowable bearing capacity
of pile foundation on area unit p = total pressure acting on foundation
Rfea = Qaua / p / FSfea
1.0 : high applicability
< 1.0 : low applicapility
APPLICABILITY OF PREFABRICATED
PILES FOUNDATION
Where: Pa = Allowable bearing capacity of a pile
d = pile size
Qaua = Pa / (3dx3d)
p = 15kPa x number of storeys
Distribution
maps of
soil types
in area of
old Ha Noi
Sub-soil type Name Description Distribution
ASingle layer
A1 Clayed soils, up to 30m thick, PI=0.15~0.4, SPT=12~15, E0=10Mpa
West Từ Liêm;Đông Anh
A2 Clayed soils, up to 30m thick, PI=0.35~0.6, SPT=8~12, E0=5~8Mpa Hà Nội center
BTwo
layers
B1
Upper layer: Clayed soils, up to 10m thick, PI=0.15~0.4, SPT=12~15, E0>10Mpa;Lower layer: Medium sand, medium dense, up to 20m thick, SPT30,E0>20Mpa.
North Đông Anh
B2
Upper layer: Clayed soils, 5~10m thick, PI=0.35~0.6, SPT=9Lower layer: small sand, medium dense, up to 20m thick, SPT12, E0>10Mpa;
South Đông Anh and
Thanh Trì; Gia Lâm
CMulti layers with
weak soil
C1
Upper layer: Clayed soils, up to 10m thick, PI=0.15~0.4, SPT=12~15, E0=10Mpa;Middle layer: Organic soils, up to 10m thick, PI>0.8, SPT=5, E0=3~5Mpa;Lower layer: Medium sand, up to 10m thick, SPT30, E020Mpa;
North Đông Anh
C2-3
Upper layer: Clayed soils, up to 10m thick, PI=0.35~0.6, SPT=5~8, E0=6~8Mpa;Middle layer: Organic soils, up to 15m thick, PI>1.2, SPT=2~4, E0=3Mpa;Lower layer: Sandy soil, up to 10m thick, SPT20, E015Mpa;
Đông Anh, Gia Lâm (small
area) Thanh Trì,
South Từ Liêm
Main soil strata types in the area of Ha Noi
Feasibility ratio of prefabricated square piles for 15 storeys buildings – Hanoi Area
Pile size (cm)
Feasibility ratio of prefabricated square piles for 20 storeys buildings – Hanoi Area
Pile size (cm)
Feasibility ratio of prefabricated square piles for 25 storeys buildings – Hanoi Area
Pile size (cm)
Feasibility ratio of prefabricated square piles for 30 storeys buildings – Hanoi Area
Pile size (cm)
Distribution
maps of
soil types
in area of
HoChiMinh
city
Sub-soil Description Distribution
A1
Upper layer: Clayed soils (CuChi, ThuDuc), up to 10m thick, PI=-0.25~0.25, E013Mpa;Middle layer: Clayed soild (Trang Bom), >10m thick, PI=-0.23~0.4; E08Mpa.Lower layer: Medium sand, medium dense, large thickness, E0>20Mpa.
Northern of ThuDuc & CuChi
and a part at central of the city
A2Upper layer: Clayed soils (BInhChanh), up to 10m thick, PI=-0.25~0.25, E013Mpa;Middle and Lower layer are the same as A1
North-western of CuChi and most of
the central
B1
Upper layer: Organic layer (CuChi, ThuDuc), up to 10m thick, PI=1.0~2.5, E01Mpa;Middle layer: Clayed soild (Trang Bom), >10m thick, PI=-0.23~0.4; E08Mpa.Lower layer: Medium sand, medium dense, large thickness, E0>20Mpa.
NhaBe, BinhChanh district,
southern of ThuDuc, South-
Western of CuChi, along SaiGon river and coastal area.B2
Upper layer: Organic layer (CuChi, ThuDuc), up to 20m thick, PI=1.0~2.5, E01Mpa;Middle and Lower layer are the same as B1
B3Upper layer: Organic layer (CuChi, ThuDuc), up to 30m thick, PI=1.0~2.5, E01Mpa;Middle and Lower layer are the same as B1
Main soil strata types in HoChiMinh city
Feasibility ratio of prefabricated circle piles for 15 storeys buildings – HoChiMinh city
Pile size (cm)
Feasibility ratio of prefabricated circle piles for 20 storeys buildings – HoChiMinh city
Pile size (cm)
Feasibility ratio of prefabricated circle piles for 25 storeys buildings – HoChiMinh city
Pile size (cm)
Feasibility ratio of prefabricated circle piles for 30 storeys buildings – HoChiMinh city
Pile size (cm)
Case history of 20 storeys twin buildings
45x45cm of piles with bearing capacity of 1800kN
Settlement of about 2cm with 70% design load
CONCLUSIONS - HANOI
- Large prefabricated pile foundation could be applied to the high-rise buildings up to 30 storeys.
- In Ha Noi, soil types of A1 and B1 are most suitable for prefabricated pile foundation of buildings up to 30 storeys.
- In case of B2, C1 soil types, the applicability of the piles for buildings up to 25 storeys is highly reliable.
- Buildings of 15 storeys and buildings of 20 storeys could be settled on C2-3 and A2 soil types, respectively, with large size of pile (45x45cm and 50x50cm).
CONCLUSIONS – HOCHIMINH CITY
- In HoChiMinh city, soil types of A1 and A2 are most suitable for prefabricated pile foundation of buildings up to 30 storeys but a careful consideration must be carried out for 30 storeys buildings.
- In case of B1 soil types, the piles foundation could be applied for buildings up to 20 storeys with high reliability.
- Buildings of 15 storeys could be settled on B2 and B3 soil types.
CONCLUSIONS
- To apply the large prefabricated pile, the construction site must be large enough so that a big driven/jacked rig could have a space to work.
- Using large prefabricated pile could save money because of almost no environmental treatment and using prestressed concrete.
- Last but not least, the construction site was pretty clean therefore the construction works of foundation could be carried out smoothly and the construction time may be reduced.
THANK YOU FOR
YOUR ATTENTION