Orientation about the project
Refoundation of the Vestbanen in Oslo with jet piles (J2-
method). The building is today listed. Restrictions imposed by
Byatikvaren was large and challenging.
Foundation conditions
The Vestbane building is founded with hewn foundation walls
natural stone. The south wing is founded on mountains, while
The arrivals hall and the north wing are based on wooden rafters.
The raft was heavily attacked by rot in some places.
The floor construction inside the access hall consists of vaulted ceilings.
These are based on stone foundations on wooden rafts i
crawl space and takes up floor loads and column loads from the structures
above 1st floor level. Three of the foundations were characterized as i
very poor constitution. The Vestbane building was partially affected
major settlement damage, especially in the column and arch structures.
Basic conditions
The ground consists of medium firm clay over mountains with assumed
shear strength of 50kPa and bulk density of 20kN/m2. The elevation varies
from 0 to -12. It is shallowest to the mountains in the south with increasing depth towards
north-west. The groundwater level is approx. at elevation + 0.26.
Solution options
In the preliminary project phase, two reimbursement methods were considered: 1)
Drill down steel posts on each side of the walls and then install
ride through that spans from pile to pile. 2) Use Jet-pel
the method.
Selected solution
The project group recommended a solution with jet piles. The reason was
based on the following points: Great predictability with regard to
quality and execution. Minimal sentences and good in-situ control
any deformations that may occur underneath
the refunding works, so that corrective measures could be taken
be implemented immediately. No vibrations/shakes that can
cause secondary damage to the building structure. It won’t
reinforcements of the gray stone walls may be necessary. All
the walls will receive direct support (contact moulding). Large portions
of the works can be carried out from the outside of the building, with the exception of
the internal foundations of the building. The execution will require small
interventions in the constructions and will therefore be in line with
the conservation decision. All interior work can be carried out from 1.
floor plan. Great flexibility, low uncertainty/risk.
Sentences/raises
Accumulated sentences are not larger than +/- 3mm. But with one
stated measurement accuracy of +/- 2mm is therefore minimal
deformations of the floor and column construction.
Statsbygg
