Bridge Jacking
Bridge Jacking
(OP)
I'm currently working on a bridge rehab project requiring a complete abutement replacement. This of course requires constructing a temporary bent and jacking the superstructure up off the existing abutment. Does anybody have any helpful tips or "lessons learned" with this type of project?





RE: Bridge Jacking
RE: Bridge Jacking
RE: Bridge Jacking
From a Contractor's viewpoint, leave the "means and methods" to the Contractor. If the design engineer specifies the details he is not only taking on the responsibility for success, but also may drive the bid price higher - not all Contractors will have the materials and equipment it takes to meet the Engineer's requirements. Contractors may have suitable substitutes, but will most likely place a bid based on renting or purchasing items that the Engineer required. If the Contractor gets the job, then he will try to talk you into allowing him to use his substitutes. This may be totally acceptable, but the Contractor will "pocket" most or all of the cost savings.
From an Engineer's viewpoint, while leaving the "means and methods" to the Contractor, require that he submit plans for your review and acceptance. These plans to signed and sealed by an Engineer of the Contractor's choosing, at the Contractor's expense. You avoid the liability, yet have control of what is done.
www.SlideRuleEra.net
RE: Bridge Jacking
RE: Bridge Jacking
However, your plans should have a workable concept as well as any precautions the contractor must observe. The contractor doesn't have to follow your concept but it shows bidders that the jacking scheme has been thought out.
That's how it is typically done on NYSDOT projects. The contractor submits a design that's been prepared by a PE.
RE: Bridge Jacking
Relocating the support to the abutment raises several questions: Can the load be transfered to that point structurally? What will the temporary bearings be? How much deflection will there be at the ends of the beams?
Will the new support be able to take lateral loads from the demolition such as unintentinal equipment strikes?
What code will the temporary supports be designed to?
RE: Bridge Jacking
If you have big service bays on a smallish bridge, you may require different jacking forces at the external beams, compared with the internal beams.
In Britain, temporary supports for highway bridges need to be protected from or designed to withstand vehicle impact loading.
RE: Bridge Jacking
RE: Bridge Jacking