Bridges – Girder
Patent
1998-07-21
2000-02-01
Will, Thomas B.
Bridges
Girder
14 21, 14 26, 14 73, 14 735, 14 771, E01D 1902
Patent
active
060188340
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD OF THE INVENTION
This invention relates to the building of bridges and especially to the building of girder bridges of the kind where one, two or more longitudinal beams of steels rests against supports at their ends and supports a roadway.
GROUND OF THE INVENTION
Conventional girder bridges have up until now been made as bridges with a main supporting structure of steel or aluminium with or without interaction with the roadway whom the roadway as a rule is made of concrete.
Bridges are loaded by their inherent dead load and by movable load such as traffic load, against its horizontal portions by earth pressure and besides that from movements caused by temperature changes and when concrete is used in composite, also its creep and shrink.
Besides dimensioning the bridges with consideration to strength the deformation of the construction because of traffic load must not exceed given values.
The quality of steel for the supporting girders has been improved so that it has both a highter yield point and is more easily welded. The strength of the new steels qualities cannot be taken advantage of as the allowable deformations of the roadway normally has been used up long before the strength of the steel is fully utilized.
Steel girder bridges because of that will have at large spans high girders with a low exploitation of the potential strength of the steel together with the fact that the volume of steel in the construction is large.
Bridges over existing traffic roads such as roads or railways or waterways normally demand bypass arrangements for existing traffic or temporary closing thereof or speed reductions on the crossing traffic road. Such restrictions of the traffic are very expensive not only with regard to economics because of increased transport work but also from compensations required by the holder of the earlier traffic rights. For instance restrictions in train traffic may result in demands for compensation from the right of way holder to amounts comparable with the building costs for the bridge.
Bridges over for instance railways or motorroads are normally constructed with one or more intermediary supports in order to avoid the need of very heavy main girders as carriers. If such a bridge were to be constructed with only one frame very heavy carring girders would be necessary which from an estetical point of view would be unwanted and result in a construction so heavy that launching out or lifting out of a prefabricated bridge alternatively a partly prefabricated supporting structure were unrealistic.
ASPECTS OF THE INVENTION
One aspect with the invention is to make it possible to build bridges over traffic roads without disturbing the flow of traffic in any essential degree. This means that the works with the bridge abutments in most cases will have to be done without disturbing of the flow of traffic on the lower traffic road and only exceptionally intermediary supports for supporting the bridge girders will have to be done. One aspect is that a bridge over a standard clearance section for railway for fast trains or a bridge crossing a motor road is to be constructed with a minimum influence on traffic, i.e. restriction of traffic during a few hours preferably low traffic hours only.
SUMMARY OF THE INVENTION
The invention is based on the idea that the bridge is made as a frame with a predetermined support moment for dead weight over the frame legs independently of the dimensions of the bridge. This support moment may vary from 0 and up to the value which from the view of the function is the most optimal one.
The predetermined support moment of dead weight is acheived by positioning the entire ready super structure of the bridge or parts thereof including at least the supporting main beams or steal girders freely on the abutments for the bridge. The abutments are made with great stiffness as for example concrete plates. The abutments are provided with supports for the main beams dose to the side of the abutments facing the bridge opening. On the opposite side of each abut
REFERENCES:
patent: 11467 (1854-07-01), Baldwin
patent: 1842136 (1932-01-01), Wichert
patent: 3296638 (1964-04-01), Morlon
patent: 4665578 (1987-05-01), Kawada et al.
patent: 4799279 (1989-01-01), Muller
patent: 4825492 (1989-05-01), Zehavi et al.
Derwent's abstract, No. 93-203945/25, week 9325, Abstract of SU, 174392 (Khlopenkov P R), Jun. 23, 1992 (23.06.92).
Derwent's abstract, No. 86-92906/14, week 8614, Abstract od SU, 1178827 (Sibe Motor Road Ins), Sep. 15, 1985 (15.09.85).
Addie Raymond
Jada AB
Will Thomas B.
LandOfFree
Method for building a bridge and bridge built according to said does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for building a bridge and bridge built according to said , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for building a bridge and bridge built according to said will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-928707