System for construction of composite U shaped reinforced girders bridge deck and methods thereof

Abstract

A composite bridge deck including U shaped reinforced concrete and steel girders, and construction methods thereof. The bridge deck consists of a plurality of steel main girders with unsymmetrical top flange, the plurality of cross girders being connected above bottom flange of main girders and U shaped RCC girder comprising of concrete flange above main girder, web and deck slab above cross girder. Inspection path/crash barrier provided for Rail/Road. This bridge deck is adoptable up to 3 Tracks/four lane Roads. In Cast in situ construction, main girders are placed over supports. Cross girders are connected and concreted. In precast construction, main girder with top slab is precast and placed over supports. Two or more cross girders with precast slab are connected to web of main girder. Concrete web portion is cast in situ.

Claims

1. A composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders, comprising: a plurality of main girders including an unsymmetrical top flange, a symmetrical bottom flange and a web; a plurality of cross girders including end cross girders and intermediate cross girders, being connected to said main girders, wherein said cross girders are carved near support in such a way to match said bottom flange of said main girder; at least one U shaped RCC girder provided with a top concrete flange, a second web and a concrete deck slab, wherein, said concrete deck slab and said second web are constructed over said cross girders and concrete flange over unsymmetrical top flange of main girder and whereas said concrete deck slab, said second web and concrete flange over said top flange of main girder forms U shape; and at least one crash barrier, wherein foot path of 1.5 m or service path of 0.45 m is provided between said crash barrier and said second web of U shaped RCC girder.

2. The composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders as claimed in claim 1, wherein each cross girder has a uniform spacing distance of 2.5 m from an adjacent cross girder.

3. The composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders as claimed in claim 1, wherein said end cross girders are U shaped encasing RCC beam and intermediate cross girders are I girders.

4. The composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders as claimed in claim 1, further comprising stiffeners being provided on outer face of said main girders.

5. The composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders as claimed in claim 1, comprising said main girders which are made of steel.

6. The composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders as claimed in claim 1, comprising said cross girder whose top flange is bent to provide camber in a carriage way which is used upto four lanes for highway and upto three lanes for railway/metro track.

7. The composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders as claimed in claim 1, whose frame action reduces the moment and deflections in said main and cross girders making it suitable for longer spans.

8. A precast method of construction of composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders, comprising the steps of: assembling steel main girders and cross girder fabricated with shear connectors at site for spans more than 15 m; casting upside down said main girders with top concrete flange, precasting two or more cross girders with top slab to get moment of inertia enhanced thereby to carry dead loads and live loads; and placing said main girders including an unsymmetrical top flange, with top concrete flange in a position over supports where cross girders with deck are to be connected to the web of main girder and casting of web portion in situ.

9. An in situ method of construction of composite bridge deck including U shaped reinforced cement concrete (RCC) and steel girders, comprising the steps of: assembling steel main girders and cross girders fabricated with shear connectors at site for spans more than 15 m; placing main girders including an unsymmetrical top flange, in a position where said cross girders are to be connected; performing concreting in slab over top flange of main girder and web portion; spreading 6 mm mild steel (MS) deck sheet over top of said cross girders and being welded with 3 mm fillet welds; and performing concreting in the deck portion after 14 days of concreting over top flange and web portion of main girders slab.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

(1) The above set forth and other features of the invention are made more apparent in the ensuring detailed description of the invention, when read in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 illustrates the schematic representation of system of construction of composite U shaped reinforced concrete and steel girders bridge deck implemented in a railway bridge, according to the present invention.

(3) FIG. 2 illustrates the schematic representation of system of construction of composite U shaped reinforced concrete and steel girders bridge deck implemented in a highway bridge, according to the present invention.

(4) FIG. 3 illustrates an alternative version of a main girder having a stiffener, according to the present invention.

(5) FIG. 4. illustrates an intermediate cross girder that is an I-shaped girder, according to the present invention.

(6) FIG. 5 illustrates an end cross girder that is a U shaped encasing RCC beam, according to the present invention.

(7) FIG. 6 illustrates an alternative view of FIG. 2 with a stiffener, according to the present invention.

DETAILED DESCRIPTION OF INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

(8) The preferred embodiment of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessary obscure the present invention in detail.

(9) With reference to the FIG. 1, the invention is illustrated as applied to, the schematic representation of system of construction of composite U shaped reinforced concrete and steel girders bridge deck implemented in a railway bridge, comprising a plurality of main girder (1), a plurality of cross girders (2) including end cross girders and intermediate cross girders, U shaped RCC girder, drainage duct (4), and a track (5). The main girders (made of steel) are illustrated at FIG. 3 and provided with an unsymmetrical top flange (1a), a symmetrical bottom flange (1b) and a web (1c). The cross girders (2) are connected to the main girders. The cross girders are bent near support in such a way to match said bottom flange (1b) of said main girder. The uniform spacing distance of main girders and said cross girders is at 2.5 m. The end cross girders are, as illustrated at FIG. 5, the U shaped encasing RCC beam (2 and 200) and the intermediate cross girders, as illustrated at FIG. 4, are I girders (2 and 202). The U shaped RCC girder is provided with a top flange (3a), a web (3b) and a deck slab (3c), such that said deck slab (3c) and said web (3b) are constructed over cross girders and flange (3) over unsymmetrical top flange (1a) of main girder. The concrete deck slab (3c), web (3b) and the said concrete flange (3a) forms U shape. The top flange (1a) of said main girder is unsymmetrical to thereby take said U shaped RCC girder over said top flange (1a). The top flange (1a) of said main girder is projected inside a concrete by 3 cm for welding.

(10) In one embodiment of the present invention, the stiffeners (210), as illustrated at FIG. 6 are provided on outer face of said main girders. The top flange of cross girder (2) is bent to provide camber in a carriage way which is used up to four lanes for Highway and up to three lanes for Railway/Metro track. Construction of composite U shaped reinforced concrete and steel girders bridge deck by a way of providing a new force transfer system with composite interaction of U shaped RCC girder, main girder and cross girders resulting in substantial reduction of deflection and moments at centre of span in main girder and cross girders and adoptable for longer span.

(11) With reference to the FIG. 2, the invention is illustrated as applied to, schematic representation of system of construction of composite U shaped reinforced concrete and steel girders bridge deck implemented in a Highway bridge, comprising a plurality of main girder, a plurality of cross girders (2) including end cross girders and intermediate cross girders, U shaped RCC girder and a crash barrier (4).

(12) In another embodiment of the present invention, wherein foot path of 1.5 m or service path of 0.45 m is provided between said crash barrier (4) and said web (3b) of U shaped RCC girder.

Advantages of the Present Invention

(13) 1. The present invention ensures that light weight and less depth deck results in lighter sub structure and foundation and also lesser approach length and in turn reduces land acquisition. It reduces bridge and approach cost and helps fast track construction and thus eliminates cost and time overrun. Composite action of main girder makes the structure lighter and adoptable for longer spans up to 72 m span with improved aesthetic appearance. 2. For the existing Railway, Metro and Highway bridges lighter deck without trestle beam is suitable for fast track rehabilitation/rebuilding with increased spans apart from increased vertical clearance and overall saving in the bridge cost. 3. The girders can be factory made resulting in better quality and lesser work at site leading to fast track and quality construction. 4. The main girder with slab on top can be precast and the deck can be precast with cross girder and being connected to each other, which leads to fast track construction. Precast twin girder system can be launched over supports with minimum concreting over web portion. Absence of bracing system diaphragm, trestle beam connecting columns/supports, elaborate formwork arrangements and least interference to the traffic also makes it suitable for fast track construction. 5. Alternately main girder and cross girder can be launched and deck sheet of 6 mm mild steel can be spread and welded to cross girder and concreted in situ construction method. The reinforcements can be pre-assembled. Absence of bracing system diaphragm, trestle beam connecting columns/supports, elaborate formworks and least interference to traffic makes it suitable for fast track construction. 6. Part or full deck can be precast to have composite properties in advance to reduce the girder depth, weight, deflection and the weight of substructure and foundation. The overall cost of bridge can be reduced by more than rd. 7. The weight of steel used is reduced by designing two main girders with U shaped RCC girder to share the load in place of half through steel girder deck with steel girder property alone. 8. The depth of construction is less compared to twin girder composite ladder deck whereas the depth of construction (i.e) road top to bottom of cross/main girder is around 1 m for carriage way upto four lanes for highways and upto three lanes for railway or metro track. The meter reduction in road level reduces the approach length by 60 m. 9. The durability of bridge is more due to lesser exposure to rain and weathering agents compared to Twin girder ladder deck and half through steel girder.

(14) It is emphasized that the Abstract of the Disclosure is provided to allow a reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. In the appended claims, the terms including and in which are used as the plain-English equivalents of the respective terms comprising and wherein, respectively. Moreover, the terms first, second, third, and so forth, are used merely as labels, and are not intended to impose numerical requirements on their objects.

(15) Without further description, it is believed that one of ordinary skill in the art can, using the preceding description and the illustrative examples, make and utilize the present invention and practice the claimed methods. It should be understood that the foregoing discussion and examples merely present a detailed description of certain preferred embodiments. It will be apparent to those of ordinary skill in the art that various modifications and equivalents can be made without departing from the spirit and scope of the invention.