CN207672411U - A kind of widening structure of width cantilever boxgirder - Google Patents

Abstract

The utility model is specifically a widening structure of a wide cantilever box girder, which solves the problems of complex process, high cost, large damage to the original structure and inconvenience of later maintenance caused by the widening of the existing wide cantilever box girder. The upper end of the beam bottom steel plate is provided with longitudinal stiffening steel plates and connecting steel bars, the left and right sides of the longitudinal stiffening steel plates are provided with vertical anchor bolts, and the inner sides of the adjacent webs of the original box girder and the widened box girder are provided with transverse anchor bolts. On the adjacent side of the box girder and the widened box girder, there are bottom plate implanted steel bars and bottom plate reserved steel bars, and a concrete bottom plate cast-in-place layer is set on the beam bottom steel plate; Steel bars and reserved steel bars at the bottom of the top slab, and cast-in-place steel bars and reserved steel bars for the cast-in-place layer of the original box girder and widened box girder. The utility model improves the safety performance of the structure, ensures the durability of the original structure at the same time, and has the advantages of low construction cost and short construction period.

Description

A Widening Structure of Wide Cantilever Box Girder

technical field

The utility model relates to a widening technology for highway bridge and culvert engineering, in particular to a widening structure of a wide cantilever box girder.

Background technique

At present, the construction of new highways in my country has reached an unprecedented scale, and the reconstruction and expansion projects in operation in the future will gradually become a major focus of highway construction. In highway reconstruction and expansion projects, one of the key technical issues is the widening and reconstruction of existing bridges. Different from general bridge design, the design of bridge widening and reconstruction must consider the interaction between the old and new beam-slab structures during the construction phase and the use phase. It is necessary to adopt reasonable structural measures and appropriate construction methods to minimize the damage to the original structure, so as to ensure Safety, durability and serviceability of wide rear bridges.

For wide cantilever box girder structures, the problem of widening and reconstruction is more prominent. In conventional design methods, only the flange plates of the main girder are generally connected laterally. The lateral connection stiffness of the old and new structures is poor, and the structure cannot overcome the deflection difference between the old and new box girders. In the long-term operation, it is inevitable that pavement cracks will appear at the joints, which will bring safety hazards to later maintenance. However, in other horizontal connection designs using steel reinforcement technology, the construction technology is complicated, there are many steps, the project cost is high, and the original structure is greatly damaged.

Contents of the invention

The utility model provides a widening structure of a wide cantilever box girder in order to solve the problems of complex process, high cost, large damage to the original structure and inconvenience of later maintenance caused by poor connection stiffness when the existing wide cantilever box girder is widened.

The utility model is realized by adopting the following technical scheme: a widening structure of a wide cantilever box girder, including a beam bottom steel plate arranged between the original box girder and the widened box girder and closely attached to the lower end surfaces of the two bottom plates, the beam bottom steel plate There are several longitudinally stiffened steel plates distributed left and right on the upper end surface, and several connecting steel bars distributed front and rear are pierced through the longitudinally stiffened steel plates. Bolts, the inner side of the adjacent web of the original box girder and the widened box girder are provided with transverse anchor bolts fixed to the longitudinal stiffening steel plates at the left and right ends, and the right side of the bottom plate of the original box girder is provided with a bottom plate implanted steel bar fixed with the connecting steel bars , the left side of the bottom plate of the widened box girder is provided with the reserved steel bars fixed to the connecting steel bars, and the concrete bottom plate cast-in-place layer is set on the beam bottom steel plate; The left side of the roof of the wide box girder is provided with the reserved steel bar of the top plate connected with the steel bar of the roof and the reserved steel bar of the bottom of the roof connected with the bottom steel bar of the roof. The left side of the cast-in-place layer of the beam is provided with a reserved steel bar for the cast-in-place layer connected with the steel bars of the cast-in-place layer.

The structural design utilizes the characteristics of concrete compression resistance and steel plate bending resistance, and good deformation adaptability. The steel plate at the bottom of the beam is used to form a new steel-concrete composite box girder between the old and new box girders, which improves the overall rigidity and stability between the old and new box girders. The torsion resistance greatly reduces the damage at the joints of the old and new bridges during the operation stage, and increases the bending resistance of the widened structure. At the same time, because the large-area reinforcement process is not used, the damage to the original structure is minimized. It overcomes the problems of complex process, high cost, large damage to the original structure and poor connection rigidity that cause inconvenience in later maintenance when the existing wide cantilever box girder is widened.

The structure design of the utility model is reasonable and reliable, greatly improves the overall rigidity and torsional performance between the old and new box girders, greatly reduces the disease in the operation stage, increases the driving comfort, and increases the bending bearing capacity of the structure. The safety performance of the structure is improved, while the damage to the original structure is reduced, the durability of the original structure is guaranteed, and it has the advantages of low construction cost and short construction period.

Description of drawings

Fig. 1 is the structural representation of the utility model.

In the figure: 1-original box girder, 2-widened box girder, 3-beam bottom steel plate, 4-longitudinal stiffening steel plate, 5-connecting steel bar, 6-vertical anchor bolt, 7-horizontal anchor bolt, 8-bottom plate planting Reinforcement, 9- cast-in-place layer of concrete floor, 10- roof reinforcement, 11- roof bottom reinforcement, 12- cast-in-place layer reinforcement, 13- reserved reinforcement for bottom floor, 14- reserved reinforcement for roof, 15- reserved reinforcement for roof bottom , 16-Reserved reinforcement for the cast-in-place layer.

Detailed ways

A widening structure of a wide cantilever box girder, comprising a beam bottom steel plate 3 arranged between the original box girder 1 and the widened box girder 2 and close to the lower end surfaces of the bottom plates of the two. The longitudinally stiffened steel plate 4 is pierced with a number of connecting steel bars 5 distributed front and rear, and the left and right sides of the longitudinally stiffened steel plate 4 are provided with vertical anchor bolts fixed to the bottom plates of the original box girder 1 and the widened box girder 2 6. The inner sides of the adjacent webs of the original box girder 1 and the widened box girder 2 are provided with transverse anchor bolts 7 fixed to the longitudinal stiffening steel plates 4 at the left and right ends, and the right side of the bottom plate of the original box girder 1 is provided with connecting steel bars 5 The fixed bottom plate is implanted with steel bars 8, and the left side of the bottom plate of the widened box girder 2 is provided with a reserved steel bar 13 fixed to the connecting steel bar 5, and a concrete bottom plate cast-in-place layer 9 is set on the beam bottom steel plate 3; the original box girder 1 top plate The right side of the roof is provided with a roof reinforcement 10 and a roof bottom reinforcement 11, and the left side of the widened box girder 2 roof is provided with a roof reserved reinforcement 14 connected with the roof reinforcement 10 and a roof bottom reinforcement 15 connected with the roof bottom reinforcement 11. , the left side of the cast-in-place layer of the original box girder 1 is provided with a cast-in-place layer reinforcement 12, and the left side of the widened box girder 2 cast-in-place layer is provided with a cast-in-place layer reserved reinforcement 16 connected with the cast-in-place layer reinforcement 12.

When carrying out the bridge widening operation, the horizontal anchor bolt 7, the vertical anchor bolt 6 and the bottom plate are implanted with steel bars 8 on the bottom plate and widened side web of the original box girder 1, and then the beam bottom steel plate 3 and the After the connecting steel bar 5 is hoisted in place, it is anchored and connected with the original box girder 1, and then the beam bottom steel plate 3 and the connecting steel bar 5 pierced thereon are anchored and connected with the widened box girder 2, and then the concrete is poured to form a whole; b. When the original box girder 1 roof flange part has the same thickness as the flange end of the cast-in-situ box girder 2 roof, the roof steel bar 10 in the original box girder 1 and the widened box girder 2 roof, the roof reserved steel bar 14 and the roof The bottom steel bar and the reserved steel bar 15 at the bottom of the roof are welded and connected, and then the roof concrete is poured; c, the cast-in-place layer at the cantilever of the original box girder 1 is chiseled, and the cast-in-place layer steel bar 12 and the cast-in-place layer reserved steel bar 16 are used for welding Finally, the cast-in-place layer of the original box girder 1 bridge deck was poured to complete the widening operation of the wide cantilever box girder.

Claims (1)

1. A widening structure of a wide cantilever box girder, characterized in that: it includes a beam bottom steel plate (3) arranged between the original box girder (1) and the widened box girder (2) and close to the bottom surface of both bottom plates , the upper end of the beam bottom steel plate (3) is provided with a number of longitudinally stiffened steel plates (4) distributed left and right, the longitudinally stiffened steel plates (4) are pierced with a number of connecting steel bars (5) distributed front and rear, and the left and right sides of the longitudinally stiffened steel plates (4) Vertical anchor bolts (6) fixed to the bottom plates of the original box girder (1) and the widened box girder (2) are arranged on both sides, and the inner sides of the adjacent webs of the original box girder (1) and the widened box girder (2) Both are equipped with transverse anchor bolts (7) fixed to the longitudinal stiffening steel plates (4) at the left and right ends, and the right side of the bottom plate of the original box girder (1) is provided with a bottom plate implanted steel bar (8) fixed to the connecting steel bar (5), The left side of the bottom plate of the widened box girder (2) is provided with a reserved steel bar (13) fixed to the connecting steel bar (5), and a concrete bottom plate cast-in-place layer (9) is set on the beam bottom steel plate (3); the original box girder (1) The right side of the roof is provided with roof reinforcement (10) and roof bottom reinforcement (11), and the widened box girder (2) the left side of the roof is provided with roof reinforcement (14) connected to the roof reinforcement (10) and the reserved steel bars (15) at the bottom of the roof (11) connected to the roof, the left side of the cast-in-place layer of the original box girder (1) is provided with a cast-in-place steel bar (12), and the widened box girder (2) is cast-in-place A cast-in-place layer reserved reinforcement (16) connected with the cast-in-place layer reinforcement (12) is arranged on the left side of the layer.