CN205205654U - Seam construction of precast concrete festival segmentation bridge - Google Patents

Abstract

The utility model discloses a seam construction of precast concrete festival segmentation bridge belongs to the bridge engineering field. The utility model discloses an on the basis that does not basically change conventional used template, at prefabricated lug in section both ends and corresponding recess to reserve connecting reinforcement's pore on the lug. After the festival section concatenation, penetrate connecting reinforcement in reserving the pore, and the anchor. Festival section junction extrusion is inseparable, and the shear strength of seam is high between prefabricated segment, has strengthened the anti -bending strength of the roof beam body to the fracture of seam bottom has been delayed. Even the crack appears, connecting reinforcement also can prevent fissured extension effectively to improve the bearing capacity of the roof beam body. Compared with prior art, construction convenience should construct, and the bridge wholeness that adopts this structure to build up is good.

Description

Joint structure of a concrete prefabricated segmental bridge

technical field

The utility model relates to a joint structure of a concrete prefabricated segmental bridge, which belongs to the field of bridge engineering.

Background technique

The prefabricated assembly construction method of the bridge is to divide the beam body into several segments, and transport it to the bridge site for assembly after prefabrication in the prefabrication plant, which has become a construction method for medium-span beam bridges. Due to the prefabrication in the factory in advance, there is little interference to the construction site, the construction speed is relatively fast, and the quality of the beam body is easy to control. It is especially suitable for bridges with a bridge length of more than 2 kilometers and urban viaducts. It has been widely used in recent years and is the future bridge construction. important direction of development. When the segmental method is used for construction, the joints between the prefabricated segments generally adopt wet joints and dry joints. The wet joints are connected by pouring concrete, and the wet joints are connected by ordinary steel bars. The joints are well connected, but the concrete maintenance takes a long time and the cost is high; the dry joints are connected by applying epoxy glue and then tensioned and prestressed, and dry joint construction It is convenient, speeds up the construction, saves the construction period, reduces the cost, and has been widely promoted.

However, when dry joints are used, since the main girder is discontinuous in the joint area, the ordinary steel bars that can transmit part of the normal stress and shear stress are broken here, and only the shear keys and prestressed steel tendons set at the joint Each segment is connected, and the length of a single segment is short, and the number of joints in each span is large, so the joints between segments are the weak links of the structure, and the mechanical behavior of the joints directly affects the overall structure of the bridge. performance. If the treatment is not good, the moisture and acid components in the atmosphere will enter the joints, which will lead to poor durability of the structure; or with the increase of traffic flow on the road and the increase of overloaded vehicles, it will cause damage to the joints between the segments . The general manifestation is that the bottom of the hinge joint cracks first, weakening the connection between the segments, and cracks appear in the seam. Rainwater infiltrates into the joints from the bridge deck, reducing the force transmission capacity of the joints, weakening the coordinated bearing capacity of each segment, cracks continue to develop upwards, and it is easy to form cracks that penetrate from bottom to top. When it reaches a certain level, the segments will fracture and cause the vehicle to fall down the bridge with it. Therefore, there is an urgent need for a new type of joint structure of prefabricated spliced beam segments to strengthen the integrity of the bridge and prevent the generation of cracks from bottom to top.

Contents of the invention

The purpose of this utility model is to solve the deficiencies and problems in the above-mentioned prior art, and to provide a joint structure of a concrete prefabricated segmental bridge. The joint structure of the new prefabricated segmental concrete bridge is assembled by adjacent prefabricated segments, including the bumps and grooves where the two prefabricated segments are connected, as well as the bonding colloid between them, the bumps A vertical channel for connecting steel bars is reserved on the top, and connecting steel bars are worn in the reserved channels. Segmental joints are squeezed tightly, and the bumps and grooves occlude each other. The overall performance of the bridge is good, the shear resistance is improved, the bending resistance of the beam body and the tensile performance of the bottom are enhanced, and the cracking at the bottom of the joint is delayed. . Even if there are cracks, the connecting steel bars can effectively prevent the expansion of cracks, thereby improving the bearing capacity of the structure.

Further, the connecting steel bar is a high-strength prestressed steel bar, and a pre-embedded steel plate is arranged at the joint between the connecting steel bar and the upper and lower surfaces of the segment. The steel bars can be high-strength steel bars, precision-rolled threaded steel bars, etc., so that the surfaces of the bumps and grooves at the bottom are squeezed tightly, effectively preventing the formation and expansion of cracks.

Further, mortar or chemical cementing material is poured around the connecting reinforcement in the reserved channel. The chemical bonding material can be polyurethane or modified epoxy resin structural adhesive. The connection between the steel bar and the tunnel wall is tight, the structural integrity is good, the bearing capacity of the structure is improved, and the steel bar is not easy to corrode.

The steel bar between the segments can be U-shaped steel bar or the like. At the web, multiple rows of connecting steel bars can be arranged in the transverse and longitudinal directions. The front end of the bump can also be made to have a certain angle with the plumb line, so that the entire joint structure is inclined.

Compared with the prior art, the utility model has the following beneficial effects:

1. This form of prefabricated joint joint structure improves the shear resistance of the joint, and the overall performance of the bridge is good. At the same time, the bending resistance of the joint is improved, so that the joint no longer becomes the weak surface of the main beam;

2. The regular templates are still used in the production of segments, the modification work is minimal, and the difficulty of prefabrication is not increased;

3. This form only needs to add pre-embedded steel plates and connecting steel bars, and the increased material cost is negligible;

4. Tensile vertical prestressing is a conventional prestressing operation, and the construction operation is simple;

5. It avoids the phenomenon that the joint between the two segments is easy to crack and prevents cracks from penetrating through. Even if cracks appear, the connecting steel bars can effectively prevent the expansion of cracks, making full use of the basic principles of fracture mechanics and improving the crack resistance of the joints ability.

Description of drawings

Fig. 1 is the schematic diagram of the longitudinal section of the over-connected reinforcing bar corresponding to embodiment one;

Fig. 2 is the local schematic diagram among the embodiment one;

Fig. 3 is the schematic diagram of the longitudinal section of the over-connected reinforcing bar corresponding to embodiment two;

Fig. 4 is a schematic diagram of U-shaped connecting reinforcement;

In the drawings: 1—prefabricated segment, 2—bump, 3—groove, 4—hole, 5—connecting reinforcement, 6—joint, 7—embedded steel plate, 8—U-shaped connecting reinforcement.

detailed description

The following are specific embodiments of the utility model, and describe the technical solutions of the utility model in conjunction with the accompanying drawings, but the utility model is not limited to these embodiments.

Embodiment one

This embodiment adopts the segmental seam form shown in Fig. 1 and Fig. 2, wherein Fig. 2 is a partial schematic diagram of the bottom of the seam. Figure 1 includes two adjacent prefabricated segments (1). A bump (2) and a corresponding groove (3) are prefabricated at both ends of the prefabricated segment (1). The front face of the bump (2) It is a vertical surface with a vertical channel (4) on it, and the angle between the upper and lower surfaces of the bump (2) and the horizontal plane is 20 degrees. The joint structure has two rows of tunnels (4) in the longitudinal direction of the bridge, and three rows of tunnels (4) in the transverse bridge direction of the same web. The seam (6) between the vertical bump (2) and the groove (3) is bonded with a modified epoxy resin structural adhesive. After the prefabricated segment (1) is glued, the connecting steel bar (5) made of finished rolled threaded steel bar is penetrated into the tunnel (4), and the connecting steel bar (5) is connected with the upper and lower surfaces of the prefabricated segment (1). Embed the steel plate (7), see Figure 2 for details. Correspondingly, a steel plate is pre-embedded on the upper part of the prefabricated section (1). After the bonding glue in the joint (6) is cured and reaches the required strength, the connecting steel bar (5) is stretched and fixed, and the mortar is injected into the gap of the channel (4).

Embodiment two

This embodiment is a modification to Embodiment 1, adopting the segmental seam form shown in FIG. 3 . The two ends of the prefabricated segment (1) have a vertical row of four protrusions (2) and corresponding grooves (3), and the protrusions (2) have a row of vertical tunnels (4) in the longitudinal direction of the bridge. After the bonding glue in the joint (6) is cured and reaches the required strength, the connecting steel bar (5) is stretched and fixed, and the modified epoxy resin structural glue is injected into the gap of the channel (4).

Embodiment three

This embodiment is an amendment to Embodiment 1, using the U-shaped connecting reinforcement ( 8 ) shown in FIG. 4 , and the turning point at the bottom of the U-shaped connecting reinforcement ( 8 ) is arc-shaped. The two limbs of the U-shaped connecting steel bar (8) respectively penetrate in the two longitudinal tunnels (4) from bottom to top. There is also a corresponding arc knuckle at the place where the lower pre-embedded steel plate (7) is in contact with the arc knuckle of the U-shaped connecting steel bar (8).

Claims (3)

1. A joint structure of a concrete prefabricated segmental bridge, which is assembled by adjacent prefabricated segments, including the bumps and grooves at the joints of the two prefabricated segments, and the bonding colloid between them , which is characterized in that: vertical channels for connecting steel bars are reserved on the bumps, and connecting steel bars are pierced in the reserved channels. 2. The joint structure of a concrete prefabricated segmental bridge according to claim 1, characterized in that: the connecting steel bars are high-strength prestressed steel bars, and there are pre-embedded steel plates at the joints between the connecting steel bars and the upper and lower surfaces of the segments . 3. The joint structure of a concrete prefabricated segmental bridge according to claim 2, characterized in that: mortar or chemical cementing materials are poured around the connecting steel bars in the reserved channels.