CN110792042A - Anti-overturning reinforcing method for rectangular single-column pier bridge - Google Patents

Abstract

The invention discloses an anti-overturning reinforcement method for a bridge with rectangular piers. Steel cover beams are assembled at the bottom of the pier, the steel cover beams are lifted, ultra-high-performance concrete is poured between the steel cover beams and the piers, and the steel cover beams and The support components on both sides are added between the bottom of the bridge girder to realize the force transmission between the existing bridge superstructure and the anti-overturning reinforcement structure. The invention can effectively improve the anti-overturning safety performance of the existing rectangular single-column pier bridge, and has good construction convenience, wide applicability and good economy.

Description

An anti-overturning reinforcement method for rectangular single-column pier bridges

technical field

The invention relates to a method for repairing or reinforcing existing bridges, in particular to an anti-overturning reinforcing method for existing rectangular single-column pier bridges.

Background technique

In recent years, there have been incidents of simply supported and continuous girder bridges in which the overall transverse bridge overturned and collapsed. This kind of thing has no obvious manifestation before the story, and it happens suddenly and is extremely harmful. Therefore, the problem of anti-overturning stability of bridge structures has gradually been paid attention to, and the requirements for anti-overturning design of bridge design codes have been continuously refined and improved.

However, for existing bridges with a high risk of overturning, the current methods and reinforcement structures for the anti-overturning reinforcement of the substructure are relatively limited: an effective method is to widen the existing piers, or extend the width of the existing piers on both sides of the existing piers. The new pier column is used as the bearing surface of the new bearing. This method is widely used in highway bridges, but in urban bridges, it has a great impact on the clearance of ground roads and lower bridges, and its applicability is weak; another The other is to add a cover beam structure on the top of the pier for anti-overturning. At present, common technologies include post-cast concrete cover beams, or steel cover beams combined with steel corbels and steel hoops. The former has a large amount of on-site construction. The disadvantage is that it is larger and needs to lift the superstructure, and the latter is suitable for circular piers, but less suitable for rectangular piers.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an anti-overturning reinforcement method for an existing rectangular single-column pier bridge, which can effectively improve the anti-overturning performance of the single-column pier bridge, and has better construction convenience, wide applicability and good performance. economical.

In order to achieve the above object, the technical solution of the present invention is as follows: a method for overturning reinforcement for an existing rectangular single-column pier bridge, characterized in that the method comprises the following steps:

Step 1: Anchor bolts are planted on the lateral side of the pier in the transverse direction of the bridge, and the anchor bolt holes avoid the position of the main reinforcement; two pieces of steel corbels are integrated at the bottom of the pier, and the prestressed steel bars are installed and initially twisted to form a steel cap beam ;

Step 2: Lift the steel cover beam and place the steel cover beam in place;

Step 3: Pour ultra-high performance concrete into the gap between the steel cap beam and the bridge pier. When the concrete strength reaches 90% of the design strength and the age reaches 7 days, the tension and tension prestressed steel bars can be finally twisted and protected with polysulfide sealant anchor head;

Step 4: Add plate rubber bearings on both sides, and install wedge-shaped steel plates on the upper bearing by bonding and anchoring bolts at the bottom of the bridge beam corresponding to the new bearing. Before construction, the bottom of the bridge beam is smoothed with mortar, and the steel plate and the bridge beam Epoxy glue is applied between the bottoms for compactness; the top of the steel cover beam is provided with a support stone, and the top of the support stone is pre-buried with steel plates; the plate rubber support is tightly installed on the wedge-shaped steel plate and the lower stone Between the embedded steel plates, the self-weight effect ensures that it can bear a certain initial pressure.

Further, the inner end plate of the steel corbel is provided with a welding stud connector, and the welding stud connector is staggered with the welding stud connector on the end plate of the steel corbel. connected to the bridge pier.

The advantages of the present invention are:

1. The reinforcement device does not occupy the ground position near the pier, and has little impact on the urban ground roads;

2. Strong applicability, can be used for bridge piers with various cross-sectional shapes, and is most suitable for rectangular bridge piers;

3. There is no need to lift the bridge superstructure, and there is no need to interrupt the traffic on the bridge deck;

4. It has little influence on the force mode of existing bridges. While maintaining the original bearing system in normal operation, it still plays the main bearing role, and can play a safety auxiliary role in the case of partial load, so as to improve the anti-overturning ability of the bridge;

5. The reinforcement device is made in the factory and assembled on site, no welding is required on site, the construction is relatively convenient, and the number of brackets required is small.

Description of drawings

Figure 1 is the elevation layout of the anti-overturning reinforcement structure;

Figure 2 is the plan layout of the anti-overturning reinforcement structure;

Figure 3 is a schematic diagram of a support assembly;

The figure includes: pier 1, steel corbel 2, welding stud connector 3, anti-tensile prestressed steel bar 4, concrete post-casting belt 5, rear anchor bolt 6, pier top plane 7, original support 8, lower support Cushion 9, plate rubber bearing 10, upper bearing wedge-shaped steel plate 11, polysulfide sealing paste 12, embedded steel plate 13, angle steel 14, bolt 15.

Detailed ways

The preferred embodiments of the present invention will be described in detail below according to FIG. 1 to FIG. 2 .

As shown in Figure 1 and Figure 2, the present invention provides an anti-overturning structure for a rectangular single-column pier bridge pier, comprising:

The steel cover beam structure is sleeved on the outside of the bridge pier. The steel cover beam structure includes two steel corbels 2 arranged on both sides of the cross bridge at the top of the bridge pier 1, and welding studs arranged on the inner end plate of the steel corbel The connecting piece 3, and the anti-tensile prestressed steel bar 4 arranged on the top and bottom sides of the steel corbel, the welding nail connecting piece is connected with the pier 1 through the concrete post-casting belt 5 and the back anchor bolt 6, and the prestressed steel bar makes the two sides The steel corbels are combined into a whole steel cover beam structure to bear the force;

The anti-overturning reinforcement bearing system includes bearing components arranged between the steel cover beams on both sides of the transverse bridge at the top of the pier and the bottom of the bridge beam;

The rear anchor bolt 6 is fixed on the existing bridge pier by opening and planting on the lateral side of the existing bridge pier in the transverse bridge direction, and has a certain exposed length. Using formed mechanical anchor bolts or chemical anchor bolts, so as to realize the force transmission between the concrete post-cast belt and the existing bridge piers;

The concrete post-pouring belt 5 is arranged between the lateral outer side of the existing bridge pier and the steel corbel end plate, so that the steel corbel and the existing bridge pier form a whole, and can be poured with ultra-high performance concrete.

The support assembly includes:

Plate type rubber bearing 10;

The wedge-shaped steel plate 11 of the upper bearing: set between the rubber plate bearing 10 and the bottom of the bridge beam, the upper surface is closely attached to the bottom of the beam according to the slope of the bottom of the bridge beam, and the lower surface is horizontal and closely attached to the upper surface of the rubber plate bearing. Four bolts are arranged near the four corners of the upper bearing steel plate and embedded in the bridge beam;

Lower support rock 9: set between the plate rubber support 10 and the steel corbel 2, the upper and lower surfaces are horizontal, and are closely attached to the lower surface of the plate rubber support and the top surface of the steel corbel, concrete or high-strength mortar can be used Pouring, the interior is equipped with steel bars, and the upper surface is provided with pre-embedded steel plates 13.

Further, the concrete post-casting belt 5 is poured with ultra-high performance concrete with steel fibers.

Further, the rear anchoring bolt 6 adopts a formed chemical anchoring product.

Further, the pair of tensile prestressed steel bars 4 are high-strength threaded steel bars with an anti-corrosion system.

Adopting the anti-overturning reinforcement structure for the rectangular single-column pier bridge pier provided by the present invention to carry out the anti-overturning reinforcement of the bridge pier, the following steps are included:

Step 1: Install temporary supports, build construction platforms, and install lifting tools and corresponding supports on the top of the pier;

When planting chemical anchor bolts on bridge piers, the position of the main reinforcement of the pier column should be ascertained in advance, and the anchor bolt holes should avoid the position of the main reinforcement.

At the bottom of the pier, two pieces of steel corbels are combined into a whole, and high-strength threaded steel bars are installed and initially screwed.

Step 2: Lift the steel cover beam and place the steel cover beam in place;

Step 3: Pour ultra-high performance concrete into the gap between the steel cap beam and the bridge pier. When the concrete strength reaches 90% of the design strength and the age reaches 7 days, the tensile prestressed high-strength threaded steel bar can be finally screwed, and protected with polysulfide sealant anchor head;

Step 4: Add plate rubber bearings on both sides, and set the wedge-shaped steel plate of the upper bearing at the bottom of the beam corresponding to the new bearing by bonding and anchoring bolts. The wedge-shaped steel plate should be adjusted according to the actual slope of the beam bottom. Before construction, the beam bottom should be It should be troweled with mortar, the actual size of the wedge-shaped steel plate should be based on the lofting of the beam bottom after troweling.

The top of the steel cover beam is provided with a lower support cushion 9, the height of which is flexibly controlled according to the thickness of the new support and the space under the beam. The top of the lower support cushion 9 is pre-buried with a steel plate 13; the plate rubber support 10 is tightly installed on the upper support Between the seat wedge-shaped steel plate and the embedded steel plate of the underlying rock, the self-weight action ensures that it can bear a certain initial pressure.

Claims (2)

1. an anti-overturning reinforcement method for an existing rectangular single-column pier bridge is characterized in that the method comprises the following steps: Step 1: Anchor bolts are planted on the lateral side of the pier top in the transverse bridge direction, and the anchor bolt holes avoid the position of the main reinforcement; two steel corbels are combined at the bottom of the pier, and the two ends of the prestressed reinforcement are anchored to the two steel corbels respectively. On the outer side of the leg, install and initially screw the prestressed steel bar to form a steel cover beam; Step 2: Lift the steel cover beam to the top of the pier and place the steel cover beam in place; Step 3: Pour ultra-high performance concrete into the gap between the steel cap beam and the bridge pier. When the concrete strength reaches 90% of the design strength and the age reaches 7 days, the tension and tension prestressed steel bars can be finally twisted and protected with polysulfide sealant anchor head; Step 4: Add plate rubber bearings on both sides, and install wedge-shaped steel plates on the upper bearing by bonding and anchoring bolts at the bottom of the bridge beam corresponding to the new bearing. Before construction, the bottom of the bridge beam is smoothed with mortar, and the steel plate and the bridge beam Epoxy glue is applied between the bottoms for compactness; the top of the steel cover beam is provided with a support stone, and the top of the support stone is pre-buried with steel plates; the plate rubber support is tightly installed on the wedge-shaped steel plate and the lower stone Between the embedded steel plates, the self-weight effect ensures that it can bear a certain initial pressure. 2. The anti-overturning reinforcement method for a rectangular pier bridge according to claim 1 is characterized in that the inner end plate of the steel corbel is provided with a welding stud connector, and the welding stud connector and the welding stud on the steel corbel end plate The connectors are staggered, and the welded stud connectors are connected to the piers through ultra-high performance concrete and rear anchor bolts.

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