CN110792042A

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

Info

Publication number: CN110792042A
Application number: CN201910951225.8A
Authority: CN
Inventors: 卢永成; 沈维芳; 周丹; 肖纬; 朱蔚; 牛长彦; 王博
Original assignee: Shanghai Municipal Engineering Design Insitute Group Co Ltd
Current assignee: Shanghai Municipal Engineering Design Insitute Group Co Ltd
Priority date: 2019-10-08
Filing date: 2019-10-08
Publication date: 2020-02-14

Abstract

The invention discloses an anti-overturning reinforcing method for a rectangular bridge pier, which is characterized in that a steel capping beam is assembled at the bottom of the bridge pier, the steel capping beam is lifted, ultrahigh-performance concrete is poured between the steel capping beam and the bridge pier, and two side support assemblies are additionally arranged between the steel capping beam and the bottom of the bridge pier to realize the force transmission of an upper structure and an anti-overturning reinforcing structure of the existing bridge. 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 better economy.

Description

Anti-overturning reinforcing method for rectangular single-column pier bridge

Technical Field

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

Background

In recent years, accident cases of overturning instability and collapse of the whole transverse bridge of the simply supported and continuous beam bridge occur in various places in succession. The accidents are not obvious in advance, occur suddenly and are extremely harmful. Therefore, the anti-overturning stability problem of the bridge structure is gradually emphasized, and the requirements of the bridge design specification on the anti-overturning design are also refined and improved continuously.

However, for existing bridges with a high risk of capsizing, the current methods for capsizing and reinforcing the substructure are relatively limited: an effective method is to widen the existing pier stud or add new pier studs on both sides of the existing pier stud to serve as the bearing surfaces of the new added supports, the method is widely applied to highway bridges, but has great influence on ground roads and lower-layer bridge clearance in urban bridges, and the applicability is weak; the other type is that a capping beam structure for resisting overturning is additionally arranged on the pier top, the current common technology comprises a post-cast concrete type capping beam or a steel capping beam which is formed by combining a steel corbel and a steel hoop, the former has the defects of large field construction amount and requirement of jacking an upper structure, and the latter is suitable for a round pier and has poor applicability to a rectangular pier.

Disclosure of Invention

The invention aims to provide an anti-overturning reinforcing 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 economy.

In order to achieve the purpose, the technical scheme of the invention is as follows: an anti-overturning reinforcing method for an existing rectangular single-column pier bridge is characterized by comprising the following steps:

the method comprises the following steps: anchoring anchor bolts after planting on the lateral surfaces of the bridge pier in the transverse bridge direction, wherein anchor bolt holes avoid the positions of main ribs; combining two steel brackets into a whole at the bottom of the pier, installing and primarily screwing the oppositely-pulled prestressed reinforcement to form a steel bent cap;

step two: hoisting the steel cover beam, and placing the steel cover beam in place;

step three: pouring ultra-high performance concrete into the gap between the steel cap beam and the pier, screwing and tensioning the tension prestressed reinforcement finally when the strength of the concrete reaches 90% of the design strength and after the age reaches 7 days, and protecting the anchor head by adopting polysulfide sealant;

step four: adding two side plate type rubber supports, arranging an upper support wedge-shaped steel plate at the bridge bottom corresponding to the newly added support in a mode of bonding and anchoring bolts, leveling mortar at the bridge bottom before construction, and closely attaching the steel plate and the bridge bottom by coating epoxy glue; the top of the steel cover beam is provided with a support lower cushion stone, and a steel plate is embedded at the top of the support lower cushion stone; the plate-type rubber support is tightly installed between the wedge-shaped steel plate of the upper support and the embedded steel plate of the lower cushion stone, and the dead weight action ensures that certain initial pressure can be borne.

Furthermore, the inner side end plate of the steel bracket is provided with a welding nail connecting piece, the welding nail connecting piece and the welding nail connecting piece on the end plate of the steel bracket are arranged in a staggered mode, and the welding nail connecting piece is connected with the bridge pier through ultrahigh-performance concrete and a rear anchoring anchor bolt.

The invention has the advantages that:

1. the reinforcing device does not occupy the ground position near the bridge pier, and has little influence on urban ground roads;

2. the applicability is strong, the bridge pier is applicable to bridge piers with various section shapes, and is most suitable for rectangular bridge piers;

3. the upper structure of the bridge does not need to be jacked, and bridge deck traffic does not need to be interrupted;

4. the influence on the stress mode of the existing bridge is small. The original support system still plays a main bearing role in normal operation, and can play a safety auxiliary role under the condition of unbalance loading so as to improve the anti-overturning capacity of the bridge;

5. the reinforcing device is manufactured in a factory, assembled on site, free of welding on site, convenient and fast to construct and small in required number of supports.

Drawings

FIG. 1 is a vertical layout of an anti-capsizing reinforcement structure;

FIG. 2 is a plan view of an anti-capsizing reinforcement structure;

FIG. 3 is a schematic view of a pedestal assembly;

the figure includes: the steel bracket comprises a pier 1, a steel corbel 2, a welding nail connecting piece 3, a counter-pull prestressed steel bar 4, a concrete post-cast strip 5, a rear anchoring anchor bolt 6, a pier top plane 7, an original support 8, a lower support base stone 9, a plate type rubber support 10, an upper support wedge-shaped steel plate 11, polysulfide sealant 12, an embedded steel plate 13, angle steel 14 and a bolt 15.

Detailed Description

The following describes a preferred embodiment of the present invention with reference to fig. 1 to 2.

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

the steel cover beam structure is sleeved on the outer side of the pier and comprises two steel corbels 2 arranged on the top of the pier 1 and on the two sides in the transverse direction of the bridge, a welding nail connecting piece 3 arranged on an end plate on the inner side of each steel corbel and a counter-pulling prestressed steel bar 4 arranged on the top bottom side of each steel corbel, wherein each welding nail connecting piece is connected with the pier 1 through a concrete post-cast strip 5 and a rear anchoring anchor bolt 6, and the prestressed steel bars enable the steel corbels on the two sides to be combined into an integral steel cover beam structure to be stressed;

the anti-overturning reinforced support system comprises support assemblies arranged between steel cover beams on two lateral sides of the top of a pier in the bridge direction and the bottom of a bridge beam;

the rear anchoring anchor bolt 6 is fixed on the existing bridge pier by perforating and planting on the lateral side of the existing bridge pier in the transverse direction, has a certain exposed length, is arranged in a staggered manner with the connecting piece on the steel bracket end plate, and can adopt a formed mechanical anchor bolt or a formed chemical anchor bolt, so that the force transmission between the concrete post-cast strip and the existing bridge pier is realized;

and the concrete post-cast strip 5 is arranged between the outer side of the existing bridge pier transverse bridge and the steel corbel end plate, so that the steel corbel and the existing bridge pier form a whole, and the concrete with ultrahigh performance can be adopted for pouring.

The support assembly comprises:

a plate-type rubber support 10;

upper bracket wedge-shaped steel plate 11: the upper surface is closely attached to the bottom of the bridge according to the same gradient of the bottom of the bridge, the lower surface is horizontal and closely attached to the upper surface of the plate-type rubber support, and four bolts are arranged near four angular points of an upper support steel plate and embedded into a bridge body;

lower support base cushion stone 9: the setting is between plate rubber support 10 and steel corbel 2, and the upper and lower surface is equal level, closely pastes in plate rubber support lower surface and steel corbel top surface respectively, can adopt concrete or high-strength mortar to pour, and inside is furnished with the reinforcing bar, and the upper surface is equipped with pre-buried steel sheet 13.

Further, the concrete post-cast strip 5 is cast by adopting ultra-high performance concrete with steel fibers.

Further, the rear anchor 6 is a molded chemical anchor product.

Further, the counter-pulling prestressed steel bars 4 adopt high-strength threaded steel bars with an anti-corrosion system.

The pier anti-overturning reinforcing structure for the rectangular single-column pier provided by the invention is used for pier anti-overturning reinforcement and comprises the following steps:

the method comprises the following steps: installing a temporary support, building a construction platform, and installing a crane tool and a corresponding support at the top of the pier;

the chemical anchor bolts are planted on the bridge piers, the positions of main ribs of the bridge piers are required to be detected in advance, and anchor bolt holes are avoided from the positions of the main ribs.

And (3) combining two steel corbels into a whole at the bottom of the pier, and installing and primarily screwing the high-strength twisted steel.

step three: pouring ultra-high performance concrete into the gap between the steel cap beam and the pier, and finally screwing and tensioning the prestressed high-strength twisted steel when the strength of the concrete reaches 90% of the designed strength and after the age reaches 7 days, and protecting the anchor head by using polysulfide sealant;

step four: adding two side plate type rubber supports, arranging an upper support wedge-shaped steel plate at the beam bottom corresponding to the newly added support in a mode of bonding and anchoring bolts, wherein the wedge-shaped steel plate is adjusted according to the actual gradient of the beam bottom, the beam bottom is screeded by mortar before construction, the actual size of the wedge-shaped steel plate is subject to the laying-out of the screeded beam bottom, and the steel plate and the beam bottom are tightly attached by coating epoxy glue;

the top of the steel bent cap is provided with a lower support base stone 9, the height of the lower support base stone 9 is flexibly controlled according to the thickness of a newly-added support and the space below the beam, and a steel plate 13 is embedded in the top of the lower support base stone 9; the plate-type rubber support 10 is tightly installed between the wedge-shaped steel plate of the upper support and the embedded steel plate of the lower cushion stone, and the dead weight action ensures that certain initial pressure can be borne.

Claims

1. An anti-overturning reinforcing method for an existing rectangular single-column pier bridge is characterized by comprising the following steps:

the method comprises the following steps: after planting, anchoring anchor bolts at the lateral sides of the pier tops of the piers in the transverse direction of the bridge, wherein anchor bolt holes avoid the positions of main ribs; combining two steel brackets into a whole at the bottom of the pier, respectively anchoring two ends of the prestressed reinforcement at the outer sides of the two steel brackets, installing and primarily screwing the oppositely-pulled prestressed reinforcement to form a steel bent cap;

step two: hoisting the steel cover beam to the pier top, and placing the steel cover beam in place;

2. The method of claim 1, wherein the inner end plate of the steel corbel is provided with a plurality of weld nail connectors, the weld nail connectors are staggered with the weld nail connectors on the end plate of the steel corbel, and the weld nail connectors are connected to the bridge pier through ultra-high performance concrete and a rear anchor bolt.