CN104532760A - Method for reinforcing simply-supported plate or simply-supported beam bridge - Google Patents

Abstract

The invention discloses a method for reinforcing a simply supported slab or simply supported beam bridge, which belongs to the field of bridge engineering and includes setting abutments on both sides of a pier abutment of a span to be reinforced, and the abutment is attached to the abutment and connected with the abutment The pier abutment is formed as a whole; an arch rib is set under the plate girder of the span to be reinforced, and the arch rib is integrated at the middle section of the plate girder and its bottom, and the two ends of the arch rib abut against the abutment on the pier abutment respectively, And the two ends form an integral body with the abutment; a transverse connection beam is arranged on the bottom surface of the slab girder that needs to be reinforced, and the transverse connection beam is perpendicular to the length direction of the slab girder and forms an integral body with the bottom surface of the bridge, and the transverse connection beam is integrated with the above-mentioned The arch rib is also formed as a whole. In this way, the force is changed from the simple plate beam force to the plate-arch composite structure force, which greatly improves the bearing capacity and stiffness of the original structure. The method of the invention has a better reinforcing effect than other reinforcing methods such as sticking boards.

Description

A kind of reinforcement method of simply supported slab or simply supported beam bridge

technical field

The invention belongs to the technical field of bridge engineering construction and relates to a bridge reinforcement method, in particular to a simply supported plate or simply supported girder bridge reinforced method.

Background technique

Among the more than 700,000 bridges in my country, bridges with small and medium-span simply supported slab structures and bridges with simply supported beam structures occupy the absolute majority in number. Due to various reasons such as design, construction and management, many bridges have quality defects before they are put into operation. Coupled with practical factors such as difficult maintenance and serious overloading, bridge diseases in operation are now common, seriously affecting bridge safety and performance. durability. In order to meet the traffic requirements, some old bridges with small and medium spans need to be demolished and rebuilt, but this method is not only uneconomical, but also interrupts traffic, which is time-consuming and labor-intensive. Therefore, in actual situations, it is often necessary to reinforce simply supported slabs or simply supported beams to meet gradually heavy traffic.

Due to the relatively small rigidity of the plates and the fact that the plates are close to each other in the transverse direction, there is no reinforcement space on the side of the web except for the space at the bottom of the plate. Therefore, although the slab structure is mainly used in small and medium bridges, its reinforcement is very difficult. At present, the main reinforcement methods for simply supported slab structures are:

(1) Paste fiber material or steel plate on the bottom of the slab: This method uses building structural glue to paste carbon fiber cloth on the concrete surface or uses epoxy resin series adhesives to bond the steel plate to the tension area or weak part of the slab bridge, so that all The pasted material is jointly stressed with the board to achieve the purpose of reinforcement. This method enhances the tensile performance of the bottom of the slab, which can improve the bending capacity of the slab to a certain extent, but has little effect on improving the stiffness of the slab;

(2) Applying prestress on the bottom surface: This method applies prestress to the bridge through the prestress tendons anchored on the supporting angle steel at the bottom of the side plates on both sides. This method can not only improve the stress state of the slab in advance, but also increase the bending capacity of the slab, but it cannot apply strong prestress to the slab structure, and the reinforcement effect is limited.

Due to the limited strengthening methods of simply supported slabs or simply supported beams, and the limited ability to increase the bearing capacity and stiffness of the original structure, the existing simply supported slabs or simply supported beam reinforcement methods cannot meet the needs of large-scale reinforcement and lifting engineering projects , and cannot meet the requirements of special circumstances such as special load bridges, and cannot meet the requirements of economical rationality and convenient construction.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the present invention provides a method for strengthening simply supported slab or simply supported beam bridges, the purpose of which is to strengthen simply supported slabs and simply supported beams by using the plate-arch combination effect. The method can not only increase the bearing capacity and rigidity of the bridge slab structure, so that the reinforced simply supported slab or simply supported beam can meet the requirements of special loads passing the bridge, the method of the invention can also meet the project requirements of large-scale reinforcement and lifting, and Therefore, the technical problem of insufficient ability to improve the bearing capacity and rigidity of the original structure in the current reinforcement method is solved.

To achieve the above object, the present invention provides a method for reinforcing a simply supported slab or simply supported beam bridge, the simply supported slab or simply supported beam bridge includes at least one span, each span includes a pier and a bridge supported by the pier A slab girder for vehicles and pedestrians to pass through is characterized in that it comprises the following steps:

An abutment is provided on both sides of the abutment of the span to be reinforced, and the abutment is attached to the abutment and integrally formed with the abutment;

An arch rib is set under the plate girder of the span to be reinforced, and the arch rib is integrated with the bottom of the plate girder at the middle section of the plate girder, and the two ends of the arch rib abut against the abutment on the pier respectively, and the two ends One end is integral with the abutment;

A horizontal connection beam is arranged on the bottom surface of the plate girder of the span to be reinforced, the length direction of the horizontal connection beam is perpendicular to the length direction of the plate girder and integrally formed with the bottom surface of the plate girder, and the horizontal connection beam is also integrally formed with the arch rib;

The wholes formed above make the stress of the simply supported slab or simply supported beam bridge change from the simple slab girder stress to the slab arch composite structure stress, so that its bearing capacity and stiffness are greatly improved, so as to achieve the original simple support Reinforcement of slab or simply supported beam bridges.

Further, there are two or more transverse connecting beams arranged on the bottom surface of the middle section of the slab girder that need to be reinforced. The transverse connecting beams have a certain width, which should be determined through specific calculations. The width is integral with the bottom surface of the plate girder, and the arch rib is integral with the transverse connecting beam over the entire width of the transverse connecting beam.

Further, arch ribs are set under the plate girder of the span to be reinforced, and the cross-sectional form or rise-to-span ratio of the arch ribs can be the same or different. In actual operation, the cross-sectional form or rise-span ratio of the arch rib can be changed according to the design requirements and navigation capacity requirements, so as to realize artificially controlled reinforcement stiffness and bearing capacity. The cross-sectional form is the cross-sectional shape and the cross-sectional area.

Further, a plurality of parallel arch ribs are arranged along the width direction of the plate girder under the plate girder of the span to be reinforced, so that the plate girder is supported by the arch ribs in its entire width direction.

Further, in the step of setting abutments on both sides of the pier of the span that needs to be reinforced, the abutment steel bars are first implanted into the pier, and the arch foot reinforcements of the left and right spans anchored on the same pier penetrate the thickness of the pier body , so that the abutment steel bars located on the two sides are connected.

Further, in the step of arranging arch ribs under the slab girder of the span to be reinforced, the arch rib reinforcements in the arch ribs, which play a load-bearing and connecting role, are first fixedly connected to the abutment reinforcement bars.

Further, in the step of setting the transverse connection beam on the bottom surface of the plate girder that needs to be reinforced, the "U" shaped steel bar connecting the plate beam and the horizontal connection beam is first implanted into the bottom surface of the plate girder, and the open end of the "U" shaped steel bar is located at Inside the slab.

Further, the "U" shaped reinforcement of the arch rib is implanted at the place where the middle section of the arch rib is in contact with the plate beam, so that the arch rib and the plate beam are firmly combined.

Further, some of the steel bars in the arch rib pass through the "U" shaped steel bar of the arch rib, so that the arch rib and the bottom surface of the plate girder are integrally formed in the middle section of the plate girder after pouring concrete.

In the present invention, the simply supported slabs and simply supported beams on which vehicles and pedestrians pass are called slab girders, and the piers and abutments of bridges that need to be reinforced are called abutments. Simply supported plates and simply supported beams may be referred to simply as simply supported plate beams.

Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

1. In the reinforcement method provided by the present invention, due to the addition of arch ribs on the bottom surface of the plate girder, the arch ribs form a whole with the bottom surface of the plate girder in the middle section of the plate girder, that is, the mid-span section, which is equivalent to combining the stress effects of the plate girder and the arch ribs , thus greatly improving the bearing capacity and stiffness of the reinforced plate girder, so that the reinforced bridge can not only meet the traffic of special loads, but also have a large margin. The method of the invention has a better reinforcement effect than reinforcement methods such as pasting boards;

2. In the method of the present invention, the force of the arch rib acting on the abutment is equivalent to "free" to provide a strong pressure between the attached abutment and the abutment, which improves the bonding force of the joint surface of the two and effectively enhances the The newly added connection between the abutment and the pier ensures reliable connection;

3. The reinforcement method of the present invention has few types of reinforcement members, simple and clear stress, and significant plate-arch combination effect;

4. The present invention is also characterized in that the overall bearing capacity and stiffness of the reinforced structure can be artificially regulated by adjusting the cross-sectional size and rise-span ratio of the arch rib;

5. The reinforcement method provided by the present invention is implemented at the bottom of the bridge, which is convenient for construction and avoids the impact on bridge deck traffic during the reinforcement construction;

6. The method of the present invention is very suitable for reinforcement projects of bridge structures with small and medium spans, especially slab structures with low rigidity.

Description of drawings

Fig. 1 is a schematic diagram of a simply supported slab bridge structure after reinforcement in an embodiment of the present invention;

Fig. 2 is the general sketch map of reinforced reinforcement in the simply supported slab bridge structure reinforced in the embodiment of the present invention;

Fig. 3 is the reinforcing steel bar schematic diagram of the abutment in the simply supported slab bridge structure reinforced in the embodiment of the present invention;

Fig. 4 is the reinforced large sample elevation view of the simply supported slab bridge structure reinforced in the embodiment of the present invention;

Fig. 5 is a reinforced cross-sectional view of a simply supported slab bridge structure reinforced in an embodiment of the present invention, and the cross-section is perpendicular to the driving direction.

Throughout the drawings, the same reference numerals are used to designate the same elements or structures, wherein:

1-arch rib 2-horizontal link beam 3-arch seat

4-Original plate girder 5-Pier 6-Abutment

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

In the present invention, the simply supported slabs and simply supported beams on which vehicles and pedestrians pass are called slab girders, and the piers and abutments of bridges that need to be reinforced are called abutments.

Simply supported slabs and simply supported beams include at least one span, and generally bridges have multiple spans.

The steps that the inventive method mainly comprises are:

First implant the abutment reinforcement in the abutment that acts as a bearing or connection, and anchor the left and right span arch foot reinforcements on the same pier. stand up. Then lay out other steel bars in the abutment, and then pour concrete, that is, set abutments on both sides of the abutment of the span to be reinforced, and after the concrete solidifies, the abutment is attached to the abutment and forms a whole with the abutment;

Under the slab girder of the span to be reinforced, a plurality of arch ribs arranged parallel to each other along the width direction of the slab girder are arranged. The arch rib is integrated with the bottom of the slab girder at the middle section of the slab girder, and the two ends of the arch rib are respectively abutted. The arch seat on the pier, and the two ends are integral with the arch seat; when the arch rib is set under the plate girder of the span to be reinforced, the cross-sectional area, cross-sectional shape or rise-to-span ratio of the arch rib can be the same or Can be different. In actual operation, the cross-sectional area, cross-sectional shape or rise-span ratio of the arch rib can be changed according to the design requirements and navigability requirements, so as to realize artificially controlled reinforcement stiffness and bearing capacity. Under the plate girder of the span to be reinforced, a plurality of arch ribs arranged parallel to each other along the width direction of the plate girder can be arranged so that the plate girder can be supported by the arch ribs in its entire width direction. The specific steps for setting the arch ribs are as follows: First, fix the arch rib steel bars in the arch ribs with some of the steel bars in the abutment. The fixed connection here is welding, and it can also be riveting, hooping and other connection methods between the steel bars. Some of the steel bars in the arch rib pass through the "U" shaped steel bars implanted in the arch rib and the bottom of the slab girder, so that the arch rib can be integrated with the bottom of the slab girder after pouring concrete;

A transverse connection beam is arranged on the bottom surface of the slab girder of the span to be reinforced. The length direction of the transverse connection beam is perpendicular to the length direction of the original slab girder and is connected with the bottom surface of the bridge by implanting steel bars to form a whole. The middle section of the beam also forms a whole. The transverse connecting beams have a certain width, and can be two or more parallel to each other. The specific number is determined according to the design calculation. In actual situations, there may be no transverse connecting beams. If there are, there must be at least two horizontal connecting beams. The width of the slab girder should be determined through specific calculations. The two transverse connecting beams are located in the middle section of the slab girder and are separated by a certain distance. The middle section of the slab girder is equivalent to the middle section of the slab girder. Integral with the transverse link beam over its entire transverse link beam width. In this step, the "U" shaped steel bar connecting the plate girder and the transverse connection beam is first implanted on the bottom surface of the plate girder, and the open end of the "U" shaped steel bar is located in the plate girder. In the transverse connection beam, there are other stressed reinforcements arranged along its length.

That is, the abutments, arch ribs and transverse connecting beams are firstly implanted with steel bars at the bottom of the pier and slab girder, and then other reinforcements of the structure are arranged, and then concrete is poured, so that the abutments, abutments, and arch ribs It forms a whole with the abutment and arch rib in the middle section of the plate girder, the transverse connection beam and the bottom surface of the plate girder. The role of the arch can also greatly improve the bearing capacity and stiffness of the upper part of the original structure; the reaction force of the arch rib acting on the abutment also provides a strong pressure between the abutment and the pier, improving the bond between the two joint surfaces. The force effectively strengthens the connection between the newly added abutment and the pier to ensure a reliable connection.

Fig. 1 is the structure schematic diagram of simply supported slab bridge after strengthening in the embodiment of the present invention, this bridge altogether has three spans, and the spans from south to north are respectively: first span 6.9m; second span 7.0m; third span 6.8m m; the total length is 20.7 meters. The width of the bridge deck is 12.5m net width plus 2×0.75m guardrails and safety belts, and the overall width of the bridge deck is 14.0m. The simply supported slab bridge in the figure includes 4 original slab girders and 6 abutments. , pier 5 and abutment 6 constitute the main stress mechanism of the bridge. The original plate girder 4 is located above the pier and is supported by the pier, and pedestrians and vehicles pass through the original plate girder. In the transverse direction of the original plate girder, that is, a horizontal connecting beam 2 is arranged perpendicular to the driving direction. Strong and reliable connection between original plate girders. The arch rib 3 is attached to the abutment, and the arch rib 3 is subjected to the force of the arch rib, which provides a strong pressure between the attached abutment and the abutment "for free", improves the bonding force of the joint surface of the two, and effectively enhances the The connection between the new abutment and the pier has been added to ensure the reliability of the connection.

In conjunction with Fig. 2, the stressed situation of the simply supported slab bridge reinforced by the method of the present invention is analyzed as follows: when pedestrians and vehicles enter the simply supported slab of the bridge, downward pressure is applied to the simply supported slab, and the pressure is determined by the original simply supported slab. The support plate or simply supported beam structure is jointly borne by the reinforced arch structure. After the arch rib is stressed, vertical reaction force, horizontal reaction force and bending moment will be generated on the section of the arch foot. The horizontal reaction force is between the abutment and the pier. The strong pressure is provided, which makes the two firmly combined and enhances the stability of the reinforced structure; the transverse connection beam plays the role of strengthening the transverse connection between the arch ribs, enhancing the transverse stiffness of the structure and improving the structural integrity. Compared with the stress of simply supported slabs or simply supported beams before reinforcement, the reinforced structure is a plate-arch composite structure, and the bearing capacity and stiffness of the upper structure are greater, so as to achieve the purpose of reinforcement.

Fig. 2 is a schematic diagram of the reinforced steel bars in the simply supported slab bridge structure reinforced in the embodiment of the present invention. It should be noted that this figure is only for illustration, and the actual reinforcement layout needs to be calculated in detail. It can be seen from the figure that the abutment steel bars are implanted in the pier, and other stress steel bars and structural steel bars for maintenance, tie and distribution are laid. The arch rib steel bar and the arch seat steel bar are fixed together to ensure a firm connection between the two. In order to ensure the firm connection between the arch rib and the bottom of the original slab beam, a "U"-shaped steel bar was implanted at the place where the middle section of the arch rib is in contact with the original slab beam. "U"-shaped reinforcement is also implanted between the connection beam and the original plate beam, but it is not drawn in this figure. In this figure, the black bold part is the steel bar, the black point is the steel bar perpendicular to the paper, and the black non-bold line is the structural shape after pouring.

Fig. 3 is a schematic diagram of reinforced steel bars in the simply supported slab bridge structure reinforced in the embodiment of the present invention. The schematic diagram is a cross-sectional view perpendicular to the length direction of the abutment, and the length direction of the abutment is consistent with the width direction of the bridge deck. In this figure, the relatively thick ones are the stressed steel bars implanted in the abutment, and the small black dots represent the steel bars arranged along the length of the abutment. In this figure, the length direction of the abutment is perpendicular to the paper.

Fig. 4 is a reinforced large-scale elevation view of the simply supported slab bridge structure reinforced in the embodiment of the present invention, which is a schematic diagram after pouring concrete on the structural steel bars and stressed steel bars. The schematic diagram is a schematic diagram along the length direction of the second span. It can be seen from the figure that the transverse connection beam 2 is integrated with the arch rib 1, and the middle section of the arch rib 3 is also integrated with the original slab beam by planting bars and pouring concrete. The arch rib 1 and the abutment 3 are also integrated by pouring concrete and binding and welding steel bars, so that the arch rib, the abutment and the transverse connecting beam are closely connected as a whole. The wavy line in this figure represents the actual water surface.

Fig. 5 is a reinforced cross-sectional view of a simply supported slab bridge structure reinforced in an embodiment of the present invention, and the cross-section is perpendicular to the driving direction. It can be seen from the figure that the bridge pier or abutment is a whole piece of reinforced concrete, and the original slab girder is located above the bridge pier and the abutment and is supported by the bridge pier and the abutment. Guardrails are also set on the original slab girder (located above the original slab girder and The left-right symmetrical protruding part is the guardrail). Immediately below the original slab beam is the transverse connection beam 2, which is in close contact with the transverse connection beam 2. There are multiple parallel arch ribs 1, the arch rib 1 and the abutment 3 form a whole, and the abutment 3 is integrally attached to the reinforced concrete On the pier or the abutment, the length of the abutment 3 is equal to or slightly smaller than the width of the pier or the abutment, and the abutment 3 is also a whole piece of reinforced concrete.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (9)

1. a reinforcement means for simply supported slab or simply supported beam bridge, this simply supported slab or simply supported beam bridge comprise at least one across, often across comprising pier and by the plate-girder for passing through thereon for vehicle and pedestrian that pier supports, it is characterized in that, comprise the steps:

Need reinforcement across two sides of pier all abut is set, this abut to be attached on pier and to form entirety with pier;

Need reinforcement across plate-girder below arch rib is set, this arch rib forms entirety bottom this plate-girder stage casing and plate-girder, and two of this arch rib ends abut the abut on pier respectively, and these two ends and abut form entirety;

Need reinforcement across plate-girder bottom surface transverse strut is set, the length direction vertical panel beam length direction of this transverse strut also forms entirety with plate-girder bottom surface, and this transverse strut and described arch rib also form entirety;

The each entirety more than formed, stressed to become plate arch combining structure stressed from simple plate-girder to make the stressing conditions of simply supported slab or simply supported beam bridge, its bearing capacity and stiffness is greatly improved, thus realizes the reinforcing to former simply supported slab or simply supported beam bridge.

2. the reinforcement means of a kind of simply supported slab as claimed in claim 1 or simply supported beam bridge, is characterized in that, need reinforcement across plate-girder stage casing bottom surface arrange transverse strut there are two or many that are parallel to each other.

3. the reinforcement means of a kind of simply supported slab as claimed in claim 1 or simply supported beam bridge, it is characterized in that, need reinforcement across plate-girder below cross sectional area and the similar and different arch rib of ratio of rise to span are set, to realize rigidity that manual control reinforces and bearing capacity.

4. the reinforcement means of a kind of simply supported slab as claimed in claim 1 or simply supported beam bridge, it is characterized in that, need reinforcement across plate-girder below the many arch ribs be parallel to each other are set along plate-girder width, to make plate-girder at its whole width all by transverse girder between arch rib.

5. the reinforcement means of a kind of simply supported slab as claimed in claim 1 or simply supported beam bridge, it is characterized in that, need reinforcement across two sides of pier arrange in abut step, first implant abut reinforcing bar to pier, and be anchored at left and right on same pier across arch springing reinforcing bar penetrate pier shaft thickness, to make the abut bar connecting being positioned at described two sides.

6. the reinforcement means of a kind of simply supported slab as claimed in claim 5 or simply supported beam bridge, is characterized in that, need reinforcement across plate-girder below arrange in arch rib step, first arch rib reinforcing bar is fixedly connected with described abut reinforcing bar.

7. the reinforcement means of a kind of simply supported slab as claimed in claim 6 or simply supported beam bridge, it is characterized in that, need reinforcement across plate-girder bottom surface arrange in transverse strut step, first implant " U " shape reinforcing bar connecting plate-girder and transverse strut to plate-girder bottom surface, described " U " shape reinforcing bar openend is positioned at plate-girder.

8. the reinforcement means of a kind of simply supported slab as claimed in claim 7 or simply supported beam bridge, is characterized in that, arch rib " U " shape reinforcing bar is implanted in the place contacted with plate-girder in arch rib stage casing, to make arch rib and plate-girder strong bonded.

9. the reinforcement means of a kind of simply supported slab as claimed in claim 8 or simply supported beam bridge, it is characterized in that, in described arch rib reinforcing bar, part reinforcing bar is through described arch rib " U " shape reinforcing bar, forms entirety to make described arch rib after concreting in plate-girder stage casing and plate-girder bottom surface.