LU502143B1

LU502143B1 - Prefabricated anti-collision guardrail for bridge engineering and construction method therefor

Info

Publication number: LU502143B1
Application number: LU502143A
Authority: LU
Inventors: Bo Liu; Peizhi Gong
Original assignee: Univ Yantai
Priority date: 2022-05-23
Filing date: 2022-05-23
Publication date: 2022-11-23

Abstract

The present invention belongs to the technology of bridge engineering, and in particular relates to a prefabricated anti-collision guardrail for bridge engineering based on the connection of prestressed steel strands, which includes a prefabricated guardrail, and a tunnel for the prestressed steel strands to penetrate is preset in the guardrail. Radial pressure generated by prestressed tensioning generates a strong vertical pressure between a concrete guardrail and a bridge deck. Frictional resistance provided by the vertical pressure in cooperation with horizontal component force generated by prestressed tensioning can effectively resist outward lateral impact force generated by vehicle impact. Prefabricated construction saves working procedures such as binding steel bars on site, erecting formwork, casting concrete in place, and curing and also reduces the environmental protection pressure.

Description

PREFABRICATED ANTI-COLLISION GUARDRAIL FOR BRIDGE LU502143

ENGINEERING AND CONSTRUCTION METHOD THEREFOR BACKGROUND OF THE PRESENT INVENTION

[0001] 1. Technical Field

[0002] The present invention belongs to the technology of bridge engineering, and in particular relates to a prefabricated anti-collision guardrail for bridge engineering based on the connection of prestressed steel strands and a construction method for the anti-collision guardrail.

[0003] 2. Description of Related Art

[0004] Concrete bridge anti-collision guardrail for a bridge is the most widely used guardrail form at present, which is crucial to ensure the safety of vehicles. However, at present, the concrete anti-collision guardrail, especially an outer concrete guardrail, basically adopts cast-in-place reinforced concrete. During construction, the working procedures such as binding steel bars, erecting formwork, pouring concrete, curing concrete, and dismantling formwork need to be completed, which takes a long time and is low in work efficiency.

BRIEF SUMMARY OF THE PRESENT INVENTION

[0005] In order to solve the above problems, the present invention provides a prefabricated anti-collision guardrail for bridge engineering and a construction method for the anti-collision guardrail, which saves the time of the construction period, facilitates construction and reduces the environmental protection pressure. The technical solution employed by the present invention is as follows:

[0006] A prefabricated anti-collision guardrail for bridge engineering 1 includes a prefabricated guardrail, and a tunnel for a prestressed steel strand-H502143 penetrate is preset in the guardrail.

[0007] Preferably, the tunnel is in an arcuate curve, and the lower end faces at both ends of the guardrail are respectively provided with a port.

[0008] Preferably, a corrugated pipe runs through the tunnel for shaping, both ends of the corrugated pipe extend out of the ports respectively, and the prestressed steel strand can pass through the corrugated pipe.

[0009] The prefabricated anti-collision guardrail for bridge engineering also includes two anchor gears, and the anchor gears are used for respectively fixing the two ends of the prestressed steel strand into a cantilever of the bridge.

[0010] Preferably, the anchor gears are fixed on the cantilever by an anchoring tooth block, the side face of the anchoring tooth block is convex, and the cross sections at both ends of the anchoring tooth block are triangular.

[0011] Preferably, two spiral steel bars are further embedded in the cantilever, the spiral steel bars are respectively used for sheathing the two ends of the corrugated pipe, and the lower ends of the spiral steel bars are fixedly connected to the anchor gears.

[0012] Preferably, a plurality of shear steel bars are arranged on the end face where the cantilever matches the guardrail, the exposed height of the shear steel bars is 100-120 mm, and the distance between two adjacent shear steel bars in the longitudinal direction of the bridge is 180-260 mm.

[0013] A construction method of the prefabricated anti-collision guardrail for bridge engineering as described above includes the following steps:

[0014] 581) prefabricating a concrete guardrail;

[0015] S2) installing spiral steel bars and conducting construction of shear steel bars at a position of a cantilever, where the guardrail is installed, of 2 the bridge; LU502143

[0016] S3) manufacturing an anchoring tooth block;

[0017] S4) coating a contact surface between the guardrail and the cantilever with an adhesive layer;

[0018] S5) hoisting the guardrail to the installation position, and after the adhesive layer is hardened, threading a prestressed steel strand in a corrugated pipe, tensioning the prestressed steel strand, and fastening both ends of the prestressed steel strand on the cantilever with anchor gears; and

[0019] S6) pressing slurry into the corrugated pipe, and completing the installation after solidification. According to the construction method, the tensile prestress of the prestressed steel strand is 1339.2 MPa-1395 MPa, and the curve radius thereof is 3000 mm.

[0020] Accord to the construction method, the adhesive layer is an epoxy mortar layer with a thickness of 4.5-6.5 mm, and the adhesive strength with concrete is greater than 4 MPa. Polypropylene fiber or steel fiber is added into the guardrail, and the content is 0.6-1.8 kg/m°.

[0021] The beneficial effects of the present present invention are as follows:

[0022] (1) Radial pressure generated by prestressed tensioning generates a strong vertical pressure between the concrete guardrail and the bridge deck. Frictional resistance provided by the vertical pressure in cooperation with horizontal component force generated by prestressed tensioning can effectively resist outward lateral impact force generated by vehicle impact. Prefabricated construction saves working procedures such as binding steel bars on site, erecting formwork, casting concrete in place, and curing and also reduces the environmental protection pressure. 3

[0023] (2) The adhesive force provided by the epoxy mortar adhesh@02143 layer and the shear resistance provided by shear steel bars can effectively enhance the ability of the guardrail to resist horizontal impact. Since the hardening time of the epoxy mortar adhesive layer is very short, the guardrail on the outer side of the bridge can be put into use after prestressed tensioning, the construction period can be obviously shortened, and the bridge can be opened to traffic in advance, which can bring obvious economic and social benefits.

[0024] (3) The application of the polypropylene fiber or steel fiber concrete improves the wear resistance and crack resistance of the concrete, and the concrete guardrail is not prone to damage when colliding with vehicles.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0025] In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the accompanying drawings required in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, and a person of ordinary skill in the art can still derive other drawings according to these accompanying drawings without creative efforts.

[0026] FIG. 1 is a schematic structure diagram of the present present invention; and

[0027] FIG. 2 is a schematic cross section diagram of the present present invention.

[0028] Where: 1. guardrail; 2. prestressed steel strand; 3. anchor gear; 4.

spiral steel bar; 5. shear steel bar; 6. adhesive layer; 7. anchoring tooth block; 8. corrugated pipe; 9. cantilever; 10. bridge deck. 4

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0029] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0030] A prefabricated anti-collision guardrail for bridge engineering includes a prefabricated guardrail 1, and a tunnel for a prestressed steel strand 3 to penetrate is preset in the guardrail 1.

[0031] The tunnel is in an arcuate curve, the lower end faces at both ends of the guardrail 1 are respectively provided with a port, a corrugated pipe 8 runs through the tunnel for shaping, both ends of the corrugated pipe 8 extend out of the ports respectively, and the prestressed steel strand 3 can pass through the corrugated pipe 8. Two anchor gears 3 are further included, and the anchor gears 3 are used for respectively fixing the two ends of the prestressed steel strand 3 into a cantilever 9 of the bridge. The anchor gears 3 are fixed on the cantilever 9 by an anchoring tooth block 7, the side face of the anchoring tooth block 7 is convex, and the cross sections of both ends of the anchoring tooth block are triangular. Two spiral steel bars 4 are further embedded in the cantilever 9, the spiral steel bars 4 are respectively used for sheathing the two ends of the corrugated pipe 8, and the lower ends of the spiral steel bars 4 are fixedly connected to the anchor gears 3. A plurality of shear steel bars 5 are arranged on the end face where the cantilever 9 matches the guardrail 1, the exposed height of the shear steel bars 5 is 100-120 mm, and the distance between two adjacent shear steel bars 5 in the longitudinal direction of the bridge is 180-260 mm.

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[0032] Construction method 1 LU502143

[0033] A construction method of the prefabricated anti-collision guardrail for bridge engineering as described above includes the following steps:

[0034] S1) a concrete guardrail 1 is prefabricated, where polypropylene fiber or steel fiber is added during prefabrication with the content of 0.6-1.0 kg/m*; and a corrugated pipe 8 in the guardrail 1 is manufactured and a hole for matching shear steel bars 5 is reserved;

[0035] S2) spiral steel bars 4 are installed and shear steel bars 5 construction is conducted on a position of a cantilever 9, where the guardrail 1 is installed, of the bridge, where the exposed height of the shear steel bar 5 is 100 mm, and the distance between two adjacent shear steel bars 5 in the longitudinal direction of the bridge is 200 mm.

[0036] S3) manufacturing an anchoring tooth block 7;

[0037] S4) a contact surface between the guardrail 1 and the cantilever 4 is coated with an adhesive layer 6, where the adhesive layer 6 is an epoxy mortar layer with a thickness of 5 mm and an adhesive strength with concrete greater than 4 MPa;

[0038] S5) the guardrail 1 is hoisted to the installation position, after the adhesive layer 6 is hardened, a prestressed steel strand 8 is threaded in a corrugated pipe 8, the prestress of the prestressed steel strand 8 is tensioned to

1339.2 MPa, where the curve radius thereof is 3000 mm, and the specification thereof is S®s15.2* length 5800 mm, and both ends of the prestressed steel strand are fastened on the cantilever 9 with anchor gears 3; and

[0039] SO) pressing slurry into the corrugated pipe 8, and completing the installation after solidification.

[0040] Construction method 2 6

[0041] The main difference between the construction method and HY@02143 above construction method 1 is that the prestress is adjusted, and the specific steps are as follows:

[0042] S1) a concrete guardrail 1 is prefabricated, where polypropylene fiber or steel fiber is added during prefabrication with the content of 1.6-1.8 kg/m*; and a corrugated pipe 8 is manufactured in the guardrail 1 and a hole for matching shear steel bars 5 is reserved;

[0043] S2) spiral steel bars 4 are installed and shear steel bars 5 construction is conducted on a position of a cantilever 9, where the guardrail 1 is installed, of the bridge, where the exposed height of the shear steel bar 5 is 200 mm, and the distance between two adjacent shear steel bars 5 in the longitudinal direction of the bridge is 260 mm.

[0044] S3) manufacturing an anchoring tooth block 7;

[0045] S4) a contact surface between the guardrail 1 and the cantilever 4 is coated with an adhesive layer 6, where the adhesive layer 6 is an epoxy mortar layer with a thickness of 6.5 mm and an adhesive strength with concrete greater than 4 MPa;

[0046] S5) the guardrail 1 is hoisted to the installation position, after the adhesive layer 6 is hardened, a prestressed steel strand 8 is threaded in a corrugated pipe 8, and the prestress of the prestressed steel strand 8 is tensioned to 1395 MPa, where the curve radius thereof is 3000 mm, and the specification thereof is S®s15.2* length 5800 mm, and both ends of the prestressed steel strand are fastened on the cantilever 9 with anchor gears 3; and

[0047] S6) pressing slurry into the corrugated pipe 8, and completing the installation after solidification.

[0048] Comparative example 7

[0049] The guardrail with the same specification as above is manufactut&tp02143 by existing on-site formwork installation, welding, and installation and connection of steel bars.

[0050] The above construction methods 1 and 2, and the comparative example are respectively provided with two groups of finished products, and a vertical maximum impact force test was conducted. The results are as follows:

TE Project 1 2 example

MA 274 285 284 (kN/m)

ES

0.10 0.10 1.0 (h/m) Number of on-site construction personnel 20 (number of persons)

[0051] It can be seen that the construction method for the application can save a lot of costs in terms of time and manpower, and the guardrail 1 is prefabricated and can be assembled on site, which simplifies the equipment on the construction site. The prestressed steel strand 8 increases the pressure, thus increasing the lateral friction of the guardrail 1, achieving high-strength connection and effectively ensuring driving safety.

[0052] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any skilled in the art may make changes of variations on the technical content disclosed above to become equivalent embodiments with the same changes. However, any simple modification, equivalent change and variation made on the 8 above embodiments by using the contents without departing from the technil@P02143 solution of the present invention based on the technical essence of the present invention are all still within the protection scope of the present invention.

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Claims

What is claimed: LUS02143

1.A prefabricated anti-collision guardrail for bridge engineering includes a guardrail(1) that prefabricated, and a tunnel for a prestressed steel strand(2) to penetrate is preset in the guardrail(1).

2. The prefabricated anti-collision guardrail for bridge engineering according to claim 1, the tunnel is in an arcuate curve, and the lower end faces at both ends of the guardrail(1) are respectively provided with a port.

3. The prefabricated anti-collision guardrail for bridge engineering according to claim 2,a corrugated pipe(8) runs through the tunnel for shaping, both ends of the corrugated pipe(8) extend out of the ports respectively, and the prestressed steel strand(2) can pass through the corrugated pipe(8).

4. The prefabricated anti-collision guardrail for bridge engineering according to claim 3, also includes two anchor gears(3), and the anchor gears(3) are used for respectively fixing the two ends of the prestressed steel strand(2) into a cantilever(9) of the bridge.

5.The prefabricated anti-collision guardrail for bridge engineering according to claim4, the anchor gears(3) are fixed on the cantilever(9) by an anchoring tooth block(7), the side face of the anchoring tooth block(7) is convex, and the cross sections at both ends of the anchoring tooth block are triangular.

6.The prefabricated anti-collision guardrail for bridge engineering according to claim 5, two spiral steel bars(4) are further embedded in the cantilever(9), the spiral steel bars(4) are respectively used for sheathing the two ends of the corrugated pipe(8), and the lower ends of the spiral steel bars(4) are fixedly connected to the anchor gears(3).

7.The prefabricated anti-collision guardrail for bridge engineering according to claim 6, plurality of shear steel bars(5) are arranged on the end face where the 10 cantilever(9) matches the guardrail(1), the exposed height of the shear ste@P02143 bars(5) is 100-120 mm, and the distance between two adjacent shear steel bars(5) in the longitudinal direction of the bridge is 180-260 mm.

8.A construction method of the prefabricated anti-collision guardrail for bridge engineering as described above includes the following steps: step 1) prefabricating a concrete guardrail(1); step 2) installing spiral steel bars(4) and conducting construction of shear steel bars(5) at a position of a cantilever(9), where the guardrail(1) is installed, of the bridge; step 3) manufacturing an anchoring tooth block(7); step 4) coating a contact surface between the guardrail(1) and the cantilever(9) with an adhesive layer(6); step 5) hoisting the guardrail(1) to the installation position, and after the adhesive layer(6) is hardened, threading a prestressed steel strand(2) in a corrugated pipe(8), tensioning the prestressed steel strand(2), and fastening both ends of the prestressed steel strand(2) on the cantilever with anchor gears(3); and step 6) pressing slurry into the corrugated pipe(8), and completing the installation after solidification.

9. The construction method according to claim 8, the tensile prestress of the prestressed steel strand(2) is 1339.2 MPa-1395 MPa, and the curve radius thereof is 3000 mm.

10. The construction method according to claim9, the adhesive layer(6) is an epoxy mortar layer with a thickness of 4.5-6.5 mm, and the adhesive strength with concrete is greater than 4 MPa; polypropylene fiber or steel fiber is added into the guardrail(1), and the content is 0.6-1.8 kg/m°. 11