CN105220623B - Reinforcement method and anchoring device of simply supported T-beam based on transverse tension prestress - Google Patents

Abstract

The invention discloses a simply support T-beam strengthening method based on transverse tensioned prestressing, and an anchor device, and aims to solve the problems in the prior art that a tensioning end is narrow in space, prestressing is large in loss, and a steering device is complex; the anchor device comprises four anchoring steel members (14), 2 support steel pads (18), and 2 prestressed steel beams (16); the four anchoring steel members (14) are symmetrically arranged on two ends of a T-beam web (20) on two sides of the simply support T-beam through high-strength bolts; the two support steel pads (18) are symmetrically arranged in the middle of the T-beam web (20) on two sides of the simply support T-beam through high-strength bolts; two ends of the two prestressed steel beams (16) are respectively fixed on the anchoring steel members (14) through an upset head anchor; the middle portions of the two prestressed steel beams (16) respectively make contacts with and are connected with the tops of the 2 support steel pads (18). The invention also provides the simply support T-beam strengthening method based on transverse tensioned prestressing and employing the anchor device.

Description

Reinforcement method and anchoring device of simply supported T-beam based on transverse tension prestress

technical field

The invention relates to a bridge reinforcement method and a special device, more precisely, the invention relates to a simply supported T-beam reinforcement method and an anchoring device based on transverse tension prestress.

Background technique

With the prolongation of the operation time of the bridge structure, the safety and durability of the bridge structure will inevitably decrease. When it is damaged to a certain extent, it will endanger the driving safety and often become a "bottleneck" in the traffic network. Both theory and fact show that it will be very uneconomical and unreasonable to rebuild them. The usual method is to repair, strengthen and upgrade them. External prestressing reinforcement technology is a common and effective active reinforcement technology. External prestressing reinforcement technology has the advantages of significantly improving the bearing capacity of bridge structures and reducing crack width. The traditional external prestressing construction technology needs to erect tensioning equipment at both ends of the beam to be strengthened. However, there are usually end diaphragms and close to the abutment here, which limits the tensioning space and affects the construction operation. Therefore, the tension end is often moved to the middle of the span for a certain distance, and this will inevitably reduce the length of the prestressed steel bar, resulting in a large loss of prestressed force, resulting in poor reinforcement effect. In response to this problem, people have proposed to apply the transverse tension prestressing technology to the reinforcement of old bridges, which can well overcome the defects of traditional external prestressing. However, it also has the disadvantages that the jack is not easy to place when tensioning, and the steering system is difficult to set. Therefore, it is very urgent to propose an external prestressing reinforcement method that is convenient and fast in construction and has a good reinforcement effect.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the problems of narrow tension end space, large prestress loss and complicated steering device in the prior art, and provide a simply supported T-beam reinforcement method and anchoring device based on transverse tension prestress .

In order to solve the above-mentioned technical problems, the present invention is realized by adopting the following technical scheme: the steps of the simply supported T-beam reinforcement method based on transverse tension prestressing are as follows:

1) According to the existing conditions of the T-beam, combined with the design specifications, calculate the tensile force of the prestressed steel beams in the limit state of the structural bearing capacity and the limit state of normal use;

2) According to the design tensile force, two prestressed steel tendons with the same structure are required for each simply supported T beam, 4 identical anchor steel members for anchoring the prestressed steel tendon at both ends of the simply supported T beam and the Two identical supporting steel pads used to support the tensioned prestressed steel beam in the middle of the prestressed steel beam are processed and manufactured;

3) Use the pier head machine to make the two ends of the prestressed steel strands into heading anchors and fix them on the anchoring steel members respectively;

4) Clean both ends of the simply supported T-beam to be strengthened, and use a percussion drill to punch holes at both ends and the middle of the simply-supported T-beam perpendicular to the web of the T-beam. The anchoring steel member is installed on the T beam web plate at both ends of the simply supported T beam, and a hole is drilled in the middle for installing the supporting steel pad;

5) Utilize high-strength bolts to anchor the anchoring steel member to the two ends of the two sides of the T beam web of the simply supported T beam, providing preparation for tensioning the prestressed steel beam;

6) Tension jacks are erected on both sides of the T-beam web in the mid-span of simply supported T-beams, and the prestressed steel tendons are symmetrically stretched perpendicular to the T-beam web to the tension required by the design. The tensioning progress must be consistent to avoid The simply supported T-beam produces transverse bending;

7) When the jack is stretched to the design position, place the supporting steel block under the tensioning jack, use bolts to anchor the round base in the supporting steel block to the T beam web of the simply supported T beam, and then adjust the telescopic The height of the cylinder to the prestressed steel beam;

8) The oil is returned to the jack, and the lateral force on the prestressed steel beam is transmitted to the simply supported T beam by using the supporting rigid pad, and finally the two ends of the simply supported T beam are eccentrically compressed;

9) Remove the tensioning equipment, and apply anti-rust paint to the supporting steel pads and anchoring steel components.

The anchoring device used in the simply supported T-beam reinforcement method based on transverse tension prestressing, the anchoring device includes 4 anchoring steel members with the same structure, 2 supporting steel pads with the same structure, and 2 steel pads with the same structure. Prestressed steel tendons and 4 heading anchors with the same structure;

Four anchor steel members with the same structure are symmetrically installed on the two ends of the T beam web on both sides of the simply supported T beam with high-strength bolts, and two supporting steel pads with the same structure are symmetrically installed on the simply supported T beam with high-strength bolts. In the middle of both sides of the T-beam web (20) of the beam, the two ends of the two prestressed steel tendons with the same structure are respectively fixed on the anchor steel members through the heading anchors, and the middle of the two prestressed steel tendons with the same structure They are respectively connected to the tops of two identical supporting steel pads.

The anchoring steel member described in the technical solution consists of a flat base, a connecting plate, two supporting plates with the same structure, supporting steel pipes and ribs. The flat base is a flat structural part, and four bolt holes are evenly arranged on the flat base; the connecting plate is a rectangular flat structural part, and the center of the connecting plate is provided with a hole for inserting prestressed steel strands. Round through holes; the support plate is an isosceles triangular plate structure, the connecting plate is vertically fixed at the center of the flat base, and two supporting plates with the same structure are fixed on the flat base at both ends of the connecting plate. The same support plate is perpendicular to the connecting plate and at the same time perpendicular to the flat base. The supporting steel pipe is installed on one side of the connecting plate and fixedly connected to it. The axes of rotation of the holes are collinear, and a reinforcing rib is arranged between the bottom end of the supporting steel pipe and the upper surface of the flat base, and the rib connects the supporting steel pipe and the flat base into one.

The supporting steel spacer described in the technical solution is composed of an upper supporting rod, a telescopic cylinder and a circular base; the upper supporting rod is a fork-shaped structural member whose top is used to fix the prestressed steel bundle, and the lower part of the upper supporting rod There are external threads for connecting with the upper end of the telescopic tube; the telescopic tube is a straight cylindrical structure with internal threads inside and a hexagonal outside; the circular base is composed of a circular plate and a base support rod It consists of four evenly distributed No. 2 bolt holes on the circular plate, external threads on the base support rod, and the base support rod is installed vertically at the center of the circular plate, and the two are fixedly connected. The base support rod is collinear with the center line of rotation of the circular disc; the base support rod in the circular base is threaded with the lower end of the telescopic tube, and the upper end of the telescopic tube is threaded with the lower part of the upper support rod.

The heading anchor described in the technical proposal is composed of an anchor plate, a prestressed steel wire and a steel wire pier head; the anchor plate is a circular or rectangular plate structure, and 5 to 150 holes of prestressed steel wire are evenly distributed on the anchor plate. Steel wire through holes with the same structure, the axes of rotation of each steel wire through holes are parallel to each other, and parallel to the center line of symmetry of the anchor plate; the prestressed steel wire is a single steel wire forming the prestressed steel bundle; the prestressed steel bundle Each single steel wire in the anchor plate, that is, the prestressed steel wire, is inserted from one end of a steel wire through hole on the anchor plate, and protrudes from the other end of the steel wire through hole, and then the protruding end of each prestressed steel wire is Pier into a cylindrical head that prevents the steel wire from being pulled out, that is, the steel wire pier head.

Compared with prior art, the beneficial effects of the present invention are:

1. The simply supported T-beam reinforcement method based on transverse tension prestressing of the present invention utilizes the heading anchor to anchor the prestressed steel bar on the anchoring steel member, and utilizes high-strength bolts to fix the anchoring steel member on the T-beam, so that During and after tensioning, the loss of prestress is extremely small;

2. The tensioning equipment adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing of the present invention can make the prestressed steel beam reach the required tension of the design by applying a small tension force, thereby simplifying the tension. pull process;

3. In the simply supported T-beam reinforcement method based on transverse tension prestressing in the present invention, the T-beam reinforcement section can be arbitrarily selected according to the reinforcement scheme, which is convenient for actual operation;

4. The simply supported T-beam reinforcement method based on transverse tension prestressing in the present invention utilizes the method of symmetrical stretching on both sides of the web, so that no additional lateral bending moment and shear force will be generated on the structure after reinforcement;

5. The simply supported T-beam reinforcement method based on transverse tension prestressing in the present invention can use the pier head machine to connect the anchoring steel member and the prestressing steel beam into a whole on the ground, which is beneficial to operation and saves man-hours;

6. The simply supported T-beam reinforcement method based on transverse tension prestressing in the present invention can place tensioning equipment on the horseshoe or web of the T-beam, which facilitates tensioning, reduces construction difficulty and improves work efficiency.

Description of drawings

Below in conjunction with accompanying drawing, the present invention will be further described:

Fig. 1 is the schematic diagram of the principle of transverse tension prestress based on the simply supported T-beam reinforcement method of transverse tension prestress according to the present invention;

Fig. 2 is a schematic diagram of the equivalent stress of the T beam under the action of the transverse prestress after adopting the simply supported T beam reinforcement method based on the transverse prestress according to the present invention;

Fig. 3-a is the front view of the structural composition of anchoring steel members adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing according to the present invention;

Fig. 3-b is the attached view of the structural composition of anchoring steel members adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing according to the present invention;

Fig. 3-c is the right side view of the structural composition of anchoring steel members adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing according to the present invention;

Fig. 4-a is the front view of the supporting steel pad structure adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing according to the present invention;

Figure 4-b is a cross-sectional view at B-B in Figure 4-a;

Fig. 5 is the front view of the composition of the heading anchor structure adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing according to the present invention;

Fig. 6. is the schematic diagram of the state before T beam stretching in the simply supported T beam reinforcement method based on transverse tension prestressing of the present invention;

Fig. 7-a is the front view of the state after the T beam reinforcement is completed in the simply supported T beam reinforcement method based on transverse tension prestress according to the present invention;

Figure 7-b is a cross-sectional view at C-C in Figure 7-a;

Fig. 8 is a flow chart of the simply supported T-beam reinforcement method based on transverse tension prestressing according to the present invention;

In the figure: 1. Bolt hole No. 1, 2. Connecting plate, 3. Supporting plate, 4. Supporting steel pipe, 5. Flat base, 6. Rib plate, 7. Upper supporting rod, 8. Telescopic tube, 9. Round base, 10.2 No. bolt hole, 11. Anchor plate, 12. Prestressed steel wire, 13 Steel wire pier head, 14. Anchor steel member, No. 15.2 Anchor steel member, 16. Prestressed steel beam, No. 17.2 Prestressed steel beam, 18. Support steel Pads, No. 19.2 supporting steel pads, 20. T beam webs, 21. T beam centroids.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing:

In order to make the simply supported T-beam reinforcement method based on transverse tension prestressing described in the present invention better applied to the T-beam reinforcement, the prestress loss of the T-beam during or after reinforcement is small, and multiple times can be achieved. The reinforcement is repeated, and the anchoring device to be used is set. The anchoring device includes an anchoring steel member 14 , a supporting steel pad 18 and a prestressed steel beam 16 .

Referring to Figure 3-a to Figure 3-c, the anchoring rigid member 14 is composed of 6 parts, that is, a flat base 5, a connecting plate 2, two supporting plates 3 with the same structure, supporting steel pipes 4 and ribs 6;

The flat base 5 is a flat structure used to connect the anchoring steel member 14 to the T beam, and the flat base 5 is evenly provided with 4 bolt holes 1,

The connecting plate 2 is a rectangular plate structure for connecting the prestressed steel tendon 16 and the anchoring steel member 14 , and a circular through hole for inserting the prestressed steel tendon 16 is provided at the center of the connecting plate 2 .

In order to fully fix the connecting plate 2 on the isosceles triangle plate structure on the flat base 5 for the two supporting plates 3 with the same structure, the connecting plate 2 is vertically fixed at the center position of the flat base 5, and the two structures The same supporting plate 3 is fixed on the flat base 5 at both ends of the connecting plate 2 , and the two supporting plates 3 with the same structure are perpendicular to the connecting plate 2 and are perpendicular to the flat base 5 at the same time.

The supporting steel pipe 4 is a cylindrical structure that better fixes the prestressed steel beam 16, the connecting plate 2 and the flat base 5. The supporting steel pipe 4 is installed on one side of the connecting plate 2 and is fixedly connected to it. The axis of rotation of 4 is collinear with the axis of rotation of the circular through hole for inserting the prestressed steel beam 16 at the center of the connecting plate 2, and a reinforcing rib is arranged between the bottom end of the supporting steel pipe 4 and the upper surface of the flat base 5 The plate 6 and the rib plate 6 connect the supporting steel pipe 4 and the flat base 5 into one. Therefore, the rib plate 6 is a flat structural member for better connecting the supporting steel pipe 4 and the flat base 5 .

Referring to Fig. 4-a and Fig. 4-b, the supporting steel block 18 is composed of three parts, that is, the upper supporting rod 7, the telescopic cylinder 8 and the circular base 9.

The upper support rod 7 is a fork-shaped structural member whose top is used to fix the prestressed steel beam 16, and the lower part of the upper support rod 7 is an external thread for connecting with the upper end of the telescopic tube 8;

The telescopic cylinder 8 is a straight cylindrical structure with threads inside and a hexagon outside;

The circular base 9 is a T-shaped structure that fixes the supporting steel pad 18 on the T-beam web 20. The circular base 9 is composed of a circular plate and a base support bar, and the base support bar is vertically installed on the circular plate. At the center of the shaped disk, the two are fixedly connected, the base support rod is in line with the rotation center line of the circular disk, the base support rod is provided with external threads, and the circular disk is provided with 4 evenly distributed No. Bolt hole 10, circular base 9 is connected with the lower end of telescopic tube 8 by this screw thread.

Referring to FIG. 5 , the heading anchor is composed of an anchor plate 11 , a prestressed steel wire 12 and a steel wire pier head 13 .

The anchor plate 11 is a circular or rectangular plate structure. The anchor plate 11 is evenly distributed with 5 to 150 steel wire through holes with the same structure for installing the prestressed steel wire 12. The rotation axes of each steel wire through hole are parallel to each other and Parallel to the centerline of symmetry of the anchor plate 11.

Described prestressed steel wire 12 is the single steel wire in the prestressed steel bundle 16 that adopts, and the end of prestressed steel bundle 16 is decomposed into many single steel wires and is prestressed steel wire 12 during use, and each single The steel wire, that is, the prestressed steel wire 12 is inserted from one end of a steel wire through hole on the anchor plate 11, and protrudes from the other end of the steel wire through hole, and then each prestressed steel wire 12 is piered into The cylindrical head that prevents steel wire from pulling out is steel wire pier head 13;

The steps of the simply supported T-beam strengthening method based on transverse tension prestressing in the present invention are as follows:

1. According to the existing condition of the T-beam, combined with the design specification, the tensile force of the prestressed steel beam 16 in the limit state of the structural bearing capacity and the limit state of normal use is calculated.

2. According to the design tensile force, two prestressed steel beams 16 with the same structure are required for each simply supported T beam, and 4 identical anchor steel members used to anchor the prestressed steel beam 16 to both ends of the simply supported T beam 14 and in the middle of the prestressed steel bundle 16 two identical supporting steel pads 18 for supporting the tensioned prestressed steel bundle 16 are processed.

3. Fix the two ends of the prestressed steel beam 16 on the anchoring steel member 14 respectively by using a pier head machine to make a heading anchor with less prestress loss.

4. Clean both ends of the simply supported T-beam that needs to be reinforced, and use an impact drill to drill holes at the beam end and mid-span of the simply-supported T-beam perpendicular to the T-beam web 20, and punch holes at both ends to facilitate the use of high-strength bolts The anchoring steel member 14 is installed on the T-beam web 20 at both ends of the simply supported T-beam, and a hole is drilled in the middle for installing the supporting steel pad 18 .

5. Refer to Fig. 6, utilize high-strength bolts to anchor the anchoring steel member 14 on the two ends of the T beam web (20) on both sides of the simply supported T beam, and provide preparation for tensioning the prestressed steel beam 16.

6. Set up tensioning jacks on both sides of the T-beam web 20 in the mid-span of the simply supported T-beam, and symmetrically stretch the prestressed steel beam 16 perpendicular to the T-beam web 20 to the tension required by the design, and the tensioning progress must be maintained Consistent, to avoid lateral bending of simply supported T-beams.

7. After the jack is stretched to the design position, place the supporting steel block 18 under the tensioning jack, and use bolts to anchor the circular base 9 in the supporting steel block 18 to the T beam web 20 of the simply supported T beam , and then adjust the telescopic cylinder 8 to the height of the prestressed steel beam 16.

8. The oil is returned from the jack, and the lateral force on the prestressed steel beam 16 is transmitted to the simply supported T beam by using the supporting rigid pad 18, and finally the two ends of the simply supported T beam are eccentrically compressed.

9. Remove the tensioning equipment, and apply anti-rust paint to the supporting steel pad 18 and the anchoring steel member 14. The simply supported T-beam transverse tension prestressed reinforcement work is completed.

Claims (5)

1. A simply supported T-beam reinforcement method based on transverse tension prestressing, characterized in that, the steps of the simply supported T beam reinforcement method based on transverse tension prestress are as follows: 1) According to the existing condition of the T-beam and in combination with the design specification, the tensile force of the prestressed steel beam (16) in the limit state of the structural bearing capacity and the limit state of normal use is calculated; 2) According to the design tension, two prestressed steel tendons (16) with the same structure are required for each simply supported T beam, and four identical prestressed steel tendons (16) are used to anchor the prestressed steel tendons (16) The anchor steel member (14) and two identical supporting steel pads (18) for supporting the tensioned prestressed steel beam (16) in the middle of the prestressed steel beam (16) are processed and manufactured; 3) Making the two ends of the prestressed steel beam (16) into heading anchors by using the pier head machine and fixing them on the anchoring steel member (14) respectively; 4) Clean the two ends of the simply supported T-beam to be reinforced, and use a percussion drill to punch holes at both ends of the simply supported T-beam and in the middle of the beam and perpendicular to the T-beam web (20). The holes at both ends are easy to use The high-strength bolt installs the anchoring steel component (14) on the T-beam web (20) at the two ends of the simply supported T-beam, and the middle punch is used to install the supporting steel spacer (18); 5) Using high-strength bolts to anchor the anchoring steel member (14) to both ends of the two sides of the T-beam web (20) of the simply supported T-beam, providing preparation for tensioning the prestressed steel beam (16); 6) Erect tension jacks on both sides of the T-beam web (20) in the mid-span of simply supported T-beams, and symmetrically tension the prestressed steel tendons (16) perpendicular to the T-beam web (20) to the required tensile force , the tensioning progress must be consistent to avoid lateral bending of simply supported T beams; 7) After the jack is stretched to the design position, place the supporting steel pad (18) under the tensioning jack, and use bolts to anchor the round base (9) in the supporting steel pad (18) to the simply supported T beam On the T beam web (20), then adjust the telescopic tube (8) to the height of the prestressed steel bundle (16); 8) The oil is returned from the jack, and the lateral force on the prestressed steel beam (16) is transmitted to the simply supported T beam by using the supporting rigid pad (18), and finally the two ends of the simply supported T beam are eccentrically compressed; 9) Remove the tensioning equipment, and apply anti-rust paint to the supporting steel pad (18) and the anchoring steel member (14). 2. The anchoring device adopted in the simply supported T-beam reinforcement method based on transverse tension prestressing, it is characterized in that, described anchoring device comprises 4 structurally identical anchoring steel members (14), 2 structurally identical supporting Steel pad (18), 2 prestressed steel beams (16) with the same structure and 4 heading anchors with the same structure; Four anchoring steel members (14) with the same structure are symmetrically installed on both ends of the T-beam web (20) on both sides of the simply supported T-beam using high-strength bolts, and two supporting steel pads (18) with the same structure are used The high-strength bolts are symmetrically installed in the middle of the two sides of the T-beam web (20) of the simply supported T-beam, and the two ends of the two prestressed steel beams (16) with the same structure are respectively fixed to the anchor steel member ( 14), the middle of 2 prestressed steel beams (16) with the same structure are respectively connected to the tops of 2 identical supporting steel pads (18). 3. The anchoring device according to claim 2, characterized in that, said anchoring steel member (14) is supported by a flat base (5), a connecting plate (2), two support plates (3) with the same structure, Steel pipe (4) and rib plate (6); The flat base (5) is a flat structure, and four bolt holes (1) are uniformly arranged on the flat base (5); The connecting plate (2) is a rectangular plate structure, and the center of the connecting plate (2) is provided with a circular through hole for inserting the prestressed steel beam (16); The supporting plate (3) is an isosceles triangular plate structure, the connecting plate (2) is fixed vertically at the center of the flat base (5), and two supporting plates (3) with the same structure are fixed on the connecting plate (2) On the flat base (5) at both ends, two supporting plates (3) with the same structure are perpendicular to the connecting plate (2), and at the same time perpendicular to the flat base (5), and the supporting steel pipe (4) is installed on the connecting plate ( 2) One side is fixedly connected with it, the axis of rotation of the supporting steel pipe (4) is collinear with the axis of rotation of the circular through hole for inserting the prestressed steel bundle (16) at the center of the connecting plate (4), and the supporting steel pipe (4) ) between the bottom end of the flat base (5) and the upper surface of the flat base (5) are provided with ribs (6) for strengthening, and the ribs (6) connect the supporting steel pipe (4) with the flat base (5). 4. The anchoring device according to claim 2, characterized in that, the supporting steel block (18) is composed of an upper supporting rod (7), a telescopic tube (8) and a circular base (9); The upper support rod (7) is a fork-shaped structural member whose top is used to fix the prestressed steel beam (16). external thread; The telescopic tube (8) is a straight cylindrical structure with an internal thread inside and a hexagon outside; The circular base (9) is composed of a circular disc and a base support rod, the circular disc is provided with 4 evenly distributed No. 2 bolt holes (10), the base support rod is provided with external threads, and the base support rod is vertically Installed vertically at the center of the circular disk, the two are fixedly connected, and the base support rod is collinear with the rotation center line of the circular disk; The base support rod in the circular base (9) is threaded with the lower end of the telescopic tube (8), and the upper end of the telescopic tube (8) is threaded with the bottom of the upper support rod (7). 5. according to the described anchoring device of claim 2, it is characterized in that, described heading anchor is made up of anchor plate (11), prestressed steel wire (12) and steel wire pier head (13); The anchor plate (11) is a circular or rectangular plate structure, and the anchor plate (11) is evenly distributed with 5 to 150 steel wire through holes with the same structure for installing prestressed steel wires (12), and each steel wire through hole The axes of rotation are parallel to each other and parallel to the center line of symmetry of the anchor plate (11); Described prestressed steel wire (12) is to form the single steel wire in the prestressed steel bundle (16); Every single steel wire in the prestressed steel beam (16) is the prestressed steel wire (12) inserted from one end of a steel wire through hole on the anchor plate (11), and stretches out from the other end of the steel wire through hole, and then Adopt the pier head machine to pier the protruding end of each prestressed steel wire (12) into a cylindrical head that prevents the steel wire from pulling out, that is, the steel wire pier head (13).