A steering device capable of adjusting the sag and prestress of an external cable and a construction method thereof

Abstract

The present invention provides a steering device capable of adjusting the sag and prestress of an external cable and a construction method thereof, comprising a fixed frame fixedly arranged on a concrete beam and an adjusting frame fixedly arranged on the fixed frame; the adjusting frame comprises a bent angle steel plate fixedly arranged on a side surface of the fixed frame on one side, an adjusting screw arranged on the other side of the bent angle steel plate relative to the fixed side, and a steel strand steering fixture fixedly arranged at the lower end of the adjusting screw; the steel strand steering fixture comprises a semicircular steel fixedly arranged at the lower end of the adjusting screw and a fixing plate fixedly arranged on the lower side of the semicircular steel, a groove is arranged at the bottom of the semicircular steel, and the fixing plate cover is fixedly arranged under the groove. The present invention has the characteristics of being able to reinforce concrete beams, improve their bearing capacity, and conveniently supplement prestress and adjust the initial sag of external cables.

Description

Technical Field

[0001] The invention relates to an engineering construction method, in particular to a steering device capable of adjusting the sag and prestress of an external cable and a construction method thereof. Background Art

[0002] With the advancement of urbanization and poverty alleviation in my country, the country and the people have been increasing their requirements for the reliability of buildings. The revision of the "Uniform Standard for Reliability Design of Building Structures" is a very favorable manifestation. For many existing buildings, there are changes in their use functions or insufficient bearing capacity. If they are demolished and rebuilt, it will not only cause considerable economic losses, but also generate a lot of construction waste and pollute the environment. Repairing and reinforcing existing buildings to improve their safety and extend their service life can not only solve the above problems, but also comply with the country's sustainable development strategy.

[0003] Combining various reinforcement methods, the external prestressed reinforcement method has the advantages of reinforcement, unloading, and changing the internal force distribution of the original structure. Conventional external prestressed reinforced beams have problems such as inconvenience in supplementing prestress, difficulty in adjusting the initial sag of the external cable, and the influence of the plate and column during construction. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a device for reinforcing a concrete beam, improving its bearing capacity and conveniently supplementing prestress and adjusting the initial sag of the external cable, and a steering device for adjusting the sag of the external cable and applying prestress, and a construction method thereof.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A steering device capable of adjusting the sag and prestress of an external cable, comprising a fixed frame fixedly arranged on a concrete beam and an adjusting frame fixedly arranged on the fixed frame;

[0007] The adjusting frame comprises a folded steel plate fixedly arranged on one side of the fixed frame, an adjusting screw arranged on the other side of the folded steel plate relative to the fixed side, and a steel strand steering fixing device fixedly arranged at the lower end of the adjusting screw;

[0008] The steel strand steering fixing device includes a semicircular steel fixedly arranged at the lower end of the adjusting screw and a fixing plate fixedly arranged at the lower side of the semicircular steel. A groove is arranged at the bottom of the semicircular steel, and the fixing plate cover is fixedly arranged below the groove.

[0009] Furthermore, the cross-sectional shape of the fixing frame is matched with the cross-sectional shape of the concrete beam.

[0010] Furthermore, one side of the angled steel plate provided with the adjusting screw is kept horizontal to the ground.

[0011] Furthermore, the cross-sectional shape of the fixing frame is U-shaped.

[0012] Furthermore, the angle between the steel plates of the angled steel plates is 90°.

[0013] A construction method of a steering device capable of adjusting the sag and prestress of an external cable, comprising the following steps:

[0014] S1: Construction preparation, carry out base treatment of reinforcement components, scrape off the plaster layer and loose layer on the surface of the concrete beam to be reinforced, and rinse the reinforcement components clean;

[0015] S2: Positioning and laying out: According to the actual design drawings, the external cables are positioned and laid out to determine the position of the steering device, the turning point of the external cables, the position of the anchor bolts of the fixed frame, and the position of the anchoring of the concrete beam end;

[0016] S3: Production and installation of external cables. After the external cables are brought into the site, they must first be straightened, bent at the steering device, installed in the groove of the semi-circular steel, and anchored to the end fixing plate;

[0017] S4: Application of prestress. After the fixed frame and the angled steel plate are fixed on the concrete beam, the initial length of the external cable and the initial height of the adjusting screw can be determined according to the magnitude of the prestress required for the reinforced beam. The external cable is tightly attached to the groove and anchored at both ends of the reinforced beam. Then, the adjusting screw moves downward to drive the extension of the external cable. When the prestress reaches the expected level, the bolt of the adjusting screw is tightened and the adjusting screw is fixed on the angled steel plate. The reaction force generated by the external cable acts on the adjusting screw, which acts on the angled steel plate and the fixed frame, and the fixed frame acts on the concrete beam to complete the reinforcement of the concrete beam.

[0018] S5: Supplementation of prestress. During the long-term service of the extracorporeal cable, there will be a loss of prestress. The loss of prestress can be supplemented by applying prestress by moving the adjusting screw downward, which is convenient for replenishing prestress.

[0019] Furthermore, in step S3, the external cable prestressed tendons in contact with the steering device are in an arc shape, and the external cable prestressed tendons are sleeved with thick-walled steel pipes recessed in the grooves of the semi-circular steel.

[0020] Furthermore, in step S4, when applying the prestress, the adjusting screw should move downward step by step to prevent the prestress from being too large.

[0021] Furthermore, after the step S4 is completed, since the external cables and other steel materials are exposed to the outside for a long time, anti-corrosion measures are taken to prevent the external cables and other steel materials from being corroded.

[0022] Furthermore, before step S5, the prestress of the external cables should be checked regularly. When insufficient prestress is found, step S5 is adopted to supplement the prestress to prevent insufficient bearing capacity of the beam caused by insufficient prestress.

[0023] The beneficial effects of adopting the above technical solution are:

[0024] The present invention relates to a steering device capable of adjusting the sag of an external cable and the application of prestress. Before applying prestress, the telescopic length of a screw can be adjusted to achieve adjustment of the linear shape of the external cable corresponding to different prestressing forces, thereby completing the support of external cables of different heights. During the long-term service of the external cable, there will be a loss of prestress, and prestress can be applied by adjusting the downward movement of the screw to supplement the loss of prestress. This method is conveniently applicable to the method of increasing the external prestress by anchoring and tensioning at both ends, and can effectively improve the efficiency and quality of external prestressed reinforced beams.

[0025] The construction method of the steering device with adjustable external cable sag and prestressing application involved in the present invention can complete the adjustment and compensation of external prestressing, ensure the effectiveness and timeliness of external prestressing, is simple and fast to operate, has high feasibility, will not affect its use clearance, can greatly improve the bearing capacity of the reinforced beam, and is also very convenient for subsequent prestressing supplementation, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the installation structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the cross-sectional structure of the present invention in the AA direction;

[0029] Figure 4 This is a schematic diagram of the enlarged structure of part A of the present invention;

[0030] Among them, 1. fixed frame, 2. angle steel plate, 3. adjusting screw, 4. semi-circular steel, 5. fixed plate, 6. groove, 7. external cable prestressed tendons, 8. thick-walled steel pipe, 9. outer sheath pipe, 10. filling material. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings.

[0032] As attached Figure 1-4As shown, this embodiment provides a steering device capable of adjusting the sag and prestress of an external cable, which comprises a fixed frame 1 fixedly arranged on a concrete beam and an adjusting frame fixedly arranged on the fixed frame 1; the fixed frame 1 is wrapped around the concrete beam and fixed; the cross-sectional shape of the fixed frame 1 is matched with the cross-sectional shape of the concrete beam; the adjusting frame comprises a beveled steel plate 2 fixedly arranged on one side of the side of the fixed frame, an adjusting screw 3 arranged on the other side of the beveled steel plate 2 relative to the fixed side, and a steel strand steering fixing device fixedly arranged at the lower end of the adjusting screw 3, the beveled steel plate 2 having one side provided with the adjusting screw 3 being kept horizontal to the ground, and the beveled steel plate 2 The angle between the steel plates is 90°, and the cross-section of the fixed frame 1 is U-shaped, which is welded by the bottom steel plate and the vertical steel plates on both sides. The fixed frame 1 is set on the concrete beam through the anchor bolt sleeve, and two rows of bolt mounting holes are evenly distributed on the vertical steel plate of the fixed frame 1. The vertical steel plate of the angled steel plate 2 has bolt holes with the same aperture size as the vertical steel plate of the fixed frame 1. The angled steel plate 2 is fixed to the fixed frame 1 by bolts passing through the bolt mounting holes and the bolt holes. When the angled steel plate 2 and the fixed frame 1 are manufactured, the component size should be strictly controlled to ensure that the vertical steel plate of the angled steel plate 2 and the vertical steel plate of the fixed frame 1 have bolt holes with the same aperture size and position, which are convenient for installation and fixation.

[0033] The steel strand steering fixing device comprises a semi-circular steel 4 fixedly arranged at the lower end of the adjusting screw 3 and a fixing plate 5 fixedly arranged at the lower side of the semi-circular steel 4. A groove 6 is arranged at the bottom of the semi-circular steel 4. The fixing plate 5 is fixedly arranged below the groove 6. The external cable prestressed tendon 7 contacted by the steering device is in an arc shape, and the external cable prestressed tendon 7 is sleeved with a thick-walled steel pipe 8 concavely arranged in the groove 6 of the semi-circular steel 4. The semi-circular steel 4 plays the role of fixing the external cable and steering the external cable. The external cable prestressed tendon 7 and the thick-walled steel pipe 8 An outer sheath tube 9 is provided between them to prevent corrosion and mechanical damage to the external cable prestressed tendons 7. The outer sheath tube 9 can be made of high-density polyethylene tube, Haversian tube or steel tube, etc. The outer sheath tube 9 should meet the following requirements: a) It has sufficient strength and toughness and will not be damaged during processing and installation. The outer sheath that needs to be filled with filler should be able to withstand a filler filling working pressure of not less than 1MPa; b) It has waterproofness and chemical stability, and has no adverse effects on the external cable prestressed tendons 7; c) It has corrosion resistance and has no adverse reactions with anti-corrosion materials. Filler 10 is provided in the gap formed between the thick-walled steel pipe 8 and the groove 6 and the fixing plate 5 of the semi-circular steel 4. The filler 10 uses cement slurry to effectively fix the external cable prestressed tendons 7 so that it meets the stability requirements of prestressing. The transverse steel plate of the angled steel plate 2 is preset with a hole of the same size as the adjusting screw, and the adjusting screw 3 is inserted into the hole of the transverse steel plate of the angled steel plate 2. Adjusting nuts are respectively arranged on the upper and lower sides of the transverse steel plate of the adjusting screw 3. When it is necessary to adjust the telescopic length of the adjusting screw 3 or to supplement the prestress, it is only necessary to loosen the adjusting nut on the lower side of the transverse steel plate first, adjust the adjusting screw 3 into place, and then tighten the adjusting nut on the upper side of the transverse steel plate to complete the adjustment of the adjusting screw 3. The steel strand steering and fixing device plays a combined role in transmitting vertical loads, supporting and constraining external cables, and adjusting the applied prestress.

[0034] A construction method of a steering device capable of adjusting the sag and prestress of an external cable, comprising the following steps:

[0035] S1: Construction preparation, carry out base treatment of reinforcement components, scrape off the plaster layer and loose layer on the surface of the concrete beam to be reinforced, and rinse the reinforcement components clean;

[0036] S2: Positioning and laying out. According to the actual design drawings, the external cables are positioned and laid out to determine the position of the steering device, the turning point of the external cables, the position of the anchor bolts of the fixed frame, and the position of the anchorage of the concrete beam end. When adjusting the verticality of the external cables in the initial design, a reasonable and reliable treatment plan should be adopted according to the prestressing requirements and clearance requirements of the concrete beam, and sufficient height space should be reserved to ensure that the bearing capacity requirements of the reinforced beam are met and that no reverse arching will occur when the prestressing is supplemented in the later adjustment;

[0037] S3: Production and installation of external cables. After the external cables are brought into the site, they must first be straightened, bent at the steering device, installed in the groove of the semi-circular steel, and anchored to the end fixing plate;

[0038] S4: Application of prestress. After the fixed frame and the angled steel plate are fixed on the concrete beam, the initial length of the external cable and the initial height of the adjusting screw can be determined according to the magnitude of the prestress required for the reinforced beam. The external cable is tightly attached to the groove and anchored at both ends of the reinforced beam. Then, the adjusting screw moves downward to drive the extension of the external cable. When the prestress reaches the expected level, the bolt of the adjusting screw is tightened and the adjusting screw is fixed on the angled steel plate. The reaction force generated by the external cable acts on the adjusting screw, which acts on the angled steel plate and the fixed frame, and the fixed frame acts on the concrete beam to complete the reinforcement of the concrete beam.

[0039] S5: Supplementation of prestress. During the long-term service of the extracorporeal cable, there will be a loss of prestress. The loss of prestress can be supplemented by applying prestress by moving the adjusting screw downward, which is convenient for replenishing prestress.

[0040] In step S3, the external cable in contact with the steering device is in an arc shape, and the external prestressed tendons of the external cable are sleeved with thick-walled steel pipes recessed in the grooves of the semi-circular steel. Since it is very difficult to fold the external prestressed tendons of the external cable at the turning point, this method can facilitate the adjustment of the initial sag of the external cable.

[0041] In the step S4, during the process of applying the prestress, the adjusting screw should move step by step when moving downward to prevent the prestress from being too large.

[0042] After step S4 is completed, since the external cables and other steel materials are exposed to the outside for a long time, anti-corrosion measures are taken to prevent the external cables and other steel materials from being corroded, thereby extending the service life of the external prestressing device and ensuring the safety of the building structure.

[0043] Before step S5, the prestress of the external cables should be checked regularly. When insufficient prestress is found, step S5 is adopted to supplement the prestress to prevent insufficient bearing capacity of the beam caused by insufficient prestress.

[0044] The external cable in the present invention is an external prestressed cable, which is reinforced on the upper part of the bridge, that is, in the tension zone of the lower part of the beam. It uses steel strands or high-strength steel wire bundles as prestressed tendons. Through tensioning, eccentric prestress is generated on the beam body. Under the action of this eccentric pressure, the beam body arches upward, the load deflection is reduced, and the stress condition of the beam body is improved, thereby achieving a device for improving the bearing capacity of the beam.

[0045] The construction work process principle is as follows:

[0046] The steering device involved in the present invention is to fix a fixed frame 1 on a reinforced concrete beam by anchor bolts at the bottom and both sides of the beam, and the angled steel plate 2 is connected and fixed to the side plate of the fixed frame 1 by two symmetrical rows of bolts. The adjusting screw 3 passes through the reserved hole on the horizontal steel plate of the angled steel plate 2, and the prestressed tendons 7 of the external cable pass through the groove 6 of the semicircular steel 4 at the bottom of the adjusting screw 3. The adjusting screw 3 can freely expand and contract in the hole to form an adjustable height of the adjusting screw, which can complete the support of external cables of different heights. Before applying prestress, the adjustment of the external cable line shape corresponding to different prestressing forces can be achieved by adjusting the telescopic length of the screw. During the long-term service of the external cable, the prestress can be applied by moving the adjusting screw downward to supplement the loss of prestress, which is convenient for the method of tensioning and applying prestress at the anchoring points at both ends.

[0047] In the construction method of the steering device of the present invention, firstly, construction preparation is carried out, the base layer of the reinforcement component is processed, the plaster layer and the loose layer on the surface of the concrete beam to be reinforced are scraped off, and the reinforcement component is rinsed clean; then positioning and laying out are carried out, and the external cable is positioned and laid out according to the actual design drawings to determine the position of the steering device, the turning point of the external cable, the position of the anchor bolt of the fixed frame, and the position of the anchor of the concrete beam end. When the verticality of the external cable is adjusted in the initial design, a reasonable and reliable treatment plan should be adopted according to the prestressing demand and the use clearance requirement of the concrete beam, and sufficient height space should be reserved to ensure that the bearing capacity requirement of the reinforced beam is met and the prestressing is supplemented in the later adjustment without generating an anti-arch; then the external cable is made and installed. After the external cable enters the site, it first needs to be straightened, bent at the steering device, installed in the groove of the semi-circular steel, and anchored and fixed with the end fixing plate;

[0048] Prestress is applied again. After the fixed frame 1 and the angled steel plate 2 are fixed on the concrete beam, the initial length of the external cable and the initial height of the adjusting screw 3 can be determined according to the magnitude of the prestress required for the reinforced beam. The prestressed tendons 7 of the external cable are tightly attached to the groove 6 and anchored at both ends of the reinforced beam. Then, the adjusting screw 3 is moved downward to drive the extension of the external cable. When the prestress reaches the expected level, the bolt of the adjusting screw 3 is tightened to fix the adjusting screw 3 on the angled steel plate 2. The reaction force generated by the external cable acts on the adjusting screw 3, and the adjusting screw 3 acts on the angled steel plate 2 and the fixed frame 1. The fixed frame 1 acts on the concrete beam to complete the reinforcement of the concrete beam. During the long-term service of the external cable, there will be a loss of prestress. When the prestress needs to be supplemented, the prestress can be applied by moving the adjusting screw 3 downward to supplement the loss of prestress, which is convenient for supplementing the prestress.

[0049] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steering device capable of adjusting the sag and prestress of an external cable, characterized in that: It comprises a fixed frame (1) fixedly arranged on a concrete beam and an adjusting frame fixedly arranged on the fixed frame (1); The adjusting frame comprises a folded steel plate (2) fixedly arranged on one side of the fixed frame, an adjusting screw (3) arranged on the other side of the folded steel plate (2) relative to the fixed side, and a steel strand steering fixing device fixedly arranged at the lower end of the adjusting screw (3); The steel strand steering fixing device comprises a semi-circular steel (4) fixedly arranged at the lower end of the adjusting screw (3) and a fixing plate (5) fixedly arranged at the lower side of the semi-circular steel (4); a groove (6) is arranged at the bottom of the semi-circular steel (4); and a sealing cover of the fixing plate (5) is fixedly arranged below the groove (6); The cross-sectional shape of the fixed frame (1) is matched with the cross-sectional shape of the concrete beam; The cross-sectional shape of the fixed frame (1) is U-shaped.

2. A steering device capable of adjusting the sag and prestress of an external cable according to claim 1, characterized in that: The side of the angled steel plate (2) on which the adjusting screw rod (3) is provided is kept horizontal to the ground.

3. A steering device capable of adjusting the sag and prestress of an external cable according to claim 2, characterized in that: The angle between the steel plates of the angled steel plates (2) is 90°.

4. A construction method of a steering device capable of adjusting the sag of an external cable and applying prestress as claimed in claim 1, characterized in that: It includes the following steps: S1: Construction preparation, carry out base treatment of reinforcement components, scrape off the plaster layer and loose layer on the surface of the concrete beam to be reinforced, and rinse the reinforcement components clean; S2: Positioning and laying out: According to the actual design drawings, the external cables are positioned and laid out to determine the position of the steering device, the turning point of the external cables, the position of the anchor bolts of the fixed frame, and the position of the anchoring of the concrete beam end; S3: Production and installation of external cables. After the external cables are brought into the site, they must first be straightened, bent at the steering device, installed in the groove of the semi-circular steel, and anchored to the end fixing plate; S4: Application of prestress. After the fixed frame and the angled steel plate are fixed on the concrete beam, the initial length of the external cable and the initial height of the adjusting screw can be determined according to the magnitude of the prestress required for the reinforced beam. The external cable is tightly attached to the groove and anchored at both ends of the reinforced beam. Then, the adjusting screw moves downward to drive the extension of the external cable. When the prestress reaches the expected level, the bolt of the adjusting screw is tightened and the adjusting screw is fixed on the angled steel plate. The reaction force generated by the external cable acts on the adjusting screw, which acts on the angled steel plate and the fixed frame, and the fixed frame acts on the concrete beam to complete the reinforcement of the concrete beam. S5: Supplementation of prestress. During the long-term service of the extracorporeal cable, there will be a loss of prestress. The loss of prestress can be supplemented by applying prestress by moving the adjusting screw downward, which is convenient for replenishing prestress.

5. A construction method of a steering device capable of adjusting the sag of an external cable and applying prestress as claimed in claim 4, characterized in that: In the step S3, the external cable prestressed tendons in contact with the steering device are in an arc shape, and the external cable prestressed tendons are sleeved with thick-walled steel pipes recessed in the grooves of the semi-circular steel.

6. A construction method of a steering device capable of adjusting the sag of an external cable and applying prestress as claimed in claim 4, characterized in that: In the step S4, during the process of applying the prestress, the adjusting screw should move downward step by step to prevent the prestress from being too large.

7. A construction method of a steering device capable of adjusting the sag of an external cable and applying prestress as claimed in claim 4, characterized in that: After the step S4 is completed, since the external cables and other steel materials are exposed to the outside for a long time, anti-corrosion measures are taken to prevent the external cables and other steel materials from being corroded.

8. A construction method of a steering device capable of adjusting the sag of an external cable and applying prestress as claimed in claim 4, characterized in that: Before step S5, the prestress of the external cables should be checked regularly. When insufficient prestress is found, step S5 is adopted to supplement the prestress to prevent insufficient bearing capacity of the beam caused by insufficient prestress.

Images