CN108755394B

CN108755394B - Method for reinforcing special-shaped pier column of bridge by using prestressed tendons

Info

Publication number: CN108755394B
Application number: CN201810757918.9A
Authority: CN
Inventors: 任凤鸣; 张立德; 郭佳瑩; 梁颖雯; 吴迪; 马文
Original assignee: Guangzhou University
Current assignee: Guangzhou University
Priority date: 2018-07-11
Filing date: 2018-07-11
Publication date: 2020-07-31
Anticipated expiration: 2038-07-11
Also published as: CN108755394A

Abstract

The invention discloses a method for reinforcing a special-shaped pier column of a bridge by using prestressed tendons, which comprises a method for reinforcing an overhanging area in a portal pier column with inclined struts, and comprises the following specific steps of: s1, construction preparation, S2, measurement lofting, S3, temporary buttress building and scaffold setting, S4, surface crack sealing, S5, jacking unloading, S6, pressure-bearing steel plate installation, S7, steel bar planting, S8, prestress device installation, S9, installation template manufacturing, S10, concrete pouring, S11, prestress tension, S12, grouting, anchor sealing, S13, beam body resetting, S14, scaffold and temporary buttress dismounting. The method organically combines the synchronous jacking of the bridge, the section enlarging method, the external prestress reinforcing method and the crack grouting method, the outside of the reinforced pier stud is not provided with an exposed anchorage device and a steel bar, the appearance of the reinforced landscape pier stud basically has no influence, and the method is suitable for the reinforcing working condition of the urban landscape bridge with higher requirement on the appearance.

Description

Method for reinforcing special-shaped pier column of bridge by using prestressed tendons

Technical Field

The invention relates to a method for reinforcing a special-shaped pier column of a bridge by using prestressed tendons.

Background

At present, concrete pier columns in railways and urban roads in China are widely applied, with the increase of service life, a great part of common reinforced concrete pier columns are damaged in different degrees, and the damage of some pier columns is serious. The damaged pier stud which can be used continuously can be prolonged in service life through reasonable reinforcement measures. If the new column is replaced, the cost is high, the normal operation of traffic is influenced in the replacement process, and the economic loss is caused by short-term transportation interruption. How to treat the diseases under the condition of not interrupting transportation and improve the service performance and durability of the bridge is an important and valuable research subject. For landscape bridge engineering, the appearance of the bridge is also important, and the appearance of the original bridge is not changed as far as possible while the service performance and the durability of the bridge are improved. The adoption of the external prestress reinforcement technology can effectively solve the problems, the reinforcement cost is relatively low, and the construction quality is easy to control, so the technology is a very effective method for reinforcing the common reinforced concrete beam and has wide development prospect.

External prestressing also has a number of disadvantages in the process of reinforcing the pier stud. The method comprises the following steps: 1. the external prestress is arranged outside the cross section, so that the corrosion resistance and the protection are relatively difficult, and the external influence is easy to occur. 2. Stress concentration is easily generated in the anchoring and steering areas, local stress is large, and anchoring construction requirements are high. 3. The external prestress tension force is small, the advantage of high strength of the external cable can not be fully exerted, and the requirements on the anchorage device and the clamping piece are high. 4. The deformation of the external prestressed tendons is inconsistent with the deformation of the concrete, so that the loss of the prestress is easily caused. 5. Because the steering device and the anchoring point are restrained, the vibration of the external cable is easily caused during driving, and the free length of the prestressed cable is limited.

Disclosure of Invention

The invention aims to solve the technical problems and provides a method for reinforcing landscape bridge reinforced concrete pier stud by using prestressed reinforcement. The method organically combines the synchronous jacking of the bridge, the section enlarging method, the external prestress reinforcing method and the crack grouting method, the outside of the reinforced pier column is not provided with exposed anchorage devices and reinforcing steel bars, the appearance of the reinforced landscape pier column is basically not influenced, and the method is suitable for the urban landscape bridge reinforcing working condition with higher appearance requirement.

The invention is realized by the following technical scheme:

a method for reinforcing a special-shaped pier column of a bridge by prestressed tendons comprises a method for reinforcing a cantilever area in a portal pier column with inclined struts, and comprises the following specific steps:

s1, construction preparation: preparing a series of materials of finish-rolled twisted steel bars, steel bars and concrete required by a reinforced area;

s2, measurement lofting: measuring and rechecking the reinforced area by using a tool;

s3, building a temporary buttress and setting a scaffold: a temporary buttress is arranged outside the reinforcing area, and a scaffold near the temporary buttress is erected after the temporary buttress is installed;

s4, sealing surface cracks: treating the visible cracks in the reinforced area to achieve the purpose of sealing the cracks;

s5, jacking and unloading: synchronously jacking and unloading the box girder above the reinforced area;

s6, mounting of pressure-bearing steel plates: the pressure-bearing steel plate is respectively fixed on the reinforcing areas on the left side surface and the right side surface of the transverse bridge through bolts, an exhaust pipe is inserted into the edge of the pressure-bearing steel plate, and then the edge of the pressure-bearing steel plate is sealed by using pressure-bearing steel plate edge sealing glue to finish edge sealing;

s7, planting bars: the section range is enlarged, concrete on the front side and the rear side along the bridge direction and concrete on the left side and the right side along the transverse bridge direction are subjected to scabbling and bar planting, and full-thread screws are adopted for bar planting;

s8, mounting a pre-stressing device: the pre-stressing device is arranged on the reinforcing areas at the front side and the rear side of the bridge along the direction of the bridge, the pre-stressing device comprises a pre-stressing pipeline, an anchoring end plate, a tensioning end plate and finish rolling threaded steel bars, the anchoring end plate and the tensioning end plate are respectively arranged on the bearing steel plates at the two sides, and the finish rolling threaded steel bars penetrate through the pre-stressing pipeline and are respectively connected with the anchoring end plate and the tensioning end plate;

s9, manufacturing an installation template; s10, pouring concrete in multiple times; s11, prestress tension; s12, vacuum grouting and anchor sealing; s13, resetting the beam body; and S14, dismantling the scaffold and the temporary buttress.

Preferably, the step of S4 sealing the surface crack includes applying a crack sealant to the crack with a crack width ω not greater than 0.15mm for processing, applying a pressure-casting adhesive to repair the crack with a crack width ω greater than 0.15mm by a wall method, and repairing the crack of the concrete with a crack width smaller than 0.15mm that is adhered to the steel plate by an automatic constant-pressure low-pressure chemical grout injection method to seal the crack.

Preferably, the wall-grouting crack repairing step comprises: checking and calibrating cracks → processing concrete on the surfaces of the cracks → fixing an injector base → sealing the surfaces of the cracks → injecting pouring glue → curing the pouring glue → grinding and repairing the surfaces of the concrete.

Preferably, the S5 jacking unloading step includes: removing the temporary buttress steel girder waste → determining the placing position of the jack → measuring the height to determine the thickness of the jack pad → installing the jack and the dial indicator → starting the integral jacking of the jacking system → filling the temporary support pad.

Preferably, the S6 pressure bearing steel plate mounting step includes: s61, removing the original pier column surface coating and scum by using an angle grinder until a new surface is completely exposed, then blowing off the concrete surface dust by using compressed air, and wiping the surface by using industrial acetone;

s62, fixing the steel plate on the bolt, and ensuring that the gap between the steel plate and the concrete surface is more than 3mm so as to ensure that the pouring glue layer has enough thickness;

s63, bonding an injection nozzle on an injection hole of the steel plate, inserting an exhaust pipe into the edge of the steel plate, covering a cover bowl on the head of the expansion bolt, and sealing the edge of the steel plate by using steel plate edge sealing glue to finish edge sealing;

s64, pouring the steel-sticking pouring glue into the gap between the steel plate and the concrete from the injection nozzle by using a pump, wherein the pouring work is continued until all the exhaust pipes have glue liquid to flow out, and in the pouring process, the steel plate is knocked by using a rubber hammer to confirm whether the steel plate is poured compactly.

Preferably, the S8 pre-stress installing step includes: s81, the anchoring end plate and the tensioning end plate are perpendicular to the prestressed pipeline;

and S82, the finish-rolled twisted steel bars pass through the prestressed pipeline to be tightly connected with the anchoring end plate and the tensioning end plate, after tensioning is completed, double nuts are adopted to be screwed on the bearing steel plate, and the second nuts need to be electrically welded.

Preferably, a steel mesh is hung on the embedded bars in the reinforcing area before the S9 manufacturing and installing of the template.

Preferably, the S10 step includes: and (3) pouring for the first time to the bottom of the bent cap, covering the tensioning end, chiseling the contact surface in time after the first pouring is finished, installing a template, reinforcing the template, performing second concrete pouring, and pouring for the second time to finish the residual pouring.

Preferably, the top layer of the reinforced area is welded with the top layer reinforcing rib by adopting a welding method of firstly welding the circular arc section and then welding the straight line sections at two sides.

The invention has the beneficial effects that: the method organically combines the synchronous jacking of the bridge, the section enlarging method, the external prestress reinforcing method and the crack grouting method, the outside of the reinforced pier stud is not provided with an exposed anchorage device and a steel bar, the appearance of the reinforced landscape pier stud basically has no influence, and the method is suitable for the reinforcing working condition of the urban landscape bridge with higher requirement on the appearance.

Drawings

FIG. 1 is a schematic diagram of the construction process of reinforcing a reinforced concrete pier stud by using prestressed reinforcements according to the present invention;

fig. 2 is an elevational view of a reinforced area of a reinforced pier stud in which the present invention is applied;

FIG. 3 is a vertical view of the arrangement of temporary buttresses and scaffolding;

FIG. 4 is a plan view of the arrangement of temporary buttresses and scaffolding;

FIG. 5 is a side view of the temporary buttress and scaffolding;

fig. 6 is an elevational view of a reinforced pier stud;

FIG. 7 is a cross-sectional view A-A of FIG. 6;

FIG. 8 is a cross-sectional view B-B of FIG. 6;

FIG. 9 is a cross-sectional view C-C of FIG. 6;

FIG. 10 is a schematic A view of the larger panel of FIG. 6;

FIG. 11 is a B-diagram of the larger panel of FIG. 6;

FIG. 12 is a rough illustration of the prestressing force;

the method comprises the following steps of 1-reinforcing an area, 2-temporary buttresses, 3-scaffolds, 4-steel plates, 5-bolts, 6-chisels, 7-full-thread screws, 8-prestressed pipelines, 9-anchoring end plates, 10-tensioning end plates, 11-finish-rolled twisted steel bars, 12-double nuts and 13-steel bar meshes.

Detailed Description

The present invention will be described in detail with reference to the drawings and specific embodiments, as shown in fig. 1 to 12, and the exemplary embodiments and descriptions of the present invention are used to explain the present invention, but not to limit the present invention.

As shown in fig. 1, a construction method of an arc-shaped structure bare concrete cast-in-place box girder comprises the following steps:

1. preparation for construction

Preparing materials for reinforcement, wherein the materials for reinforcement comprise main materials such as finish-rolled deformed steel bars, reinforcing steel bars, concrete and the like, and the reinforced materials are verified to meet various national standards.

2. Survey lofting

And (4) the engineering technicians carry out rechecking calculation on the reinforced construction drawing (including the elevation and the coordinates of the reinforced area 1), and the site construction is carried out after the examination and the error are eliminated.

The debris on the clearance pier bent cap before pier stud reinforcement construction levels, the compaction, consolidates the construction place around the pier stud, and reasonable material and machines of stacking ensure large-scale jack-up, concrete pump truck and transportation machinery's parking.

And (3) accurately determining the central elevation, the central axis, the peripheral lines and the side lines of the erecting template of the pier stud reinforcing area 1 by using a total station, and adding a protective pile for resetting the center of the pier stud. And (4) according to the measured pier periphery, retesting the elevation of the bottom of the pier, smearing a belt on the outer side line of the pier by using high-grade mortar and leveling by using a leveling ruler to ensure that the belt heights are consistent so as to facilitate formwork support.

3. Temporary buttress 2 and set up scaffold 3

The setting range of the scaffold 3 is determined according to the reinforced area 1. The reinforcement range is mainly concentrated in the overhanging area of the portal pier stud with the inclined strut, as shown in fig. 2. And annularly arranging outside the reinforced area 1, wherein the step distance of the vertical rods is 90cm, the distance between the vertical rods is 120cm, the distance between the horizontal rods is 180cm, and the reinforced composite material comprises an upper channel, a lower channel, a safety protection net, a skirting board and the like as shown in fig. 3, 4 and 5. When in construction, the temporary buttress 2 foundation is poured firstly, and meanwhile, a system of adjacent scaffolds 3 is erected, and after the foundation maintenance is finished, the upper steel pipe and the distribution beam are installed. After the temporary buttresses 2 are installed, the scaffold 3 near the temporary buttresses 2 is erected. The effect after the setting is completed is shown in fig. 3.

4. Closing surface cracks

Treating the visible cracks in the reinforced area 1, treating the tiny cracks with the crack width omega being less than or equal to 0.15mm and the small depth by coating crack sealant on the surface, repairing the cracks with the crack width omega being more than 0.15mm by pressing and injecting by a wall method, and repairing the cracks needing to be adhered to the position of the steel plate 4 and with the width being less than 0.15mm by injecting chemical grout by an automatic constant pressure and low pressure method so as to achieve the purpose of sealing the cracks. The requirement can ensure that the repairing material is uniformly injected into the thin and deep crack, and the crack repairing quality is ensured.

Surface sealing treatment of cracks: cleaning the paint and scum on the surface of the seam by a steel wire brush, then blowing out the scum on the seam by compressed air, pressing and coating a seam sealant to seal the seam, and grinding the seam after curing.

The 'wall method' pressure injection glue repairs the crack: checking and calibrating cracks → processing concrete on the surfaces of the cracks → fixing an injector base → sealing the surfaces of the cracks → injecting pouring glue → curing the pouring glue → grinding and repairing the surfaces of the concrete. When the concrete on the surface of the crack is treated, a steel wire brush or a grinding machine is used for grinding the concrete in a range of 5cm wide along the two sides of the crack, so that cement laitance, loose objects, oil stains and the like are removed, and the clean and solid concrete surface is exposed. The position of the injection base needs to be determined according to the width and the length of the crack when the injector base is fixed, about 3 bases are arranged per meter along the trend of the crack, and the base is arranged at the branch position of the crack. The base is stuck and fixed on the well-determined base position, and the central point of the base and the central point of the crack are combined together. The foundation is then sealed with a sealant around the joint with the concrete to stabilize the pressure. The pouring sealant should be prepared according to the requirements of the product specification of the supplier when the pouring sealant is injected. The perfusion gel is pressed into the syringe. The syringe is carefully mounted on the injection base. If the filling agent in the injection cylinder is used up before curing, the injection cylinder should be replaced as soon as possible to continue the pressure injection.

5. Jacking unloading

The construction process comprises the following steps: removing the rubbish of the temporary buttress 2 steel beam → determining the placing position of the jack → measuring the height to determine the thickness of the supporting pad of the jack → installing the jack and the dial indicator → starting the integral jacking of the jacking system → filling the temporary supporting pad.

The whole jacking process is controlled by jack oil pressure, a dial indicator is used for monitoring the jacking displacement condition of a beam body, working oil pressure between jacks and jacking displacement errors of all box beams are checked in time, when an elevation error exceeds +/-0.3 mm, a speed regulating stop valve which is jacked to be high is adjusted to be small or closed through ① when a jacking synchronous error is higher than the standard, the speed regulating stop valve is opened to be continuously jacked after low hydraulic pressure is jacked to be synchronous, ② all the speed regulating stop valves are closed for the jacks which exceed the jacking position, an electric hydraulic pump stops working, a reversing switch on the hydraulic pump is arranged at a return position, the speed regulating stop valve of a high-position jack is opened, a total speed regulating stop valve (the opening is preferably small), the high-jack position falls back under heavy load, a total speed regulating stop valve and a distribution speed regulating stop valve are immediately closed when the high-jack reaches a required position, the aim of synchronous jacking is fulfilled, the tracking monitoring is needed, and the monitoring result is recorded in detail.

6. Pressure-bearing steel plate 4 installation

Surface treatment of concrete in a steel-bonding area: according to the requirements of a drawing and according to the situation of field measurement and positioning, a large sample of the steel plate 4 is released on the surface of the steel-sticking area, and the layout of the pressure-bearing steel plate 4 is shown in figures 7 and 8. Removing the original paint and scum on the surface of the pier stud by using an angle grinder until a new surface is completely exposed, then blowing off dust on the surface of the concrete by using compressed air, and wiping the surface by using industrial acetone. The steel plate 4 is fixed on the bolt 5, and the gap between the steel plate 4 and the concrete surface is ensured to be more than 3mm, so that the pouring glue layer is ensured to have enough thickness. And bonding the injection nozzle on the injection hole of the steel plate 4, inserting the exhaust pipe into the edge of the steel plate 4, covering a cover bowl on the head of the expansion bolt 5, and sealing the edge of the steel plate 4 by using the edge sealing glue of the steel plate 4 to finish edge sealing. And (3) pouring the steel-sticking pouring glue into the gap between the steel plate 4 and the concrete from the injection nozzle by using a pump, wherein the pouring work is continued until all the exhaust pipes have glue liquid to flow out. During the course of the attention, the steel plate 4 was struck with a rubber hammer to confirm whether the pouring was dense. Before grouting, ventilating and testing pressure, pressing the steel-bonding pouring adhesive from an injection nozzle under the pressure of 0.2-0.4Mpa, stopping pressurizing after slurry appears in an exhaust hole, sealing the hole by using the steel plate 4 edge sealing adhesive, and maintaining the pressure for more than 10 minutes under lower pressure.

7. Bar planting

The method comprises the steps of cleaning the concrete surface of a thickening area on the side surface (including the bridge direction and the transverse bridge direction) of a pier, removing floating ash, dust, oil stain and dirt on the adhered surface of old concrete to expose a structural body, chiseling 6 the concrete surface of the area, generally removing floating layer dirt (the part with paint or oil stain is washed by acetone) on the surface by a steel wire brush or a sand blasting method to ensure that new and old concrete has good adhesion, if a base surface is seriously loosened, adopting a manual chiseling method to chisel off damaged concrete, polishing the adhered surface, chiseling a surface layer with the thickness of about 1cm, blowing off particles by compressed air to expose a hard and firm concrete surface, wherein the chiseling 6 must be complete and complete, but is not too large in depth to avoid the concrete which is not carbonized and damaged, further coating the surface of a steel bar for derusting if the steel bar is corroded, and coating a steel bar antirust agent, adopting a full-thread screw rod 7 with the depth of 16mm, exposing the steel bar, planting with the interval of cm., and the position of the steel bar planting, the steel bar combining stress, the anchor plate and the like.

As shown in fig. 9, the top reinforcing ribs are welded, and the welding principle is as follows: preferably, the arc section is welded first, and then the straight line sections on the two sides are welded. The welding seam is full, the damage to the stressed steel bar is reduced as much as possible, and the operation is specifically carried out by technical professionals. The welding length of the straight line segment is 10d in one-side welding and 5d in two-side welding. For example, the welding can be ensured to be firm and reliable in the form of welding short steel bars at local positions due to adverse factors such as the void caused by the problem of processing precision of the arc section. The short ribs have the same diameter as the main ribs and the same welding length as before.

8. Prestressed installation

The position of the prestressed pipeline 8 must be accurate, the position of the prestressed pipeline 8 is as shown in fig. 10 and 11, the anchoring end plate 9 and the tensioning end plate 10 must be perpendicular to the prestressed pipeline 8, the connection point of the prestressed pipeline 8 with the anchoring end plate 9 and the tensioning end plate 10 must be tight, slurry leakage and pipe blockage during concrete pouring are strictly prevented, in order to reduce prestressed tension loss as much as possible, a double nut 12 is adopted for screwing after tensioning is completed, an electric welding is required for a second nut, the prestressed reinforcement adopts a phi 32mm high-strength fine-rolled threaded reinforcement 11, the standard strength fpk is 930Mpa, the elastic modulus Ep is 2.00 × 105Mpa, the tension control stress is designed to be 0.7fpk, and the tension control force 523 kN. is that the prestressed pipeline 8 adopts a metal corrugated pipe with the inner diameter phi 50mm for hole forming.

A layer of interface bonding agent with high bonding performance is coated on an original concrete bonding surface, a net (a surface steel bar net piece 13) is hung on the side surface of a pier, the steel bar net piece 13 is welded with a side surface embedded steel bar, and the position accuracy of the steel bar net piece 13 is ensured in the construction process.

9. Manufacturing and installing template

The template adopts a film plate, has smooth surface, meets the requirements on strength and rigidity, is easy to process, has light self weight, does not need auxiliary equipment such as a crane and the like during installation, arranges template fixing screws according to the embedded steel bars, implants one section of the screw with the space of 20cm × 20 cm. into the existing pier stud, seals the pier stud by using embedded bar glue, opens holes on the template according to the arrangement of the steel bars, installs the template after opening the holes, protects the tensioning and anchoring ends in advance by using square foam, avoids the situation that tensioning operation cannot be carried out after concrete pouring in later period, and reinforces the template by using square wood and steel pipes.

10. Pouring of concrete

Concrete placement plans are planned in advance according to the reinforced areas 1. The two sides of the pier column are widened by 20cm respectively, the operation area is narrow during pouring, and the whole reinforcement height is 4.65m, so that the pier column is poured in multiple times. And before pouring, the template and the concrete surface are sprayed with water to be wet. The height of pouring for the first time is to the bent cap bottom, covers the stretch-draw end (the key of pouring for the first time is mainly the stretch-draw end, because the working face is narrow and small, adopts the concrete vibrting spear of minor diameter 50mm to vibrate, guarantees vibrating of concrete and targets in place), in time carries out the chisel hair processing to the contact surface after pouring for the first time is accomplished, the installation template, the reinforced formwork carries out the concrete placement for the second time, pours for the second time and accomplishes the surplus and pour.

11. Prestressed tension

And (5) timely maintaining after the concrete is poured, and tensioning after the strength reaches over 75% of the designed strength. And (4) dismantling the side die before tensioning. The prestress is tensioned twice. Because the vertical prestressed tendons are short, special jacks are needed for tensioning, and nuts are screwed after tensioning reaches the tonnage. The prestressed reinforcement is tensioned by adopting double control, mainly tensioning force and auxiliary stretching amount, and is tensioned according to the designed tensioning force, and the difference between the actual elongation and the theoretical elongation is not more than 6%. Finish rolling the twisted steel 11: 0 → initial stress 10% σ k (marked by a dash line) → σ k (holding load for 5 minutes) → measuring elongation and retraction → anchoring → large and small cylinders return to zero. The concrete process of prestressed tension and grouting and sealing anchor are strictly executed according to relevant operating regulations and the technical Specification for highway bridge and culvert construction.

12. Grouting and sealing anchor

In order to ensure the quality of prestressed construction, the prestressed pipe 8 is made of metal corrugated pipe. And after the prestressed steel bundles are tensioned, vacuum grouting must be carried out in time. The grouting adopts a vacuum auxiliary grouting process, impurities in the pipeline are removed by using compressed air or pressure water before grouting, the pore channel and two ends are sealed, the cement paste is subjected to standard culture for 28 days according to a 70mm cubic test piece, the compressive strength is more than or equal to 50MPa, the water-cement ratio is 0.3-0.35, and a proper amount of micro-expanding agent is doped through a test. The bleeding property of the slurry is less than 2% of the initial volume of the cement slurry, the average value of results of four continuous tests is less than 1%, the bleeding property of the cement slurry can be absorbed after 24h of concomitation, the initial setting time of the slurry is 3-4 h, a water reducing agent cannot be mixed, and the using amount is determined by the test.

13. Restoration of beam body

And after the pier column reinforcing construction is finished, the beam body resetting operation can be carried out. The operation method of the jacking system when the beam slab is reset is opposite to the step when the beam slab is jacked.

14. Demolish scaffold frame 3 and interim buttress 2

The scaffold 3 is dismantled according to the principle that the scaffold is firstly put on and then dismantled, and then put on and firstly dismantled; comprehensively checking whether the fastener connection, the wall connecting piece, the supporting system and the like of the scaffold 3 meet the structural requirements; the dismantling sequence and measures in the construction scheme for dismantling the scaffold 3 are supplemented and perfected according to the inspection result, and the method can be implemented after approval of the project department of the first party; before the scaffold 3 is dismantled, sundries and ground obstacles on the scaffold 3 must be cleared. For the removal of the temporary buttress 2, the sundries are removed by other machines such as a jack on the upper part of the temporary buttress 2. And then is dismantled from top to bottom. When in dismantling, the dismantling area needs to be closed, and only professional dismantling personnel can work on the spot.

The technical solutions provided by the embodiments of the present invention are described in detail above, and the principles and embodiments of the present invention are explained herein by using specific examples, and the descriptions of the embodiments are only used to help understanding the principles of the embodiments of the present invention; meanwhile, for a person skilled in the art, according to the embodiments of the present invention, there may be variations in the specific implementation manners and application ranges, and in summary, the present disclosure should not be construed as limiting the invention.

Claims

1. A method for reinforcing a special-shaped pier column of a bridge by prestressed tendons comprises a method for reinforcing a cantilever area in a portal pier column with inclined struts, and comprises the following specific steps:

2. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: and the step of S4 sealing the surface cracks comprises the steps of processing the cracks with the crack width omega less than or equal to 0.15mm by coating crack sealant on the surface, repairing the cracks with the crack width omega more than 0.15mm by pressing and injecting glue by a wall method, and repairing the concrete cracks with the crack width less than 0.15mm needing to be adhered to the position of the steel plate by injecting chemical grout with automatic constant pressure and low pressure so as to achieve the purpose of sealing the cracks.

3. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 2, is characterized in that: the step of repairing cracks through wall-compressible glue injection comprises the following steps: checking and calibrating cracks → processing concrete on the surfaces of the cracks → fixing an injector base → sealing the surfaces of the cracks → injecting pouring glue → curing the pouring glue → grinding and repairing the surfaces of the concrete.

4. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: the S5 jacking unloading step comprises the following steps: removing the temporary buttress steel girder waste → determining the placing position of the jack → measuring the height to determine the thickness of the jack pad → installing the jack and the dial indicator → starting the integral jacking of the jacking system → filling the temporary support pad.

5. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: the S6 pressure-bearing steel plate mounting step comprises the following steps: s61, removing the original pier column surface coating and scum by using an angle grinder until a new surface is completely exposed, then blowing off the concrete surface dust by using compressed air, and wiping the surface by using industrial acetone;

6. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: the S8 pre-stressing mounting step includes: s81, the anchoring end plate and the tensioning end plate are perpendicular to the prestressed pipeline;

7. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: and a steel bar mesh is hung on the steel bar planting in the reinforcing area before the S9 manufacturing and installing of the template.

8. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: the step of S10 includes: and (3) pouring for the first time to the bottom of the bent cap, covering the tensioning end, chiseling the contact surface in time after the first pouring is finished, installing a template, reinforcing the template, performing second concrete pouring, and pouring for the second time to finish the residual pouring.

9. The method for reinforcing the special-shaped pier stud of the bridge by the prestressed tendons, according to claim 1, is characterized in that: and a top layer reinforcing rib is welded on the top layer of the reinforced area, and a welding method of firstly welding the arc section and then welding the straight line sections at two sides is adopted.