Pier column reinforcing structure

Abstract

A pier column reinforcing and reinforcing structure comprises tensioning steel plate strips, prestressed tendons, steel bar grids, micro-expansion concrete and a steel casing, the tensioning steel plate strips comprise steel plate strips and a plurality of steel cushion blocks arranged on the steel plate strips, the multiple tensioning steel plate strips surround the outer surface of a pier column to be reinforced in parallel, the tops of the steel cushion blocks are in a concave shape, and the steel cushion blocks are arranged on the steel plate strips. The prestressed tendons are tensioned on the peripheries of the tensioning steel plate strips in a surrounding mode and are positioned through concave faces at the tops of the tensioning steel plate strips, each tensioning steel plate strip corresponds to one prestressed tendon, the steel bar grid is arranged on the peripheries of the prestressed tendons and wraps the prestressed tendons, the tensioning steel plate strips and the pier column to be reinforced, and the steel casing is arranged on the peripheries of the steel bar grid and wraps the prestressed tendons, the tensioning steel plate strips and the pier column to be reinforced. And the micro-expansion concrete is filled between the steel casing and the pier column to be reinforced. Axial constraint is provided through combination of an active mode and a passive mode, the bearing capacity and the bending resistance of an original bridge pier column are greatly improved, and the bridge pier column is environmentally friendly, economical, high in space utilization rate and good in reinforcing effect.

Description

Technical Field

[0001] The utility model relates to the technical field of building construction, in particular to a pier column reinforcement structure. Background Art

[0002] At present, the total number of bridges built in my country has exceeded 1 million. With the rapid development of my country's transportation industry, the transportation volume has increased significantly, the vehicle load has increased day by day, and the requirements for the bearing capacity of bridge piers have become higher and higher; at the same time, many built bridge piers have suffered various types of damage under the long-term natural environment and external loads, such as surface concrete peeling, exposed steel corrosion, stress loss, cracks, etc., which make the bridge piers insufficient in bearing capacity and reduce the usability and durability of the bridge. Therefore, it is particularly important to timely maintain and reinforce and expand the damaged bridge piers to improve their bearing capacity and ensure the normal use and safety performance of the bridge.

[0003] The existing bridge pier reinforcement methods mainly use the steel plate bonding method or the cross-section enlargement reinforcement method to maintain and strengthen damaged bridge piers. By bonding the steel plate to the outer structural surface of the damaged pier, it only bears axial force, increasing the axial resistance of the original pier and improving its compression and bending capacity; or by planting steel bars, installing steel bars, and pouring concrete, the cross-section of the pier is enlarged to improve its bearing capacity. The reinforcement effect of the steel plate bonding method depends largely on the bonding process, operation level and the performance of the bonding material. At the same time, its connection is easily corroded by aging under various harsh conditions, causing the steel plate to fall off. The cross-section enlargement reinforcement method is a reinforcement method that is enlarged on the original pier, so its resistance and integrity are far from being comparable to the cast-in-place piers with the same cross-section, and its reinforcement effect is not ideal. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the above-mentioned prior art and provide a pier reinforcement structure that can actively improve the axial constraint of the original pier, significantly improve its bearing capacity, and passively improve its constraint force and improve its bending resistance.

[0005] The utility model is realized by the following technical solutions:

[0006] A pier reinforcement structure comprises tensioned steel strips, prestressed tendons, a steel bar grid, micro-expansive concrete and a steel casing, wherein the tensioned steel strips comprise steel strips and a plurality of steel pads arranged on the steel strips, wherein the plurality of tensioned steel strips are mutually parallel and wrapped around the outer surface of the pier to be reinforced, and the bottom surface of the steel strips is in close contact with the outer surface of the pier to be reinforced, and the top of the steel pad is concave in shape, the prestressed tendons are wrapped around and tensioned on the tensioned steel strips, and are positioned by the concave surface of the top of the tensioned steel strips, each tensioned steel strip corresponds to a prestressed tendon, the steel bar grid is arranged on the periphery of the prestressed tendons, and surrounds the prestressed tendons, the tensioned steel plate and the pier to be reinforced, the steel casing is arranged on the periphery of the steel bar grid, and the micro-expansive concrete is filled between the steel casing and the pier to be reinforced.

[0007] A further optimized technical solution is that the steel strips are bent into semicircles, two semicircular steel strips are pasted and wrapped around the outer surface of the pier to be reinforced, and after the prestressed tendons are tensioned, the two ends of the two steel strips are anchored or welded to each other by bolts.

[0008] A further optimized technical solution is that the joints of several parallel-arranged tensioned steel strips are staggered in the vertical direction.

[0009] A further optimized technical solution is that it also includes a tensioning pedestal for prestressing the prestressed tendons, and the tensioning pedestal is fixed to the pier to be reinforced by anchor bolts passing through the tensioning steel strips.

[0010] A further optimized technical solution is that the tensioning pedestal is a concrete pedestal with a sleeve reserved in it for passing the prestressed tendons. Both ends of the prestressed tendons pass through the sleeves respectively and are tensioned and then fixed by an anchoring structure.

[0011] A further optimized technical solution is that the tensioning pedestal is a steel box with reinforcing ribs arranged inside the steel box and through holes arranged on the sides of the steel box, and both ends of the prestressed tendons pass through the through holes respectively and are tensioned and then anchored by grouting.

[0012] A further optimized technical solution is that the height of the steel pad is greater than 25 mm.

[0013] A further optimized technical solution is that the steel pad is welded or integrated with the steel strip.

[0014] A further optimized technical solution is that a plurality of the tensioned steel strips are arranged around the outer surface of the pier to be reinforced at intervals.

[0015] A further optimized technical solution is that the steel casing is connected to the steel grid through tie bars.

[0016] The utility model adopts prestressed tensioning combined with steel casing and concrete to form a composite force-bearing structure, and provides axial constraints by combining active and passive methods, which greatly improves the bearing capacity and bending resistance of the original bridge piers, and achieves the effect of repairing damaged piers and reinforcing and upgrading them; prefabricated tensioned steel strips are used to diffuse the tightening force of the prestressed tendons through the steel plates on them, so that they act evenly on the original piers, avoiding the prestressed tendons directly acting on the piers to cause secondary damage. At the same time, the lifting of the prestressed tendons by the steel pads is beneficial to the wrapping of the prestressed tendons and the subsequent concrete, forming a pre-tensioned reinforced concrete structure to provide stronger constraints; steel strips, steel The pads and interval arrangement are equivalent to forming a tooth joint structure on the surface of the original pier, which is beneficial to the combination of the newly poured concrete and the original pier. At the same time, the steel strips can also be used as the welding base surface for the steel bars of the steel grid structure. After the prefabricated tensioned steel strips are investigated for the size of the piers in a specific large area, they can be prefabricated in batches after the size is determined, which can save costs. The prestressed tensioning form is used to actively increase the axial constraint on the original pier, which can greatly reduce the amount of steel bars and the amount of cross-sectional expansion, is environmentally friendly and economical, and has high space utilization. The use of steel casing concrete to fully enclose the prestressed tendons and related tensioning components is beneficial to protect the internal steel components and avoid rust. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view of an embodiment of the utility model.

[0018] Figure 2 for Figure 1 A magnified view of some details.

[0019] Figure 3 It is a schematic diagram of the structure of the tensioned steel strips in the embodiment of the utility model.

[0020] Figure 4 It is a schematic cross-sectional view of the tensioned steel strip in the embodiment of the utility model.

[0021] Figure 5 It is a schematic diagram of the expansion of the tensioned steel strips in the embodiment of the utility model.

[0022] Figure 6 It is a schematic diagram of the installation of tensioned steel strips and prestressed tendons in an embodiment of the utility model.

[0023] Figure 7 It is a schematic diagram of the tensioning and anchoring structure of the prestressed tendons in the embodiment of the utility model.

[0024] Figure 8 It is a front schematic diagram of the tensioning and anchoring structure of the prestressed tendons in the embodiment of the utility model.

[0025] Figure numerals: 1- pier to be reinforced; 2- tensioning steel strip; 21- steel strip; 22- steel pad; 23- concave surface; 3- prestressed tendons; 4- steel grid; 5- slightly expansive concrete; 6- steel casing; 7- tensioning pedestal; 8- anchor bolt; 9- anchoring structure; 91- anchor plate; 92- anchor; 93- spiral tendons; 94- clip. DETAILED DESCRIPTION

[0026] A pier column reinforcement structure, such as Figure 1 , Figure 2 As shown, it includes tensioning steel strips 212, prestressed tendons 3, steel mesh 4, micro-expansion concrete 5 and steel casing 6, as shown in FIG. Figures 3 to 6 As shown, the tensioned steel strip 212 includes a steel strip 21 and a plurality of steel pads 22 arranged on the steel strip 21, the plurality of tensioned steel strips 212 are mutually parallel and wrapped around the outer surface of the pier 1 to be reinforced, and the bottom surface of the steel strip 21 is close to the outer surface of the pier 1 to be reinforced, the top of the steel pad 22 is in the shape of a concave surface 23, the prestressed tendon 3 is wrapped around and tensioned on the tensioned steel strip 212, and is positioned by the concave surface 23 on the top of the tensioned steel strip 212, the concave surface 23 is adapted to the shape of the prestressed tendon 3 after being wrapped, each tensioned steel strip 212 corresponds to a prestressed tendon 3, the steel bar grid 4 is arranged on the periphery of the prestressed tendon 3, and surrounds the prestressed tendon 3, the tensioned steel plate and the pier 1 to be reinforced, the steel casing 6 is arranged on the periphery of the steel bar grid 4, and the micro-expansive concrete 5 is filled between the steel casing 6 and the pier 1 to be reinforced. The steel casing 6 can be connected to the steel mesh 4 through tie bars.

[0027] The tensioning steel strips 212 can be prefabricated uniformly by the factory. The steel pads 22 and steel strips 21 can be made by welding or integrated molding. The steel plates are bent according to the existing bridge pier size and curved surface form. For the convenience of production, as one of the implementation methods, the steel strips 21 are bent into a semicircle, and two semicircular steel strips 21 are pasted and wrapped around the outer surface of the pier 1 to be reinforced, and after the prestressed tendons 3 are tensioned, the two ends of the two steel strips 21 are fixedly connected to each other. The height of the steel pads 22 is greater than 25mm, which can ensure that the concrete effectively wraps the prestressed tendons 3. At the same time, the top surface of the steel pads 22 is provided with a concave surface 23 to constrain the prestressed tendons 3 and avoid the prestressed tendons 3 from slipping during the tensioning process. The size and form of the pads and the concave surface 23 can be determined according to the type, quantity, size and form of the prestressed tendons 3.

[0028] The two ends of the tensioning steel strip 212 are connected to each other by bolt anchoring or welding. For example, grooves are set on the two ends of the steel strip 21 in advance, and the grooves are used as the base surface for butt welding later. The tensioning steel strip 212 can be customized uniformly after fixing the size according to the established pier size and prestressed tensioning related components, or it can be manufactured in batches for the reinforcement of regional piers.

[0029] As one embodiment, the joints of the plurality of parallel tensioned steel strips 212 are staggered in the vertical direction. The plurality of tensioned steel strips 212 can surround the outer surface of the pier 1 to be reinforced in an intermittent or fully distributed manner.

[0030] In order to realize the anchoring of the prestressed tendons 3 , the utility model further comprises a tensioning pedestal 7 for prestressing the prestressed tendons 3 , and the tensioning pedestal 7 is fixed to the pier 1 to be reinforced by anchor bolts 8 passing through the tensioning steel strips 212 .

[0031] As one embodiment, the tensioning pedestal 7 is a concrete pedestal, and a sleeve is reserved in the concrete pedestal for passing the prestressed tendons 3. The two ends of the prestressed tendons 3 pass through the sleeves and are tensioned and then fixed by the anchoring structure 9. The anchoring structure 9 can be an existing structure. Figure 7 , Figure 8 As shown, it includes an anchor plate 91, an anchor 92, a spiral reinforcement 93 and a clip 94. The spiral reinforcement 93 is pre-buried in the concrete pedestal, and the anchor plate 91 is also preset on the concrete pedestal. The anchor 92 is connected to the anchor plate 91. After the prestressed reinforcement 3 is bundled, it passes through the through holes on the anchor 92 and is fixed by the clip 94.

[0032] As another embodiment, the tensioning pedestal 7 is a steel box with reinforcing ribs arranged inside. The side of the steel box is provided with through holes, and both ends of the prestressed tendons 3 pass through the through holes respectively and are tensioned and then anchored by grouting.

[0033] After technical assessment of the original pier 1 to be reinforced, the strip tensioned steel plate structure set on the surface of the pier was tensioned and tightened to apply axial force, and the external casing reinforced concrete structure was used for restraint to form a three-way compressive composite stress state. The empirical formula for its longitudinal compressive strength is:

[0034] f cc =f c +kf1,

[0035] In the formula, f cc is the axial compressive strength under three-way compression; f c is the axial compressive strength of concrete; f1 is the lateral pressure (restraint force); k is the lateral pressure coefficient, 4.5-7, with an average value of 5.6.

[0036] The construction process of the utility model pier column reinforcement structure can be as follows:

[0037] 1. Prefabricated tensioned steel slats 212.

[0038] 2. Technical assessment: Conduct technical assessment on the piers that need to be repaired or reinforced, and at the same time clean, roughen and treat the cracks.

[0039] 3. Paste the steel plate. Paste the tensioned steel plate strip 212 on the surface of the pier column. It can be pasted in intervals or all over. After pasting and fixing, connect the seams on one side. The seams of the upper and lower steel plates should be staggered.

[0040] 4. Arrange the prestressed tendons 3. Arrange the prestressed tendons 3 at the lower concave surface 23 at the top of the steel pad 22, and perform preliminary tightening in combination with the anchor 92, the clamp and the tensioning pedestal 7 to prevent them from slipping.

[0041] 5. Prestressing. Prestressing is performed according to the technical evaluation results and design requirements. After the prestressing is completed, the other side of the prestressing steel strip 212 is connected. If the prestressing steel strip 212 is connected by welding, the prestressed tendons 3 need to be protected.

[0042] 6. Install the steel grid 4. The grid structure steel bars can be welded to the steel plate before arranging the prestressed bars 3, and the indirect posting steel plate structure can use embedded bars.

[0043] 7. Install the steel casing 6. The steel casing 6 needs to be installed in blocks, and the internal reinforcement is connected to the steel grid 4 by tensioning, and external support is set for fixing. The outer surface of the casing needs to be treated with anti-corrosion, and the steel casing 6 made of weathering steel can be used.

[0044] 8. Concrete pouring. The concrete shall be micro-expansion concrete 5, and its strength shall be one level higher than the original pier column structure. The vibration can be done by flat plate vibration.

[0045] 9. The sealing layer on the steel casing 6 is connected.

[0046] The present invention adopts the form of prestressing to actively improve the axial constraint of the original pier column, which can significantly improve its bearing capacity. The casing-type reinforced concrete structure can provide passive constraint and can also serve as an anti-corrosion structure for the tensioned steel strips 212. The enlarged cross-section structure can also improve its bending resistance.

[0047] The above detailed description is a specific description of a feasible embodiment of the utility model. The embodiment is not intended to limit the patent scope of the utility model. Any equivalent implementation or modification that does not deviate from the utility model should be included in the patent scope of this case.

Claims

1. A pier column reinforcement structure, characterized in that: It includes tensioned steel strips, prestressed tendons, steel grids, micro-expansive concrete and steel casings. The tensioned steel strips include steel strips and a number of steel pads arranged on the steel strips. The plurality of tensioned steel strips are mutually parallel and wrapped around the outer surface of the pier to be reinforced, and the bottom surface of the steel strips is in close contact with the outer surface of the pier to be reinforced. The top of the steel pad is concave. The prestressed tendons wrap around and are tensioned on the tensioned steel strips and are positioned by the concave surface on the top of the tensioned steel strips. Each tensioned steel strip corresponds to a prestressed tendon. The steel grid is arranged on the periphery of the prestressed tendons and surrounds the prestressed tendons, the tensioned steel plates and the pier to be reinforced. The steel casing is arranged on the periphery of the steel grid, and the micro-expansive concrete is filled between the steel casing and the pier to be reinforced.

2. A pier column reinforcement structure according to claim 1, characterized in that: The steel strips are bent into a semicircle, and two semicircular steel strips are pasted and wrapped around the outer surface of the pier to be reinforced. After the prestressed tendons are tensioned, the two ends of the two steel strips are bolted or welded to each other.

3. A pier column reinforcement structure according to claim 1, characterized in that: The joints of the plurality of parallel-arranged tension steel strips are staggered in the vertical direction.

4. The pier column reinforcement structure according to claim 1, characterized in that: It also includes a tensioning pedestal for prestressing the prestressed tendons, and the tensioning pedestal is fixed to the pier to be reinforced by anchor bolts passing through the tensioning steel strips.

5. A pier column reinforcement structure according to claim 4, characterized in that: The tensioning pedestal is a concrete pedestal, in which a sleeve is reserved for passing the prestressed tendons. Both ends of the prestressed tendons pass through the sleeves respectively and are tensioned and then fixed by an anchoring structure.

6. A pier column reinforcement structure according to claim 4, characterized in that: The tensioning pedestal is a steel box, and reinforcing ribs are arranged inside the steel box. The side of the steel box is provided with perforations, and the two ends of the prestressed tendons pass through the perforations respectively and are tensioned and then sealed and anchored by grouting.

7. The pier column reinforcement structure according to claim 1, characterized in that: The height of the steel pad is greater than 25 mm.

8. The pier column reinforcement structure according to claim 1, characterized in that: The steel pad is welded or integrated with the steel strip.

9. The pier column reinforcement structure according to claim 1, characterized in that: A plurality of the tensioned steel strips are spaced around the outer surface of the pier to be reinforced.

10. The pier column reinforcement structure according to claim 1, characterized in that: The steel casing is connected to the steel bar grid through tie bars.

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