A semi-fixed constraint device and construction method for lengthening a rigid-frame bridge pier

Abstract

The present invention discloses a semi-fixed constraint device and a construction method for lengthening a rigid-frame bridge pier. The semi-fixed constraint device includes a lower bridge pier and an upper bridge pier. A lower fixing device is arranged at the upper end of the lower bridge pier, and an upper sliding device is arranged at the lower end of the upper bridge pier. The upper sliding device is assembled with the lower fixing device and can be adjusted by sliding. An elongation adjustment space is also formed between the upper sliding device and the lower fixing device. The construction method includes the following steps: constructing the bridge pier; cutting off the main reinforcement bars of the bridge pier between the lower fixing device and the upper sliding device, and chiseling the concrete therebetween; installing a jack for jacking operation; installing an embedded steel plate; pouring concrete to seal the inner cavity gap of the cover plate, and removing the jack; connecting the main reinforcement bars of the bridge pier between the lower fixing device and the upper sliding device in an equal-strength manner, and binding stirrups and tie bars; pouring the post-lifting pier body concrete. The present invention can meet the transformation objectives such as safety and environmental protection, rapidity and high efficiency, and low traffic impact during the structural upgrading and transformation process.

Description

Technical Field

[0001] The invention belongs to the field of bridge structure construction, and particularly relates to a semi-fixed constraint device and a construction method for lengthening a rigid-frame bridge pier. Background Art

[0002] The continuous rigid-frame system without bearings has large structural stiffness, good integrity, can significantly reduce the size of bridge piers, has good economy, and at the same time has good durability and convenience in operation and maintenance. In recent years, it has been more and more widely used in rail transit and high-speed railway bridges. In soft soil and karst areas, due to large differential settlement and deformation of the foundation, the continuous rigid-frame system without bearings cannot be adjusted in height through bearings, and settlement reset is often required.

[0003] To realize the function upgrade and settlement reset of the continuous rigid-frame bridge without bearings, cutting off the bridge pier and jacking it up is a feasible construction method. Compared with demolition and reconstruction, it has a short construction period, low cost, less impact on traffic, and less environmental pollution.

[0004] The traditional method of cutting off and jacking up the bridge pier is to directly cut off the bridge pier, use a jacking device to jack it up to the design elevation, and then reinforce and reconnect the upper and lower parts of the cut-off bridge pier. Since the continuous rigid-frame system without bearings is a statically indeterminate structure and the bridge pier is a compression-bending member, if the traditional method of cutting off and jacking up the bridge pier is used, it will cause redistribution of structural internal forces, and there are safety risks in the force of the beam part.

[0005] Therefore, in the area where the bending moment in the middle of the rigid-frame bridge pier is small, a semi-fixed constraint device is studied to realize the longitudinal elongation deformation of the bridge pier, and at the same time, it can resist bending moment, shear force and torque, meet the force requirements of the pier body, and ensure the relative stability of the structure force without causing redistribution of internal forces. Summary of the Invention

[0006] The invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a semi-fixed constraint device and a construction method for lengthening a rigid-frame bridge pier.

[0007] The technical solution of the invention is: a semi-fixed constraint device for lengthening a rigid-frame bridge pier, including a lower bridge pier and an upper bridge pier. A lower fixing device is arranged at the upper end of the lower bridge pier, and an upper sliding device is arranged at the lower end of the upper bridge pier. The upper sliding device is assembled with the lower fixing device, and the upper sliding device can slide and adjust with the lower fixing device as a guide. An elongation adjustment space is also formed between the upper sliding device and the lower fixing device.

[0008] Furthermore, the sliding direction between the upper sliding device and the lower fixing device is parallel to the center line of the lower bridge pier and the upper bridge pier.

[0009] Furthermore, a matching structure for facilitating the passage of the main reinforcement of the bridge pier is formed in both the upper sliding device and the lower fixing device.

[0010] Furthermore, the fixing method between the upper sliding device and the upper pier is embedded connection, and the fixing method between the lower fixing device and the lower pier is also embedded connection.

[0011] Furthermore, the lower fixing device includes a base plate, and an outer steel plate of a convex platform is arranged at the upper end of the base plate. The outer steel plates of the convex platform enclose to form a guiding foundation for the outer wall.

[0012] Furthermore, the upper sliding device includes a top cover plate, and a cover plate is arranged at the lower end of the top cover plate. The cover plates enclose to form a sliding space, and the sliding space is sleeved on the guiding foundation, and a clearance fit is provided between the sliding space and the guiding foundation.

[0013] Furthermore, the inner space enclosed by the outer steel plates of the convex platform is filled with inner concrete of the convex platform, and a tetrafluoroethylene sliding plate is arranged at the outer wall of the outer steel plates of the convex platform.

[0014] Furthermore, a reinforcing structure is arranged at the outer wall of the cover plate, and the reinforcing structure is a stiffening plate, and the upper end of the stiffening plate is connected to the top cover plate.

[0015] Furthermore, a jack for lifting the upper pier is arranged in the lengthening and adjusting space during lifting, and post-lifting pier body concrete is poured in the lengthening and adjusting space after lifting.

[0016] A construction method of a semi-fixed constraint device for rigid frame pier lengthening includes the following steps:

[0017] A. Construct the pier, and construct and install the lower fixing device and the upper sliding device to the designed positions;

[0018] B. Cut off the main reinforcement bars of the pier between the lower fixing device and the upper sliding device, and chisel the concrete between them;

[0019] C. Install the jack, and lift the upper pier and the upper sliding device;

[0020] D. After lifting to the designed elevation, install the embedded steel plate;

[0021] E. Pour concrete to seal the inner cavity gap of the cover plate, and remove the jack;

[0022] F. Connect the main reinforcement bars of the pier between the lower fixing device and the upper sliding device with equal strength, and tie the stirrups and tie bars;

[0023] G. Set up the formwork, and pour the post-lifting pier body concrete between the base plate and the top cover plate.

[0024] The beneficial effects of the present invention are as follows:

[0025] The present invention adopts a semi-fixed restraint device in the area with relatively small bending moment in the middle of the bridge pier. This device can realize the longitudinal elongation deformation of the bridge pier, and at the same time can resist bending moment, shear force and torque to meet the stress requirements of the pier body, ensure relatively stable structural stress, not cause internal force redistribution, and has simple construction, avoiding the use of a large number of temporary auxiliary measures, and can meet the renovation goals such as safety, environmental protection, high speed and efficiency, and low traffic impact during the structural lifting and renovation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the elevation view of the overall structure of the present invention;

[0027] Figure 2 is the side view of the overall structure of the present invention;

[0028] Figure 3 is the plan view of the lower fixing device of the present invention;

[0029] Figure 4 is the elevation view of the lower fixing device of the present invention;

[0030] Figure 5 is the plan view of the upper sliding device of the present invention;

[0031] Figure 6 is the elevation view of the upper sliding device of the present invention;

[0032] Figure 7 is the schematic diagram of the installation position of the device in the embodiment of the present invention;

[0033] Figure 8 is the schematic diagram of the first construction step before the bridge pier lifting and renovation of the present invention;

[0034] Figure 9 is the schematic diagram of the second construction step before the bridge pier lifting and renovation of the present invention;

[0035] Figure 10 is the schematic diagram of the third construction step before the bridge pier lifting and renovation of the present invention;

[0036] Figure 11 is the schematic diagram of the first construction step during the bridge pier lifting and renovation of the present invention;

[0037] Figure 12 is the schematic diagram of the second construction step during the bridge pier lifting and renovation of the present invention;

[0038] Figure 13 is the schematic diagram of the third construction step during the bridge pier lifting and renovation of the present invention;

[0039] Figure 14 is the schematic diagram of the fourth construction step during the bridge pier lifting and renovation of the present invention;

[0040] Figure 15 It is a schematic diagram of the fifth construction step during the pier lifting and reconstruction of the present invention;

[0041] Among them:

[0042] 1 Lower fixing device 2 Upper sliding device

[0043] 3 Embedded connecting piece 4 Lower pier

[0044] 5 Upper pier 6 Pier main reinforcement

[0045] 8 Jack 9 Embedded fixing steel plate

[0046] 10 Inner cavity concrete cast after jacking 11 Pier body concrete cast after jacking

[0047] 1-1 Base plate 1-2 Outer steel plate of convex platform

[0048] 1-3 Teflon slide plate 1-4 Inner concrete of convex platform

[0049] 2-1 Top cover plate 2-2 Cover plate

[0050] 2-3 Stainless steel plate 2-4 Stiffening plate

[0051] 6-1 Nut

[0052] 7-1 Reserved position for jack support foot 7-2 Reserved position for jack piston. Specific implementation mode

[0053] Hereinafter, the present invention will be described in detail with reference to the drawings and embodiments:

[0054] As Figures 1 to 15 shown, a semi-fixed constraint device for rigid frame pier extension includes a lower pier 4 and an upper pier 5. A lower fixing device 1 is provided at the upper end of the lower pier 4, and an upper sliding device 2 is provided at the lower end of the upper pier 5. The upper sliding device 2 is assembled with the lower fixing device 1, and the upper sliding device 2 can slide and adjust with the lower fixing device 1 as a guide. An extension adjustment space is also formed between the upper sliding device 2 and the lower fixing device 1.

[0055] The sliding direction between the upper sliding device 2 and the lower fixing device 1 is parallel to the center lines of the lower pier 4 and the upper pier 5.

[0056] Matching structures facilitating the passing of pier main reinforcement 6 are formed in both the upper sliding device 2 and the lower fixing device 1.

[0057] The fixing method between the upper sliding device 2 and the upper pier 5 is embedded connection, and the fixing method between the lower fixing device 1 and the lower pier 4 is embedded connection.

[0058] The lower fixing device 1 includes a base plate 1-1, and a convex outer steel plate 1-2 is arranged at the upper end of the base plate 1-1. The convex outer steel plate 1-2 encloses to form a guiding foundation for outer wall guiding.

[0059] The upper sliding device 2 includes a top cover plate 2-1, and a cover plate 2-2 is arranged at the lower end of the top cover plate 2-1. The cover plate 2-2 encloses to form a sliding space, and the sliding space is sleeved on the guiding foundation, and there is a clearance fit between the sliding space and the guiding foundation.

[0060] Convex inner concrete 1-4 is poured in the inner space enclosed by the convex outer steel plate 1-2, and a tetrafluoroethylene slide plate 1-3 is arranged at the outer wall of the convex outer steel plate 1-2.

[0061] A reinforcing structure is arranged at the outer wall of the cover plate 2-2, and the reinforcing structure is a stiffening plate 2-4. The upper end of the stiffening plate 2-4 is connected to the top cover plate 2-1.

[0062] A jack 9 for lifting the upper pier 5 is arranged in the lengthening and adjusting space during lifting, and post-lifting cast-in-place pier body concrete 11 is poured in the lengthening and adjusting space after lifting.

[0063] Specifically, the lower end of the base plate 1-1 is connected to the lower pier 4 through a pre-embedded connecting piece 3, so as to realize the consolidation of the lower fixing device 1 and the lower pier 4. Correspondingly, the upper end of the top cover plate 2-1 is connected to the upper pier 5 through a pre-embedded connecting piece 3, so as to realize the consolidation of the upper sliding device 2 and the upper pier 5.

[0064] Specifically, the base plate 1-1 and the top cover plate 2-1 are parallel, and the base plate 1-1 and the top cover plate 2-1 have the same shape.

[0065] More preferably, the matching structures in the base plate 1-1 and the top cover plate 2-1 are both grooves, and the positions of the grooves correspond to the positions of the pier main reinforcement 6 in the pier. The pier main reinforcement 6 can pass through the above grooves.

[0066] More preferably, the pier main reinforcement 6 is placed in the groove, and two nuts 6-1 are penetrated through the pier main reinforcement 6 and are respectively fastened to the upper edge of the base plate 1-1 and the lower edge of the top cover plate 2-1.

[0067] The following is a structural description of the lower fixing device 1 and the upper sliding device 2

[0068] Specifically, the lower fixing device 1 includes a base plate 1-1, an outer steel plate of the convex platform 1-2, a tetrafluoroethylene slide plate 1-3, and in-convex-platform concrete 1-4. The outer steel plate of the convex platform 1-2 is welded into a box shape and welded to the base plate 1-1. The tetrafluoroethylene slide plate 1-3 is pasted on the outer surface of the outer steel plate of the convex platform 1-2. The in-convex-platform concrete 1-4 is filled in the box-shaped cavity formed by welding the outer steel plate of the convex platform 1-2.

[0069] Specifically, the upper sliding device 2 includes a top cover plate 2-1, a cover plate 2-2, a stainless steel plate 2-3, and a stiffening plate 2-4. The cover plate 2-2 is welded into a box shape and welded to the top cover plate 2-1. The stainless steel plate 2-3 is pasted on the inner surface of the cover plate 2-2. The side wall of the stiffening plate 2-4 is welded to the outer surface of the cover plate 2-2, and the bottom is welded to the top cover plate 2-1 to stiffen the cover plate 2-2.

[0070] The embedded connecting piece 3 is welded to the surfaces of the base plate 1-1 and the top cover plate 2-1. There are multiple embedded connecting pieces 3.

[0071] The tetrafluoroethylene slide plate 1-3 and the stainless steel plate 2-3 are closely attached to form a sliding surface, and the surface of the sliding surface is fully coated with anti-corrosion lubricating grease.

[0072] An elongation adjustment space is formed between the upper sliding device 2 and the lower fixing device 1. For the elongation adjustment space, jack operation spaces are reserved on both sides of the lower fixing device 1 and the upper sliding device 2. The position of the jack support foot 7-1 is located on the base plate 1-1, and the position of the jack piston 7-2 is located on the top cover plate 2-1. The position of the jack support foot 7-1 and the position of the piston 7-2 correspond up and down.

[0073] The concrete between the base plate 1-1 and the top cover plate 2-1 needs to be chiseled off first and then re-poured during the pier lifting and renovation. The main pier reinforcement bars 6 need to be cut off first and then connected with equal strength.

[0074] Specifically, the cross-section of the guiding foundation formed by enclosing the outer steel plate of the convex platform 1-2 can be, but is not limited to, a rectangle.

[0075] Specifically, the lower fixing device 1 is installed at the position where the constant load bending moment of the pier is the smallest.

[0076] A construction method for a semi-fixed constraint device for rigid frame pier elongation includes the following steps:

[0077] A. Construct the pier and install the lower fixing device and the upper sliding device to the designed positions.

[0078] B. Cut off the main pier reinforcement bars between the lower fixing device and the upper sliding device, and chisel off the concrete between the two.

[0079] C. Install the jacks and lift the upper pier and the upper sliding device.

[0080] D. After jacking up to the design elevation, install the embedded steel plate;

[0081] E. Pour concrete to seal the inner cavity gap of the cover plate and remove the jack;

[0082] F. Connect the main reinforcement bars of the pier between the lower fixing device and the upper sliding device by equal-strength connection, and bind the stirrups and tie bars;

[0083] G. Set up the formwork and pour the post-lifting pier body concrete between the base plate and the top cover plate.

[0084] Specifically, for step A, construct the pier and install the lower fixing device and the upper sliding device to the design positions. The specific process is as follows:

[0085] First, complete the welding of the lower fixing device 1, the upper sliding device 2 and the embedded connecting piece 3 in the factory;

[0086] Then, after binding the steel bars of the lower pier 4 and before pouring the concrete, select the position with the minimum dead load bending moment of the pier to install the lower fixing device 1, and pour the concrete of the lower pier 4 and the concrete 1-4 in the boss;

[0087] Next, fully coat the tetrafluoroethylene slide plate with anti-corrosion lubricating grease, install the upper sliding device 2, and tighten the nut 6-1 of the main reinforcement bar of the pier;

[0088] Finally, bind the steel bars and pour the concrete between the base plate 1-1 and the top cover plate 2-1 and the concrete of the upper part 5 of the pier.

[0089] Specifically, for step B, cut off the main reinforcement bars of the pier between the lower fixing device and the upper sliding device, and chisel the concrete between them. The specific process is as follows:

[0090] First, cut off the main reinforcement bar 6 of the pier between the base plate 1-1 and the top cover plate 2-1;

[0091] Then, chisel the concrete between the base plate 1-1 and the top cover plate 2-1.

[0092] Specifically, for step C, install the jack and jack up the upper pier and the upper sliding device. The specific process is as follows:

[0093] First, install the jack at the reserved jack support position 7-1 and the reserved jack piston position 7-2 between the base plate 1-1 and the top cover plate 2-1;

[0094] Then, in this embodiment, install the jacks on both sides of the lower fixing device 1 one by one;

[0095] Finally, the jack jacks up the upper sliding device 2 and the upper pier 5.

[0096] Specifically, after the step D is jacked up to the design elevation, the embedded steel plate is installed, and the specific process is as follows:

[0097] First, the upper sliding device 2 and the upper pier 5 are jacked up to the design elevation by a jack;

[0098] Then, the embedded steel plate 9 is installed;

[0099] Finally, the embedded steel plate 9 is welded to the cover plate 2-2, the stiffening plate 2-4 and the base plate 1-1.

[0100] In the present invention, a semi-fixed restraint device is adopted in the area with a relatively small bending moment in the middle of the pier. This device can realize the longitudinal elongation deformation of the pier, and at the same time can resist bending moment, shear force and torque to meet the force requirements of the pier body, ensure the relatively stable force of the structure, do not cause internal force redistribution, and has simple construction and avoids using a large number of temporary auxiliary measures, which can meet the transformation goals such as safety, environmental protection, high speed and efficiency, and low traffic impact during the structure lifting and transformation process.

[0101] The above embodiments have described the present invention in detail, but the described content is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. Any equivalent changes and improvements made according to the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A construction method of a semi-fixed constraint device for lengthening a rigid-frame bridge pier. The device includes a lower bridge pier (4) and an upper bridge pier (5). A lower fixing device (1) is provided at the upper end of the lower bridge pier (4), and an upper sliding device (2) is provided at the lower end of the upper bridge pier (5). The upper sliding device (2) is assembled with the lower fixing device (1), and the upper sliding device (2) can slide and adjust with the lower fixing device (1) as a guide. An elongation adjustment space is also formed between the upper sliding device (2) and the lower fixing device (1). The construction method is characterized in that: It includes the following steps: A. Construct the bridge pier and install the lower fixing device and the upper sliding device at the designed positions. B. Cut off the main reinforcement bars of the bridge pier between the lower fixing device and the upper sliding device, and chisel the concrete between them. C. Install the jacks and lift the upper bridge pier and the upper sliding device. D. After lifting to the designed elevation, install the embedded steel plates. E. Pour concrete to seal the inner cavity gap of the cover plate and remove the jacks. F. Connect the main reinforcement bars of the bridge pier between the lower fixing device and the upper sliding device with equal strength, and tie the stirrups and tie bars. G. Set up the formwork and pour the post-lifting pier body concrete between the base plate and the top cover plate. The lower fixing device (1) includes a base plate (1-1), and a convex outer steel plate (1-2) is arranged at the upper end of the base plate (1-1). The convex outer steel plate (1-2) encloses to form a guiding foundation with an outer wall guide. The upper sliding device (2) includes a top cover plate (2-1), and a cover plate (2-2) is arranged at the lower end of the top cover plate (2-1). The cover plate (2-2) encloses to form a sliding space, and the sliding space is sleeved on the guiding foundation. There is a clearance fit between the sliding space and the guiding foundation. Convex inner concrete (1-4) is poured in the internal space enclosed by the convex outer steel plate (1-2), and a tetrafluoroethylene sliding plate (1-3) is arranged at the outer wall of the convex outer steel plate (1-2). A reinforcing structure is arranged at the outer wall of the cover plate (2-2), and the reinforcing structure is a stiffening plate (2-4). The upper end of the stiffening plate (2-4) is connected to the top cover plate (2-1). In the lengthening and adjusting space, jacks (9) for lifting the upper bridge pier (5) are arranged during lifting, and post-lifting pier body concrete (11) is poured after lifting. In step A, construct the bridge pier and install the lower fixing device and the upper sliding device at the designed positions. The specific process is as follows: First, complete the welding of the lower fixing device (1), the upper sliding device (2) and the embedded connecting parts (3) in the factory. Then, after the steel bars of the lower bridge pier (4) are tied and before the concrete is poured, select the position with the minimum dead load bending moment of the bridge pier to install the lower fixing device (1), and pour the concrete of the lower bridge pier (4) and the convex inner concrete (1-4). After that, coat the tetrafluoroethylene sliding plate with anti-corrosion lubricating grease, install the upper sliding device (2), and tighten the nuts (6-1) of the main reinforcement bars of the bridge pier. Finally, tie the steel bars and pour the concrete between the base plate (1-1) and the top cover plate (2-1) and the concrete of the upper bridge pier (5). In step B, cut off the main reinforcement bars of the bridge pier between the lower fixing device and the upper sliding device, and chisel the concrete between them. The specific process is as follows: First, cut off the main reinforcement bars (6) of the bridge pier between the base plate (1-1) and the top cover plate (2-1). Then, chisel the concrete between the base plate (1-1) and the top cover plate (2-1). In step C, install the jacks and lift the upper bridge pier and the upper sliding device. The specific process is as follows: Install the jacks at the reserved jack support positions (7-1) and the reserved jack piston positions (7-2) between the base plate (1-1) and the top cover plate (2-1). Then, the jacks on both sides of the lower fixing device (1) are installed one by one; Finally, the jacks lift the upper sliding device (2) and the upper pier (5); After the jacks in step D are lifted to the design elevation, the embedded steel plates are installed, and the specific process is as follows: First, the upper sliding device (2) and the upper pier (5) are lifted to the design elevation by the jacks; Then, the embedded steel plates (9) are installed; Finally, the embedded steel plates (9) are welded to the cover plate (2-2), the stiffening plate (2-4) and the base plate (1-1).

2. The construction method of a semi-fixed constraint device for the lengthening of a rigid frame bridge pier according to claim 1, characterized in that: The sliding direction between the upper sliding device (2) and the lower fixing device (1) is parallel to the center line of the lower pier (4) and the upper pier (5).

3. The construction method of a semi-fixed constraint device for rigid frame bridge pier lengthening according to claim 1, characterized in that: A matching structure facilitating the passing of the main reinforcement bars (6) of the pier is formed in both the upper sliding device (2) and the lower fixing device (1).

4. The construction method of a semi-fixed constraint device for connecting and lengthening rigid frame bridge piers according to claim 1, characterized in that: The fixing method between the upper sliding device (2) and the upper pier (5) is pre-buried connection, and the fixing method between the lower fixing device (1) and the lower pier (4) is pre-buried connection.

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