Downward-bending and upward-bending driving device for broken-line pre-tensioning prestressed tendons

Abstract

The utility model discloses a broken line pre-tensioning method prestressed tendon downward-pressing bending driving device which comprises a precast beam bottom die and a tool steel strand, and further comprises a downward-pressing anchor device, a counter-force device and a downward-pressing driving device, the downward-pressing anchor device is located above the precast beam bottom die, and the counter-force device is located below the precast beam bottom die; the lower pressure anchor device comprises a lower pressure anchor limiting block and a lower pressure anchor piece, the tool steel strand sequentially penetrates through the lower pressure anchor piece, the lower pressure anchor limiting block, the precast beam bottom die and the middle of the counter-force device, and the lower pressure anchor limiting block is located above the precast beam bottom die and tightly connected with the precast beam bottom die. The lower pressure anchor piece is located above the lower pressure anchor limiting block, and the lower end of the lower pressure anchor piece is tightly connected with the lower pressure anchor limiting block. According to the utility model, the tool steel strand is adopted for anchor penetrating and pressing, and the bending angle is easy to control.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge engineering, in particular to a bending driving device for prestressed tendons using a folding line pre-tensioning method. Background Art

[0002] The pre-tensioned zigzag prestressed concrete beam is a new type of prestressed concrete beam that has been used in bridge engineering in my country in recent years. It overcomes the disadvantage that traditional pre-tensioned straight-line prestressed concrete components cannot be used for larger spans, and has the advantage of post-tensioned components that can change the linear shape of prestressed tendons, and can be used to build larger span concrete bridges; more importantly, it eliminates the processes of post-tensioning, such as reserved channels, reinforcing bars, and grouting, and fundamentally overcomes the disadvantage that the channel grouting of post-tensioned prestressed concrete beams is not easy to be dense, so that the prestressed tendons and concrete can be effectively bonded, which can avoid the corrosion of prestressed tendons caused by concrete cracking and significantly improve the durability of concrete bridges; due to some obvious advantages of the zigzag pre-tensioned concrete beam, it has begun to be used in cross-sea bridges, highway bridges and high-speed railway bridges at home and abroad in recent years.

[0003] Existing technical solutions: There are two main types of bender used in engineering projects: roller type and plate type; the roller type bender uses a circular cross-section guide roller to achieve the bending of the prestressed tendons, while the plate type often directly drills holes on the plate to achieve the fixation of the prestressed tendons. During prestressing, there is sliding friction between the steel strand and the traditional bender. After passing through the bender, the prestress loss value of the steel strand is large, which seriously reduces the safety of the prestressed beam in use. The steel plate pulled down by the traditional bender often exceeds the bottom surface of the beam and slab, and then is anchored to the foundation through the base. After the prestressing is released, the steel plate that exceeds the beam and slab needs to be cut, and the steel plate exposed on the surface of the beam and slab will form a corrosion channel, which is not conducive to the durability of the beam and slab concrete. The anchoring of the bender is relatively complicated, and it cannot be installed and disassembled quickly, and is not suitable for large-scale construction.

[0004] The existing prefabrication of prestressed concrete beams with broken lines is mainly done by the short-line method and the long-line method. Regardless of the short-line method or the long-line method, the installation of the bending system must be done before the steel strands of the web of the beam are tied together, and the side formwork, inner formwork and end formwork are installed only after the steel strands and non-prestressed steel bars are all tied in place. After the steel strands are released, the side formwork, end formwork and inner formwork must be removed, the bending constraint rods must be cut off, and finally the prestressed concrete beam must be hoisted. This construction process and the flipping speed of the formwork are completely unable to meet the needs of the general trend of industrialized production. Therefore, there is an urgent need for a production process for prefabricating prestressed concrete beams with broken lines without the need for a bending device to be put in place first and then pre-tightened, with a fast flipping speed, convenient and simple construction, short time, and fast prefabrication of prestressed concrete beams with broken lines. Summary of the invention

[0005] In order to solve the above-mentioned deficiencies in the prior art, the utility model proposes a bending driving device for prestressed tendons using a folding line pre-tensioning method.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions: a prestressed tendon bending driving device of a folding line pre-tensioning method, comprising a precast beam bottom mold and a tool steel strand, comprising a down-pressing anchor device, a reaction device and a down-pressing driving device, wherein the down-pressing anchor device is located above the precast beam bottom mold, and the reaction device is located below the precast beam bottom mold;

[0007] The down-pressure anchor device comprises a down-pressure anchor limit block and a down-pressure anchor member. The tool steel strand passes through the down-pressure anchor member, the down-pressure anchor limit block, the precast beam bottom mold, and the middle of the reaction device in sequence. The down-pressure anchor limit block is located above the precast beam bottom mold and is tightly connected to the precast beam bottom mold. The down-pressure anchor member is located above the down-pressure anchor limit block and its lower end is tightly connected to the down-pressure anchor limit block.

[0008] The downward pressure driving device includes a downward pressure fixed end through-core P anchor and a downward pressure driving end single anchor. The downward pressure fixed end through-core P anchor is sleeved on the tool steel strand and connected to the upper end of the downward pressure anchor. The downward pressure driving end single anchor is sleeved on the tool steel strand and tightly connected to the lower end of the reaction device.

[0009] Preferably, the down-pressing anchor comprises a first down-pressing block, a third down-pressing block and a plurality of second down-pressing blocks, the third down-pressing block, the second down-pressing block and the first down-pressing block are tightly connected in sequence from top to bottom, the first down-pressing block is tightly connected to the upper end of the precast beam bottom mold, and the upper end of the third down-pressing block is tightly connected to the down-pressing fixed end through-core P anchor.

[0010] Preferably, the reaction force device includes a bending reaction force shaft, two embedded channel steels and a fixing part for fixing the bending reaction force shaft and the embedded channel steel. The tool steel strand runs through the middle of the bending reaction force shaft. Embedded channel steels are provided on the upper ends of both sides of the bending reaction force shaft. The embedded channel steels are fixedly connected to the bending reaction force shaft through the fixing part.

[0011] Preferably, the fixing part includes a reaction shaft anchor bolt, a reaction shaft anchor nut, a channel steel gasket, a bent reaction shaft bushing and a bent reaction shaft seat. The reaction shaft anchor bolt passes through the embedded channel steel and the bent reaction shaft. One end of the reaction shaft anchor bolt is fixed by the reaction shaft anchor nut and the channel steel gasket, and the other end is fixed by the bent reaction shaft bushing and the bent reaction shaft seat.

[0012] Preferably, the single anchor at the downward pressure driving end includes a single anchor seat at the downward pressure driving end and a clip at the downward pressure driving end. The clip at the downward pressure driving end is located in the single anchor seat at the downward pressure driving end and is sleeved on the tool steel strand and tightly connected to the bending reaction shaft.

[0013] Preferably, a tool steel strand protection tube is sleeved on the third pressing block, and the tool steel strand protection tube is used to protect the tool steel strand and the pressing fixed end through-core P anchor.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] 1. Use tool steel strands to penetrate the anchor and press down, and the bending angle is easy to control.

[0016] 2. By setting up a bending operation platform and pre-burying the downward pressure reaction end, the construction operation is safe and controllable.

[0017] 3. Leave enough space under the reaction seat so that the jack can apply pressure with a larger stroke and press down in one go.

[0018] 4. The bending operation platform reserves sufficient adjustment space according to needs, which can meet the applicability adjustment of different beam lengths and different bending starting points.

[0019] 5. The device is used to turn, position, bend and shape the prestressed tendons of the precast beam, forming a way of arranging prestressed tendons that is suitable for its stress form. Its bending moment diagram is similar to the bending moment diagram of the beam under load, overcoming the disadvantage that the traditional pre-tensioned beam cannot be used for a larger span, and finding solutions to the current technical problems such as the loose grouting of the post-tensioned prestressed concrete duct, and the excessive local pressure at the tensioning end causing the concrete and anchor damage. The folded line pre-tensioned prestressed concrete beam is a new type of structure that has both the advantages of the traditional pre-tensioned structure and overcomes the disadvantages of the post-tensioned structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the utility model.

[0021] Markings in the figure: 2--downward pressure anchor limit block, 3--first downward pressure block, 5--second downward pressure block, 6--gasket, 7--third downward pressure block, 8--tool steel strand, 11--tool steel strand protection tube, 12--reaction shaft anchor bolt, 13--reaction shaft anchor nut, 14--gasket for channel steel, 15--bent reaction shaft, 16--bent reaction shaft bushing, 17--bent reaction shaft seat, 18--single anchor seat at downward pressure driving end, 19--clamp at downward pressure driving end, 20--embedded channel steel, 21--precast beam bottom formwork, 22--through P anchor at downward pressure fixed end. DETAILED DESCRIPTION

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0023] The utility model is described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1

[0025] like Figure 1 As shown, a prestressed tendon bending driving device for the folding line pre-tensioning method includes a precast beam bottom mold 21 and a tool steel strand 8, including a downward pressure anchor device, a reaction device and a downward pressure driving device, wherein the downward pressure anchor device is located above the precast beam bottom mold 21, and the reaction device is located below the precast beam bottom mold 21;

[0026] The down-pressure anchor device includes a down-pressure anchor limit block 2 and a down-pressure anchor. The tool steel strand 8 passes through the down-pressure anchor, the down-pressure anchor limit block 2, the precast beam bottom mold 21, and the middle part of the reaction device in sequence. The down-pressure anchor limit block 2 is first installed and fixed at the reserved notch position on the precast beam bottom mold 21. The down-pressing anchor comprises a first down-pressing block 3, a third down-pressing block 7 and a plurality of second down-pressing blocks 5, the third down-pressing block 7, the second down-pressing block 5 and the first down-pressing block 3 are tightly connected in sequence from top to bottom, the first down-pressing block 3 is tightly connected to the upper end of the precast beam bottom mold 21, the upper end of the third down-pressing block 7 is tightly connected to the down-pressing fixed end through-core P anchor 22, the down-pressing anchor limit block 2 is located above the precast beam bottom mold 21, and is tightly connected to the precast beam bottom mold 21, the down-pressing anchor is located above the down-pressing anchor limit block 2 and the lower end is tightly connected to the down-pressing anchor limit block 2, according to the number of layers of the bent beam, the corresponding number of second pressing blocks 5 are reasonably arranged; finally, a layer of down-pressing anchor block (upper) 7 is arranged, and according to different beam type designs, a bending operation platform with a longitudinal length of 1m along the pedestal is arranged at the prestressed tendon bending position (according to the site location and prefabrication requirements, the down-pressing reaction beam is pre-buried, and the construction operation is safe and controllable), and the platform is arranged in the space below the pedestal ground;

[0027] The downward driving device is composed of a single anchor seat at the downward driving end and a clamp at the downward driving end. When the steel strand is bent downward, the through-core P anchor at the downward fixed end passes through the tool steel strand and is locked at the upper end of the third pressing block 7. The tool steel strand 8 is tensioned and pressed downward by a double-headed front-clip jack to achieve the arrangement of prestressed tendons in accordance with the design requirements for the bent steel strands of the prefabricated beam body. The tool steel strand and the through-core P anchor 8 at the downward fixed end are protected by a tool steel strand protection tube 11. After the construction of the prefabricated beam is completed, the tool steel strand and the through-core P anchor 8 at the downward fixed end can be taken out and reused;

[0028] The reaction device mainly consists of three parts: embedded channel steel, bent reaction shaft and channel steel reaction shaft anchor. During the prefabrication design stage of the pedestal, two channel steels 20 are embedded at the position of the bent operation platform, and the bent reaction shaft 15 is installed under the embedded channel steel 20, and is anchored and locked through the bent reaction shaft seat 17 with the bent reaction shaft bushing 16 using the reaction shaft anchor bolt 12 + reaction shaft anchor nut + channel steel gasket.

[0029] In this embodiment, a tool steel strand protection tube 11 is sleeved on the third downward pressure anchor block 7, and the tool steel strand protection tube 11 is used to protect the tool steel strand 8 and the downward pressure fixed end through-core P anchor 22.

[0030] The above embodiments only express several implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the patent and protection scope of the utility model shall be subject to the attached claims.

Claims

1. A bending driving device for prestressed tendons by a folding line pretensioning method, comprising a precast beam bottom mold (21) and a tool steel strand (8), characterized in that: It comprises a downward pressure anchor device, a reaction force device and a downward pressure driving device, wherein the downward pressure anchor device is located above the precast beam bottom mold (21), and the reaction force device is located below the precast beam bottom mold (21); The down-pressure anchor device comprises a down-pressure anchor limit block (2) and a down-pressure anchor member, the tool steel strand (8) sequentially passes through the down-pressure anchor member, the down-pressure anchor limit block (2), the precast beam bottom mold (21), and the middle of the reaction device, the down-pressure anchor limit block (2) is located above the precast beam bottom mold (21) and is tightly connected to the precast beam bottom mold (21), and the down-pressure anchor member is located above the down-pressure anchor limit block (2) and its lower end is tightly connected to the down-pressure anchor limit block (2); The downward pressure driving device comprises a downward pressure fixed end through-core P anchor (22) and a downward pressure driving end single anchor. The downward pressure fixed end through-core P anchor (22) is sleeved on the tool steel strand (8) and connected to the upper end of the downward pressure anchor. The downward pressure driving end single anchor is sleeved on the tool steel strand (8) and tightly connected to the lower end of the reaction device.

2. A bending driving device for prestressed tendons by folding line pretensioning method as claimed in claim 1, characterized in that: The down-pressing anchor comprises a first down-pressing block (3), a third down-pressing block (7) and a plurality of second down-pressing blocks (5); the third down-pressing block (7), the second down-pressing block (5) and the first down-pressing block (3) are tightly connected in sequence from top to bottom; the first down-pressing block (3) is tightly connected to the upper end of the precast beam bottom mold (21); and the upper end of the third down-pressing block (7) is tightly connected to the down-pressing fixed end through-core P anchor (22).

3. A bending driving device for prestressed tendons by folding line pretensioning method as claimed in claim 1, characterized in that: The reaction device comprises a bending reaction shaft (15), two embedded channel steels (20) and a fixing member for fixing the bending reaction shaft (15) and the embedded channel steels (20), the tool steel strand (8) passes through the middle of the bending reaction shaft (15), and the upper ends of both sides of the bending reaction shaft (15) are provided with embedded channel steels (20), and the embedded channel steels (20) are fixedly connected to the bending reaction shaft (15) through the fixing member.

4. A bending driving device for prestressed tendons by folding line pretensioning method as claimed in claim 3, characterized in that: The fixing part comprises a reaction shaft anchor bolt (12), a reaction shaft anchor nut (13), a channel steel gasket (14), a bent reaction shaft bushing (16) and a bent reaction shaft seat (17); the reaction shaft anchor bolt (12) passes through the embedded channel steel (20) and the bent reaction shaft (15); one end of the reaction shaft anchor bolt (12) is fixed by the reaction shaft anchor nut (13) and the channel steel gasket (14), and the other end is fixed by the bent reaction shaft bushing (16) and the bent reaction shaft seat (17).

5. A bending driving device for prestressed tendons by folding line pretensioning method as claimed in claim 4, characterized in that: The single anchor at the downward pressure driving end comprises a single anchor seat (18) at the downward pressure driving end and a clip (19) at the downward pressure driving end. The clip (19) at the downward pressure driving end is located in the single anchor seat (18) at the downward pressure driving end and is sleeved on the tool steel strand (8) and tightly connected to the bending reaction shaft (15).

6. A bending driving device for prestressed tendons by folding line pretensioning method as claimed in claim 2, characterized in that: The third pressing block (7) is sleeved with a tool steel strand protection tube (11), and the tool steel strand protection tube (11) is used to protect the tool steel strand (8) and the pressing fixed end through-core P anchor (22).

Images