Prestressed rigid beam segmented tensioning construction method

Abstract

The present application relates to a kind of prestressed stiff beam segmented tension construction method, it relates to the technical field of construction, it includes prestressed stiff beam construction according to subarea advancement, in turn complete support formwork support setting, prestressed beam and non-prestressed beam steel banding.Deepening design stage optimization beam-column joint and stiff column structure, adjust beam-column reinforcement arrangement, avoid prestressed pipe and steel member collision, clear prestressed tendon burying and tensioning space.Prestressed construction stage embedded bellows, wear bundle and reserve grouting exhaust hole, after acceptance grouting concrete.When strength reaches standard, complete equipment calibration, quality detection and platform erection, to cantilever beam segmented tension and check elongation, implement over-tension anchoring.Tensioning in time hole grouting, seal anchor, realize prestressed tendon and concrete integrated combination, complete prestressed stiff beam forming construction.The present application can improve the construction quality of cantilever prestressed beam.

Description

Technical Field

[0001] This invention relates to the technical field of building construction, and in particular to a method for segmented tensioning construction of prestressed stiffened beams. Background Technology

[0002] In building construction, prestressed stiffened beam technology is widely used in large-span building structures to improve the crack resistance and load-bearing capacity of the structure. Concrete has extremely high compressive strength but extremely low tensile strength. When ordinary reinforced concrete beams are subjected to load, cracks are very likely to appear first in the tensile zone. The propagation of cracks will reduce the structural stiffness and durability, and even affect the load-bearing capacity.

[0003] Currently, in frame beam structures, prestressing and pre-tension are applied. By tensioning the prestressing tendons, the elastic recoil force of the prestressing tendons is used to apply active and uniform pre-compressive stress to the tension zone of the concrete beam. When the beam is subjected to loads during its service life, the loads will cause tensile stress in the tension zone of the beam. At this time, the pre-applied pre-compressive stress will cancel out the tensile stress generated by the load. Ultimately, the concrete in the tension zone of the beam is always in a state of compressive stress or low tensile stress, thus avoiding cracks in the concrete due to tension. At the same time, the prestressing tendons work together with ordinary steel bars and concrete to give full play to the performance advantages of each material.

[0004] Regarding the aforementioned technologies, during the construction of cantilever prestressed beams, the collision between prestressed ducts and steel components, as well as the limited space for tensioning operations, can easily lead to excessive bending or even damage of the prestressed ducts during construction, seriously affecting the construction quality. Summary of the Invention

[0005] To improve the construction quality of cantilever prestressed beams, this invention provides a method for segmented tensioning of prestressed stiffened beams.

[0006] This invention provides a method for segmental tensioning construction of prestressed stiffened beams, employing the following technical solution: A method for segmental tensioning of prestressed stiffened beams includes the following steps: Zoning plan: In each construction zone, the prestressed beam support formwork erection, prestressed beam ordinary steel bar binding, and non-prestressed beam steel bar binding are completed sequentially; Detailed design: Detailed design of the stiffened column at the beam-column joint is carried out, the arrangement of column reinforcement and beam reinforcement is adjusted, collisions between prestressed ducts and steel components are avoided, and the location of prestressed tendon embedment and tensioning operation space are planned. Prestressed tendon pre-embedding construction: Corrugated pipes are laid and fixed in the prestressed beam, prestressed tendons are inserted, grouting holes and vent holes are left, the bearing plate structure is installed, and after the concealed works are accepted, the beam concrete is poured. Preparations before tensioning: After the concrete of the beam reaches the design strength requirements, complete the calibration and inspection of the tensioning equipment, the quality inspection of the beam structure, the erection of the tensioning operation platform, and the cleaning of the anchor plates and the centering and installation of the anchors and tensioning equipment. Segmented tensioning at the cantilever end: The cantilever prestressed beam is tensioned in segments using tensioning equipment to establish effective prestress. During the tensioning process, the elongation of the prestressing tendons is checked. After tensioning is completed, over-tensioning is performed and the beam is anchored. Forming and construction: After tensioning, the prestressing ducts are grouted in a timely manner to bond the prestressing tendons to the beam concrete as a whole. The tensioning ends are then sealed and anchored to complete the construction of the prestressed stiffened beam.

[0007] Preferably, the detailed design includes adjustments to the column reinforcement and beam reinforcement to ensure sufficient clearance between the prestressed ducts and steel components.

[0008] Preferably, when the corrugated pipe is laid out, a welded fixing bracket is used to position and fix the corrugated pipe, and the corrugated pipe joint is sealed with a special connector.

[0009] Preferably, when the prestressing tendons are installed, protective components are provided at the ends of the prestressing tendons.

[0010] Preferably, the pressure plate structure includes an end template, a sealing element, a pressure plate, and a spiral rib. The pressure plate is fixedly sleeved on one end of the corrugated pipe, the sealing element is filled between the pressure plate and the corrugated pipe, one end of the spiral rib is fixed to the pressure plate, and one end of the pressure plate is fixedly connected to the end template by bolts. The tensioning device includes a hydraulic cylinder, a machine body, fixed anchor bolts, a fixed sleeve, a telescopic sleeve, and a fixed mold. One end of the fixed sleeve abuts against the end template. The fixed anchor bolts are arranged circumferentially through the fixed sleeve. The telescopic sleeve is slidably fitted inside the fixed sleeve, and one end of the telescopic sleeve is engaged with the machine body. The hydraulic cylinder is fixedly installed on the machine body, and the telescopic rod of the hydraulic cylinder abuts against one end of the fixed sleeve. The fixed mold is disposed inside the machine body, and the fixed mold is provided with fixing holes for fixing prestressing tendons. One end of the fixed mold is fixedly connected to the telescopic rod of the hydraulic cylinder.

[0011] Preferably, the body of the machine has a snap-fit ​​groove, and the outer end of the telescopic sleeve is fixedly installed with multiple snap-fit ​​blocks.

[0012] Preferably, a fixing plate extends from one end of the fixing sleeve, the fixing plate is fixedly connected to the end template by bolts, a plurality of sliding grooves are provided inside the fixing sleeve, and a plurality of sliding blocks are provided on the outer circumferential surface of the telescopic sleeve, the telescopic sleeve slides inside the fixing sleeve through the sliding blocks and the sliding grooves.

[0013] Preferably, a plurality of clamping plates are slidably disposed inside the fixed sleeve. One end of the clamping plate is rotatably connected to the fixed anchor bolt through a rotating component, and the other end of the clamping plate abuts against the outer peripheral surface of the telescopic sleeve. The clamping plate is arranged in an arc shape.

[0014] Preferably, an abutment ring is fixedly installed on the outer circumferential surface of the fixed sleeve, and the telescopic rod of the hydraulic cylinder abuts against the abutment ring.

[0015] Preferably, an arc-shaped pressure plate is installed on the corrugated pipe, a vent pipe is fixedly installed at the upper end of the arc-shaped pressure plate, a buffer pad is provided between the arc-shaped pressure plate and the corrugated pipe, and the arc-shaped pressure plate is fixed to the corrugated pipe by a fixing ring.

[0016] In summary, the present invention has at least one of the following beneficial technical effects: 1. Detailed design of stiffened columns at beam-column joints to avoid collisions between prestressed ducts and steel components from the source, reduce component adjustments and rework during on-site construction, and lower the construction difficulty of complex joints; standardize the entire process from prestressed tendon embedding to forming construction, and focus on the pain points of cantilever prestressed beam construction through segmented tensioning, effectively establish prestress, prevent deformation and cracking of cantilever structures, and improve the construction quality of cantilever beam structures.

[0017] 2. By clearly defining the targeted adjustment requirements for column and beam reinforcement, the clearance space between prestressed ducts and steel components is precisely guaranteed, avoiding problems such as duct disassembly and re-binding of reinforcement due to space conflicts during subsequent construction. This further simplifies the on-site construction operation of beam-column joints and reduces the difficulty of laying prestressed ducts in complex stiffened structures.

[0018] 3. Installing protective components at the ends of prestressing tendons can effectively prevent the tendons from puncturing the corrugated pipe wall during the tendon installation process, avoid corrugated pipe damage and grout leakage, reduce damage to embedded pipes during tendon installation, reduce the extra construction workload of corrugated pipe repair, and improve the construction efficiency of prestressing tendon installation.

[0019] 4. Through the coordinated design of components such as hydraulic cylinders, fixed molds, and telescopic sleeves, the prestressed tendons are precisely clamped and tensioned, ensuring the alignment accuracy between the tensioning equipment, anchor plates, and prestressed tendons, improving the stress control accuracy of segmented tensioning, and adapting to the construction requirements of segmented tensioning of cantilever beams; the matching design of the bearing plate structure and tensioning equipment reduces the adaptation and adjustment time between the equipment and embedded components, and reduces the difficulty of equipment debugging during on-site tensioning operations. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the construction positions of the pressure plate and the corrugated pipe in Embodiment 2 of the present invention; Figure 3This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 4 yes Figure 3 A diagram from another perspective; Figure 5 yes Figure 3 A schematic diagram of the cross-sectional view; Figure 6 yes Figure 3 A schematic diagram of the structure after the machine body has been concealed; Figure 7 This is a schematic diagram of the organism's structure; Figure 8 This is a cross-sectional view of the location of the arc-shaped pressure plate.

[0021] Explanation of reference numerals in the attached drawings: 101, end template; 102, sealing element; 103, pressure plate; 104, spiral rib; 105, corrugated pipe; 106, arc-shaped pressure plate; 107, vent pipe; 108, buffer pad; 201, hydraulic cylinder; 202, machine body; 203, fixed anchor bolt; 204, fixed sleeve; 205, telescopic sleeve; 206, fixed mold; 207, fixed hole; 208, snap-fit ​​groove; 209, snap-fit ​​block; 210, sliding groove; 211, sliding block; 212, clamping plate; 213, abutment ring; 214, fixed plate. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1 To be continued Figure 8 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0027] Example 1: This invention discloses a method for segmental tensioning construction of prestressed stiffened beams. (Refer to...) Figure 1 A method for segmental tensioning of prestressed stiffened beams mainly includes the following steps: S1: Zoning planning: In each construction zone, the prestressed beam support formwork erection, prestressed beam ordinary steel bar binding, and non-prestressed beam steel bar binding are completed sequentially; S2: Detailed design: Detailed design of stiffened columns at beam-column joints, adjustment of column and beam reinforcement arrangement, avoidance of collision between prestressed ducts and steel components, planning of prestressed tendon embedment location and tensioning operation space; S3: Prestressed tendon pre-embedded construction: Corrugated pipes are laid and fixed in the prestressed beam, prestressed tendons are inserted, grouting holes and vent holes are left, the bearing plate structure is installed, and after the concealed works are accepted, the beam concrete is poured. S4: Preparations before tensioning: After the concrete of the beam reaches the design strength requirements, complete the calibration and inspection of the tensioning equipment, the quality inspection of the beam structure, the erection of the tensioning operation platform, and the cleaning of the anchor plates and the centering and installation of the anchors and tensioning equipment. S5: Segmented tensioning at the cantilever end: The cantilever prestressed beam is tensioned in segments using tensioning equipment to establish effective prestress. During the tensioning process, the elongation value of the prestressing tendons is checked. After the tensioning is completed, over-tensioning is performed and the beam is anchored. S6: Forming Construction: After tensioning, the prestressed ducts are grouted in a timely manner to bond the prestressed tendons to the concrete of the beam as a whole. The tensioning end is then sealed with anchors to complete the construction of the prestressed stiffened beam.

[0028] By implementing a construction zoning plan, the prestressing process is reasonably integrated with the ordinary steel reinforcement and formwork processes, reducing mutual interference between processes, improving overall construction efficiency, and reducing the difficulty of multi-process collaborative construction organization. Specialized detailed design of stiffened columns at beam-column joints avoids collisions between prestressing ducts and steel components from the source, reducing component adjustments and rework during on-site construction and lowering the construction difficulty of complex joints. The entire process from prestressing tendon embedding to forming construction is standardized, and segmented tensioning focuses on the pain points of cantilever prestressed beam construction, effectively establishing prestress, preventing deformation and cracking of the cantilever structure, and improving the construction quality of cantilever beam structures.

[0029] In some embodiments, the S2 detailed design step includes adjusting the column reinforcement and beam reinforcement to ensure sufficient clearance between prestressed ducts and steel components.

[0030] The specific steps include: S2-1: Node Collision Simulation and Path Planning: For stiffened steel columns and steel plate walls at beam-column joints, the path of prestressed corrugated pipes is simulated in advance to identify spatial conflict points between prestressed pipes and steel components, column reinforcement, and beam reinforcement. S2-2: Adaptive adjustment of ordinary steel bars: When the prestressed bearing plate, anchor ring or corrugated pipe conflicts with the ordinary column bars or beam bars, the ordinary steel bars at the conflicting position are locally bent, moved or rearranged without reducing the structural reinforcement ratio, so as to make room for the accurate placement of the prestressed tendons and ensure that the prestressed tendon curve elevation meets the design requirements. S2-3: Steel component reservation and avoidance: Accurately locate the prestressed ducts at the corresponding locations on the stiffened steel columns or steel plate walls. If necessary, reserve through holes or set avoidance gaps during the steel component processing stage to avoid cutting steel components on site. S2-4: Optimization of tensioning operation space: Combine the installation angle of the bearing plate, adjust the spacing of the stirrups and additional steel bars in the core area of ​​the node to ensure the installation space and operation channel of the tensioning end jack and tool anchor, and ensure that the prestressing tendons, anchor rings and jacks are concentric. S2-5: Fixed support welding positioning: Based on the adjusted steel reinforcement layout, calculate and weld the prestressed tendon fixed support, and weld the support to the beam stirrups or steel flange to prevent the corrugated pipe from shifting during concrete pouring.

[0031] By clearly defining the targeted adjustment requirements for column and beam reinforcement, the clearance space between prestressed ducts and steel components is precisely guaranteed, avoiding problems such as duct disassembly and re-binding of reinforcement due to space conflicts during subsequent construction. This further simplifies the on-site construction operation of beam-column joints and reduces the difficulty of laying prestressed ducts in complex stiffened structures.

[0032] In some embodiments, during the S3 prestressed tendon pre-embedding construction step, when the corrugated pipe is laid out, a welding fixing bracket is used to position and fix the corrugated pipe, and the corrugated pipe joint is sealed with a special connector.

[0033] Welded fixing brackets position and fix the corrugated pipe, effectively preventing the corrugated pipe from shifting during concrete pouring, ensuring the forming accuracy of the prestressed duct, reducing the risk of tension failure caused by duct deviation, and reducing the difficulty of quality control in duct forming; the corrugated pipe joints are sealed with special connectors to prevent cement slurry from seeping into the duct during pouring and causing the prestressing tendons to jam, eliminating rework and repairs caused by slurry leakage, improving the first-pass yield of duct construction, and reducing the difficulty of on-site construction.

[0034] In some embodiments, during the S3 prestressed tendon pre-embedding construction step, a protective component is installed at the end of the prestressed tendon when the prestressed tendon is being threaded through.

[0035] Specifically, the following steps are included: S3-1: End sealing and wrapping: After the prestressing tendons are threaded through and before the concrete is poured, use waterproof tape or special plastic caps to tightly wrap the exposed ends of the prestressing tendons and the bell mouth of the anchor plate in multiple layers to form a closed space, preventing cement slurry from seeping into the corrugated pipe and causing blockage during concrete pouring, and at the same time avoiding slurry from sticking to the anchor components. S3-2: Rust and corrosion prevention treatment: For the ends of prestressed tendons that are exposed for a long time due to the need for segmented tensioning, apply rust-preventive grease or anti-corrosion wax before wrapping, and fill the inside of the protective component with desiccant or inject anti-corrosion grease to isolate air and moisture and prevent the prestressed tendons from rusting during the tensioning interval. S3-3: Protection against mechanical damage: Install rigid protective sleeves or anti-collision corner guards on the outside of the protective components to prevent damage to the surface of the prestressed tendons or the protective layer caused by personnel stepping on them, material collisions, or welding sparks. S3-4: Tensioning Reserved Length Control: The setting of protective components must take into account subsequent tensioning operations, ensuring that the reserved length of prestressed tendons meets the requirements of jack installation and tool anchor clamping, and that the protective components are easy to remove quickly without damaging the prestressed tendon body. S3-5: Identification and Monitoring: Set clear identification labels on the outer surface of the protective components, indicating the prestressed tendon number, tensioning stage and expected tensioning time, and regularly check the integrity of the protective components, and repair or replace them in a timely manner if any damage is found.

[0036] Setting protective components at the ends of prestressed tendons can effectively prevent the tendons from puncturing the corrugated pipe wall during the tendon installation process, avoid corrugated pipe damage and grout leakage, reduce damage to embedded pipes during tendon installation, reduce the extra construction workload of corrugated pipe repair, and improve the construction efficiency of prestressed tendon installation.

[0037] The implementation principle of a segmental tensioning construction method for prestressed stiffened beams according to an embodiment of the present invention is as follows: Specialized detailed design was carried out for the stiffened columns at beam-column joints, clarifying the adjustment requirements for column and beam reinforcement, avoiding collisions between prestressed ducts and steel components, and reducing the difficulty of construction and duct layout for complex joints; protective components were installed at the ends of prestressed tendons to prevent damage to corrugated pipes during tendon threading, reducing repair workload and improving threading efficiency; at the same time, the entire process from prestressed tendon embedding to forming was standardized, and prestress was effectively established through segmented tensioning at the cantilever end to prevent deformation and cracking of the cantilever structure and improve construction quality.

[0038] Example 2: This invention discloses a method for segmental tensioning construction of prestressed stiffened beams. (Refer to...) Figures 2 to 8 The main difference between this embodiment and embodiment 1 is that the structure of the pressure plate 103 includes an end template 101, a sealing element 102, a pressure plate 103, and a spiral rib 104. The pressure plate 103 fixing sleeve 204 is provided at one end of the bellows 105, the sealing element 102 is filled between the pressure plate 103 and the bellows 105, one end of the spiral rib 104 is fixed to the pressure plate 103, and one end of the pressure plate 103 is fixedly connected to the end template 101 by bolts. The tensioning equipment includes a hydraulic cylinder 201, a body 202, fixed anchor bolts 203, a fixed sleeve 204, a telescopic sleeve 205, and a fixed mold 206. One end of the fixed sleeve 204 abuts against the end template 101. Multiple fixed anchor bolts 203 are arranged circumferentially along the fixed sleeve 204. The telescopic sleeve 205 is slidably fitted inside the fixed sleeve 204, and one end of the telescopic sleeve 205 is snapped into the body 202. The hydraulic cylinder 201 is fixedly installed on the body 202, and the telescopic rod of the hydraulic cylinder 201 abuts against one end of the fixed sleeve 204. The fixed mold 206 is set inside the body 202, and the fixed mold 206 is provided with fixing holes 207 for fixing prestressing tendons. One end of the fixed mold 206 is fixedly connected to the telescopic rod of the hydraulic cylinder 201. The prestressing tendons correspond to and pass through the fixing holes 207. A fixing ring, made of metal, is fixed inside the fixing holes 207. The prestressing tendons are fixed to the fixing mold 206 by welding or extrusion deformation. The hydraulic cylinder 201 functions similarly to the jack described above. The fixing mold 206 and the telescopic sleeve 205 are detachably fixed together by bolts.

[0039] The bearing plate 103 structure, through the matching of components such as end template 101 and sealing element 102, achieves sealing and fixing of the end of the corrugated pipe 105, preventing grout from entering and blocking the channel during concrete pouring, ensuring the forming quality of the tension end, and at the same time simplifying the connection and installation process between the bearing plate 103 and the corrugated pipe 105, reducing the construction difficulty of the tension end node.

[0040] When tensioning is required, the hydraulic cylinder 201 provides a hydraulic power source through the oil supply system, driving the telescopic rod to extend or retract. The telescopic rod abuts against the fixed sleeve 204 at one end and continues to extend, causing the machine body 202 to move outward as a whole. Simultaneously, the telescopic sleeve 205 inside the machine body 202 moves outward synchronously, pushing the fixed mold 206 to move, thereby achieving overall tensioning of the prestressed tendons. Through the coordinated design of components such as the hydraulic cylinder 201, fixed mold 206, and telescopic sleeve 205, precise clamping and tensioning of the prestressed tendons are achieved, ensuring the alignment accuracy of the tensioning equipment with the anchor plate and prestressed tendons, improving the stress control accuracy of segmented tensioning, and adapting to the construction requirements of segmented tensioning of cantilever beams. The matching design of the bearing plate 103 structure and the tensioning equipment reduces the adaptation and adjustment time between the equipment and embedded components, and lowers the difficulty of equipment debugging during on-site tensioning operations.

[0041] Reference Figure 6 and Figure 7 In some embodiments, a snap-fit ​​groove 208 is provided inside the body 202, and multiple snap-fit ​​blocks 209 are fixedly installed on the outer end of the telescopic sleeve 205.

[0042] During installation of the body 202, the locking block 209 is inserted by aligning it with the locking groove 208. Once in position, the body 202 is rotated to engage the locking block 209 within the locking groove 208, thus securing the outer end of the telescopic sleeve 205 to the body 202. The engagement between the locking groove 208 inside the body 202 and the locking block 209 outside the telescopic sleeve 205 enables rapid assembly, disassembly, and positioning of the telescopic sleeve 205 and the body 202. This simplifies the on-site assembly process of the tensioning equipment, reduces installation time, improves preparation efficiency for tensioning construction, and ensures connection stability during equipment operation, reducing the risk of operational malfunctions.

[0043] Reference Figure 3 In some embodiments, a fixing plate 214 extends from one end of the fixing sleeve 204. The fixing plate 214 is fixedly connected to the end template 101 by bolts. A plurality of sliding grooves 210 are provided inside the fixing sleeve 204. A plurality of sliding blocks 211 are provided on the outer peripheral surface of the telescopic sleeve 205. The telescopic sleeve 205 slides inside the fixing sleeve 204 through the sliding blocks 211 and the sliding grooves 210.

[0044] The bolted connection between the fixing plate 214 and the end template 101 ensures a firm and precise fixation between the tensioning equipment and the bearing plate 103 structure, guaranteeing the stability of the equipment during tensioning, preventing tension stress deviation caused by equipment misalignment, and improving the accuracy of segmented tensioning. The sliding engagement between the sliding block 211 and the sliding groove 210 guides the movement trajectory of the telescopic sleeve 205, ensuring the coaxiality of the telescopic sleeve 205 during its extension and retraction, avoiding uneven stress on the prestressing tendons caused by the misalignment of the telescopic sleeve 205, and reducing the risk of structural damage during tensioning.

[0045] Reference Figure 5 In some embodiments, a plurality of clamping plates 212 are slidably disposed inside the fixed sleeve 204. One end of the clamping plate 212 is rotatably connected to the fixed anchor bolt 203 through a rotating member, and the other end of the clamping plate 212 abuts against the outer peripheral surface of the telescopic sleeve 205. The clamping plate 212 is arranged in an arc shape.

[0046] The arc-shaped clamping plate 212, through the linkage between the fixed anchor bolt 203 and the rotating component, pushes the clamping plate 212 inward when the fixed anchor bolt 203 rotates, achieving uniform clamping of the telescopic sleeve 205. This ensures the force balance of the telescopic sleeve 205, preventing deformation of the telescopic sleeve 205 due to excessive tightness or slippage caused by excessive looseness, thus improving the stability of equipment operation. The arc-shaped design of the clamping plate 212 fits snugly against the outer circumference of the telescopic sleeve 205, increasing the clamping contact area and further enhancing the clamping firmness. This prevents the telescopic sleeve 205 from shifting during tensioning, ensuring stable transmission of tension stress and reducing the risk of tensioning failure due to component displacement. Anti-slip surfaces can be provided on both the contact surfaces of the telescopic sleeve 205 and the clamping plate 212 to further increase friction.

[0047] Reference Figure 5 In some embodiments, an abutment ring 213 is fixedly installed on the outer peripheral surface of the fixed sleeve 204, and the telescopic rod of the hydraulic cylinder 201 abuts against the abutment ring 213.

[0048] The setting of the abutment ring 213 increases the contact area between the extension rod of the hydraulic cylinder 201 and the fixed sleeve 204, so that the thrust of the extension rod is evenly transmitted to the fixed sleeve 204, avoiding deformation or damage of the fixed sleeve 204 caused by local stress concentration, ensuring the structural durability of the tensioning equipment, while reducing the maintenance and replacement costs of equipment parts and reducing the difficulty of later maintenance of the tensioning equipment.

[0049] Reference Figure 8 In some embodiments, an arc-shaped pressure plate 106 is installed on the corrugated pipe 105, and a vent pipe 107 is fixedly installed on the upper end of the arc-shaped pressure plate 106. A buffer pad 108 is provided between the arc-shaped pressure plate 106 and the corrugated pipe 105, and the arc-shaped pressure plate 106 is fixed to the corrugated pipe 105 by a fixing ring.

[0050] The cooperation between the arc-shaped pressure plate 106 and the buffer pad 108 achieves a sealed connection between the vent pipe 107 and the corrugated pipe 105, preventing cement slurry from seeping into the grouting hole during pouring, ensuring the unobstructed flow of the duct, avoiding the problem of incomplete grouting caused by duct blockage, and improving the quality of grouting construction. The fixing ring enables quick fixing of the arc-shaped pressure plate 106 and the corrugated pipe 105, simplifying the installation process of the grouting hole and reducing the construction difficulty of the duct auxiliary components. Before grouting, the channel between the corrugated pipe 105 and the vent pipe 107 is not opened, and the corrugated pipe 105 is not opened to reduce the possibility of leakage. Before tensioning is required, the corrugated pipe 105 is opened using a steel chisel or drilling machine.

[0051] The implementation principle of the prestressed stiffened beam segmental tensioning construction method of this invention is as follows: The bearing plate 103 structure is equipped with end template 101 and sealing element 102 to achieve sealing and fixing of the end of the corrugated pipe 105, prevent grout from entering and blocking the hole, ensure the forming quality of the tensioning end, simplify installation and reduce the construction difficulty of the tensioning end node; the special tensioning equipment uses hydraulic cylinder 201 to drive the telescopic rod to move the components to complete the prestressing tendon tensioning. All components work together to achieve precise clamping and tensioning of the tendon, ensuring centering accuracy, improving the segmented tensioning stress control accuracy, adapting to the segmented tensioning requirements of cantilever beams, and the equipment is matched with the bearing plate 103 structure, reducing adaptation and adjustment time and reducing the difficulty of on-site debugging; the arc-shaped clamping plate 212 clamps the telescopic sleeve 205 evenly through the linkage structure. The arc design increases the contact area, improves the clamping firmness and equipment stability, ensures stable transmission of tensioning stress, and reduces the risk of tensioning failure.

[0052] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for segmental tensioning construction of prestressed stiffened beams, characterized in that, Includes the following steps: Zoning plan: In each construction zone, the prestressed beam support formwork erection, prestressed beam ordinary steel bar binding, and non-prestressed beam steel bar binding are completed sequentially; Detailed design: Detailed design of the stiffened column at the beam-column joint is carried out, the arrangement of column reinforcement and beam reinforcement is adjusted, collisions between prestressed ducts and steel components are avoided, and the location of prestressed tendon embedment and tensioning operation space are planned. Prestressed tendon pre-embedding construction: Corrugated pipes are laid and fixed in the prestressed beam, prestressed tendons are inserted, grouting holes and vent holes are left, the bearing plate structure is installed, and after the concealed works are accepted, the beam concrete is poured. Preparations before tensioning: After the concrete of the beam reaches the design strength requirements, complete the calibration and inspection of the tensioning equipment, the quality inspection of the beam structure, the erection of the tensioning operation platform, and the cleaning of the anchor plates and the centering and installation of the anchors and tensioning equipment. Segmented tensioning at the cantilever end: The cantilever prestressed beam is tensioned in segments using tensioning equipment to establish effective prestress. During the tensioning process, the elongation of the prestressing tendons is checked. After tensioning is completed, over-tensioning is performed and the beam is anchored. Forming and construction: After tensioning, the prestressing ducts are grouted in a timely manner to bond the prestressing tendons to the beam concrete as a whole. The tensioning ends are then sealed and anchored to complete the construction of the prestressed stiffened beam.

2. The method for segmental tensioning of prestressed stiffened beams according to claim 1, characterized in that: The detailed design includes adjustments to column and beam reinforcement to ensure sufficient clearance between prestressed ducts and steel components.

3. The method for segmental tensioning of prestressed stiffened beams according to claim 1, characterized in that: During the installation of the corrugated pipe, a welded fixing bracket is used to position and fix the corrugated pipe, and the corrugated pipe joint is sealed with a special connector.

4. The method for segmental tensioning of prestressed stiffened beams according to claim 1, characterized in that: When the prestressing tendons are installed, protective components are set at the ends of the prestressing tendons.

5. The method for segmental tensioning construction of prestressed stiffened beams according to any one of claims 1-4, characterized in that: The pressure plate (103) structure includes an end template (101), a sealing element (102), a pressure plate (103), and a spiral rib (104). The pressure plate (103) fixing sleeve (204) is provided at one end of the corrugated pipe (105). The sealing element (102) is filled between the pressure plate (103) and the corrugated pipe (105). One end of the spiral rib (104) is fixed to the pressure plate (103). One end of the pressure plate (103) is fixedly connected to the end template (101) by bolts. The tensioning device includes a hydraulic cylinder (201), a body (202), a fixed anchor bolt (203), a fixed sleeve (204), a telescopic sleeve (205), and a fixed mold (206). One end of the fixed sleeve (204) abuts against the end mold (101). The fixed anchor bolt (203) is circumferentially inserted through the fixed sleeve (204). The telescopic sleeve (205) is slidably fitted inside the fixed sleeve (204). One end of the telescopic sleeve (205)... The hydraulic cylinder (201) is fixedly installed on the machine body (202) and the telescopic rod of the hydraulic cylinder (201) abuts against one end of the fixed sleeve (204). The fixed mold (206) is set inside the machine body (202) and the fixed mold (206) is provided with a fixing hole (207) for fixing the prestressing tendon. One end of the fixed mold (206) is fixedly connected to the telescopic rod of the hydraulic cylinder (201).

6. The method for segmental tensioning of prestressed stiffened beams according to claim 5, characterized in that: The body (202) has a snap-fit ​​groove (208) inside, and multiple snap-fit ​​blocks (209) are fixedly installed on the outer end of the telescopic sleeve (205).

7. The method for segmental tensioning of prestressed stiffened beams according to claim 6, characterized in that: One end of the fixed sleeve (204) extends to a fixed plate (214), which is fixedly connected to the end template (101) by bolts. The fixed sleeve (204) has multiple sliding grooves (210) inside, and the telescopic sleeve (205) has multiple sliding blocks (211) on its outer circumferential surface. The telescopic sleeve (205) slides in the fixed sleeve (204) through the sliding blocks (211) and the sliding grooves (210).

8. The method for segmental tensioning of prestressed stiffened beams according to claim 7, characterized in that: Multiple clamping plates (212) are slidably arranged inside the fixed sleeve (204). One end of the clamping plate (212) is rotatably connected to the fixed anchor bolt (203) through a rotating component, and the other end of the clamping plate (212) abuts against the outer peripheral surface of the telescopic sleeve (205). The clamping plate (212) is arranged in an arc shape.

9. The method for segmental tensioning of prestressed stiffened beams according to claim 5, characterized in that: An abutment ring (213) is fixedly installed on the outer circumferential surface of the fixed sleeve (204), and the telescopic rod of the hydraulic cylinder (201) abuts against the abutment ring (213).

10. The method for segmental tensioning of prestressed stiffened beams according to claim 5, characterized in that: An arc-shaped pressure plate (106) is installed on the corrugated pipe (105). A vent pipe (107) is fixedly installed on the upper end of the arc-shaped pressure plate (106). A buffer pad (108) is provided between the arc-shaped pressure plate (106) and the corrugated pipe (105). The arc-shaped pressure plate (106) is fixed to the corrugated pipe (105) by a fixing ring.

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