Method for using a large cantilevered cap beam telescopic full-enclosed protective device

Abstract

The application discloses a use method of a large-cantilever cap beam telescopic full-enclosed protective device, which is composed of an I-shaped steel cross beam, a U-shaped frame, a trolley assembly, a cross bracing, an end cross rod, a long-side cross rod, a limiting pull rod, a limiting pin and a dense-mesh net; the U-shaped frame can slide on the lower flange plate of the I-shaped steel cross beam through the trolley assembly, the adjacent U-shaped frames are connected through the cross bracing and can be telescopic, and the outside is fully enclosed by the dense-mesh net; during use, the device is installed near a pier column, stretched to the cantilever end of the cap beam, retracted and disassembled after completion, and the whole process does not need to be operated without protection and traffic interruption above the auxiliary road, so that the device is safe, convenient, convenient in turnover, time-saving and cost-saving.

Description

Technical Field

[0001] This invention relates to the field of municipal bridge construction technology, and in particular to the method of using a telescopic fully enclosed protective device for large cantilever cap beams. Background Technology

[0002] To improve road capacity while also serving the surrounding areas, many cities have constructed numerous elevated expressways on top of existing surface arterial roads. These expressway viaducts utilize large cantilevered cap beams, with auxiliary roads constructed on both sides beneath the viaducts. To maintain the traffic capacity of the city's main roads, there are often requirements to ensure the smooth flow of traffic on the auxiliary roads under the viaducts during construction. To guarantee the safety of vehicles traveling on the auxiliary roads below the viaduct cap beams during construction, the portion of the cap beams above the auxiliary roads is required to be fully enclosed and protected.

[0003] Currently, the main protective measures for the construction of large cantilever cap beams above the auxiliary road are twofold: constructing anti-collision openings on the ground and installing underlayment on the cap beam supports. Constructing anti-collision openings requires occupying ground space, affecting visibility on the auxiliary road, and necessitates temporary traffic interruption when constructing the opening canopy. Furthermore, constructing openings is costly and time-consuming. Given the large number of large cantilever cap beams on elevated bridges and the short construction period for each individual beam, frequent turnover is necessary, making the construction of openings extremely inconvenient and uneconomical. Installing underlayment on the cap beam supports typically involves constructing the underlayment on-site using steel pipes and dense mesh netting after the cap beam supports are erected, or prefabricating several pieces of the underlayment structure, hoisting them into place on-site, and assembling them sequentially. However, both on-site construction and prefabrication require some unprotected construction work above the auxiliary road, necessitating temporary traffic interruption. Summary of the Invention

[0004] The purpose of this invention is to overcome the difficulties of existing technologies and provide a method for using a telescopic fully enclosed protective device for large cantilever cap beams that can improve construction safety, reduce protection costs, and improve construction efficiency.

[0005] The present invention provides a telescopic fully enclosed protective device for a large cantilever cap beam, comprising two I-beam crossbeams respectively installed on the front and rear sides of the pier column and parallel to the long axis of the cap beam of the pier column. The two I-beam crossbeams are respectively supported on the embedded parts of the pier column and simultaneously serve as the main crossbeams of the cap beam support on the pier column.

[0006] Multiple U-shaped frames with the same structure and spaced apart are respectively set at the cantilever sections of the cap beams to be constructed on the left and right sides outside the pier. Each U-shaped frame includes a lower horizontal bar that is perpendicular to the I-beam and set in the horizontal direction. The bottoms of two vertical bars set in the vertical direction are fixedly connected to the front and rear ends of the lower horizontal bar, respectively. The top surface of the vertical bars is not lower than the top surface of the cap beam. The two I-beams are set above the lower horizontal bars of all the U-shaped frames.

[0007] A trolley assembly is connected to the front and rear sides of the lower crossbar of each U-shaped frame. Each trolley assembly includes a U-shaped shell. The axles of two parallel lower rollers are rotatably connected to the lower parts of the front and rear uprights of the U-shaped shell. One end of the axles of two sets of upper rollers arranged opposite each other are rotatably connected to the front and rear uprights, respectively. A steel pipe fastener is fixed to the bottom wall of the U-shaped shell. The steel pipe fastener is fixedly connected to the lower crossbar, and the axis of the steel pipe fastener is aligned with the lower crossbar. The crossbars of the U-shaped frame are aligned in the same direction. The lower flange of each I-beam is respectively set between the upper and lower rollers of the trolley assembly at the corresponding position. The two sets of upper rollers are respectively supported on the top wall of the lower flange of the I-beam at the corresponding position and are located on the front and rear sides of the web of the I-beam. The two sets of upper rollers are in rolling contact with the top wall of the lower flange of the I-beam, and the lower rollers are in rolling contact with the bottom wall of the lower flange of the I-beam at the corresponding position.

[0008] The two vertical bars of adjacent U-shaped frames are connected by cross bracing. Each cross bracing between two adjacent vertical bars includes two diagonal bars that cross each other in the middle. The intersection of the two diagonal bars is hinged by a first pin. All the cross bracing forms a mesh structure. A sleeve is slidably fitted at the lower end of each vertical bar. The sleeve can slide up and down along the vertical bar. The upper end of each diagonal bar is hinged to the vertical bar of the corresponding U-shaped frame by a second pin. The lower end of each diagonal bar is hinged to the sleeve by a third pin.

[0009] Between the vertical members of the two U-shaped frames closest to the left and right ends of the cap beam to be poured, horizontal end bars are connected by fasteners and are set in the horizontal direction; long side bars are connected by fasteners to the vertical members on the same side of all the U-shaped frames.

[0010] A fastener is used to connect the lower crossbars of the two U-shaped frames closest to the pier, thereby clamping the lower crossbars of the two U-shaped frames to the pier. A dense mesh net is hung outside the U-shaped frames to completely enclose the space enclosed by the U-shaped frames on all four sides and the bottom. A limiting device is installed at the left and right ends of each of the I-beams, which is used to limit the movement of the trolley assembly.

[0011] The advantages and positive effects of this invention are as follows: The telescopic fully enclosed protective device for large cantilever cap beams is attached to the cap beam support, does not occupy the space under the bridge, does not affect the visibility of the auxiliary road, and can be rotated together with the cap beam support. It is easy to construct, and after being assembled near the pier, it extends above the auxiliary road. Subsequent construction can be carried out under the bottom protection. After the construction is completed, it is retracted near the pier for disassembly. The entire process does not require unprotected construction above the auxiliary road and does not interrupt auxiliary road traffic. It can improve construction safety, reduce protection costs, and improve construction efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the telescopic fully enclosed protective device for the large cantilever beam of the present invention;

[0013] Figure 2 for Figure 1 A schematic diagram of the U-shaped frame in the device shown;

[0014] Figure 3 for Figure 1 A schematic diagram of the trolley assembly in the device shown;

[0015] Figure 4 for Figure 1 A schematic diagram of the trolley assembly and the I-beam structure in the device shown.

[0016] Figure 5 for Figure 1 A schematic diagram of the cross bracing structure in the device shown;

[0017] Figure 6 for Figure 1 A schematic diagram of the installation structure of the limit pin in the device shown. Detailed Implementation

[0018] To further understand the invention's content, features, and effects, the following embodiments are provided, along with accompanying drawings. Figures 1-6 Detailed explanation is as follows:

[0019] This invention discloses a telescopic fully enclosed protective device for a large cantilever cap beam, comprising two I-beam crossbeams 1 respectively installed on the front and rear sides of a bridge pier column and parallel to the long axis of the cap beam. The two I-beam crossbeams are supported on embedded parts of the pier column and simultaneously serve as the main crossbeams of the cap beam support. The cap beam is subsequently poured at the top of the bridge pier column under the support of the cap beam support. The cap beam support is supported by the embedded parts of the pier column and consists of, from bottom to top, the main I-beam crossbeams, longitudinal distribution beams, and the cap beam bottom formwork. This cap beam construction utilizes existing common methods and structures.

[0020] Multiple U-shaped frames 2, spaced apart and structurally identical, are respectively installed on the cantilever sections of the cap beams to be constructed on the left and right sides of the pier. Each U-shaped frame 2 includes a lower horizontal bar 201 perpendicular to the I-beam 1 and arranged horizontally, and two vertical bars 202 fixedly connected at their bottoms to the front and rear ends of the lower horizontal bar, respectively. The top surface of the vertical bars 202 is not lower than the top surface of the cap beam. The two I-beams 1 are positioned above the lower horizontal bars of all the U-shaped frames. For easy disassembly, the bottom ends of the two vertical bars are connected to the lower horizontal bars 201 using right-angle fasteners. More preferably, the length of the lower horizontal bar 201 is equal to the width of the cap beam to be poured plus the width of the operating platforms on both sides of the cap beam. The operating platforms are generally constructed using scaffolding boards on both sides of the cap beam, with a width of 50-70cm, and are used for the installation and dismantling of the cap beam formwork and concrete pouring. Preferably, both the lower horizontal bar 201 and the vertical bars 202 are made of φ48mm steel pipe.

[0021] A trolley assembly 3 is connected to both the front and rear sides of the lower crossbar of each U-shaped frame. Each trolley assembly includes a U-shaped shell 301. The axles of two parallel lower rollers 303 are rotatably connected to the lower parts of the front and rear uprights of the U-shaped shell. One end of the axles of two sets of opposite upper rollers 302 are rotatably connected to the front and rear uprights, respectively. A steel pipe fastener 304 is fixed to the bottom wall of the U-shaped shell and is fixedly connected to the lower crossbar. The axis of the steel pipe fastener 304 is aligned with the direction of the lower crossbar 201 of the U-shaped frame. The lower flange of each I-beam is respectively set between the upper and lower rollers of the trolley assembly at the corresponding position. The two sets of upper rollers 302 are respectively supported on the top wall of the lower flange of the I-beam at the corresponding position and are located on the front and rear sides of the web of the I-beam. The two sets of upper rollers are in rolling contact with the top wall of the lower flange of the I-beam, and the lower rollers are in rolling contact with the bottom wall of the lower flange of the I-beam at the corresponding position.

[0022] The two vertical rods 202 of adjacent U-shaped frames are connected by cross braces 4. Each cross brace 4 between two adjacent vertical rods 202 includes two diagonal rods 401 that cross at the middle position. The intersection of the two diagonal rods 401 is hinged by a first pin 403. All the cross braces 4 form a mesh structure. A sleeve 402 is slidably fitted at the lower end of each vertical rod 202. The upper end of each diagonal rod 401 is hinged to the vertical rod 202 of the corresponding U-shaped frame by a second pin 404. The lower end of each diagonal rod 401 is hinged to the sleeve 402 by a third pin 405. The cross braces 4 deform according to the principle of parallelism of opposite sides of a parallelogram, and maintain the equal spacing between adjacent U-shaped frames 202.

[0023] Between the vertical members 202 of the two U-shaped frames 2 closest to the left and right ends of the cap beam to be poured, horizontal end members 5 are connected by fasteners in the horizontal direction; long side members 6 are connected by fasteners on the vertical members 202 on the same side of all the U-shaped frames 2, so that all the U-shaped frames form a stable whole.

[0024] A fastener is used to connect the lower crossbars of the two U-shaped frames 2 closest to the pier, and a limiting tie rod 7 is used to clamp the lower crossbars 201 of the two U-shaped frames 2 to the pier, thereby fixing the relative distance between the two U-shaped frames 2 and fixing the position of the protective device.

[0025] A dense mesh net is hung outside the U-shaped frame 2 to completely enclose the space enclosed by the U-shaped frame 2 on all four sides (front, back, left, right) and the bottom.

[0026] A limiting device is installed at each of the left and right ends of each of the aforementioned I-beam beams 1. The limiting device is used to limit the movement of the trolley assembly 3. The limiting device includes two holes at each of the left and right ends of the upper and lower flanges of each I-beam beam 1. The two pins of the n-shaped limiting pin 8 pass through the openings in the upper and lower flanges. The limiting pin 8 can be made of round steel. The position of the limiting pin 8 must meet the requirement of preventing the trolley assembly 3 from passing through, thus preventing the U-shaped frame 2 from slipping off the end of the I-beam beam 1. Alternatively, other existing limiting devices can also be used.

[0027] In use, the required number of pulley assemblies 3 are first installed on the lower flange plate of the I-beam 1 via the end of the I-beam beam 1. The pulley assemblies 3 are symmetrically arranged on both sides of the pier as needed, with adjacent pulley assemblies 3 closely packed together to keep the protective device in a retracted state. Wooden wedges are used to temporarily fix the position of the pulley assemblies 3 between the upper rollers of the pulley assemblies 3 and the lower flange plate of the I-beam beam 1. After the pulley assemblies 3 are installed, the limiting pins 8 are installed at the end of the I-beam beam to prevent the pulley assemblies 3 and the subsequently installed U-shaped frame 2 from slipping off the end of the I-beam beam 1.

[0028] The two I-beams 1 are hoisted and installed in place at corresponding positions before and after the pier. The lower crossbars 201 of the U-shaped frame 2 are installed on the fasteners 304 at the bottom of the trolley assembly 3, and then the vertical bars 202 of the U-shaped frame 2 and the cross braces 4 are installed to form a complete U-shaped frame and connection system. Limiting tie rods 7 are installed between the U-shaped frames 2 on the left and right sides of the pier, so that the lower crossbars 201 of the two U-shaped frames 2 clamp the pier on the left and right sides of the pier to fix the position of the protective device. End crossbars 5 are installed on the vertical bars 202 of the U-shaped frame 2 closest to the end face of the cap beam to form an end protective surface frame. A dense mesh net is installed on the outer side, bottom surface, and end protective surface of the U-shaped frame; the dense mesh net between adjacent U-shaped frames is loose, and the looseness of the dense mesh net is such that it is just tightened when the protective device is extended to the normal use state; the dense mesh net has a hole at the position of the I-beam crossbeam 1, so that the dense mesh net can bypass the I-beam crossbeam 1 to form a complete enclosure of other parts.

[0029] After the dense mesh netting is installed, the wooden wedges temporarily fixing the position of the pulley assembly 3 are removed. The U-shaped frame is then moved towards the left and right ends of the I-beam crossbeam 1 using either a steel pipe pusher or a front-end steel wire rope puller, so that the protective device is in the deployed state until it is fully extended for normal use. Once the protective device is in place, under the protection of the dense mesh netting, the long side crossbar 6 is installed on the vertical bar 202 on the same side of the U-shaped frame 2 using fasteners, connecting adjacent vertical bars 202 to form a stable whole with the entire U-shaped frame. Throughout this process, the entire area is enclosed by the dense mesh netting, preventing any falling objects from posing a hazard to vehicles on the auxiliary road below; therefore, there is no need to close the auxiliary road.

[0030] The cap beam construction proceeds according to normal construction procedures. After the cap beam construction is completed and the formwork is removed, any debris that may have fallen into the protective device is cleared. Then, the long side crossbars 6 between adjacent U-shaped frame uprights 202 and the end crossbars 5 and end mesh netting on the U-shaped frame uprights 202 closest to the cap beam end face are removed. A steel wire rope is installed on the U-shaped frame 2 closest to the cap beam end face, and the steel wire rope is used to pull the U-shaped frame 2 back to the position close to the pier, so that the protective device returns to its initial retracted state. Wooden wedges are used to temporarily fix the position of the pulley assembly 3 between the rollers of the trolley assembly 3 and the lower flange of the I-beam crossbeam 1. The mesh netting, the U-shaped frame uprights 202 and the cross braces 4, and the lower crossbars 201 of the U-shaped frame are removed in sequence. The I-beam crossbeam 1 is then removed, and the entire construction process is completed.

[0031] Although preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these modifications are within the scope of protection of the present invention.

Claims

1. A method for using a telescopic fully enclosed protective device for a large cantilever beam, characterized in that: The device includes a telescopic fully enclosed protective device for a large cantilever cap beam. The telescopic fully enclosed protective device for a large cantilever cap beam includes two I-beam crossbeams (1) that are respectively set on the front and rear sides of the pier column and parallel to the long axis of the cap beam of the pier column. The two I-beam crossbeams are respectively supported on the embedded parts of the pier column and at the same time serve as the main crossbeams of the cap beam support on the pier column. Multiple U-shaped frames (2) with the same structure and spaced apart are respectively set at the cantilever sections of the cap beams to be constructed on the left and right sides outside the pier. Each U-shaped frame includes a lower horizontal bar (201) that is perpendicular to the I-beam and set in the horizontal direction. The bottoms of two vertical bars (202) set in the vertical direction are fixedly connected to the front and rear ends of the lower horizontal bar respectively. The top surface of the vertical bar is not lower than the top surface of the cap beam. The two I-beams are set above the lower horizontal bars of all the U-shaped frames. A trolley assembly (3) is connected to the front and rear sides of the lower crossbar of each U-shaped frame. Each trolley assembly includes a U-shaped shell (301). The axles of two parallel lower rollers (303) are rotatably connected to the lower parts of the front and rear uprights of the U-shaped shell. One end of the axles of two sets of upper rollers (302) arranged opposite to each other are rotatably connected to the front and rear uprights, respectively. A steel pipe fastener (304) is fixed on the bottom wall of the U-shaped shell. The steel pipe fastener is fixedly connected to the lower crossbar. The axis of the steel pipe fastener is aligned with the direction of the lower crossbar (201) of the U-shaped frame. The lower flange of each I-beam is respectively set between the upper and lower rollers of the trolley assembly at the corresponding position. The two sets of upper rollers are respectively supported on the top wall of the lower flange of the I-beam at the corresponding position and are located on the front and rear sides of the web of the I-beam. The two sets of upper rollers are in rolling contact with the top wall of the lower flange of the I-beam, and the lower rollers are in rolling contact with the bottom wall of the lower flange of the I-beam at the corresponding position. The two vertical bars of the adjacent U-shaped frame are connected by cross bracing (4). Each cross bracing between two adjacent vertical bars includes two diagonal bars (401) that cross at the middle position. The intersection of the two diagonal bars is hinged by a first pin (403). All the cross bracing forms a mesh structure. A sleeve (402) is slidably fitted at the lower end of each vertical bar. The sleeve can slide up and down along the vertical bar (202). The upper end of each diagonal bar is hinged to the vertical bar of the U-shaped frame at the corresponding position by a second pin (404). The lower end of each diagonal bar is hinged to the sleeve by a third pin (405). Between the vertical members of the two U-shaped frames closest to the left and right ends of the cap beam to be poured, there are end crossbars (5) set in the horizontal direction, which are connected by fasteners; on the vertical members on the same side of all the U-shaped frames, there are long side crossbars (6) connected by fasteners. A fastener is used to connect the lower crossbars of the two U-shaped frames closest to the pier, and a limiting rod (7) is used to clamp the lower crossbars of the two U-shaped frames to the pier. A dense mesh net is hung outside the U-shaped frame to completely enclose the space enclosed by the U-shaped frame on all four sides and the bottom. A limiting device is installed at the left and right ends of each of the I-beams. The limiting device includes two holes at the left and right ends of the upper and lower flanges of each I-beam. The pins on both sides of the n-shaped limiting pin pass through the openings at the upper flanges and the lower flanges. The limiting device is used to limit the movement of the trolley assembly. The method for using the telescopic fully enclosed protective device for large cantilever beams includes the following steps: First, install the required number of trolley assemblies onto the lower flange of the I-beam beam via the end of the I-beam beam. The trolley assemblies are symmetrically arranged on both sides of the pier as needed, with adjacent trolley assemblies close together to keep the protective device in a retracted state. Use wooden wedges to temporarily fix the position of the trolley assemblies between the upper rollers of the trolley assemblies and the lower flange of the I-beam beam. After the trolley assemblies are installed, install the limiting pins at the end of the I-beam beam to prevent the trolley assemblies and the subsequently installed U-shaped frame from slipping off the end of the I-beam beam. Two I-beams are hoisted and installed in place at corresponding positions before and after the pier. The lower crossbar of the U-shaped frame is installed on the fastener at the bottom of the trolley assembly. Then, the vertical bar of the U-shaped frame and the cross brace are installed to form a complete U-shaped frame and connection system. Limiting tie rods are installed between the U-shaped frames close to the left and right sides of the pier, so that the lower crossbars of the two U-shaped frames clamp the pier on the left and right sides to fix the position of the protective device. End crossbars are installed on the vertical bar of the U-shaped frame closest to the end face of the cap beam to form an end protective surface frame. Dense mesh is hung on the outer side, bottom surface and end protective surface of the U-shaped frame. The dense mesh between adjacent U-shaped frames is loose, and the looseness of the dense mesh is such that it is just tightened when the protective device is extended to the normal use state. The dense mesh has holes at the I-beam positions so that the dense mesh can bypass the I-beams to form a complete enclosure for other parts. After the dense mesh netting is installed, remove the wooden wedges that temporarily fix the position of the pulley assembly, and move the U-shaped frame to the left and right ends of the I-beam by pushing with steel pipes or pulling with front wire ropes, so that the protective device is in the unfolded state until it is extended to the normal use state; after the protective device is extended and in place, under the protection of the dense mesh netting, use fasteners to install long side crossbars on the vertical bars on the same side of the U-shaped frame, connect adjacent vertical bars, so that the entire U-shaped frame forms a stable whole; The cap beam construction is carried out according to the normal construction procedures. After the cap beam construction is completed and the formwork is removed, any debris that may fall into the protective device is removed. Then, the long side crossbars between the adjacent U-shaped frame uprights and the end crossbars and end mesh netting on the U-shaped frame verticals closest to the cap beam end face are removed. A steel wire rope is installed on the U-shaped frame closest to the cap beam end face, and the steel wire rope is used to pull the U-shaped frame back to the position close to the pier column, so that the protective device returns to its initial retracted state. Wooden wedges are used to temporarily fix the position of the pulley assembly between the rollers of the pulley assembly and the lower flange plate of the I-beam. The mesh netting, the U-shaped frame verticals and cross braces, and the lower crossbars of the U-shaped frame are removed in sequence. The I-beam is then removed, and the entire construction process is completed.

2. The method of using the telescopic fully enclosed protective device for large cantilever beams according to claim 1, characterized in that: The bottom ends of the two vertical bars are connected to the lower horizontal bar using right-angle fasteners.

3. The method of using the telescopic fully enclosed protective device for large cantilever beams according to claim 2, characterized in that: The length of the lower crossbar is equal to the width of the cap beam to be poured plus the width of the operating platforms on both sides of the cap beam.

Images