Template system with few pull rods and construction method thereof

Abstract

The invention discloses a few-pull-rod formwork system and a construction method thereof.The few-pull-rod formwork system comprises a formwork device, a stiff framework and pull rods, the formwork device is composed of an outer formwork back ridge, an outer formwork, an inner formwork back ridge and an inner formwork, and the stiff framework is arranged between inner-layer steel bars and outer-layer steel bars of a tower column; and a plurality of layers of pull rods are arranged on the plane in the stiff framework. A stiff framework in the tower column is composed of a plurality of layers of plane trusses and interlayer vertical connecting systems, the interlayer vertical connecting systems are arranged between every two layers of plane trusses, and the interlayer vertical connecting systems and the plane trusses form a whole through angle steel. And the pull rod is divided into an internal pull rod and an external pull rod which are connected through a threaded sleeve, and the plane truss and the internal and external creeping formwork templates are connected into a whole. The problems that when the formwork is installed, the usage amount of pull rods is large, and the pull rods are difficult to arrange are effectively solved, and a new thought is provided for installation and construction of the large bridge tower standard section formwork.

Description

Technical Field

[0001] This invention relates to the field of construction of standard sections for ultra-high piers (towers), and in particular to a formwork system with fewer tie rods and its construction method. Background Technology

[0002] As long-span bridges extend into complex environments such as deep valleys and sea areas, the application of ultra-high pier (tower) structures is gradually increasing. For the formwork installation of standard sections of ultra-high piers (towers), the conventional installation method involves using through-rods to connect the inner and outer formwork into a whole, or arranging short tie rods to connect with the stiffening frame. The spacing between adjacent tie rods is approximately 1.0m, and the large number of tie rods easily leads to conflicts with the tower column reinforcement. Furthermore, the installation efficiency of tie rods is low, resulting in numerous tie rod holes after concrete pouring and poor concrete appearance quality.

[0003] To solve the above problems, there is an urgent need to develop an economical, practical, convenient, and fast formwork system with fewer tie rods and its construction method. Summary of the Invention

[0004] By combining the rigid frame inside the ultra-high pier (tower) with the tie rod formwork system, the first objective of this invention is to provide a tie rod formwork system with fewer tie rods and higher construction efficiency.

[0005] The second objective of this invention is to provide a construction method for formwork with fewer tie rods that is convenient, quick, economical, practical, and has good economic benefits.

[0006] The first objective of this invention is achieved as follows: A formwork system with fewer tie rods is characterized by comprising: a formwork device, a stiffening frame, and tie rods. The formwork device consists of an outer formwork back rib, an outer formwork, an inner formwork back rib, and an inner formwork. The outer formwork back rib, which provides support, is located on the back of the outer formwork, and the inner formwork back rib, which provides support, is located on the back of the inner formwork. The stiffening frame is arranged between the inner and outer layers of steel bars in the tower column and does not interfere with the inner and outer steel bars. Several layers of tie rods are provided on the plane within the stiffening frame.

[0007] Furthermore, the internal stiffening frame of the tower column consists of multiple layers of planar trusses and inter-layer vertical connections. The inter-layer vertical connections are located between two layers of planar trusses. Each layer of planar trusses is made of channel steel welded flat. The arrangement height of each layer of planar trusses corresponds one-to-one with the vertical arrangement of the tie rods. The inter-layer vertical connections are made of angle steel and form an integral whole with the planar trusses. The structural dimensions of the planar trusses and the inter-layer vertical connections are adjusted section by section according to the cross-section of the tower column.

[0008] Furthermore, the tie rods of each layer are arranged at the nodes of the planar truss, and the flanges of the channel steel are slotted at the tie rods, with a reinforcing structure welded to the back.

[0009] Furthermore, the tie rod consists of an external tie rod, an internal tie rod, and threaded sleeves. The tie rods are divided into short tie rods and long tie rods according to their anchoring positions. Short tie rods are arranged around the chamfered areas of the planar truss and anchored to the planar truss. Long tie rods are arranged at the centrally symmetrical positions of the planar truss and directly anchored to the outer and inner formwork. For short tie rods, one end of the internal tie rod's threaded sleeve is anchored to the flange of the channel steel of the planar truss, and the other end of the internal tie rod's threaded sleeve is in close contact with the outer formwork. After mold closing, the external tie rod is screwed into the threaded sleeve and anchored to the anchor seat of the back rib of the outer formwork, forming a load-bearing system. For long tie rods, both ends of the internal tie rod's threaded sleeves are in close contact with the outer and inner formwork. After mold closing, the external tie rod is screwed into the threaded sleeve and anchored to the anchor seat of the back rib of the outer and inner formwork, forming a load-bearing system.

[0010] Furthermore, the tie rods are arranged in several layers on the facade. Based on the distribution characteristics of the lateral pressure of the concrete, the tie rods are spaced more densely at the bottom and more sparsely at the top to ensure that the tie rods are subjected to uniform stress as much as possible. The tie rods at the bottom layer are close to the concrete pouring segment line to prevent grout leakage.

[0011] Furthermore, the plane of the tie rod is symmetrically arranged along the centerline of the super-high pier (tower).

[0012] The second objective of this invention is achieved as follows: A construction method for formwork with fewer tie rods, characterized by the following specific construction steps: 1. After the concrete of the previous stage of the bridge tower is poured and reaches the design strength, the stiffening frame inside the tower column is hoisted onto the tower as a whole, and the stiffening frame inside the tower column is welded to the stiffening frame of the previous segment. 2. Install built-in tie rods around the perimeter of the planar truss and anchor the built-in tie rods to the planar truss of the stiffening frame according to the design; III. Tying the reinforcing bars; 4. Close the mold, install the external tie rod and screw it into the threaded sleeve on the side of the internal tie rod near the tower wall to form a connection; V. Pouring segmental concrete; 6. After the demolding conditions are met, tighten the external tie rod in the reverse direction, retrieve it for later use, demold, seal the holes of the tie rod, and prepare for the next segment construction.

[0013] Compared with the prior art, the advantages of the present invention are as follows: 1. This invention relies on the reliable force transmission between the internal rigid frame and the external template back ribs and the internal template back ribs, which greatly reduces the number of tie rods, reduces the possibility of conflict between tie rods and tower column reinforcement, and improves the installation efficiency of tie rods. 2. The present invention reduces the number of tie rod holes after concrete pouring, thereby improving the appearance quality of the concrete; 3. For the construction of ultra-high piers (towers) in confined spaces, the installation and dismantling of ultra-long through-rods is extremely inconvenient. This invention divides the tie rod into two parts: an internal tie rod and an external tie rod. This not only reduces the difficulty of installing and dismantling the tie rod, but also enables the external tie rod to be reused repeatedly, resulting in good economic benefits.

[0014] This invention effectively solves the problems of large number of tie rods used and difficulty in setting tie rods during template installation, and provides a new approach for the installation and construction of standard sections of large bridge tower templates. Attached Figure Description

[0015] Figure 1 This is an elevation view of the tie rod-less formwork system used in an embodiment of the present invention; Figure 2 This is a plan view of the tie rod-less template system used in this embodiment of the invention; Figure 3 This is a schematic elevation view showing the arrangement of the short tie rods in an embodiment of the present invention; Figure 4 This is a schematic plan view showing the arrangement of the short tie rods in an embodiment of the present invention; Figure 5 This is a schematic elevation view of the arrangement of the long tie rods in an embodiment of the present invention; Figure 6 This is a schematic plan view showing the arrangement of the long tie rods in an embodiment of the present invention; In the diagram: 1-Formwork device, 2-Strengthened frame, 3-Tie rod, 11-External formwork back rib, 12-External formwork, 13-Internal formwork back rib, 14-Internal formwork, 15-Anchor seat, 21-Planar truss, 22-Inter-layer vertical connection system, 211-Channel steel, 212-Reinforcing structure, 31-Short tie rod, 32-Long tie rod, 311-Built-in tie rod, 312-External tie rod, 313-Threaded sleeve, 41-Inner layer reinforcement, 42-Outer layer reinforcement. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the embodiments and the accompanying drawings.

[0017] A formwork system with fewer tie rods includes: a formwork device 1, a rigid frame 2, and tie rods 3. The formwork device 1 consists of an outer formwork back rib 11, an outer formwork 12, an inner formwork back rib 13, and an inner formwork 14. The outer formwork back rib 11, which provides support, is located on the back of the outer formwork 12, and the inner formwork back rib 13, which provides support, is located on the back of the inner formwork 14. The rigid frame 2 is arranged between the inner layer steel bars 41 and the outer layer steel bars 42 of the tower column, and does not interfere with the inner layer steel bars 41 and the outer layer steel bars 42. Several layers of tie rods 3 are provided on the plane inside the rigid frame 2.

[0018] The internal stiffening frame 2 of the tower column consists of multi-layer planar trusses 21 and inter-layer vertical connection system 22. The inter-layer vertical connection system 22 is located between two layers of planar trusses 21. Each layer of planar truss 21 is made of channel steel 211 welded flat. The arrangement height of each layer of planar truss 21 corresponds one-to-one with the vertical arrangement of tie rods 3. The inter-layer vertical connection system 22 is made of angle steel and forms an integral whole with the planar truss 21. The structural dimensions of the planar truss 21 and the inter-layer vertical connection system 22 are adjusted section by section according to the cross-section of the tower column.

[0019] The tie rods 3 of each layer are arranged at the nodes of the planar truss 21, and the flanges of the channel steel 211 are slotted at the tie rods 3, and a reinforcing structure 212 is welded to the back.

[0020] Tie rod 3 consists of an external tie rod 312, an internal tie rod 311, and a threaded sleeve 313. Tie rod 3 is divided into short tie rods 31 and long tie rods 32 according to their anchoring positions. Short tie rods 31 are arranged around the chamfered areas of the planar truss 21 and anchored to the planar truss 21. Long tie rods 32 are arranged at the centrally symmetrical positions of the planar truss 21 and directly anchored to the outer template 12 and the inner template 14. For short tie rods 31, one end of the internal tie rod 311 of the short tie rod 31 has its threaded sleeve 313 anchored to the flange of the channel steel 211 of the planar truss 211, while the other end of the internal tie rod 311 of the short tie rod 31 has its threaded sleeve 313 tightly attached to the outer template 12. After mold closing, the external tie rod 312 is screwed into the threaded sleeve 313 and anchored to the anchor seat 15 of the back rib of the outer template 11, forming a force-bearing system. For the long tie rod 32, the threaded sleeves 313 at both ends of the built-in tie rod 311 of the long tie rod 32 are tightly attached to the outer template 12 and the inner template 14. After the mold is closed, the outer tie rod 311 is screwed into the threaded sleeve 313 and anchored to the anchor seat 15 of the back rib of the outer template 11 and the anchor seat 15 of the back rib of the inner template 13 to form a force-bearing system.

[0021] The tie rods 3 are arranged in several layers on the facade. Based on the distribution characteristics of the lateral pressure of the concrete, the spacing of the tie rods 3 is denser at the bottom and sparser at the top to ensure uniform stress distribution. The tie rods 3 at the bottom layer are close to the concrete pouring segment line to prevent grout leakage. The tie rods 3 are symmetrically arranged along the centerline of the super-high pier (tower) to ensure symmetrical stress distribution on the planar truss 21 and guarantee the stability of the formwork device 1. After the standard section concrete pouring is completed, the external tie rods 312 can be reused for the next standard section.

[0022] During construction, the lateral pressure of the concrete borne by the formwork device 1 is transmitted through the tie rods 3 to the stiffening frame 2 inside the tower column and the formwork system 1 on the inner side of the tower column; utilizing the symmetrical force characteristics of the stiffening frame 2, a self-balancing system is formed. The number of tie rods 3 determines the bearing capacity of the tie rods 3, and the external formwork back ribs 11, internal formwork back ribs 13, and the stiffening frame 2 inside the tower column that anchor the tie rods 3 must have sufficient strength, rigidity, and stability.

[0023] A construction method for formwork with fewer tie rods, the specific construction steps are as follows: 1. After the concrete of the previous stage of the bridge tower is poured and reaches the design strength, the stiffening frame 2 inside the tower column is hoisted onto the tower as a whole, and the stiffening frame 2 inside the tower column is welded to the stiffening frame 2 of the previous segment. 2. Install built-in tie rods 311 around the planar truss 21 and anchor the built-in tie rods 311 to the planar truss 21 of the stiffening frame 2 according to the design. III. Tying the reinforcing bars; 4. Close the mold, install the external tie rod 312 and screw it into the threaded sleeve 313 on the side of the internal tie rod 311 near the tower wall to form a connection; V. Pouring segmental concrete; 6. After the demolding conditions are met, tighten the external tie rod 312 in the reverse direction, retrieve it for later use, demold, seal the hole of tie rod 3, and prepare for the next segment construction.

[0024] Although the present invention has been disclosed above, the present invention is not limited thereto, such as the positioning and measurement of the bracket next to the pier; any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention, therefore the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A formwork system with fewer tie rods, characterized in that: It includes a formwork device, a rigid frame, and tie rods. The formwork device consists of an outer formwork back rib, an outer formwork, an inner formwork back rib, and an inner formwork. The outer formwork back rib, which provides support, is located on the back of the outer formwork, and the inner formwork back rib, which provides support, is located on the back of the inner formwork. The rigid frame is arranged between the inner and outer layers of steel bars in the tower column and does not interfere with the inner and outer layers of steel bars. Several layers of tie rods are provided on the plane inside the rigid frame.

2. The formwork system with fewer tie rods according to claim 1, characterized in that: The internal rigid frame of the tower column consists of multiple layers of planar trusses and inter-layer vertical connections. The inter-layer vertical connections are located between two layers of planar trusses. Each layer of planar trusses is made of channel steel welded flat. The arrangement height of each layer of planar trusses corresponds one-to-one with the vertical arrangement of the tie rods. The inter-layer vertical connections are made of angle steel and form an integral whole with the planar trusses. The structural dimensions of the planar trusses and the inter-layer vertical connections are adjusted section by section according to the cross-section of the tower column.

3. The formwork system with fewer tie rods according to claim 2, characterized in that: The tie rods of each layer are arranged at the nodes of the planar truss, and the flanges of the channel steel are slotted at the tie rods, and a reinforcing structure is welded on the back.

4. The formwork system with fewer tie rods according to claim 1, characterized in that: The tie rod consists of an external tie rod, an internal tie rod, and threaded sleeves. Based on their anchorage positions, the tie rods are divided into short tie rods and long tie rods. Short tie rods are arranged around the chamfered areas of the planar truss and anchored to the planar truss. Long tie rods are arranged at the centrally symmetrical positions of the planar truss and directly anchored to the outer and inner formwork. For short tie rods, one end of the internal tie rod's threaded sleeve is anchored to the flange of the channel steel of the planar truss, and the other end of the internal tie rod's threaded sleeve is in close contact with the outer formwork. After mold closing, the external tie rod is screwed into the threaded sleeve and anchored to the anchor seats of the outer formwork back ribs, forming a load-bearing system. For long tie rods, both ends of the internal tie rod's threaded sleeves are in close contact with the outer and inner formwork. After mold closing, the external tie rod is screwed into the threaded sleeve and anchored to the anchor seats of the outer and inner formwork back ribs, forming a load-bearing system.

5. The formwork system with fewer tie rods according to claim 4, characterized in that: The tie rods are arranged in several layers on the facade. Based on the distribution characteristics of the lateral pressure of the concrete, the spacing between the tie rods on the facade is denser at the bottom and sparser at the top to ensure that the tie rods are subjected to uniform stress as much as possible. The tie rods at the bottom layer are close to the concrete pouring segment line to prevent grout leakage.

6. The formwork system with fewer tie rods according to claim 5, characterized in that: The plane of the tie rod is symmetrically arranged along the centerline of the super-high pier / tower.

7. A construction method for a formwork system with fewer tie rods as described in claim 1, characterized in that: The specific construction steps are as follows:

1. After the concrete of the previous stage of the bridge tower is poured and reaches the design strength, the stiffening frame inside the tower column is hoisted onto the tower as a whole, and the stiffening frame inside the tower column is welded to the stiffening frame of the previous segment.

2. Install built-in tie rods around the perimeter of the planar truss and anchor the built-in tie rods to the planar truss of the stiffening frame according to the design; III. Tying the reinforcing bars; 4. Close the mold, install the external tie rod and screw it into the threaded sleeve on the side of the internal tie rod near the tower wall to form a connection; V. Pouring segmental concrete; 6. After the demolding conditions are met, tighten the external tie rod in the reverse direction, retrieve it for later use, demold, seal the holes of the tie rod, and prepare for the next segment construction.

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