Overall lowering and dismantling method for movable formwork support

Abstract

The invention discloses an integral descending and dismantling method for a movable formwork support, and belongs to the technical field of bridge construction. The method comprises the steps that S1, a temporary support is arranged on the ground according to the size, shape and lowering position requirements of a movable formwork support main beam; s2, a supporting structure is erected on the upper portion of the box girder, and a jack is arranged on the supporting structure; s3, hoisting holes are formed in a flange plate of the box girder and a top plate and a bottom plate of the movable formwork support girder, one end of a steel strand is anchored to the supporting structure through a jack and dragged, and the other end of the steel strand penetrates through the hoisting holes and then is anchored to the bottom plate of the girder through an anchor plate; s4, the jack is controlled to gradually lift the movable formwork support main beam to a set height from the corbel cross beam, and then the corbel and the corbel cross beam are dismantled; and S5, the jack is controlled to lower the movable formwork support main beam to the temporary support. According to the overall lowering and dismantling method for the movable formwork support, the movable formwork support can be overall lowered and dismantled, and the efficiency and safety of dismantling work are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge construction, and in particular relates to a method for overall lowering and dismantling of a movable formwork support. Background Art

[0002] In the construction of large concrete structures such as modern bridges and high-rise buildings, mobile formwork supports play an extremely important role. It can provide a stable support platform for concrete pouring and can move along the construction direction, greatly improving the construction efficiency and the molding quality of the concrete structure. As the construction progresses, when the concrete structure of a certain construction section is poured and reaches a certain strength, the mobile formwork supports need to be dismantled in order to carry out subsequent construction processes or transfer to other construction areas. The traditional formwork support removal method often adopts a component-by-component and segment-by-segment removal method. For example, the formwork is removed first, then the support of the beam body is removed, and finally the support of the foundation part such as the column is removed. In addition, a large amount of high-altitude operations are required during the removal of each part, such as workers loosening bolts at high altitudes and lifting individual components. The traditional removal method has the disadvantages of great risks of high-altitude operations, low removal efficiency, high construction costs, and easy damage to the surface of the built structure. Summary of the invention

[0003] In view of the deficiencies existing in the related art, the purpose of the present invention is to provide a method for lowering and dismantling a mobile formwork support as a whole, so that the mobile formwork support can be lowered smoothly from a completed construction position to a specified position as a whole while ensuring safety.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for lowering and dismantling a movable formwork support as a whole, comprising:

[0006] S1. Arrange temporary supports on the ground according to the size, shape and lowering position requirements of the main beam of the mobile formwork support;

[0007] S2. Set up a supporting structure on the upper part of the box girder, and install a jack on the supporting structure;

[0008] S3. Open lifting holes on the flange plate of the box beam, the top plate and the bottom plate of the main beam of the movable formwork support, anchor one end of the steel strand to the supporting structure with a jack and pull it, pass the other end of the steel strand through each lifting hole and anchor it to the bottom plate of the main beam with an anchor plate;

[0009] S4, control the jack to gradually lift the main beam of the mobile formwork support from the corbel beam to a set height, and then remove the corbel and the corbel beam;

[0010] S5. Control the jack to lower the main beam of the mobile formwork support to the temporary support.

[0011] In some embodiments, step S2 comprises:

[0012] S21. Clean and smooth the upper surface of the box beam;

[0013] S22, arranging Bailey plate bolsters at preset positions along the longitudinal direction of the box girder, with the center line of the Bailey plate bolsters being parallel to the longitudinal center line of the box girder;

[0014] S23, assembling and splicing Bailey sheets to form a truss structure, and hanging the assembled Bailey sheet truss on the Bailey sheet bolster for fixing;

[0015] S24, laying steel sections on the Bailey sheet truss along the transverse direction of the Bailey sheet at a preset interval;

[0016] S25. Place a jack on the steel section and pass a steel strand through the middle of the jack.

[0017] In some of the embodiments, the Bailey bolster is made of 36A I-beam.

[0018] In some of the embodiments, in step S25, the oil cylinder bolster is firstly preliminarily fixed on the steel section, and then the jack is hoisted onto the oil cylinder bolster for fixed connection.

[0019] In some of the embodiments, the cylinder bolster is made of 56A I-beam.

[0020] In some of the embodiments, in step S5, the main beams of the movable formwork support are lowered simultaneously on both sides and placed at different heights, the main beams of the movable formwork support on both sides are not connected, and each main beam of the movable formwork support is provided with four hanging points, which are provided on the bottom plate of the main beam of the movable formwork support.

[0021] In some of the embodiments, a stiffening plate is provided inside the main beam of the movable formwork support.

[0022] In some of the embodiments, in step S2, eight jacks are provided on the supporting structure, and the eight jacks are 200-ton jacks.

[0023] In some of the embodiments, in step S4, during the process of the jack lifting the main beam of the movable formwork support, the lifting pressure and travel progress of the jack are monitored, and whether the main beam of the movable formwork support and the box beam are abnormally deformed or displaced is monitored.

[0024] In some of the embodiments, in step S4, the jack gradually lifts the movable formwork support main beam from the corbel beam by 1.3 meters.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The overall lowering and dismantling method of the mobile formwork support provided by the present invention can lower the mobile formwork support as a whole from the completed construction position to the designated position smoothly under the premise of ensuring safety. This dismantling method has low construction cost and will not damage the surface of the built structure, thereby effectively improving the efficiency and safety of the dismantling work.

[0027] 2. In the overall lowering and dismantling method of the movable formwork support provided by the present invention, a supporting structure is set up on the upper part of the box girder, which can effectively disperse the concentrated stress to the web position of the box girder body. The evenly dispersed stress helps to maintain the stable shape of the box girder structure and prevent local damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 It is a work flow chart of an embodiment of the method for lowering and removing the movable formwork support as a whole of the present invention;

[0030] Figure 2 It is a structural schematic diagram of an embodiment of the method for lowering and removing the movable formwork support as a whole according to the present invention;

[0031] Figure 3 A schematic diagram of the details of the lifting points of an embodiment of the method for lowering and removing the movable formwork support as a whole according to the present invention;

[0032] Figure 4 A schematic diagram of the height setting of the main beam of the movable formwork support when lifting in accordance with an embodiment of the method for lowering and removing the movable formwork support as a whole according to the present invention;

[0033] Figure 5 A schematic diagram of removing a corbel and a corbel crossbeam according to an embodiment of a method for lowering and removing a movable formwork support as a whole according to the present invention;

[0034] Figure 6 This is a schematic diagram of lowering the main beam of a movable formwork support to a temporary support in one embodiment of a method for lowering and dismantling a movable formwork support as a whole according to the present invention.

[0035] In the figure:

[0036] 1. Main beam of mobile formwork support; 11. Top plate; 12. Bottom plate; 121. Lifting point; 2. Temporary support; 3. Box beam; 31. Flange plate; 32. Web plate; 4. Support structure; 41. Bailey plate bolster; 42. Bailey plate truss; 421. Bailey plate; 43. Steel section; 5. Jack; 51. Cylinder bolster; 6. Lifting hole; 7. Steel strand; 8. Anchor plate; 9. Corbel beam; 10. Corbel. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] See attached Figures 1 to 6 , a schematic embodiment of the overall lowering and dismantling method of the movable formwork support proposed by the present invention is given, and the overall lowering and dismantling method of the movable formwork support comprises the following steps:

[0041] S1. Arrange temporary supports 2 on the ground according to the size, shape and lowering position requirements of the mobile formwork support main beam 1;

[0042] S2, erecting a support structure 4 on the upper part of the box beam 3, and installing a jack 5 on the support structure 4;

[0043] S3, opening hoisting holes 6 on the flange plate 31 of the box beam 3, the top plate 11 and the bottom plate 12 of the main beam 1 of the movable formwork support, anchoring one end of the steel strand 7 on the supporting structure 4 with a jack 5 and pulling it, passing the other end of the steel strand 7 through each hoisting hole 6 and anchoring it on the bottom plate 12 of the main beam with an anchor plate 8;

[0044] S4, control the jack 5 to gradually lift the main beam 1 of the mobile formwork support from the corbel beam 9 to a set height, and then remove the corbel 10 and the corbel beam 9;

[0045] S5. Control the jack 5 to lower the main beam 1 of the mobile formwork support to the temporary support 2.

[0046] The weight of the mobile formwork support body is too large. If it is directly lifted, it cannot meet the bearing conditions. Therefore, a support structure 4 is set up on the upper part of the box beam 3 to effectively disperse the concentrated stress to the web 32 of the box beam 3. In this embodiment, step S2 includes:

[0047] S21. Clean and level the upper surface of the box girder 3; before erecting the supporting structure 4, remove debris, dust and any raised or sunken parts on the surface of the box girder 3 that may affect the stability of the supporting structure 4 to ensure that the surface of the box girder 3 is flat and smooth, which can provide a stable and reliable foundation for subsequent construction work.

[0048] S22. Bailey sheet bolsters 41 are arranged at preset positions along the longitudinal direction of the box beam 3. The center line of the Bailey sheet bolsters 41 is parallel to the longitudinal center line of the box beam 3 to ensure that the load can be evenly distributed on the box beam 3. In order to control the deviation within a very small range, a total station or other high-precision measuring instruments can be used to accurately measure and locate the position of the Bailey sheet bolsters 41. In order to prevent the box beam 3 and the Bailey sheet bolsters 41 from relative displacement, full welding can be performed at the contacting parts of the Bailey sheet bolsters 41 and the box beam 3 to ensure a firm and reliable connection.

[0049] S23, assembling and splicing Bailey sheets 421 to form a truss structure, hanging the assembled Bailey sheet truss 42 on the Bailey sheet bolster 41 for fixing; the Bailey sheets 421 are firmly installed to each other so that the structure of the Bailey sheet truss 42 formed by them is stable. During the assembly process, the level and straightness of the Bailey sheets 421 are measured and adjusted using tools such as a level and a steel ruler to ensure the assembly quality.

[0050] S24, laying the steel sections 43 on the Bailey sheet truss 42 along the lateral direction of the Bailey sheet 421 at a preset spacing; the laid steel sections 43 are measured and cut in advance to make their lengths meet the size requirements of laying on the Bailey sheet truss 42. The steel sections 43 are fixedly connected to the Bailey sheet 421 so that the steel sections 43 and the Bailey sheet truss 42 form an integral support structure 4, providing a stable and reliable basic platform for the subsequent overall lowering and removal construction of the mobile formwork support.

[0051] S25. Place a jack 5 on the steel section 43, and pass a steel strand 7 through the jack 5.

[0052] In step S24 , the surface of the steel section 43 is subjected to rust removal and anti-corrosion treatment, such as painting with anti-rust paint, so as to extend the service life of the steel section 43 .

[0053] In this embodiment, the Bailey sheet bolster 41 is made of 36A I-beam. The 36A I-beam has a high section modulus and moment of inertia. In the subsequent construction process, when a load acts on the Bailey sheet bolster 41 through the Bailey sheet truss 42, the 36A I-beam can effectively resist the bending and torsional deformations caused by these loads, ensuring the stability of the entire structure.

[0054] In step S25, the oil cylinder bolster 51 is first preliminarily fixed on the steel section 43, and then the jack 5 is lifted to the oil cylinder bolster 51 and fixedly connected. In this embodiment, the oil cylinder bolster 51 is made of 56A I-beam. The cross-sectional shape and size of the 56A I-beam give it excellent bending resistance, and its web and flange thickness are sufficient. The oil cylinder bolster 51 made of 56A I-beam can withstand the huge pressure from the jack 5 without easily bending and deforming, and can withstand a large axial pressure. When the vertical downward force of the jack 5 is transmitted through the oil cylinder bolster 51, the oil cylinder bolster 51 can evenly disperse the pressure to the supporting structure 4 below, and no local crushing phenomenon will occur.

[0055] In step S5 , the movable formwork support main beam 1 is lowered simultaneously on both sides and placed at different heights. The movable formwork support main beams 1 on both sides are not connected. Each movable formwork support main beam 1 is provided with four hanging points 121 , and the hanging points 121 are provided on the bottom plate 12 of the movable formwork support main beam 1 .

[0056] In order to further improve the stability, a stiffening plate is provided in the main beam 1 of the movable formwork support, specifically, a steel plate is added in the main beam 1 of the movable formwork support for reinforcement, so that the stress can be effectively dispersed to the web of the main beam 1 of the movable formwork support.

[0057] In step S2, eight jacks 5 are arranged on the supporting structure 4, and the eight jacks 5 are 200-ton jacks 5. Specifically, four jacks 5 are arranged on the main beams 1 of the movable formwork support on both sides, and two jacks 5 are arranged on the two ends of each movable formwork support main beam 1, so as to be able to lift or lower the movable formwork support main beam 1 stably.

[0058] In step S4, when the jack 5 lifts the main beam 1 of the movable formwork support, the lifting pressure and travel progress of the jack 5 are monitored, and whether the main beam 1 of the movable formwork support and the box beam 3 have abnormal deformation or displacement is monitored.

[0059] In step S4, the jacks 5 gradually lift the main beam 1 of the mobile formwork support 1.3 meters from the corbel beam 9. It is necessary to ensure that the eight jacks 5 are stressed at the same time to evenly disperse the load, and evenly distribute the total load to the supporting points of each jack 5 to avoid structural damage caused by excessive local pressure, which helps to maintain the balance of the main beam 1 of the mobile formwork support during the lifting process.

[0060] In the above exemplary embodiment, the overall lowering and dismantling method of the mobile formwork support basically does not involve high-altitude work, and the upper support and lower reinforcement are all carried out on a safe platform. After the template crossbeam is dismantled, the two main beams of the mobile formwork support are placed on the pre-arranged support on the ground with a jack, and the subsequent work is completed on land, which greatly improves the safety factor in terms of the crane's lifting height and lifting distance, ensuring that the demolition work is finally completed safely and satisfactorily.

[0061] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0062] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A method for lowering and dismantling a movable formwork support as a whole, characterized in that: include: S1. Arrange temporary supports on the ground according to the size, shape and lowering position requirements of the main beam of the mobile formwork support; S2. Set up a supporting structure on the upper part of the box girder, and install a jack on the supporting structure; S3. Open lifting holes on the flange plate of the box beam, the top plate and the bottom plate of the main beam of the movable formwork support, anchor one end of the steel strand to the supporting structure with a jack and pull it, pass the other end of the steel strand through each lifting hole and anchor it to the bottom plate of the main beam with an anchor plate; S4, control the jack to gradually lift the main beam of the mobile formwork support from the corbel beam to a set height, and then remove the corbel and the corbel beam; S5. Control the jack to lower the main beam of the mobile formwork support to the temporary support.

2. The method for lowering and dismantling the movable formwork support as a whole according to claim 1 is characterized in that: Step S2 includes: S21. Clean and smooth the upper surface of the box beam; S22, arranging Bailey plate bolsters at preset positions along the longitudinal direction of the box girder, with the center line of the Bailey plate bolsters being parallel to the longitudinal center line of the box girder; S23, assembling and splicing Bailey sheets to form a truss structure, and hanging the assembled Bailey sheet truss on the Bailey sheet bolster for fixing; S24, laying steel sections on the Bailey sheet truss along the transverse direction of the Bailey sheet at a preset interval; S25. Place a jack on the steel section and pass a steel strand through the middle of the jack.

3. The method for lowering and dismantling the movable formwork support as a whole according to claim 2 is characterized in that: The Bailey bolster is made of 36A I-beam.

4. The method for lowering and dismantling the movable formwork support as a whole according to claim 2 is characterized in that: In step S25, the oil cylinder bolster is firstly preliminarily fixed on the steel section, and then the jack is hoisted onto the oil cylinder bolster for fixed connection.

5. The method for lowering and dismantling the movable formwork support as a whole according to claim 4 is characterized in that: The cylinder bolster is made of 56A I-steel.

6. The method for lowering and dismantling a movable formwork support as a whole according to claim 1, characterized in that: In step S5, the main beams of the movable formwork support are lowered simultaneously on both sides and placed at different heights. The main beams of the movable formwork support on both sides are not connected. Each main beam of the movable formwork support is provided with four hanging points, and the hanging points are provided on the bottom plate of the main beam of the movable formwork support.

7. The method for lowering and dismantling the movable formwork support as a whole according to claim 6 is characterized in that: A stiffening plate is arranged inside the main beam of the movable formwork support.

8. The method for lowering and dismantling a movable formwork support as a whole according to claim 6, characterized in that: In step S2, eight jacks are arranged on the supporting structure, and the eight jacks are 200-ton jacks.

9. The method for lowering and dismantling a movable formwork support as a whole according to claim 1, characterized in that: In step S4, when the jack lifts the main beam of the movable formwork support, the lifting pressure and travel progress of the jack are monitored, and whether the main beam of the movable formwork support and the box beam have abnormal deformation or displacement is monitored.

10. The method for lowering and dismantling a movable formwork support as a whole according to claim 1, characterized in that: In step S4, the jack gradually lifts the main beam of the mobile formwork support from the corbel beam by 1.3 meters.

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