A construction method for a formwork arrangement for a shaft

Abstract

The present application relates to a kind of construction method of formwork device suitable for shaft, the method uses the following steps: excavating shaft, after hardening ground, splicing edge angle at the bottom of shaft, and assembling shaft segment in the upper portion of edge angle;The outside of edge angle is used as the pouring area of lock mouth ring beam, and a plurality of annular protection blocks are arranged on the side between the area and shaft segment;Formwork is inserted into the gap between lock mouth ring pouring area and shaft segment in turn.Compared with prior art, the pouring formwork provided by the present application is simple to install, the formwork leak stop effect is good, easy to disassemble, the concrete surface after pouring is more flat, and has good economic value.The concrete protection layer support block provided by the present application is circular ring structure, during the installation process of formwork from top to bottom, annular protection block can roll around the axis steel bar, reduce the friction effect to formwork.

Description

Technical Field

[0001] This invention belongs to the field of vertical shaft construction technology, specifically relating to a construction method for a formwork device suitable for vertical shafts. Background Technology

[0002] Shaft construction is an important construction method in modern foundation pit engineering. In suspended shaft construction, a foundation pit of a certain height needs to be excavated before sinking. Then, steel cutting edges and the first layer of shaft segments are placed in the pit. Afterward, a ring of concrete beams, called the locking ring beam, is poured around the segments and cutting edges. Due to the limited construction space for the locking ring beam, conventional formwork erection methods are difficult, and conventional formwork removal methods are also challenging. Therefore, a formwork and construction method suitable for the concrete pouring of the locking ring beam in a shaft is designed. Summary of the Invention

[0003] In order to overcome the above-mentioned problems in the prior art, the present invention provides a construction method for a formwork device suitable for vertical shafts, which solves the above-mentioned problems in the prior art.

[0004] A construction method for a formwork device suitable for vertical shafts, the method comprising the following steps: S1. Excavate a vertical shaft, harden the ground, splice the cutting edge at the bottom of the shaft, and assemble the shaft segments at the upper part of the cutting edge; S2. The outer side of the cutting edge is used as the casting area for the lock ring beam, and a support block is set on the side between this area and the shaft segment; S3. Insert the templates sequentially into the gaps between the interlocking ring beam casting area and the shaft segments.

[0005] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the template is configured as several blocks, each block having insertable chamfered ends, the chamfered side closer to the casting area of ​​the lock ring beam being longer, and the chamfered side closer to the shaft segment being shorter.

[0006] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the cutting edge is spliced ​​at the bottom of the interlocking ring beam casting area, the shaft segment is disposed above the cutting edge, and a gap is provided between the interlocking ring beam casting area and the shaft segment.

[0007] In addition to the aspects and any possible implementations described above, a further implementation is provided in which, prior to S3, the long side of the insert chamfer of each template is sealed.

[0008] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the template is an extruded polystyrene board.

[0009] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the height of the template is greater than the height of the lock ring beam.

[0010] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the support blocks are arranged at intervals around the casting area of ​​the lock ring beam in the gap.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the support block is annular and is provided in plurality.

[0012] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the annular support block includes an annular concrete protective layer support block and a main reinforcement bar on the outer side of the lock ring beam, the main reinforcement bar being inserted into the annular concrete protective layer support block.

[0013] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the extruded board is a rigid foam plastic sheet formed by heat extrusion.

[0014] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the rigid foam board is a board with a closed-cell honeycomb structure made of polystyrene resin and other additives.

[0015] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the gap is 10 cm.

[0016] Beneficial effects of the present invention The present invention discloses a construction method for a formwork device applicable to vertical shafts, comprising the following steps: excavating a vertical shaft, hardening the ground, splicing a cutting edge at the bottom of the shaft, and assembling shaft segments on the upper part of the cutting edge; designating the outer side of the cutting edge as the casting area for the locking ring beam, and setting a support block on the side between this area and the shaft segments; inserting the formwork sequentially into the gap between the locking ring beam casting area and the shaft segments. Compared with the prior art, the casting formwork provided by the present invention is simple to install, has good leakage prevention effect, is easy to disassemble, produces a smoother concrete surface after casting, and has good economic value. The concrete protective layer support block provided by the present invention has a circular ring structure, which can roll around the central reinforcing bar during the installation of the formwork from top to bottom, reducing friction on the formwork. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view of the template installation of the present invention; Figure 2 This is a top view of the template installation of the present invention; Figure 3This is a top view of the template installation and overlapping method of the present invention; Figure 4 This is a schematic diagram of the annular concrete protective block of the present invention; Figure 5 This is a schematic diagram of the template installation process of the present invention. Detailed Implementation

[0018] To better understand the technical solution of this invention, the content of this invention includes, but is not limited to, the specific embodiments described below. Similar technologies and methods should be considered within the scope of protection of this invention. To make the technical problems to be solved, the technical solutions, and advantages of this invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0019] It should be understood that the embodiments described in this invention are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0020] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0021] like Figures 1-5 As shown, the present invention provides a construction method for a formwork device suitable for vertical shafts, the method comprising the following steps: S1. Excavate a vertical shaft, harden the ground, splice the cutting edge at the bottom of the shaft, and assemble the shaft segments at the top of the cutting edge; S2. The outer side of the cutting edge is used as the casting area for the lock ring beam, and a support block is set on the side between this area and the shaft segment; S3. Insert the templates sequentially into the gaps between the interlocking ring beam casting area and the shaft segments.

[0022] The shaft segments 2, the cutting edge 3, and the locking ring beam are structural components of the shaft. The template 4 is the construction object required by this invention, used as a concrete pouring template. The locking ring beam is located on the outer part of the shaft segments 2, and an anti-uplift pile is installed below the locking ring beam, connected to the locking ring beam. After the shaft construction is completed, the locking ring beam is poured and connected to the shaft wall, thus forming a unified whole with the locking ring beam and anti-uplift piles, resulting in minimal deformation. The shaft is a shaft wall structure formed by a top-down sinking construction method. The shaft is equipped with a locking ring beam, and the cutting edge, made of steel and with a pointed tip, is inserted at the bottom of the shaft wall structure to push aside the soil during sinking. The shaft wall structure is realized using segments 2, which can be either cast-in-place or precast. Therefore, the cutting edge 3 is set at the bottom of the concrete casting area of ​​the lock ring beam or the casting area 1 of the lock ring beam, and the shaft segment 2 is set at the top of the cutting edge 3. The two are in close contact and connected, and a gap is provided between the concrete casting area 1 of the lock ring beam and the shaft segment 2. The support block is arranged in the gap and fixed on the concrete casting area 1 of the lock ring beam, and the template 4 is set in the gap. During shaft construction, a gap is left between the shaft wall and the lock ring beam. During construction, lubricating mud is injected into this gap to reduce the friction between the shaft wall and the outer soil, which helps with sinking. However, this gap is very narrow, only about 10cm. During on-site construction, a starting foundation pit is excavated first. The diameter of the starting foundation pit is larger than the diameter of the shaft. For example, if the diameter of the shaft is 20m, the diameter of the starting foundation pit is 2-3m larger than this diameter. This 2-3m space is used to place the lock ring beam. During construction, the cutting edge 3 is first assembled in the initial foundation pit. Because the assembly of the cutting edge requires a certain amount of space, the locking ring beam cannot be constructed at this stage. After the cutting edge 3 is completed, the uppermost well wall of the cutting edge is constructed. The well wall is made of concrete, i.e., segment 2. The outer arc diameter of the cutting edge 3 is 10cm larger than the outer arc diameter of the well wall; this 10cm is the gap mentioned earlier. After the cutting edge 3 and segment 2 are constructed, the locking ring beam is constructed. Since the locking ring beam is reinforced concrete, the cutting edge 3, made of steel, directly serves as the supporting formwork during pouring. However, since both the locking ring beam and the well wall are reinforced concrete, if the formwork 4 of this invention is not placed in the gap between them, the locking ring beam and the well wall will be poured together directly. Therefore, a component is needed in this gap to prevent the pouring of the two components, and this component should be easily removed or broken and eliminated after each component is poured. However, due to the limited space during the construction of this project, there is no space for construction workers to enter and install the corresponding components after the construction of the lock ring beam is completed.Therefore, the present invention uses templates as components of this device, and the templates 4 are inserted from top to bottom, relying on close contact with the vertical shaft wall for insertion, and are fixed and inserted downwards with the support blocks of the locking ring beam, so that each template is inserted into the gap.

[0023] Furthermore, the template 4 is made of extruded polystyrene (XPS) board. XPS board is a rigid foam plastic board formed by heating and extrusion. It is made of polystyrene resin and other additives through an extrusion process, resulting in a board with a continuous, uniform surface and a closed-cell honeycomb structure. This structure can insulate against temperature and prevent concrete leakage during pouring. Before construction, the XPS board material is cut into rectangular blocks of several widths according to the diameter of the shaft. Both sides along the height direction are cut into insertable chamfered structures. The chamfer length is larger on the pouring side (i.e., the shaft wall side) and smaller on the other side to prevent concrete seepage during pouring.

[0024] Furthermore, the height of the template is greater than the height of the locking ring beam to prevent concrete from overflowing during the pouring process.

[0025] Furthermore, the support blocks are spaced at intervals in the concrete casting area 1 of the lock ring beam. The distance and number are determined according to the height of the shaft, facilitating the subsequent insertion of the template 4. It includes a circular concrete protective layer support block 7 and outer main reinforcement bars 8 of the lock ring beam. The main reinforcement bars 8 are inserted into the circular concrete protective layer support block 7. Different specifications of protective blocks can be used depending on the diameter of the outer main reinforcement bars and the thickness of the protective layer. Circular protective blocks of different diameters are used depending on the thickness of the protective layer. The thickness of the protective layer refers to the distance of the small pad layer on top of the circular concrete. The circular concrete protective layer refers to the portion of concrete in the support block that protects the reinforcement bars 8 from direct exposure, i.e., the entire concrete layer from the outermost layer of the reinforcement bars 8 to the concrete surface of the circular concrete protective layer support block 7, with a thickness of approximately 5cm. During construction, after the reinforcement bars 8 are tied, pad blocks are fixed on the reinforcement bars 8, and then wooden templates are made outside the pad blocks. This ensures that the outermost reinforcement bars are not exposed on the outside of the concrete after casting. The pad used in this invention is circular, and the reinforcing bar 8 passes through the central ring. Therefore, the circular concrete protective layer support block 7 formed by the circular pad and the protective layer can rotate around the reinforcing bar 8. Thus, when installing the template 4, it is only necessary to insert each template 4 from top to bottom. Each template 4 rolls on the pad of the support block and sinks into place with the help of the rolling action of the pad, that is, it contacts the tip of the blade angle 3. Therefore, the pad is set to be circular. If it is square or other shapes, the insertion and installation of each template 4 will be difficult.

[0026] In this invention, extruded polystyrene (XPS) boards are used instead of traditional concrete formwork. The materials selected are those with good impermeability, good compressive strength, and are relatively easy to break. XPS boards are used as an example, but the invention is not limited to XPS boards.

[0027] Specifically, the construction process of this invention is as follows: First, before splicing the shaft segments, a starting foundation pit of a certain height and range is excavated. After hardening the ground, the bottom steel cutting edge of the shaft and the prefabricated shaft segments are spliced. After the main reinforcement of the lock ring beam is transferred to the concrete annular protective block, the reinforcing bars are arranged, and at the same time, the prefabricated shaft segments are welded and fixed to the bottom steel cutting edge on both the inner and outer sides.

[0028] Based on the perimeter of the shaft and the distance between the concrete outer surface and shaft segment 2, the extruded polystyrene (XPS) board is cut to a certain specification. Both sides of the XPS board are cut with easily insertable chamfered edges, with the chamfered edge closer to the pouring area being longer and the chamfered edge closer to segment 2 being shorter to prevent concrete leakage. This is based on the height of the shaft, such as... Figure 3 As shown, the cut extruded polystyrene board can be made by splicing two long strips together to achieve the required height.

[0029] The cut extruded polystyrene (XPS) boards are inserted sequentially from top to bottom into the pre-reserved template positions. Due to the action of the annular concrete protective layer support block, the XPS boards roll downwards along the annular support block during insertion, and their sides are tightly fitted to the shaft segments and support blocks, preventing template movement during pouring. Since the template insertion position is fixed by the shaft segments and the annular protective block on both sides, the template thickness needs to be strictly controlled. Too thin a thickness will lead to unstable template fixation, while too thick a thickness will make template insertion and installation difficult. The appropriate thickness should be selected based on the actual conditions of the construction site.

[0030] During splicing, the templates need to be spliced ​​into a ring shape. Therefore, the sides closest to the pipe segments are pressed together to ensure that the templates are in direct and tight contact, preventing concrete leakage. In addition, the area near the pouring area may not be completely sealed due to its location on the outside of the ring. Therefore, it is set to overlap along the long side. If necessary, the overlap edge can be sealed with solid glue in advance to further prevent concrete leakage.

[0031] Furthermore, the formwork needs to be inserted at a certain height above the interlocking ring beam to prevent concrete from overflowing during pouring. Concrete for the interlocking ring beam location should only be poured after all formwork has been installed.

[0032] When removing the template, the extruded polystyrene board is easily damaged due to its inherent properties. Therefore, you can simply use tools to break the extruded polystyrene board into pieces and then remove it.

[0033] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A construction method for a formwork device suitable for vertical shafts, characterized in that, The method comprises the following steps: S1. Excavate a vertical shaft, harden the ground, splice the cutting edge at the bottom of the shaft, and assemble the shaft segments at the upper part of the cutting edge; S2. The outer side of the cutting edge is used as the casting area for the lock ring beam, and a support block is set on the side between this area and the shaft segment; S3. Insert the template into the gap between the interlocking ring beam pouring area and the shaft segment in sequence, with both sides tightly attached to the shaft segment and the support block.

2. The construction method according to claim 1, characterized in that, The template is set as several pieces, and both ends of each piece are set with an insert-type chamfer shape. The chamfer side closer to the casting area of ​​the lock ring beam is longer, and the chamfer side closer to the shaft segment is shorter.

3. The construction method according to claim 1, characterized in that, The cutting edge is spliced ​​at the bottom of the lock ring beam casting area, the shaft segment is set at the upper part of the cutting edge, and a gap is provided between the lock ring beam casting area and the shaft segment.

4. The construction method according to claim 2, characterized in that, Before S3, seal the long side of the insert chamfer of each template.

5. The construction method according to claim 1, characterized in that, The template is extruded polystyrene board.

6. The construction method according to claim 1, characterized in that, The height of the template is greater than the height of the lock ring beam.

7. The construction method according to claim 1, characterized in that, The support block is ring-shaped and there are several of them.

8. The construction method according to claim 7, characterized in that, Several of the aforementioned support blocks are spaced at a certain distance and arranged in the casting area of ​​the lock ring beam.

9. The construction method according to claim 7 or 8, characterized in that, The annular support block includes an annular concrete protective layer support block and the outer main reinforcement of the lock ring beam, wherein the main reinforcement is inserted into the annular concrete protective layer support block.

10. The construction method according to claim 5, characterized in that, The extruded board is a rigid foam plastic sheet formed by heating and extrusion.

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