A top-down method shaft and formwork template used thereby

Abstract

This utility model discloses a reverse-construction shaft and the formwork used therein, belonging to the field of underground construction engineering technology. The shaft includes a top ring beam, which is cast and spliced ​​with multiple single-section shaft walls below it to form the sidewalls of the shaft. Each single-section shaft wall includes a main body with a rectangular longitudinal section. The inner top side of the main body is bent upwards to form a protrusion, and the inner top side of the protrusion extends downwards at an angle to the inner sidewall of the main body to form an inclined surface. The distance between the top of the main body and the bottom of the protrusion is 200-250mm. The outer side of the protrusion and the top of the main body form an L-shaped concrete joint with a 90° angle, used for splicing with the bottom of the upper shaft wall or the bottom of the ring beam. This solution also provides a formwork adapted to the aforementioned single-section shaft wall. By optimizing the structure of the single-section shaft wall, this solution not only reduces the space occupied by the shaft but also eliminates the need for complex formwork at its bottom.

Description

Technical Field

[0001] This utility model relates to the field of underground construction engineering technology, and more specifically, to a reverse construction method vertical shaft and the formwork template used therein. Background Technology

[0002] The reverse construction method for vertical shafts employs a top-down, layered excavation and simultaneous support construction. This technology effectively controls the deformation of the surrounding soil during deep shaft excavation, reducing adverse impacts on surrounding buildings, underground pipelines, and roads. Therefore, it is particularly suitable for urban core areas, densely populated building complexes, and other areas with extremely high requirements for the construction environment, and has become a key technical means to ensure construction safety and environmental stability in modern underground engineering construction.

[0003] Existing reverse-construction shafts generally consist of a ring beam arranged sequentially from top to bottom and multiple shaft wall sections. The inner wall of these existing shafts is typically sawtooth-shaped; specifically, the inner wall of a single shaft section is an inclined sidewall that slopes upwards towards the shaft's axis. For example, Chinese patent application CN117926895A discloses a reverse-construction inverted shaft construction process, and as shown in the accompanying drawings, the inner wall of this shaft is sawtooth-shaped. In such applications, the inner wall of the shaft is an inclined surface, and this structure occupies a large space, making it unsuitable for applications in confined spaces.

[0004] Existing vertical shafts also have straight-walled inner walls. Specifically, this type of structure improves the shape of the top and bottom of a single section of the shaft wall to achieve a stable connection between adjacent sections. For example, Chinese patent application CN106759383A discloses a reverse-construction method for casting short-section shaft walls. This shaft wall includes a structural starting section, a first structural maintenance section, a second structural maintenance section, and a third structural maintenance section connected in sequence. The structural starting section includes a vertical starting section and a horizontal starting section, with the horizontal structure placed on an auxiliary rigid slope support. The third structural maintenance section is fixedly connected to the bottom formwork. The connection points between the structural starting section, the first structural maintenance section, the second structural maintenance section, and the third structural maintenance section are stepped, and connecting ribs are provided at the connection points. In this type of application, the inner wall of a single section of the shaft wall is straight, but because its bottom end has a protruding chamfer, i.e., the bottom end of the shaft wall is a discontinuous plane, the supporting formwork structure corresponding to its bottom end becomes overly complex during the casting process.

[0005] In summary, the structure of single-section shaft walls in existing reverse-construction vertical shafts needs to be optimized. Utility Model Content

[0006] 1. Technical problems to be solved To address the technical problems of vertical shafts with serrated inner walls occupying a large space or the overly complex supporting formwork structure required for the bottom of single-section shaft walls in existing vertical shafts with straight inner walls, this utility model provides a reverse-construction vertical shaft and the supporting formwork used therein. This solution, through optimized design of the single-section shaft wall structure, not only reduces the space occupied by the vertical shaft but also eliminates the need for complex supporting formwork at its bottom.

[0007] 2. Technical solutions adopted To achieve the above objectives, the technical solution provided by this utility model is as follows: The first aspect of this utility model provides a reverse-construction vertical shaft, including a top ring beam and multiple single-section shaft walls located below the ring beam; the top ring beam and the multiple single-section shaft walls are sequentially cast and spliced ​​from top to bottom to form the sidewalls of the vertical shaft, each single-section shaft wall including a shaft wall body, the longitudinal section of the shaft wall body being rectangular, and the inner side of the top of the shaft wall body being bent upward to form a protrusion, the inner side of the top of the protrusion extending downward at an incline to the inner sidewall of the shaft wall body to form an inclined surface of the protrusion, the distance between the top of the shaft wall body and the bottom of the protrusion being 200~250mm; the outer sidewall of the protrusion and the top of the shaft wall body forming an L-shaped concrete joint, the angle of the L-shape being 90°, used for splicing with the bottom of the adjacent upper shaft wall body or the bottom of the ring beam.

[0008] Furthermore, the horizontal distance between the top of the inclined surface and the inner wall of the main body of the well is 150~200mm.

[0009] Furthermore, the angle between the inclined plane and the horizontal plane is 45°~75°.

[0010] Furthermore, the height of the vertical sidewall in the concrete joint is 100~150mm.

[0011] Furthermore, waterproof components are provided between the ring beam and the single-section well wall located below it or between two adjacent single-section well walls. The waterproof components include a waterstop and a waterproof membrane. The waterstop is set perpendicular to the concrete joint and extends to the interior of the adjacent single-section well wall and the ring beam at both ends. The waterproof membrane is set on the outer wall of the single-section well wall.

[0012] Furthermore, a waterproof reinforcing plate is provided on the outer wall of the waterproof membrane. The height of the waterproof reinforcing plate is less than that of the waterproof membrane, and it is positioned directly opposite the concrete joint.

[0013] The second aspect of this utility model provides a formwork template for the above-mentioned reverse construction vertical shaft. The formwork template includes an inner template component for supporting a single section of shaft wall. The inner template component is adapted to the shape of the inner wall of the single section of shaft wall. The inner template component includes a vertical template, an inclined template, and a connecting hinge. The top end of the vertical template is spliced ​​with the bottom end of the inclined template. The connecting hinge is located on the side of the inclined template away from the single section of shaft wall, and its two ends are fixedly connected to the vertical template and the inclined template, respectively.

[0014] Furthermore, a support steel pipe is provided at the top of the inclined template on the side away from the single section of the well wall to support the inclined template.

[0015] Compared with the prior art, the technical solution provided by this utility model has the following advantages: (1) This utility model optimizes the structure of the reverse construction shaft. Specifically, it optimizes the structure of the protrusions and the main body of the shaft wall in a single section. The distance between the top of the main body of the shaft wall and the bottom of the protrusion is 200~250mm. Compared with the rectangular toothed inner wall, it can not only reduce the space occupied by the protrusion in the shaft, but also effectively reduce the amount of grout required for the protrusion. Moreover, since the longitudinal section of the main body of the shaft wall is rectangular, it can be seen that the bottom surface of the main body of the shaft wall is a continuous plane, which simplifies the structure of the support template required for the bottom surface of the main body of the shaft wall.

[0016] (2) This utility model further optimizes the relative positional relationship between the protrusion and the main body of the well wall. Specifically, the angle θ between the inclined surface and the horizontal plane is 45~75°. This angle θ design is conducive to the flow of grout from the pouring space unit corresponding to the protrusion to the pouring space unit corresponding to the main body of the well wall. Furthermore, the horizontal distance between the top of the inclined surface and the inner sidewall of the main body of the well wall is 150~200mm. This size limits the width of the pouring opening, which is conducive to the injection of grout into the pouring space of the lower single section of the well wall. Furthermore, the height of the vertical sidewall in the concrete joint is 100~150mm, which can effectively ensure the lateral contact area between two adjacent single sections of the well wall or between the ring beam and the single section of the well wall located below it. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a vertical cross-section of a single section of well wall in the prior art.

[0018] Figure 2 This is a schematic diagram of the vertical cross-section of the overall structure of the reverse construction method shaft according to an embodiment of this utility model.

[0019] Figure 3 This is a structural schematic diagram of the vertical cross-section of a single section of the shaft wall in the reverse construction method of this utility model embodiment.

[0020] Figure 4 This is a partial structural schematic diagram of the vertical cross-section of the reverse construction method shaft and its accessories according to an embodiment of this utility model.

[0021] Figure 5 This is a schematic diagram of the vertical cross-sectional structure of the formwork used in the reverse construction method of the present invention during the construction process.

[0022] Explanation of icon numbers: 1. Ring beam; 2. Single section of well wall; 201. Protrusion; 2011. Inclined surface; 202. Main body of well wall; 203. Pouring port; 204. Concrete joint; 3. Waterproof components; 301. Waterproof reinforcing plate; 302. Waterproof membrane; 303. Waterstop strip; 4. Inner formwork components; 401. Inclined formwork; 402. Vertical formwork; 403. Connecting hinges; 404. Supporting steel pipes; 5. Base plate. Detailed Implementation

[0023] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0024] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0025] The cross-section of a reverse-construction shaft is generally circular, with a few being elliptical or rectangular. It has a central axis in the vertical direction. In the following embodiments, the outer side of a single-section shaft wall 2 refers to the side away from the shaft axis, and its outer side wall refers to the side wall away from the shaft axis. The inner side of a single-section shaft wall 2 refers to the side closer to the shaft axis, and its inner side wall refers to the side wall closer to the shaft axis. For other components in this embodiment and the components included in the single-section shaft wall 2, the terms inner side, inner side wall, outer side, or outer side wall are all defined relative to the shaft axis, and the definition method is the same as that of the single-section shaft wall 2.

[0026] This embodiment provides a reverse construction method for vertical shafts, referencing... Figures 2-4As shown, the shaft includes a top ring beam 1 and multiple single-section shaft walls 2 located below the ring beam 1. The top ring beam 1 and the multiple single-section shaft walls 2 are poured and spliced ​​from top to bottom to form the sidewalls of the shaft. Each single-section shaft wall 2 includes a shaft wall body 202. The longitudinal section of the shaft wall body 202 is rectangular, and the inner side of the top is bent upward to form a protrusion 201. The inner side of the top of the protrusion 201 extends downward to the inner sidewall of the shaft wall body 202 to form the inclined surface 2011 of the protrusion 201. The distance between the top of the shaft wall body 202 and the bottom of the protrusion 201 is 200~250mm. The outer sidewall of the protrusion 201 and the top of the shaft wall body 202 form an L-shaped concrete joint 204. The angle of the L-shape is 90°, which is used to splice with the bottom of the adjacent upper shaft wall body 202 or the bottom of the ring beam 1.

[0027] It should be noted that the single section of the well wall 2 is integrally formed during the casting process, that is, the main body of the well wall 202 and the protrusion 201 are integrally formed during the casting process. In order to facilitate the description of the vertical cross section or its shape of the single section of the well wall 2, it is divided into two parts: the main body of the well wall 202 and the protrusion 201.

[0028] refer to Figure 1 As shown, the inner wall of the vertical shaft mentioned in the background art is a sawtooth-shaped vertical shaft. The sawtooth-shaped vertical shaft can be understood as the bottom end of the protrusion 201 being flush with the bottom end of the shaft wall body 202. Figure 1 The dashed line is not the actual outline of a single-section well wall in the prior art. The dashed line is used to indicate the difference in outline between the single-section well wall provided by this invention and the single-section well wall in the prior art. In the pouring space of the single-section well wall 2 formed by the upper single-section well wall 2 and the supporting template, the inclined surface 2011 of the protrusion 201 of this invention and the inner wall of the well wall body 202, i.e. Figure 1 The area between the two surfaces indicated by the dashed line and the corresponding outer contour line in the existing single-section well wall 2 is generally not equipped with binding steel bars. Therefore, this part of the area can bear a smaller load, so this part of the area can be omitted. This invention optimizes the structure of the protrusion 201 and the main body 202 of the single-section well wall 2, with the distance d1 between the bottom of the inclined surface 2011 and the main body 202 of the well wall being 200-250mm. Compared to the rectangular toothed inner wall, this not only reduces the space occupied by the protrusion 201 in the vertical shaft, but also effectively reduces the amount of mortar required for the protrusion 201.

[0029] The longitudinal section of the bottom of the single section of the well wall 2 is rectangular, indicating that the bottom surface of the main body of the well wall 202 is a continuous plane, which simplifies the structure of the support template required for the bottom surface of the main body of the well wall 202.

[0030] The adjacent single-section well wall 2 is spliced ​​and cast into a whole by L-shaped concrete joint 204. The angle of the L-shape is 90°. In order to adapt to the shape of the bottom of the ring beam 1 or the inner bottom of the upper well wall body 202, the L-shaped concrete joint 204 can effectively ensure the contact area between the adjacent single-section well wall 2 or between the ring beam 1 and the single-section well wall 2 located below it, as well as the structural strength of the adjacent two layers cast and connected into a whole.

[0031] Furthermore, the upper section of the well wall 2 and the supporting template form the pouring space for the lower section of the well wall 2. This pouring space consists of two pouring space units corresponding to the protrusion 201 and the main body of the well wall 202, respectively. Because the bottom of the protrusion 201 is 200-250mm lower than the top of the main body of the well wall 202, the two pouring space units are connected, allowing the grout to smoothly enter the pouring space corresponding to the main body of the well wall 202 during the pouring process. Moreover, the structural design of the inclined surface 2011 is conducive to the flow of grout and subsequent compaction.

[0032] The height of the ring beam 1 is generally 1.0 to 1.5m, and the height of each single section of the well wall 2 can be adjusted according to geological conditions, and its height is generally 0.8 to 1.5m.

[0033] Specifically, the horizontal distance d2 between the top of the inclined surface 2011 and the inner wall of the main body of the well wall 202 is 150~200mm. This size limits the width of the pouring port 203, which is conducive to the pouring space of the grout injection into the lower single section of the well wall 2.

[0034] For more specific details, please refer to Figure 4 As shown, the angle θ between the inclined surface 2011 and the horizontal surface is 45~75°. The design of this angle θ is conducive to the flow of grout from the pouring space unit corresponding to the protrusion 201 to the pouring space unit corresponding to the main body of the well wall 202, and to the formation of a pouring port 203 with a suitable diameter between the upper single section of the well wall 2 and the supporting template.

[0035] To further ensure the contact area between two adjacent single-section well walls 2, the height of the vertical sidewall in the concrete joint 204 is 100~150mm, which can effectively ensure the lateral contact area between two adjacent single-section well walls 2 or between the ring beam 1 and the single-section well wall 2 located below it.

[0036] During the pouring process, the grout forms the top end face of the protrusion 201 at the pouring port 203.

[0037] As a further preferred embodiment of any of the above embodiments, waterproof components 3 are provided between two adjacent single-section well walls 2 and between the ring beam 1 and the single-section well wall 2 located below it. The waterproof components 3 include a waterstop 303 and a waterproof plate 302. The waterstop 303 is set perpendicular to the concrete joint 204 and its two ends extend to the interior of the adjacent single-section well wall 2 and the ring beam 1, respectively. The waterproof plate 302 extends along the height direction and is set on the outer wall of the single-section well wall 2.

[0038] In this design, each individual waterproof membrane 302 extends along its height at both ends, and adjacent waterproof membranes 302 are spliced ​​together to form a waterproof layer covering the outer wall of the shaft. The joints of adjacent individual waterproof membranes 302 are staggered from the concrete joints 204. The waterproof membrane 302 is preferably a galvanized waterproof steel plate.

[0039] Furthermore, the outer wall of the waterproof membrane 302 is also provided with a waterproof reinforcing plate 301. The height of the waterproof reinforcing plate 301 is less than the height of the waterproof membrane 302, and the center of each waterproof reinforcing plate 301 is positioned directly opposite the concrete joint 204. The waterproof reinforcing plate 301 is preferably an EVA waterproof membrane.

[0040] To achieve the pouring of the reverse-construction shaft mentioned in any of the above embodiments, refer to Figure 5 As shown, the formwork for the reverse construction shaft is optimized. Accordingly, the formwork includes an inner template component 4, which is adapted to the shape of the inner wall of the single-section shaft wall 2. The inner template component 4 includes a vertical template 402, an inclined template 401, and a connecting hinge 403. The top end of the vertical template 402 is spliced ​​with the bottom end of the inclined template 401. The connecting hinge 403 is located on the side of the inclined template 401 away from the single-layer shaft wall 2, and its two ends are fixedly connected to the vertical template 402 and the inclined template 401, respectively.

[0041] A pouring port 203 is formed between the inclined template 401 and the upper single-section well wall 2. Grout is injected into the pouring space of the lower single-section well wall 2 through the pouring port 203.

[0042] As a further optimization of the support method for the inclined template 401, a support steel pipe 404 is also provided at the top of the inclined template 401 on the side away from the single-layer well wall 2 to support the inclined template 401.

[0043] On the side of the inner template component 4 away from the pouring space, support steel pipes 404 are erected at a density of 800mm in the horizontal direction and 800mm in the vertical direction. The support steel pipes 404 are erected from bottom to top along the bottom end of the vertical template 402 and extend to the top end of the inclined template 401.

[0044] refer to Figure 5As shown, the supporting steel pipe 404 is shown in an enlarged diagram only to illustrate its installation position. Its specifications can be selected as φ48x3.2mm. The longitudinal cross-sectional area of ​​the supporting steel pipe 404 is much smaller than the dimensions of the vertical formwork 402 and the inclined formwork 401 in the inner formwork component 4, and should not be misinterpreted. Figure 5 The diagram defines the relative dimensional relationships between the supporting steel pipe 404, the shaft, and the components included in the inner template component 4.

[0045] After the single-section well wall 2 of this layer is poured and solidified to the preset strength requirement, the inner template component 4 of this layer is removed to build the pouring space required to form the inner wall of the lower single-section well wall 2.

[0046] refer to Figure 2 As shown, the bottom end of the lowest single-section well wall 2 is provided with a bottom plate 5. The bottom plate 5, the ring beam 1, and multiple single-section well walls 2 together form a reverse construction vertical shaft.

[0047] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A reverse-construction vertical shaft, comprising a top ring beam (1) and multiple single-section shaft walls (2) located below the ring beam (1); the top ring beam (1) and the multiple single-section shaft walls (2) are sequentially cast and spliced ​​from top to bottom to form the sidewalls of the vertical shaft, characterized in that, The single-section well wall (2) includes a well wall body (202), the longitudinal section of the well wall body (202) is rectangular, and the inner side of the top is bent upward to form a protrusion (201). The inner side of the top of the protrusion (201) extends downward to the inner wall of the well wall body (202) to form the inclined surface (2011) of the protrusion (201). The distance between the top of the well wall body (202) and the bottom of the protrusion (201) is 200~250mm. The outer wall of the protrusion (201) and the top of the well wall body (202) form an L-shaped concrete joint (204), with the L-shaped angle being 90°, which is used to splice with the bottom of the adjacent upper well wall body (202) or the bottom of the ring beam (1).

2. The top-down construction method shaft according to claim 1, characterized in that The horizontal distance between the top of the inclined surface (2011) and the inner wall of the main body of the well (202) is 150~200mm.

3. The reverse construction method vertical shaft according to claim 2, characterized in that, The angle between the inclined surface (2011) and the horizontal surface is 45°~75°.

4. The reverse construction method vertical shaft according to claim 1, characterized in that, The height of the vertical sidewall in the concrete joint (204) is 100~150mm.

5. The reverse construction method vertical shaft according to any one of claims 1-4, characterized in that, Waterproof components (3) are provided between the ring beam (1) and the single-section well wall (2) located below it or between two adjacent single-section well walls (2). The waterproof components (3) include a waterstop (303) and a waterproof plate (302). The waterstop (303) is set perpendicular to the concrete joint (204) and its two ends extend to the interior of the adjacent single-section well wall (2) and the ring beam (1), respectively. The waterproof plate (302) is set on the outer wall of the single-section well wall (2).

6. The reverse construction method vertical shaft according to claim 5, characterized in that, The outer wall of the waterproof membrane (302) is also provided with a waterproof reinforcing plate (301), the height of which is less than that of the waterproof membrane (302), and is set directly opposite the concrete joint (204).

7. A formwork template for a reverse-construction shaft as described in any one of claims 1-6, the formwork template comprising an inner template component (4) for supporting a single section of shaft wall (2), the inner template component (4) being adapted to the shape of the inner wall of the single section of shaft wall (2); characterized in that, The inner template component (4) includes a vertical template (402), an inclined template (401), and a connecting hinge (403). The top of the vertical template (402) is spliced ​​with the bottom of the inclined template (401). The connecting hinge (403) is located on the side of the inclined template (401) away from the single section well wall (2), and its two ends are fixedly connected to the vertical template (402) and the inclined template (401) respectively.

8. The formwork template for a top-down method shaft according to claim 7, wherein, The top of the inclined template (401) on the side away from the single section well wall (2) is also provided with a support steel pipe (404) for supporting the inclined template (401).

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