A method of shaft construction

Abstract

This invention discloses a method for constructing a vertical shaft, comprising the following steps: S1, prefabricating ring segments and assembling them into pipe sections; S2, installing cutting edges and assembling pipe sections on top of the cutting edges; S3, stacking pipe sections layer by layer; S4, pouring the base slab and initial inner lining wall; S5, installing steel retaining walls on the initial inner lining wall; S6, sinking the base slab, initial inner lining wall, and steel retaining walls, and then pouring the inner lining wall; S7, removing the steel retaining walls and pouring concrete. This invention, by setting up steel retaining walls and pre-pouring the base slab and initial inner lining wall of a certain height outside the shaft, allows all water to be drained during the sinking of the steel retaining walls along with the base slab and initial inner lining wall, preventing water from entering the space enclosed by the steel retaining walls, base slab, and initial inner lining wall. This directly provides the dry working environment required for pouring the inner lining wall. Throughout the construction process, there is no need to seal the bottom of the shaft with concrete, avoiding excessively thick sealing that increases the excavation depth of the shaft, thus reducing construction difficulty and risk.

Description

Technical Field

[0001] This invention specifically relates to a method for constructing vertical shafts. Background Technology

[0002] Currently, ultra-large diameter prefabricated vertical shafts are a new type of deep vertical shaft construction method. Compared with traditional open-cut retaining methods, they have advantages such as safety and controllability, less disturbance to the surrounding area, rapid construction, and small footprint.

[0003] However, this construction method requires directly pouring concrete to seal the bottom of the well underwater, then draining the water from the shaft before pouring the base slab in a dry working environment. To ensure the seal is firm and prevent large amounts of groundwater from entering, the underwater seal is usually quite thick, which in turn increases the excavation depth of the shaft, making the construction difficult and risky. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a vertical shaft construction method to address the difficulty of vertical shaft construction.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a vertical shaft construction method, comprising the following steps: S1, prefabricating ring segments and assembling the ring segments into a ring-shaped pipe section; S2, installing a ring of cutting edges at the planned excavation location of the vertical shaft, and assembling pipe sections at the top of the cutting edges; S3, excavating the vertical shaft, with the cutting edges and pipe sections sinking along the inner wall of the vertical shaft into the shaft, and stacking pipe sections layer by layer as the excavation depth increases, until the vertical shaft is excavated to a preset depth, and the uppermost pipe section is flush with the shaft opening; S4, pouring concrete for the vertical shaft construction. The process involves: S5, installing a steel retaining wall of the same depth as the shaft on the outside of the initial retaining wall; S6, lowering the bottom plate, initial retaining wall, and steel retaining wall into the space enclosed by the pipe sections to the bottom of the shaft, then continuing to pour concrete above the initial retaining wall to form a retaining wall with its top flush with the shaft opening; and S7, pulling the steel retaining wall out of the shaft, creating a pouring gap between the retaining wall and the ring segment that communicates with the groove, and pouring concrete into the pouring gap. This technical solution offers the following technical advantages:

[0006] This invention, by setting up a steel enclosure and pre-casting the shaft's base slab and initial inner lining wall of a certain height outside the shaft, eliminates the need to pump out large amounts of water from the shaft during construction. This prevents excessive water flow from the shaft's inner wall into the shaft, thus avoiding collapse due to excessive water loss and ensuring the shaft's stability. As the steel enclosure sinks with the base slab and initial inner lining wall, the water in the shaft is compressed and flows into the gap between the steel enclosure and the shaft's inner wall, exiting from the shaft opening. Because of the steel enclosure, the water flowing out of the opening will not enter the space enclosed by the steel enclosure, base slab, and initial inner lining wall. When the steel enclosure sinks into place with the base slab and initial inner lining wall, all the water in the shaft has been drained. The steel enclosure can support and block water from the excavated inner wall of the shaft. The base plate can block water from the bottom wall of the excavated shaft. Since the bottom of the steel retaining is located between the initial inner lining wall and the pipe section, the overlapping area of ​​the steel retaining and the initial inner lining wall can seal the contact point to a certain extent, preventing groundwater from entering the cavity formed by the base plate, the initial inner lining wall and the steel retaining through the gap between the initial inner lining wall and the steel retaining. This provides a dry working environment required for the inner lining wall pouring. After the inner lining wall is poured, the steel retaining is removed, and concrete is poured in the space where the steel retaining is placed to connect the inner lining wall and the ring pipe segment, thus completing the shaft construction. Throughout the construction process, there is no need to seal the bottom of the shaft with concrete, avoiding excessively thick sealing that would increase the excavation depth of the shaft and reducing construction difficulty and risk.

[0007] In the aforementioned shaft construction method, in section S1, the annular segments are wedge-shaped, and multiple annular segments are spliced ​​together circumferentially to form a pipe section. Adjacent annular segments are connected by circumferential fasteners. The annular segments are connected by circumferential fasteners to achieve locking and make the connection more secure.

[0008] In the aforementioned shaft construction method, the annular segment has a groove with its opening facing the center of the segment. In step S7, concrete is poured into the groove and the pouring gap to connect the inner lining wall and the annular segment. When the steel cladding is pulled out of the shaft, the groove and the pouring gap become connected. When concrete enters the pouring gap, it simultaneously enters the groove. The concrete solidifies within the groove and the pouring gap, increasing the connection area between the annular segment and the inner lining wall, making the connection between them tighter and enhancing their connection strength.

[0009] In the aforementioned vertical shaft construction method, in step S3, adjacent pipe sections on both the upper and lower levels are locked together using longitudinal fasteners. These longitudinal fasteners enhance the stability of the connection between adjacent pipe sections on both the upper and lower levels.

[0010] In the aforementioned shaft construction method, S4 includes the following steps: erecting a formwork on the water surface inside the shaft, and then pouring the shaft base slab and the initial inner lining wall surrounding the shaft base slab onto the formwork. During the pouring process, the water flow in the shaft can prevent excessive water flow from the inner wall of the shaft into the shaft before the steel enclosure is installed, thereby avoiding collapse due to excessive water loss from the inner wall of the shaft and ensuring the stability of the shaft. By directly erecting the formwork on the water surface of the shaft for pouring the base slab and the initial inner lining wall, it is possible to eliminate the need for transportation of the base slab and the inner lining wall and alignment with the shaft opening after pouring, facilitating the rapid lowering of the base slab and the initial inner lining wall to the bottom of the shaft later.

[0011] In the above-mentioned shaft construction method, in step S6, water is poured into the groove formed by the bottom plate and the initial inner lining wall to assist sinking. After the bottom plate sinks to the bottom of the shaft, the water in the groove is pumped out, and then the initial inner lining wall is poured again. The operation is simple and convenient.

[0012] In the aforementioned shaft construction method, in step S6, the inner lining wall above the initial inner lining wall is constructed using segmented casting. Segmented casting reduces the intensity of each pour, minimizing the risk of concrete shrinkage cracks. It also avoids structural defects caused by insufficient concrete supply or uneven vibration, ensuring the density of the inner lining wall, distributing construction pressure, shortening the construction period, and significantly improving construction efficiency.

[0013] In the aforementioned shaft construction method, in step S7, the concrete poured into the pouring gap is self-compacting concrete. The high fluidity of self-compacting concrete allows it to fill the complex spaces formed by the pouring gaps and grooves automatically without vibration, significantly shortening the pouring time. Simultaneously, it reduces defects such as honeycomb and voids, improving structural durability and making the connection between the inner lining wall and the ring segment more robust and reliable.

[0014] The features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0016] Figure 1 This is a flowchart illustrating the construction process of a vertical shaft construction method according to the present invention.

[0017] Figure 2 A schematic diagram of the internal structure of the shaft when the inner lining wall is bolted to the steel enclosure;

[0018] Figure 3 This is a top view of the pipe section.

[0019] Figure label:

[0020] 100. Shaft;

[0021] 200, pipe section; 210, ring segment; 211, groove;

[0022] 300. Blade foot;

[0023] 410. Base plate; 420. Initial inner lining wall;

[0024] 500. Steel enclosure;

[0025] 600. Bolts. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, unless explicitly defined otherwise.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] Example 1: A method for constructing a vertical shaft, such as... Figures 1 to 3 As shown, it includes the following steps:

[0032] S1, prefabricated ring segments 210, multiple ring segments 210 are spliced ​​together circumferentially to form a ring-shaped pipe section 200, and any two adjacent ring segments 210 of the same pipe section 200 are connected by circumferential fasteners.

[0033] S2, delineate the area to be excavated for shaft 100, install a ring of cutting edges 300 along the inner wall of shaft 100 at the planned excavation location, and assemble a small number of pipe sections 200 on the top of the cutting edges 300.

[0034] S3, excavate shaft 100. Cutting foot 300 and pipe section 200 sink into shaft 100 as excavation proceeds. As excavation continues, cutting foot 300 and pipe section 200 adhere to the inner wall of shaft 100 and continue to sink. As the excavation depth increases, pipe sections 200 are stacked on top of each other. For every layer of pipe section 200 excavated to the depth of shaft 100, another layer of pipe section 200 is stacked on top of the pipe section 200 already stacked on the cutting foot 300, so that the top pipe section 200 is flush with the shaft opening, until shaft 100 is excavated to the preset depth and the topmost pipe section 200 is flush with the shaft opening.

[0035] S4, the outer shaft is cast with a base plate 410 of shaft 100 and an initial inner lining wall 420 surrounding the base plate 410 of shaft 100. The initial inner lining wall 420 has a certain height and is an integral structure with the base plate 410.

[0036] S5, a steel enclosure 500 with the same depth as the shaft 100 is installed on the outside of the initial inner lining wall 420. The steel enclosure 500 is cylindrical and surrounds and locks the outside of the initial inner lining wall 420.

[0037] S6, the base plate 410, the initial inner lining wall 420 and the steel enclosure 500 are lowered to the bottom of the shaft 100 within the space enclosed by the pipe section 200. Then, pouring continues above the initial inner lining wall 420 to extend the initial inner lining wall 420 upwards until it extends to be flush with the top and the shaft opening to form the inner lining wall. The inner lining wall above the initial inner lining wall 420 is poured in sections. By dividing into sections, the intensity of a single pour is reduced, the risk of concrete shrinkage cracks is reduced, and structural defects caused by insufficient concrete supply or uneven vibration can be avoided. This ensures compactness, disperses construction pressure, shortens the construction period, and can significantly improve construction efficiency.

[0038] S7. Unlock the steel retaining wall 500 from the initial inner lining wall 420, and then pull it out from the shaft 100. This creates a pouring gap between the inner lining wall and the ring segment 210, which was originally used to accommodate the steel retaining wall 500, and the gap is connected to the groove 211. Finally, pour concrete into the pouring gap. The concrete poured into the pouring gap is preferably self-compacting concrete. The high fluidity of self-compacting concrete allows it to fill the complex space formed by the pouring gap and the groove 211 automatically without vibration, significantly shortening the pouring time. Simultaneously, it reduces honeycomb surface defects and voids, improving structural durability and making the connection between the inner lining wall and the ring segment 210 more robust and reliable.

[0039] This invention, by setting up a steel enclosure 500 and pre-casting the bottom plate 410 of the shaft 100 and an initial inner lining wall 420 of a certain height outside the shaft 100, eliminates the need to pump out a large amount of water from the shaft 100 during construction, preventing excessive water flow from the inner wall of the shaft 100 into the shaft, thereby avoiding collapse due to excessive water loss from the inner wall of the shaft 100 and ensuring the stability of the shaft 100. As the steel enclosure 500 sinks along with the base plate 410 and the initial inner lining wall 420, the water in the shaft 100 is squeezed and flows into the gap between the steel enclosure 500 and the inner wall of the shaft 100, and flows out from the wellhead. Because of the steel enclosure 500, the water flowing out of the wellhead will not enter the space enclosed by the steel enclosure 500, the base plate 410 and the initial inner lining wall 420. When the steel enclosure 500 sinks into place along with the base plate 410 and the initial inner lining wall 420, all the water in the shaft 100 has been discharged. The steel retaining wall 500 supports and blocks water from the inner wall of the excavated shaft 100, while the bottom plate 410 blocks water from the bottom wall of the excavated shaft 100. Since the bottom of the steel retaining wall 500 is located between the initial inner lining wall 420 and the pipe section 200, the overlapping area of ​​the steel retaining wall 500 and the initial inner lining wall 420 can partially seal the junction between them, preventing groundwater from entering the bottom plate 410 and the initial inner lining wall through the gap between the initial inner lining wall 420 and the steel retaining wall 500. Within the cavity enclosed by 420 and the steel retaining 500, a dry working environment required for the pouring of the inner lining wall can be obtained directly without the need for large-scale water pumping. After the inner lining wall is poured and formed, the steel retaining 500 is removed, and concrete is poured in the space where the steel retaining 500 is placed to connect the inner lining wall and the ring segment 210, thus completing the construction of the shaft 100. Throughout the entire construction process, there is no need to seal the bottom of the shaft with concrete, avoiding excessively thick sealing that would increase the excavation depth of the shaft 100, and reducing construction difficulty and risk.

[0040] The annular segments 210 can take various shapes. In this embodiment, the preferred shape is wedge-shaped. In S1, multiple wedge-shaped annular segments 210 are spliced ​​circumferentially to form a pipe section 200. Adjacent annular segments 210 are connected by circumferential fasteners to achieve locking and make the connection more secure. In S3, the annular segments 210 of the upper and lower adjacent pipe sections 200 are locked by longitudinal fasteners to improve the stability of the connection. The gap between two adjacent annular segments 210 of the same pipe section 200 is defined as the splicing seam. In order to improve the overall rigidity of the structure formed by the multiple layers of pipe sections 200, it is preferable to stagger the splicing seams of the upper and lower adjacent layers of pipe sections 200.

[0041] In this embodiment, the annular segment 210 is provided with a groove 211, the opening of which is positioned facing the center of the pipe section 200. In S7, when the steel enclosure 500 is pulled out from the shaft 100, the groove 211 is connected to the pouring gap. When concrete enters the pouring gap, it will simultaneously enter the groove 211. The concrete solidifies in the groove 211 and the pouring gap, increasing the connection area between the annular segment 210 and the inner lining wall, making the connection between the annular segment 210 and the inner lining wall tighter and enhancing their connection strength.

[0042] In S4, there are various ways to pour the bottom plate 410 of the shaft 100 and the initial inner lining wall 420. In this embodiment, the preferred method includes the following steps: erecting a template on the water surface inside the shaft 100, and then pouring the bottom plate 410 of the shaft 100 and the initial inner lining wall 420 around the bottom plate 410 of the shaft 100 on the template. During the pouring process, the water flow in the shaft 100 can prevent the water in the inner wall of the shaft 100 from flowing excessively into the shaft before the steel enclosure 500 is installed, thereby avoiding the collapse caused by excessive water loss from the inner wall of the shaft 100 and ensuring the stability of the shaft 100. By directly erecting the template on the water surface of the shaft 100 for pouring the bottom plate 410 and the initial inner lining wall 420, it is possible to eliminate the need for transportation of the bottom plate 410 and the inner lining wall and alignment with the shaft opening after pouring, which facilitates the rapid sinking of the bottom plate 410 and the initial inner lining wall 420 to the bottom of the shaft 100 later.

[0043] In S6, auxiliary equipment can be used to assist the base plate 410 and the initial inner lining wall 420 in sinking within the shaft 100. Preferably, water is injected into the groove 211 formed by the base plate 410 and the initial inner lining wall 420 to facilitate their sinking. After the base plate 410 sinks to the bottom of the shaft, a small amount of water in the groove 211 is pumped out to provide a dry working environment for the subsequent pouring of the inner lining wall. In order to ensure the stable connection between the steel enclosure 500, the base plate 410, and the initial inner lining wall 420, and thus ensure its water-blocking effect, the initial inner lining wall 420 and the steel enclosure 500 are locked together with locking components. Bolts 600 are preferred as locking components, which are easy to install and disassemble, have a simple structure, and are securely locked.

[0044] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for constructing a vertical shaft, characterized in that, Includes the following steps: S1, prefabricate ring segments and assemble the ring segments into a ring-shaped pipe section; S2, install a ring of cutting edges at the planned excavation location of the shaft, and assemble pipe sections at the top of the cutting edges; S3, excavate the shaft, the cutting edge and pipe section sink into the shaft along the inner wall of the shaft. As the excavation depth increases, the pipe sections are stacked layer by layer until the shaft is excavated to the preset depth, and the uppermost pipe section is flush with the shaft opening. S4, pour the bottom slab of the shaft and the initial inner lining wall surrounding the bottom slab; S5, Install a steel enclosure with the same depth as the shaft on the outside of the initial inner lining wall. The steel enclosure is cylindrical. S6, the base plate, initial inner lining wall and steel enclosure are lowered to the bottom of the shaft within the space enclosed by the pipe section, and then the pouring continues above the initial inner lining wall to form an inner lining wall with the top flush with the shaft opening; S7. The steel enclosure is pulled out of the shaft, so that a pouring gap is formed between the inner lining wall and the ring segment, which is connected to the groove, and concrete is poured into the pouring gap.

2. The method for constructing a vertical shaft according to claim 1, characterized in that: In S1, the ring segment is wedge-shaped, and multiple ring segments are spliced ​​together circumferentially to form the pipe section. Adjacent ring segments are connected by circumferential fasteners.

3. The method for constructing a vertical shaft according to claim 2, characterized in that: The annular segment has a groove with an opening facing the center of the segment. In step S7, concrete is poured into the groove and the pouring gap to connect the inner lining wall and the annular segment.

4. The method for constructing a vertical shaft according to claim 1, characterized in that: In S3, the upper and lower adjacent pipe sections are locked together by longitudinal fasteners.

5. The method for constructing a vertical shaft according to claim 1, characterized in that: The S4 includes the following steps: setting up a template on the water surface inside the shaft, and then pouring the shaft bottom slab and the initial inner lining wall around the shaft bottom slab on the template.

6. The method for constructing a vertical shaft according to claim 1, characterized in that: In step S6, water is poured into the groove formed by the base plate and the initial inner lining wall to assist in sinking. After the base plate sinks to the bottom of the well, the water in the groove is pumped out, and then the initial inner lining wall is poured again.

7. A vertical shaft construction method according to claim 6, characterized in that: In S6, the inner lining wall above the initial inner lining wall is constructed in sections.

8. A vertical shaft construction method according to claim 1, characterized in that: In S7, the concrete poured into the pouring gap is self-compacting concrete.

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