Construction method for shaft lining annular rollover structure

Abstract

SOLUTION: The present invention relates to a technical field of tunnel shield construction, and more particularly to a construction method for a shaft lining annular rollover structure, which includes a shaft, an anchor is fixedly attached to an inner wall of a shaft, an annular formwork bracket is supported by the anchor, secondary lining concrete is poured between an inner wall of the shaft and the annular formwork bracket, and the annular formwork bracket includes a support truss (21), a horizontal bar (22), a vertical bar (23), and a concrete formwork (24).EFFECT: By controlling horizontal pitch of vertical bars (23), the present invention can distribute the vertical bars (23) on an annular formwork bracket at an optimal pitch, thereby ensuring the stability and safety of a structure of the annular formwork bracket without wasting material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel shield construction, and specifically to a construction method for a vertical shaft lining annular roll-over structure.

Background Art

[0002] When constructing a shield tunnel, in order to reinforce a tunnel vertical shaft with relatively poor geological conditions at a deep layer, secondary lining by the bottom-up method is often required. The construction of the conventional scaffolding occupies a large amount of the internal space of the vertical shaft, affects the progress of other construction works, and requires a large amount of time to remove the brackets, resulting in a significant waste of the construction period. Therefore, in the present invention, a vertical shaft lining annular roll-over structure is adopted, and a relatively large space is left in the middle of the vertical shaft by using an annular formwork bracket, and a construction method for the vertical shaft lining annular roll-over structure that does not affect the construction period is proposed. Such a method needs to accurately calculate and define the structural parameters of the annular formwork bracket according to various factors such as different vertical shaft radii, bedrock conditions, and different secondary lining thicknesses, so as to ensure that the stability and safety of the structure of the annular formwork bracket can be guaranteed without wasting materials.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The object of the present invention is to accurately calculate and define the structural parameters of the annular formwork bracket according to various factors such as different vertical shaft radii, bedrock conditions, and different secondary lining thicknesses, so as to ensure that the stability and safety of the structure of the annular formwork bracket can be guaranteed without wasting materials, and to provide a construction method for a vertical shaft lining annular roll-over structure.

Means for Solving the Problems

[0004] The object of the present invention is to provide a construction method for a shaft lining annular roll-over structure, including a shaft, on the inner wall of the shaft, an anchor is fixedly attached, on the anchor, an annular formwork bracket is supported, between the inner wall of the shaft and the annular formwork bracket, secondary lining concrete is placed, the annular formwork bracket includes a support truss, a horizontal bar, a vertical bar, and a concrete formwork, the horizontal bar is fixedly connected to the surface of the support truss through a bolt fastener, the vertical bar is fixed to the surface of the horizontal bar through a bolt fastener, the concrete formwork is fixedly connected to the side of the vertical bar away from the support truss, and the horizontal pitch control requirement formula of the vertical bar is as follows: In Equation 1 of JPEG2025084642000002.jpg11170, m is the pitch of the vertical bar, h is the height of a single segment of the inner form, γ is the unit volume weight of the placed body, α is the lateral pressure coefficient of the placed body, P is the uniformly distributed live load for the construction of the upper surface of the placed body, f is the design value of the bending strength of the vertical bar, W is the section resistance moment of the vertical bar, k Δ is the bending moment coefficient due to the action of uniformly distributed load, k is the bending moment coefficient due to the action of triangular distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar.

[0005] Preferably, the formula for the bending moment value of the vertical bar cross-section under static load is as follows: In JPEG2025084642000003.jpg11170 of JPEG2025084642000004.jpg5170m, m is the pitch of the vertical bar, h is the height of a single segment of the inner form, γ is the unit volume weight of the placed body, α is the lateral pressure coefficient of the placed body, k Δis the bending moment coefficient under the action of uniformly distributed load, h / n is the pitch evenly distributed in the longitudinal direction of the horizontal bar.

[0006] Preferably, the formula for the bending moment value of the live load on the cross-section of the longitudinal bar is as follows: JPEG2025084642000005.jpg11170JPEG2025084642000006.jpg5170m is the pitch of the longitudinal bar, α is the lateral pressure coefficient of the placed body, P is the uniformly distributed live load for the upper surface construction of the placed body, k is the bending moment coefficient under the action of triangular distributed load, h / n is the pitch evenly distributed in the longitudinal direction of the horizontal bar.

[0007] Preferably, the combined design formula for the load of the longitudinal bar is as follows: JPEG2025084642000007.jpg5170JPEG2025084642000008.jpg19170

[0008] Preferably, the bending strength checking formula of the longitudinal bar is as follows: JPEG2025084642000009.jpg10170In Formula 5, f is the design value of the bending strength of the longitudinal bar, W is the sectional resistance moment of the longitudinal bar, JPEG2025084642000010.jpg5170

[0009] Preferably, a plurality of layers of the annular formwork brackets are installed, the lower-layer annular formwork brackets are continuously rolled over above the upper-layer annular formwork brackets, the horizontal bar presents an arc shape, and the concrete formwork presents an arc shape.

[0010] Preferably, both sides of the longitudinal bar are bent at 90 degrees, the whole longitudinal bar presents a "U" shape, and the longitudinal bar is annularly and uniformly distributed on the side away from the support truss of the horizontal bar.

Advantages of the Invention

[0011] The present invention provides a construction method for a shaft lining annular roll-over structure, including a shaft. An anchor is fixedly attached to the inner wall of the shaft, and an annular formwork bracket is supported by the anchor. Secondary lining concrete is placed between the inner wall of the shaft and the annular formwork bracket. The annular formwork bracket includes a support truss, a horizontal bar, a vertical bar, and a concrete formwork. The horizontal bar is fixedly connected to the surface of the support truss through a bolt fastener. The vertical bar is fixed to the surface of the horizontal bar through a bolt fastener. The concrete formwork is fixedly connected to the side of the vertical bar away from the support truss. The horizontal pitch control requirement formula for the vertical bar is as follows: JPEG2025084642000011.jpg11170 By controlling the horizontal pitch of the vertical bar, the vertical bars can be distributed on the annular formwork bracket at an optimal pitch, ensuring the structural stability and safety of the annular formwork bracket without wasting materials.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiment for Carrying Out the Invention

[0013] An embodiment of the present invention provides a shaft lining annular roll-over structure construction method, including a shaft 11. An anchor 14 is fixedly attached to the inner wall of the shaft 11. An annular formwork bracket 12 is supported by the anchor 14. Secondary lining concrete 13 is placed between the inner wall of the shaft 11 and the annular formwork bracket 12. The annular formwork bracket 12 includes a support truss 21, a horizontal bar 22, a vertical bar 23, and a concrete form 24. The horizontal bar is fixedly connected to the surface of the support truss via a bolt fastener. The vertical bar is fixed to the surface of the horizontal bar via a bolt fastener. The concrete form is fixedly connected to the side of the vertical bar away from the support truss. The inner wall of the shaft 11 is primary lining concrete. By continuously rolling over the lower secondary lining concrete 13 to the upper layer, the placement task of the secondary lining concrete 13 is completed. The horizontal pitch control requirement formula for the vertical bar 23 is as follows: In Equation 1 of JPEG2025084642000012.jpg11170, m is the pitch of the vertical bar, h is the height of a single segment of the inner form, γ is the unit volume weight of the placed body, α is the lateral pressure coefficient of the placed body, P 0 is the uniformly distributed live load for the upper surface construction of the placed body, f is the design value of the bending strength of the vertical bar, W 0 is the section resistance moment of the vertical bar, k Δ is the bending moment coefficient due to the action of uniformly distributed load, k 0 is the bending moment coefficient due to the action of triangular distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar. The distribution of the horizontal pitch of the vertical bars 23 directly affects the overall structural strength of the annular formwork bracket 12 and needs to be calculated based on the total load gravity borne by the annular formwork bracket 12, thereby calculating the optimal distance of the horizontal distribution of the vertical bars 23. It can be ensured that the distribution of the optimal distance of the vertical bars 23 can guarantee the structural stability and safety of the annular formwork bracket 12 without wasting materials.

[0014] Here, the formula for the bending moment value due to the static load of the cross-section of the vertical bar 23 is as follows: JPEG2025084642000013.jpg11170JPEG2025084642000014.jpg5170m is the pitch of the vertical bar, h is the height of a single segment of the inner form, γ is the unit volume weight of the placed body, α is the lateral pressure coefficient of the placed body, k Δ is the bending moment coefficient due to the action of uniformly distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar.

[0015] The formula for the bending moment value due to the live load of the cross-section of the vertical bar 23 is as follows: JPEG2025084642000015.jpg11170JPEG2025084642000016.jpg5170m is the pitch of the vertical bar, α is the lateral pressure coefficient of the placed body, P 0 is the uniformly distributed live load for the construction of the upper surface of the placed body, k 0 is the bending moment coefficient due to the action of triangularly distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar, k Δ is the bending moment coefficient due to the action of uniformly distributed load, k 0 is the bending moment coefficient due to the action of triangularly distributed load, as shown in the following table.

[0016] JPEG2025084642000017.jpg64170

[0017] As can be seen, with the increase in the number of loads, the bending moment coefficient k Δ due to the action of uniformly distributed load and the bending moment coefficient k 0 due to the action of triangularly distributed load both tend to increase gradually. When the number of loads is the same, the bending moment coefficient k 0 due to the action of triangularly distributed load is always greater than the bending moment coefficient k Δ due to the action of uniformly distributed load. This indicates that the influence of the triangularly distributed load on the bending moment generated in the structure is relatively large. With the increase in the number of loads, the increase rate of the bending moment coefficient k Δ due to the action of uniformly distributed load and the bending moment coefficient k 0 due to the action of triangularly distributed load gradually decreases. This indicates that within a certain range, the influence of the increase in the number of loads on the bending moment coefficient gradually weakens.

[0018] Here, the combined design formula for the loads on the vertical bar 23 is as follows: JPEG2025084642000018.jpg5170JPEG2025084642000019.jpg20170

[0019] By calculating the total strength of the loads on the annular frame bracket 12, the stability and safety of the bracket under various load conditions can be ensured. This contributes to preventing accidents during construction, ensuring the smooth progress of the project, and can also achieve the optimization of design, material conservation, ensuring construction efficiency, and ensuring the optimization of the overall plan of the annular frame bracket 12.

[0020] Here, the bending strength checking formula for the vertical bar 23 is as follows: JPEG2025084642000020.jpg10170In Equation 5, f is the design value of the bending strength of the vertical bar, W 0 is the sectional resistance moment of the vertical bar, JPEG2025084642000021.jpg5170 Calculating the bending strength of the annular formwork bracket 12 is of great significance to ensuring construction safety, optimizing design, reducing costs, improving construction efficiency and complying with regulations, which contributes to improving the performance of the annular formwork bracket 12 and reducing construction risks, creating favorable conditions for the success of the project.

[0021] Here, multiple layers of annular formwork brackets 12 are installed, and the lower layer annular formwork brackets 12 are constantly rolled over above the upper layer annular formwork brackets 12, and the rollover process can only be carried out after the secondary lining concrete 13 between the lower layer annular formwork brackets 12 and the inner wall of the shaft 11 has solidified.

[0022] Here, both sides of the vertical bars 23 are bent by 90 degrees, so that the entire vertical bars 23 present a "U" shape, and the vertical bars 23 are uniformly distributed in a ring shape on the side of the horizontal bar 22 away from the support truss 21, and the pitch of the vertical bars 23 on the horizontal bar 22 can determine the overall strength of the annular formwork bracket 12, and the installation pitch of the vertical bars 23 should adapt to the internal environment of the shaft 11, thereby achieving the optimal arrangement.

[0023] Working principle: First, define the horizontal pitch m of the vertical bars and the height h of a single segment of the inner mold. The pitch of the horizontal bars distributed equally in the vertical direction is h / n. The unit weight of the concrete body is γ. The side pressure coefficient of the concrete body is α. The uniformly distributed live load of the upper surface construction of the concrete body is P. 0 The bending strength design value of the vertical bar is f, and the cross-sectional resistance moment of the vertical bar is W 0 and k Δ is the bending moment coefficient due to uniformly distributed load action, and k 0 is the bending moment due to the triangular distributed load action, and the bending moment value generated in the cross section of the vertical bar due to the static load is obtained, JPEG2025084642000022.jpg11170And, the bending moment value generated in the cross section of the vertical bar due to the live load was obtained, When combining the bending moment value generated in the cross-section of the vertical bar 23 due to the static load and the bending moment value generated in the cross-section of the vertical bar 23 due to the live load, the following is obtained. JPEG2025084642000024.jpg5170 Ensure that the bending strength of the vertical bar meets the requirements and check the following formula. JPEG2025084642000025.jpg10170 At this time, the horizontal pitch control requirement of the vertical bar can be obtained. JPEG2025084642000026.jpg11170 By controlling the horizontal pitch of the vertical bar 23, the vertical bar 23 can be distributed on the annular formwork bracket 12 at the optimal pitch, ensuring the stability and safety of the annular formwork bracket 12 structure without wasting materials.

Explanation of Symbols

[0024] 11 Shaft 12 Annular formwork bracket 13 Secondary lining concrete 14 Anchor 21 Support truss 22 Horizontal bar 23 Vertical bar 24 Concrete formwork

Claims

1. A construction method for a shaft lining annular roll-over structure, including a shaft, wherein an anchor is fixedly attached to the inner wall of the shaft, an annular formwork bracket is supported by the anchor, secondary lining concrete is placed between the inner wall of the shaft and the annular formwork bracket, the annular formwork bracket includes a support truss, a horizontal bar, a vertical bar, and a concrete formwork, the horizontal bar is fixedly connected to the surface of the support truss via a bolt fastener, the vertical bar is fixed to the surface of the horizontal bar via a bolt fastener, the concrete formwork is fixedly connected to the side of the vertical bar away from the support truss, and the horizontal pitch control requirement formula for the vertical bar is as follows: In Formula 1, m is the pitch of the vertical bar, h is the height of a single segment of the inner form, γ is the unit volume weight of the placed body, α is the lateral pressure coefficient of the placed body, P is the uniformly distributed live load for the construction of the upper surface of the placed body, f is the design value of the bending strength of the vertical bar, W is the section resistance moment of the vertical bar, k Δ is the bending moment coefficient due to the action of a uniformly distributed load, k is the bending moment coefficient due to the action of a triangular distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar. A construction method for a shaft lining annular roll-over structure is characterized by the above.

2. The formula for the bending moment value of the vertical bar under static load of the cross-section is as follows: m is the pitch of the vertical bar, h is the height of a single segment of the inner form, γ is the unit volume weight of the placed body, α is the lateral pressure coefficient of the placed body, k Δ is the bending moment coefficient due to the action of a uniformly distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar. The construction method for a shaft lining annular roll-over structure according to Claim 1 is characterized by the above.

3. The formula for the bending moment value of the vertical bar under live load of the cross-section is as follows: m is the pitch of the vertical bar, α is the lateral pressure coefficient of the placed body, P is the uniformly distributed live load for the construction of the upper surface of the placed body, k is the bending moment coefficient due to the action of a triangular distributed load, h / n is the pitch evenly distributed in the vertical direction of the horizontal bar. The construction method for a shaft lining annular roll-over structure according to Claim 2 is characterized by the above.

4. The combined design formula for the load of the vertical bar is as follows: The construction method for a shaft lining annular roll-over structure described in 3.

5. The bending strength checking formula for the vertical bar is as follows: In Formula 5, f is the design value of the bending strength of the vertical bar, W is the moment of resistance of the vertical bar, Construction method for circular rollover structure.

6. The method for constructing the shaft lining annular rollover structure according to claim 1, characterized in that the annular formwork bracket is installed in multiple layers, the lower layer annular formwork bracket is constantly rolled over above the upper layer annular formwork bracket, the cross bar has an arc shape, and the concrete formwork has an arc shape.

7. The shaft lining annular rollover structure construction method according to claim 6, characterized in that both sides of the vertical bar are bent by 90 degrees, the whole vertical bar presents a "U" shape, and the vertical bars are uniformly distributed in a ring shape on the side of the horizontal bar away from the support truss.

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