Supporting structure for variable-section end of underground cavern of cross-fault fracture zone
By using a combined support structure of advanced small guide pipes, embedded arches, and guide steel pipes, the problem of unstable reinforcement during construction when a large cross-section suddenly becomes a small cross-section was solved, thus improving construction safety and economy.
Patent Information
- Application Number
- CN202520115404.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2035-01-17
AI Technical Summary
In the construction of underground caverns where the cross-section abruptly changes from large to small, the traditional pipe roof reinforcement method is unstable and cannot guarantee construction safety and economy.
A combined support structure consisting of advanced small guide pipes, embedded arches, guide steel pipes, and pipe roofs is adopted. The excavation face is reinforced by grouting through advanced small guide pipes, the embedded arches provide support, the guide steel pipes guide the drilling, and the pipe roofs provide final reinforcement.
It effectively solves the problem of instability in traditional pipe roof reinforcement, ensures construction safety, reduces construction risks and saves costs.
Smart Images
Figure CN223536369U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of tunnel and underground engineering construction technology, and in particular to a support structure for the variable cross-section end of an underground cavern across a fault fracture zone. Background Technology
[0002] In underground cavern excavation projects, stress concentration is prone to occur between different cross sections, posing significant construction risks. For excavation and support under fault zones with varying cross sections, pipe roof reinforcement is a suitable conventional method. However, in situations where a large cross section abruptly changes to a small cross section, the stability of the pipe roof ends is greatly affected by the strata, making it difficult to guarantee the reinforcement effect. Therefore, ensuring the safe and economical effectiveness of pipe roof reinforcement has become a challenging engineering problem. Utility Model Content
[0003] In order to solve the above-mentioned technical problems, this utility model provides a support structure for the variable cross-section end of an underground cavern across a fault fracture zone, which can effectively ensure the reinforcement effect of the variable cross-section end.
[0004] To achieve the above objectives, the present invention provides a support structure for a variable cross-section end of an underground cavern spanning a fault fracture zone, comprising a variable cross-section end that abruptly changes from a large cross-section to a small cross-section. The structure is characterized by further comprising a pre-inserted small guide pipe, an embedded arch, a guide steel pipe, and a pipe roof. The pre-inserted small guide pipe is inserted into the soil from the edge of the variable cross-section end. The embedded arch is a concrete-cast arch structure embedded in the variable cross-section end. The guide steel pipe is mounted on the embedded arch, and the pipe roof is installed into the soil via the guide steel pipe.
[0005] As a further improvement of this utility model, the advanced small guide tubes are spaced along the upper edge of the variable cross-section end and are inclined upwards and outwards from the edge of the cross-section end, with a spacing of at least 0.4m between the advanced small guide tubes.
[0006] As a further improvement of this utility model, the variable cross-section end is provided with an excavation face, and the advanced small guide pipe is used for grouting to reinforce the excavation face. The length and position of the advanced small guide pipe can make its reinforcement range 1-2m on each side of the excavation face in the left and right lateral directions and 5-10m in the longitudinal direction.
[0007] As a further improvement of this utility model, a steel arch frame is provided inside the embedded arch, and the embedded arch is formed by pouring concrete on the steel arch frame.
[0008] As a further improvement of this utility model, the thickness of the embedded arch at the variable cross-section end is at least 0.6m.
[0009] As a further improvement of this utility model, the guide steel pipes are spaced along the upper edge of the variable cross-section end and are inclined upwards towards the outer edge of the cross-section end. The interval between the guide steel pipes is at least 0.4m, and the upward inclination angle of the guide steel pipes is 1° to 3°.
[0010] The beneficial effects of this utility model are as follows: This structure is applied to the transition and support construction of underground spaces with large fractures and excavation that abruptly changes from a large cross section to a small cross section. By setting an embedded arch at the end of the variable cross section, it can effectively solve the engineering problem of unstable end of traditional pipe roof grouting reinforcement, effectively ensure the reinforcement effect of the variable cross section end, and reduce construction safety risks. Attached Figure Description
[0011] Figure 1 This is a schematic cross-sectional view of the structure described in this utility model;
[0012] Figure 2 This is a schematic diagram of the longitudinal section of the structure described in this utility model;
[0013] Figure 3 This is a partially enlarged longitudinal section view of the structure described in this utility model;
[0014] Marking description: 1. Variable cross section end, 2. Advanced small guide pipe, 3. Embedded arch, 4. Steel arch frame, 5. Guide steel pipe, 6. Pipe shed. Detailed Implementation
[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0016] like Figure 1-3 As shown, a support structure for the variable cross-section end of an underground cavern across a fault fracture zone is used for the variable cross-section end 1 where the cross-section changes abruptly from a large cross-section to a small cross-section. It includes a pre-conducting small guide pipe 2, an embedded arch 3, a steel arch frame 4, a guide steel pipe 5, and a pipe roof 6.
[0017] The advanced small guide pipes 2 are made of steel perforated pipes and are installed in a ring around the upper edge of the variable cross-section end 1. They are inserted into the soil from the edge of the variable cross-section end 1 and are installed at an angle upwards and outwards from the edge of the cross-section end. The spacing between the advanced small guide pipes 2 is at least 0.4m. The excavation face is reinforced by grouting through the advanced small guide pipes 2. The length and position of the advanced small guide pipes 2 allow the reinforcement range to be 1-2m on each side of the excavation face laterally and 5-10m longitudinally. Grouting through the advanced small guide pipes 2 reinforces the excavation area of the embedded arch 3 and ensures construction safety.
[0018] A steel arch frame 4, made of I-beams, is installed inside the embedded arch 3. The steel arch frame 4 is located inside the embedded arch 3, offset upwards by a protective thickness, and arranged towards the excavation face. The arrangement length is 2m, and the spacing between rows is 0.5m. It serves to support and stabilize the surrounding rock at the excavation face, while also providing support for the embedded arch 3. The embedded arch 3 is an arch-shaped structure formed by pouring C25 concrete onto the steel arch frame 4. The embedded arch 3 is embedded in the variable cross-section end 1, with a thickness of at least 0.6m, providing end support for the pipe roof 6 to ensure the stability of the transition section during excavation.
[0019] The guide steel pipe 5 is a seamless steel pipe, which is pre-embedded in the embedded arch 3 and is set at intervals along the upper edge of the variable cross-section end 1. It is inclined upwards to the outside of the cross-section end edge. The interval between the guide steel pipes 5 is at least 0.4m, and the upward inclination angle of the guide steel pipe 5 is 1° to 3°. The guide steel pipe 5 provides the drilling position for the pipe roof 6.
[0020] Pipe roof 6 is a hot-rolled seamless steel pipe. It is drilled and installed into the excavation face along the orifice of guide steel pipe 5. It is installed on the outer ring of the small section of the excavation body. The surrounding rock and soil are reinforced and supported by grouting of the steel pipe of pipe roof 6.
[0021] The construction steps for the above structure are as follows:
[0022] Before constructing the embedded arch 3, the excavation face is advanced to the variable cross-section end 1, and the initial support is completed. After the initial support is completed, the excavation face is reinforced by grouting with pre-drilled small guide pipes 2. After reinforcement, excavation is carried out. According to the drawings, the area for the embedded arch 3 is excavated, and the steel arch frame 4 and the pre-embedded guide steel pipe 5 are installed. After the formwork is erected, the embedded arch 3 is formed by pouring concrete. After pouring, a drilling rig is used to drill holes along the guide steel pipe 5. After drilling, the pipe roof 6 is fabricated and installed. After installation, grouting is performed. Once the grout strength reaches the required level, the reinforced body is formed, and the support structure is completed.
[0023] The effects that the above structure can achieve are as follows:
[0024] I. Special Functions
[0025] The above structure is suitable for transitional support construction in underground spaces with large fractures and abrupt changes in excavation from large cross-sections to small cross-sections. The method of constructing an embedded arch 3 in the transition section solves the engineering problem of unstable ends in traditional pipe roof 6 grouting reinforcement.
[0026] II. Good security
[0027] The above-mentioned structure is simple to construct. By applying the arch-jacket technique to the variable cross-section end 1, the end stability of the pipe roof 6 construction is ensured. When there are wide fault zones in the strata, it can ensure the safety and stability of traditional construction techniques, reduce risks, and provide a safe and efficient support method for other similar working conditions.
[0028] Third, good economic efficiency
[0029] The above structure can save space and ensure safety, while also saving a lot of material costs, machinery and equipment costs, labor costs and construction time costs for the project.
[0030] The above-described embodiments are only for illustrative purposes and are not intended to limit the present invention in any way. Any person skilled in the art who makes partial modifications or alterations to the technical content disclosed in the present invention without departing from the scope of the technical features of the present invention shall still fall within the scope of the technical features of the present invention.
Claims
1. A support structure for a variable cross-section end of an underground cavern spanning a fault fracture zone, comprising a variable cross-section end that abruptly changes from a large cross-section to a small cross-section, characterized in that: It also includes advanced small guide pipes, embedded arches, guide steel pipes, and pipe roofs. The advanced small guide pipes are inserted into the soil from the edge of the variable cross-section end. The embedded arches are arch-shaped structures made of cast concrete and are embedded in the variable cross-section end. The guide steel pipes are set on the embedded arches. The pipe roofs are installed into the soil through the guide steel pipes.
2. The support structure for the variable cross-section end of an underground cavern across a fault fracture zone according to claim 1, characterized in that: The advanced small guide tubes are spaced along the upper edge of the variable cross-section end and are inclined upwards and outwards from the edge of the cross-section end, with a minimum spacing of 0.4m between the advanced small guide tubes.
3. The support structure for the variable cross-section end of an underground cavern across a fault fracture zone according to claim 1, characterized in that: The variable cross-section end is provided with an excavation face, and the advanced small guide pipe is used for grouting to reinforce the excavation face. The length and position of the advanced small guide pipe can make its reinforcement range 1-2m on each side of the excavation face and 5-10m in the longitudinal direction.
4. The support structure for the variable cross-section end of an underground cavern across a fault fracture zone according to claim 1, characterized in that: The embedded arch is provided with a steel arch frame, which is formed by pouring concrete on the steel arch frame.
5. The support structure for the variable cross-section end of an underground cavern across a fault fracture zone according to claim 1, characterized in that: The thickness of the embedded arch at the variable cross-section end is at least 0.6m.
6. The support structure for the variable cross-section end of an underground cavern across a fault fracture zone according to claim 1, characterized in that: The guide steel pipes are spaced along the upper edge of the variable cross-section end and are inclined upwards outwards from the edge of the cross-section end. The interval between the guide steel pipes is at least 0.4m, and the upward inclination angle of the guide steel pipes is 1° to 3°.