Construction structure for water conservancy irrigation area project diversion tunnel to penetrate through karst cave

Abstract

The utility model discloses a water conservancy irrigation area project diversion tunnel crossing karst cave structural design. The water conservancy irrigation area project diversion tunnel crossing karst cave structural design comprises second-stage diversion tunnel lining reinforced concrete, first-stage wrapping reinforced concrete, a karst cave, diversion tunnel foundation concrete, an upper drainage concrete culvert pipe, a lower drainage concrete culvert pipe, anchor bars, I-shaped steel and a temporary support. The diversion tunnel crossing karst cave section adopts encased concrete for safety guarantee of temporary support in the construction period so as to guarantee normal tunneling and excavation of the tunnel, culvert pipes are buried in foundation concrete of a tunnel bottom plate for small flood in the karst cave in the flood season to pass through, and when the karst cave encounters large flood, the flood can pass through the top of the encased concrete and the foundation culvert pipes on the lower portion of the encased concrete. According to the design, the downstream tunnel can be continuously tunneled under the condition that the safety of the temporary construction period is guaranteed, and meanwhile normal tunnel tunneling can still be guaranteed in the flood season even if flood exists in the karst cave.

Description

Technical Field

[0001] The utility model belongs to the technical field of water conservancy projects, and in particular relates to a construction structure for a water diversion tunnel of a water conservancy irrigation project to pass through a karst cave. Background Art

[0002] In my country's water conservancy and irrigation projects, non-pressure water diversion tunnels, as a common water diversion structure, play a key role. However, as the project line extends, the situation becomes complicated when encountering large karst caves and other unfavorable geological sections. Especially when it is impossible to change the line to avoid these karst caves, how to safely and effectively cross these geological obstacles without causing any impact on the water flow inside the karst cave has become a technical problem that needs to be overcome urgently. Utility Model Content

[0003] In order to solve the defects of the above-mentioned prior art, the utility model proposes a construction structure for a water diversion tunnel of a water conservancy irrigation project to pass through a karst cave.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A construction structure for a water diversion tunnel of a water conservancy irrigation project passing through a karst cave, comprising: a second-phase water diversion tunnel lining reinforced concrete, a first-phase external reinforced concrete and a drainage concrete culvert, wherein the first-phase external reinforced concrete is arranged on the outside of the second-phase water diversion tunnel lining reinforced concrete for temporary support during the construction period, the internal second-phase water diversion tunnel lining reinforced concrete is a pressure-bearing structure, a composite support structure composed of the first-phase external reinforced concrete and the second-phase water diversion tunnel lining reinforced concrete runs horizontally through the culvert, a plurality of drainage concrete culverts are arranged in a direction parallel to the water flow direction in the culvert, and are arranged at equal intervals below the first-phase external reinforced concrete, and the outside of the drainage concrete culvert is filled with base concrete.

[0006] In the preferred technical solution, the reinforced concrete lining shape of the first phase water diversion tunnel adopts the "city gate tunnel" cross-section type.

[0007] In the preferred technical solution, the reinforced concrete lining shape of the second phase water diversion tunnel adopts a "horseshoe-shaped flat bottom plate" cross-section type.

[0008] In the preferred technical solution, a temporary support structure fixed with I-beams is preset in advance on the outside of the first phase of reinforced concrete.

[0009] Furthermore, two rubber waterstops were installed at the joints of the first phase outsourced reinforced concrete structure and filled with polyethylene foam boards.

[0010] In the preferred technical solution, the drainage concrete culverts are arranged in two rows, upper and lower.

[0011] Further, five drainage concrete culverts are provided in each row.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0013] 1) Reasonable structure: The construction structure of the water diversion tunnel passing through the karst cave adopts a combination of reinforced concrete lining of the second-phase water diversion tunnel, reinforced concrete outsourcing of the first-phase, and drainage concrete culverts. The structure is reasonable and can effectively support temporary support during the construction process and the subsequent pressure bearing requirements.

[0014] 2) Superior strength: The reinforced concrete lining of the first phase water diversion tunnel adopts the "city gate tunnel" section type, and the reinforced concrete lining of the second phase water diversion tunnel adopts the "horseshoe-shaped flat bottom plate" section type. This design can ensure the strength and stability of the structure.

[0015] 3) Good waterproofing effect: Two rubber waterstops are set at the joints of the first-phase reinforced concrete structure and filled with polyethylene foam boards, which can effectively prevent water leakage and improve the waterproof performance of the structure.

[0016] 4) Complete drainage system: The drainage concrete culverts are arranged in two rows, with five drainage concrete culverts in each row, which can ensure the normal passage of water in the cave and improve drainage efficiency.

[0017] 5) Convenient construction: The first phase outsourced reinforced concrete has a temporary support structure fixed with I-beams, which provides convenient conditions for construction and reduces construction risks.

[0018] 6) Environmental protection and energy saving: Optimized structural design and drainage system layout can reduce material waste, improve resource utilization, and comply with the concept of environmental protection and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described by way of examples with reference to the accompanying drawings, in which:

[0020] Figure 1 It is a plan layout diagram of the construction structure in the utility model;

[0021] Figure 2 It is a longitudinal section view of the construction structure in the utility model;

[0022] Figure 3 for Figure 2 Cross-sectional view of section II.

[0023] Figure numerals: Phase II water diversion tunnel lining reinforced concrete-1, Phase I external reinforced concrete-2, cave-3, base concrete-4, drainage concrete culvert-5, anchor bar-6, temporary support-7. DETAILED DESCRIPTION

[0024] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0025] This embodiment provides a construction structure for a water diversion tunnel of a water conservancy irrigation project to pass through a karst cave 3. Figure 1-3 , which is arranged perpendicular to the water flow direction of the cave 3. The main structure includes: the second-phase water diversion tunnel lining reinforced concrete 1, the first-phase external reinforced concrete 2 and the drainage concrete culvert 5. The first-phase external reinforced concrete 2 is arranged on the outside of the second-phase water diversion tunnel lining reinforced concrete 1. The first-phase water diversion tunnel lining reinforced concrete shape adopts the "city gate hole" section type, which is used for the safety of temporary support 7 during the construction period to ensure the normal excavation of the tunnel, and is also used for the external water pressure structure during the later flood of the cave 3; the internal second-phase water diversion tunnel lining reinforced concrete 1 is shaped like a "horseshoe flat bottom The cross-section type is a "plate" type, which is used to ensure the water diversion demand and serve as a pressure-bearing structure for external and internal water pressures during a large flood in the later karst cave 3. The composite support structure is composed of the first-phase external reinforced concrete 2 and the second-phase water diversion tunnel lining reinforced concrete 1. A temporary support 7 structure fixed with I-beams is preset in advance outside the first-phase external reinforced concrete 2, and the whole horizontally runs through the culvert; in addition, the number of the drainage concrete culverts 5 is several, and the layout direction is parallel to the water flow direction in the culvert, and they are arranged at equal intervals below the first-phase external reinforced concrete 2. The outside of the drainage concrete culvert 5 is filled with base concrete 4. The culvert is buried in the base concrete 4 of the tunnel bottom plate for the passage of small floods in the karst cave 3 during the flood season. When the karst cave 3 encounters a large flood, it can pass through the top of the external concrete and the lower drainage concrete culvert 5. This design can continue to excavate the downstream tunnel while ensuring the safety of the temporary construction period. At the same time, even if there is a flood in the karst cave 3 during the flood season, the normal excavation of the tunnel can still be guaranteed.

[0026] During the construction process, the foundation of the tunnel bottom is first excavated, and then the drainage concrete culvert 5 is pre-buried and the base concrete 4 is buried. Next, the I-beam and temporary support 7 are installed, and the reinforced concrete lining of the first-phase water diversion tunnel is constructed. The anchor bars 6 are fixed to ensure temporary support 7 and safety during the construction period to ensure the normal excavation and excavation of the tunnel. Subsequently, rock excavation of the tunnel on the downstream side of the cave 3 can be carried out. After the tunnel is fully connected, the construction of the reinforced concrete lining 1 of the second-phase water diversion tunnel will be completed. The overall design of the scheme adopts a composite support structure to ensure the safety of the temporary construction period, and allows the tunnel to be excavated normally even if there is flooding in the cave 3 during the flood season.

[0027] In a specific implementation, the first phase outer reinforced concrete 2 adopts a modular assembly design. During the assembly process, due to the existence of structural joints, special treatment is performed on the structural joints to ensure a good waterproof effect. Specifically, two rubber water stop strips are set at the structural joints and filled with polyethylene foam boards to effectively prevent water penetration and leakage, thereby ensuring the waterproof performance of the building structure.

[0028] In a specific embodiment, the drainage concrete culvert 5 is arranged in two rows, one above the other. In a preferred design, five drainage concrete culverts 5 are arranged in each row, and such an arrangement can effectively ensure the normal passage of water flow in the cave 3 and ensure that the water flow is unobstructed.

[0029] In a specific embodiment, see Figure 2 The thickness of the first-phase external concrete bottom plate H1 is 1.0m, the concrete lining of the bottom plate of the water diversion tunnel H2 is 0.4m, the net height of the water diversion tunnel H3 is 4.1m, the concrete lining of the top arch of the water diversion tunnel H4 is 0.4m, the thickness of the external concrete top arch H5 is 1.0m, the water diversion tunnel adopts a horseshoe-shaped section with a bottom arc diameter R of 4.1m and a top arch radius R1 of 2.05m. The width of the bottom plate of the water diversion tunnel section B1 is 3.0m and the width B2 is 4.1m. The concrete lining B3 of the side wall of the water diversion tunnel is 0.4m, the thickness B4 of the external concrete side wall is 1.0m, the diameter R3 of the inner pipe of the water diversion tunnel foundation concrete is 1.2m, the horizontal spacing L1 between the centers of the culverts is 2.0m, the vertical spacing L2 between the centers of the culverts is 2.2m, and the length L3 of the foundation concrete 4 along the water flow direction of the cave 3 is 8.2m.

[0030] In a specific embodiment, see Figure 2 , 3 The parameters of anchor reinforcement 6 are Φ25 anchor rod (L=3m), with a spacing of 1m, a row spacing of 2m, 1m into concrete, and an end hook of 0.3m; the parameters of I-beam and temporary support 7 are I16 steel support, spacing of 0.8m, sprayed C25 concrete with a thickness of 16cm, and a double-layer steel mesh of φ6@20cm.

[0031] As described above, the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A construction structure for a water diversion tunnel of a water conservancy irrigation project passing through a karst cave, characterized in that: include: The second phase water diversion tunnel is lined with reinforced concrete, the first phase is externally coated with reinforced concrete, and the drainage concrete culvert, wherein the first phase externally coated reinforced concrete is arranged on the outside of the second phase water diversion tunnel lining reinforced concrete for temporary support during the construction period, the internal second phase water diversion tunnel lining reinforced concrete is a pressure-bearing structure, and the composite support structure composed of the first phase externally coated reinforced concrete and the second phase water diversion tunnel lining reinforced concrete runs horizontally through the culvert. The drainage concrete culvert is in a plurality of numbers, and their arrangement direction is parallel to the water flow direction in the culvert, and they are arranged at equal intervals below the first phase externally coated reinforced concrete, and the outside of the drainage concrete culvert is filled with base concrete.

2. The construction structure of a water diversion tunnel passing through a karst cave in a water conservancy irrigation project according to claim 1, characterized in that: The reinforced concrete lining shape of the first phase water diversion tunnel adopts the "city gate tunnel" cross-section type.

3. The construction structure of a water diversion tunnel passing through a karst cave in a water conservancy irrigation project according to claim 1, characterized in that: The reinforced concrete lining of the second phase water diversion tunnel adopts the "horseshoe-shaped flat bottom plate" cross-section type.

4. The construction structure of a water diversion tunnel passing through a karst cave in a water conservancy irrigation project according to claim 1, characterized in that: The first phase of the outsourced reinforced concrete also has a temporary support structure fixed with I-beams pre-set on the outside.

5. The construction structure of a water diversion tunnel passing through a karst cave in a water conservancy irrigation project according to claim 4, characterized in that: Two rubber waterstops were installed at the joints of the first phase outsourced reinforced concrete structure and filled with polyethylene foam boards.

6. The construction structure of a water diversion tunnel passing through a karst cave in a water conservancy irrigation project according to claim 1, characterized in that: The drainage concrete culverts are arranged in two rows, upper and lower.

7. The construction structure of a water diversion tunnel passing through a karst cave in a water conservancy irrigation project according to claim 6, characterized in that: Five drainage concrete culverts are set up in each row.

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