Large-section hydraulic tunnel main adit intersection excavation supporting portal

Abstract

The utility model discloses a large-section hydraulic tunnel main adit intersection excavation support door frame in the technical field of tunnel construction, which comprises a reinforcing door frame and a connecting piece, the reinforcing door frame comprises outer door beams and inner door beams, a semicircular door beam is fixedly connected between the top ends of the inner door beams, and a door frame cross beam is fixedly connected between the tops of the outer door beams; the semicircular door beam is connected with the inner side of the portal cross beam, linear reinforcing ribs are fixedly arranged between the outer door beam and the inner door beam, a plurality of sections of inclined reinforcing ribs are fixedly arranged between the semicircular door beam and the portal cross beam, oblique angle supporting pieces are jointly connected between the tops of the inclined reinforcing ribs, and the oblique angle supporting pieces are fixedly connected between the outer door beam and the portal cross beam at the same time; according to the utility model, the outer door beam can be connected and fixed with the main hole support, the inner door beam and the semicircular door beam are in transition connection with the branch hole bracket, and the outer door beam and the inner door beam are connected through the linear reinforcing rib, so that the support at the intersection forms a whole, the stress is dispersed, and a good support effect is provided.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, specifically to a gantry frame for excavation support at the intersection of main and branch tunnels in a large-section hydraulic tunnel. Background Technology

[0002] Currently, large-section hydraulic tunnels are commonly used in water conservancy projects for water diversion systems of large hydropower stations or flood discharge tunnels in cities. For large-section hydraulic tunnels, the excavation and support stage is the most risky stage of the entire construction process, and the intersection of the main tunnel and the branch tunnel is one of the most risky locations during the excavation and support stage. The main risk lies in stress concentration: due to the abrupt change in cross-section at the intersection, a three-dimensional stress redistribution occurs, resulting in a high concentration of stress in the surrounding rock at the junction of the main tunnel and the branch tunnel, which may lead to the expansion of the plastic zone of the surrounding rock or local collapse.

[0003] The entrance of the adit and the height difference between it and the main tunnel make it impossible to construct a complete steel frame support for the main tunnel at the junction. This necessitates that the support strength at the entrance of the adit be increased to withstand the stress at the intersection and to connect with the support of the main tunnel. In the current technology, there is no unified standard for the support at the entrance of the adit, and most of them are reinforced on site, which leads to unsatisfactory reinforcement and support effects, and makes it difficult to standardize construction.

[0004] Based on this, this utility model designs a gantry frame for excavation support at the intersection of main and branch tunnels in large-section hydraulic tunnels to solve the above problems. Utility Model Content

[0005] The purpose of this utility model is to provide a gantry frame for excavation support at the intersection of main and branch tunnels in large-section hydraulic tunnels, in order to solve the problem mentioned in the background art that there is no unified standard for the support at the entrance of the branch tunnel, and most of them are reinforced on site, which leads to unsatisfactory reinforcement and support effects, and makes it difficult to standardize construction.

[0006] To achieve the above objectives, the present invention provides the following technical solution: including a reinforcing gantry and connecting parts, wherein the reinforcing gantry includes an outer gantry beam and an inner gantry beam, a semi-circular gantry beam is fixedly connected between the top ends of the inner gantry beam, and a gantry crossbeam is fixedly connected between the top ends of the outer gantry beam;

[0007] The semi-circular gantry beam is connected to the inner side of the gantry crossbeam. Straight reinforcing ribs are fixed between the outer gantry beam and the inner gantry beam. Multiple inclined reinforcing ribs are fixed between the semi-circular gantry beam and the gantry crossbeam. An angled support is connected to the top of the inclined reinforcing ribs. The angled support is fixedly connected between the outer gantry beam and the gantry crossbeam.

[0008] As a further embodiment of this utility model, both the inner and outer door beams have I-shaped cross-sections, and the fixed connection is welded.

[0009] As a further embodiment of this utility model, the cross-sectional area of ​​the gantry beam is larger than the cross-sectional areas of the outer gantry beam and the inner gantry beam.

[0010] As a further embodiment of this utility model, the connecting member includes a fixed base plate and a connecting support plate, a positioning wedge is fixedly provided on the inner side of the connecting support plate, and the fixed base plate is fixedly installed in the tunnel by anchor rods.

[0011] As a further embodiment of this utility model, an implantation sleeve is fixedly connected inside the fixed base plate, and an internal screw is rotatably installed in the middle of the connecting support plate. The internal screw is located in the middle of the positioning wedge and is threadedly engaged with the implantation sleeve.

[0012] As a further embodiment of this utility model, the reinforced gantry is installed at the branch hole to support the branch hole and connect the main hole support.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] The outer portal beam can be connected and fixed to the main tunnel support, thereby compensating for the height difference between the main tunnel and the auxiliary tunnel, and enabling the main tunnel support to be effectively fixed and connected to the portal frame beam. The inner portal beam and semi-circular portal beam are connected to the auxiliary tunnel support through transition, and the outer portal beam and inner portal beam are connected by straight reinforcing ribs, so that the support at the intersection forms a whole, thereby dispersing stress and providing a good support effect.

[0015] The semi-circular portal beam provides central reinforcement support for the portal frame crossbeam and also effectively connects to the arch support of the support opening. Furthermore, the inclined reinforcing ribs and angled supports strengthen and compensate for the gaps at the corners of the semi-circular portal beam and the portal frame crossbeam, forming multiple triangular supports. This enhances the overall support strength of the reinforced portal frame, provides stable support, and effectively disperses stress at the intersection, allowing both the outer and inner portal beams to effectively bear relatively equal loads. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the gantry structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the gantry frame of this utility model when used in multiple layers;

[0018] Figure 3 This is a schematic diagram of the installation of the gantry frame of this utility model when used in multiple layers;

[0019] Figure 4 This is a half-sectional structural diagram of the gantry connection of this utility model;

[0020] Figure 5 This utility model Figure 4 Enlarged schematic diagram of the inner A section.

[0021] The attached diagram lists the components represented by each number as follows:

[0022] 1. Outer door beam; 2. Inner door beam; 3. Semi-circular door beam; 4. Door frame crossbeam; 5. Straight reinforcing rib; 6. Inclined reinforcing rib; 7. Angled support; 8. Fixed base plate; 9. Connecting support plate; 10. Positioning wedge; 11. Inserted sleeve; 12. Inner threaded rod. Detailed Implementation

[0023] Please see Figure 1-5 The technical solution provided by this utility model is as follows: it includes a reinforced gantry and connecting parts. The reinforced gantry includes an outer gantry beam 1 and an inner gantry beam 2. A semi-circular gantry beam 3 is fixedly connected between the top ends of the inner gantry beam 2, and a gantry beam 4 is fixedly connected between the top ends of the outer gantry beam 1.

[0024] The semi-circular door beam 3 is connected to the inner side of the gantry beam 4. Straight reinforcing ribs 5 are fixed between the outer door beam 1 and the inner door beam 2. Multiple inclined reinforcing ribs 6 are fixed between the semi-circular door beam 3 and the gantry beam 4. An inclined support 7 is connected to the top of the inclined reinforcing ribs 6. The inclined support 7 is fixedly connected between the outer door beam 1 and the gantry beam 4.

[0025] When performing tunnel support, reinforced gantry frames are installed at the exit of the branch tunnel. This supports the intersection and allows for a good connection with the support components of the main tunnel, thus compensating for the incomplete support structure of the main tunnel at the intersection.

[0026] The reinforced gantry can be connected and fixed to the main tunnel support through the outer gantry beam 1, thereby compensating for the height difference between the main tunnel and the branch tunnel, and enabling the main tunnel support to be effectively fixed and connected to the gantry beam 4; it is connected to the branch tunnel support through the inner gantry beam 2 and the semi-circular gantry beam 3, and the outer gantry beam 1 and the inner gantry beam 2 are connected by the straight reinforcing rib 5, so that the support at the intersection forms a whole, thereby dispersing stress and providing a good support effect.

[0027] The semi-circular portal beam 3 can provide central reinforcement support for the portal frame crossbeam 4, and can also connect well with the arch support of the support hole. At the same time, the inclined reinforcing ribs 6 and the angled support members 7 strengthen and compensate for the corner gaps between the semi-circular portal beam 3 and the portal frame crossbeam 4, forming multiple triangular supports, thereby enhancing the support strength of the entire reinforced portal frame, providing a stable support effect, and effectively dispersing the stress at the intersection, so that the outer portal beam 1 and the inner portal beam 2 can effectively bear relatively equal loads.

[0028] Both inner door beam 2 and outer door beam 1 have I-shaped cross-sections and are fixedly connected by welding. The cross-sectional area of ​​the gantry beam 4 is larger than that of both outer door beam 1 and inner door beam 2.

[0029] I-beams are readily available and durable, and their welding and fixing are reliable, effectively transmitting loads. The larger-sized portal beam 4 can effectively connect the main tunnel support structure, and as a converging connector at the intersection, it can withstand greater forces, improving support stability.

[0030] The connector includes a fixed base plate 8 and a connecting support plate 9. A positioning wedge 10 is fixedly provided on the inner side of the connecting support plate 9. The fixed base plate 8 is fixedly installed in the tunnel by anchor bolts.

[0031] An implantation sleeve 11 is fixedly connected inside the fixed base plate 8. An internal screw 12 is rotatably installed in the middle of the connecting support plate 9. The internal screw 12 is located in the middle of the positioning wedge block 10 and is threadedly engaged with the implantation sleeve 11.

[0032] Multi-layer reinforced gantry structures offer better performance. The base plate 8 can be fixedly installed by threaded connection or welding with anchor bolts. After installing the reinforced gantry at the specified intervals, connecting brackets 9 can be installed on the inner side, allowing the inner threaded rod 12 to enter the implanted sleeve 11. By continuously rotating the inner threaded rod 12, the connecting bracket 9 moves closer to the base plate 8, thereby clamping and securing the outer beam 1 of the reinforced gantry between the positioning wedges 10. This allows the outer beam 1 of the reinforced gantry to be connected and fixed in all directions via the connecting brackets 9. Compared to the welding and fixing of U-shaped parts in the prior art, this method is tighter and more secure, and the connection and installation are more convenient. At the same time, the distribution of the positioning wedges 10 also limits the spacing between adjacent outer beams 1, allowing the reinforced gantry to be evenly distributed and less prone to bending and deformation. Multiple reinforced gantry structures can be connected as a whole, providing mutual support and improving the overall support capacity.

Claims

1. A portal frame for excavation support at the intersection of main and branch tunnels in a large-section hydraulic tunnel, comprising a reinforcing portal frame and connecting components, characterized in that: The reinforced gantry includes an outer gantry beam (1) and an inner gantry beam (2). A semi-circular gantry beam (3) is fixedly connected between the top ends of the inner gantry beam (2), and a gantry crossbeam (4) is fixedly connected between the top ends of the outer gantry beam (1). The semi-circular door beam (3) is connected to the inner side of the gantry beam (4). Straight reinforcing ribs (5) are fixed between the outer door beam (1) and the inner door beam (2). Multiple inclined reinforcing ribs (6) are fixed between the semi-circular door beam (3) and the gantry beam (4). An inclined support member (7) is connected between the tops of the inclined reinforcing ribs (6). The inclined support member (7) is fixedly connected between the outer door beam (1) and the gantry beam (4).

2. The excavation support gantry frame for the intersection of main and branch tunnels in a large-section hydraulic tunnel according to claim 1, characterized in that: Both the inner door beam (2) and the outer door beam (1) have I-shaped cross sections, and the fixed connection is welded.

3. The excavation support gantry frame for the intersection of main and branch tunnels in a large-section hydraulic tunnel according to claim 1, characterized in that: The cross-sectional area of ​​the gantry beam (4) is greater than that of the outer gantry beam (1) and the inner gantry beam (2).

4. The excavation support gantry frame for the intersection of main and branch tunnels in a large-section hydraulic tunnel according to claim 1, characterized in that: The connector includes a fixed base plate (8) and a connecting plate (9). The connecting plate (9) is fixedly provided with a positioning wedge (10) on its inner side. The fixed base plate (8) is fixedly installed in the tunnel by anchor rods.

5. A portal frame for excavation support at the intersection of main and branch tunnels in a large-section hydraulic tunnel according to claim 4, characterized in that: An implantation sleeve (11) is fixedly connected inside the fixed base plate (8), and an internal screw (12) is rotatably installed in the middle of the connecting support plate (9). The internal screw (12) is located in the middle of the positioning wedge (10) and is threadedly engaged with the implantation sleeve (11).

6. The excavation support gantry frame for the intersection of main and branch tunnels in a large-section hydraulic tunnel according to claim 1, characterized in that: The reinforced gantry is installed at the branch hole to support the branch hole and connect the main hole support components.

Images