Temporary cross support for tunnel and its using method

Abstract

The application discloses a kind of tunnel temporary cross bracing and use method that can adapt to different stress field, including cross bracing unit I, cross bracing unit II and connecting box, cross bracing unit I and cross bracing unit II are I-shaped steel, cross bracing unit II is set to two, the two ends of cross bracing unit I are connected with cross bracing unit II respectively by connecting box, connecting box, cross bracing unit I and cross bracing unit II jointly constitute horizontal straight bar, the end of cross bracing unit is welded connection steel plate, connection steel plate is connected with lining connection steel plate by bolt, connecting box includes connecting box body, connecting box bottom plate and push plate, spring is assembled in the slot hole opened in connecting box body, and one end of spring is fixedly connected with connecting box bottom plate;The modular structure design of the temporary cross bracing, it is convenient to manufacture, simple to use, in low, middle stress tunnel, if temporary cross bracing is not needed to release displacement, then when temporary cross bracing is applied, it can be degraded to ordinary temporary cross bracing by inserting resistance plate, it is favorable to construction, reduce cost.

Description

Technical Field

[0001] This invention relates to the field of tunnel support construction technology, specifically to a temporary tunnel cross brace adaptable to different ground stress fields and its usage method. Background Technology

[0002] Currently, with the development of infrastructure and terrain constraints in my country, tunnel engineering is constantly developing towards large-section and deep-buried tunnels. In the construction of deep-buried or large-section tunnels in layered surrounding rock, large compression deformation often occurs due to factors such as high ground stress, bias pressure generated by layered surrounding rock, and failure of the invert arch to be closed into a ring in time. In order to prevent the occurrence of large compression deformation, temporary cross bracing is widely used.

[0003] However, the characteristics of temporary cross bracing in tunnels are too simplistic; it relies solely on its own rigidity to provide strong support and reaction force, effectively preventing deformation of the surrounding rock and support in tunnels with low to medium stress fields. But for tunnels with high stress fields, premature installation of temporary cross bracing can lead to insufficient stress release in the surrounding rock, causing damage to the support and temporary cross bracing; application too late will render the temporary cross bracing ineffective in preventing large deformations. Therefore, to utilize current temporary cross bracing in high stress tunnels, the timing of its application must first be determined, but this is extremely difficult. Furthermore, the stress field of a tunnel typically varies greatly, and selecting multiple types of temporary cross bracing to adapt to different stress fields would be detrimental to construction convenience and economy. Therefore, there is an urgent need for a tunnel temporary cross bracing system that can adapt to different stress fields. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings of existing technologies and provide a temporary tunnel cross brace and its usage method that can adapt to different stress fields. It is not limited by the size of the tunnel stress field and can adapt to tunnels with low, medium and high stress fields. In high stress fields, there is no need to consider the construction time of the temporary cross brace. It can release a certain amount of displacement while providing a large counter-support force, and the amount of displacement release can be freely controlled. In low and medium stress fields, it can degenerate into a conventional temporary support, which does not allow the release of displacement but directly provides a strong support reaction force. It is also easy to operate and can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a temporary tunnel cross brace adaptable to different ground stress fields and its usage method, comprising a cross brace unit I, a cross brace unit II, and a connecting box. Both the cross brace unit I and the cross brace unit II are I-beams. Two cross brace units II are provided. The two ends of the cross brace unit I are respectively connected to the cross brace unit II through the connecting box. The connecting box, the cross brace unit I, and the cross brace unit II together form a horizontal straight bar. The end of the cross brace unit II is welded with a connecting steel plate III. The connecting steel plate III is bolted to a lining connecting steel plate. The connecting box includes a connecting box body, a connecting box body bottom plate, and a push plate. A spring is installed in a slot in the connecting box body. One end of the spring is fixedly connected to the connecting box body bottom plate, and the other end is fixedly connected to the push plate. A rectangular through hole is provided on the push plate. The push plate can move freely with the spring in the slot of the connecting box body. Rectangular holes are provided on the upper and lower sides of the connecting box body along the length direction. The length and width of the rectangular holes are the same as the rectangular through holes of the push plate.

[0006] Furthermore, the connecting box is the outer shell of the connecting box, which is made of steel and has a wall thickness of 2-8cm.

[0007] Furthermore, a resistance plate is inserted into the rectangular through hole of the push plate. The resistance plate is a rectangular steel plate. The resistance plate is inserted into the rectangular through hole of the push plate from the rectangular holes on both sides of the connecting box. The length of the resistance plate is 10cm longer than the thickness of the connecting box. A bolt is installed at each end of the resistance plate to fix the resistance plate to both sides of the connecting box.

[0008] Furthermore, a connecting steel plate II is welded to the other end of the cross brace unit II, and the connecting steel plate II is connected to the push plate of the connecting box by bolts.

[0009] Furthermore, connecting steel plates I are welded to both ends of the cross brace unit I, and the connecting steel plates I are connected to the bottom plate of the connecting box by bolts.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] A certain amount of displacement can be released through the spring in the connecting box, and a certain reaction force is provided during the release of displacement, so that the temporary cross brace can adapt well to the high ground stress tunnel without considering the construction time of the temporary cross brace.

[0012] Furthermore, the amount of displacement released can be controlled at will by adding a resistance plate, without having to stop releasing only when the displacement of the spring reaches its range, so that the tunnel support will not be damaged by large deformation.

[0013] The modular structural design of this temporary cross brace is easy to manufacture and use. In low- and medium-stress tunnels, if it is not necessary to release displacement with the temporary cross brace, it can be degenerated into a regular temporary cross brace by inserting a resistance plate after the temporary cross brace is applied, which is beneficial to construction and reduces costs. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention;

[0015] Figure 2 This is a front view structural diagram of the connecting box of the present invention;

[0016] Figure 3 This is a top view of the connecting box structure of the present invention;

[0017] Figure 4 This is an enlarged structural diagram of point A in the present invention;

[0018] Figure 5 This is a schematic diagram of the left-side structure at point A of the present invention;

[0019] Figure 6 This is an enlarged structural diagram of section B of the present invention;

[0020] Figure 7 This is a schematic diagram of the right-side structure at point B of the present invention;

[0021] Figure 8 This is an enlarged structural diagram of point C in the present invention;

[0022] Figure 9 This is a schematic diagram of the right-side structure at point C of the present invention;

[0023] Figure 10 This is a schematic diagram of the structure in use of the present invention.

[0024] In the figure: 1 Horizontal brace unit I, 2 Horizontal brace unit II, 3 Connecting box, 4 Connecting box body, 5 Spring, 6 Push plate, 7 Connecting box body bottom plate, 8 Rectangular hole, 9 Resistance plate, 10 Bolt, 11 Bolt hole, 12 Connecting steel plate I, 13 Connecting steel plate II, 14 Lining connecting steel plate, 15 Connecting steel plate III, 16 Push plate rectangular through hole. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Please see Figure 1-10This invention provides a technical solution: a temporary tunnel cross brace adaptable to different ground stress fields and its usage method, comprising a cross brace unit I1, a cross brace unit II2, and a connecting box 3. Both cross brace units I1 and II2 are I-beams. Two cross brace units II2 are configured. The two ends of cross brace unit I1 are respectively connected to cross brace unit II2 via the connecting box 3. The connecting box 3, cross brace unit I1, and cross brace unit II2 together form a horizontal straight bar. A connecting steel plate III15 is welded to the end of cross brace unit II2. The connecting steel plate III15 is connected to a lining connecting steel plate 14 by bolts 10. The connecting box 3 includes a connecting box body 4, a connecting box body bottom plate 7, and a push plate 6. The connecting box body bottom plate 7 is welded to the connecting box body 4. On the side, a connecting steel plate II13 is welded to the other end of the cross brace unit II2. The connecting steel plate II13 is connected to the push plate 6 of the connecting box 3 by bolts 10. A spring 5 is installed in the slot in the connecting box 4. One end of the spring 5 is fixedly connected to the bottom plate 7 of the connecting box, and the other end is fixedly connected to the push plate 6. A rectangular through hole 16 is provided on the push plate 6. The push plate 6 can move freely with the spring 5 in the slot of the connecting box 4. Rectangular holes 8 are provided on the upper and lower sides of the connecting box 4 along the length direction. The length and width of the rectangular holes 8 are the same as the rectangular through holes 16 of the push plate. A connecting steel plate I12 is welded to both ends of the cross brace unit I1. The connecting steel plate I12 is connected to the bottom plate 7 of the connecting box by bolts 10.

[0027] The connecting box 4 is the outer shell of the connecting box 3. It is made of steel and has a wall thickness of 2-8cm.

[0028] A resistance plate 9 is inserted into the rectangular through hole 16 of the push plate. The resistance plate 9 is a rectangular steel plate. The resistance plate 9 is inserted into the rectangular through hole 16 of the push plate through the rectangular holes 8 on both sides of the connecting box 4. The length of the resistance plate 9 is 10cm longer than the thickness of the connecting box 4. A bolt 10 is installed at each end of the resistance plate 9 to fix the resistance plate 9 to both sides of the connecting box 4.

[0029] The method for using temporary cross bracing in high-stress tunnel construction includes the following steps:

[0030] Step 1: Determine the lengths of cross bracing unit I1 and cross bracing unit II2 according to the tunnel cross-section span. Weld both ends of cross bracing unit I1 to connecting steel plate I12 respectively. Connect one end of cross bracing unit II2 to steel plate III15 and weld the other end to connecting steel plate II13.

[0031] Step 2: Connect the connecting steel plate Ⅲ15 at one end of the cross bracing unit Ⅱ2 to the lining connecting steel plate 14 using bolts 10, and connect the connecting steel plate Ⅱ13 at the other end to the push plate 6 using bolts 10.

[0032] Step 3: Connect the bottom plate 7 of the connecting box to the connecting steel plate I12 of the cross brace unit I1 using bolts 10.

[0033] Step 4: Based on actual needs and site conditions, determine whether it is necessary to insert the resistance plate 9 and the location of insertion. If it is not necessary to insert the resistance plate 9, the installation is complete.

[0034] Step 5: If it is necessary to insert the resistance plate 9, insert the resistance plate 9 at the position where the rectangular through hole 16 of the push plate is completely aligned with the rectangular holes 8 on both sides of the connecting box 4. Then install bolts 10 at both ends of the resistance plate 9 and tighten them to complete the installation.

[0035] The method for using temporary cross bracing in low- and medium-stress tunnel construction includes the following steps:

[0036] Step 1: Determine the lengths of cross bracing unit I1 and cross bracing unit II2 according to the tunnel cross-section span. Weld both ends of cross bracing unit I1 to connecting steel plate I12 respectively. Connect one end of cross bracing unit II2 to steel plate III15 and weld the other end to connecting steel plate II13.

[0037] Step 2: Connect the connecting steel plate Ⅲ15 at one end of the cross bracing unit Ⅱ2 to the lining connecting steel plate 14 using bolts 10, and connect the connecting steel plate Ⅱ13 at the other end to the push plate 6 using bolts 10.

[0038] Step 3: Connect the bottom plate 7 of the connecting box to the connecting steel plate I12 of the cross brace unit I1 using bolts 10.

[0039] Step 4: Adjust the position of the rectangular through hole 16 of the push plate and the rectangular holes 8 on both sides of the connecting box 4 so that they are completely aligned. Then, insert the resistance plate 9 into the rectangular through hole 16 of the push plate and the rectangular holes 8 of the connecting box 4. Finally, install bolts 10 at both ends of the resistance plate 9 and tighten them to complete the installation.

[0040] The principle of this invention is as follows: by adding two connecting boxes 3 to the cross bracing unit, the connecting box 3 is a hollow structure with a slot at one end. A compressible spring 5 of a certain rigidity is installed inside the connecting box 3. One end of the spring 5 is fixedly connected to the bottom plate 7 of the connecting box, and the other end is fixedly connected to the push plate 6. When the tunnel construction begins, the temporary cross bracing is immediately installed. The cross bracing unit first transmits the force to the push plate 6. The push plate 6 is compressed by the spring 5, causing the spring 5 to deform on one side and provide a certain amount of reaction force to the push plate 6 on the other side. This allows the cross bracing to deform on one side while providing a certain amount of resistance, preventing the support and temporary cross bracing from... It can withstand greater stress and fail, and there is no need to consider the optimal construction time of temporary cross bracing; when the spring 5 deforms to a certain extent and no longer needs to release displacement or no displacement release is needed from the beginning, by adjusting the push plate 6 to align the push plate rectangular through hole 16 in the middle with the rectangular holes 8 on both sides of the connecting box 3, the resistance plate 9 is inserted into the push plate 6 and the bolts 10 on both sides of the resistance plate 9 are tightened. At this time, the spring 5 will no longer bear pressure, and the force on the connecting box 3 will be changed from the spring 5 to the force on the side wall plate of the connecting box 3, thereby causing the cross bracing to degenerate into ordinary horizontal cross bracing and ensuring that the support will not undergo large deformation and fail.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A temporary cross brace of a tunnel capable of adapting to different stress fields, comprising a cross brace unit I (1), a cross brace unit II (2) and a connecting box (3), characterized in that: The cross support unit I (1) and the cross support unit II (2) are both I-shaped steel, the cross support unit II (2) is provided as two, the two ends of the cross support unit I (1) are connected with the cross support unit II (2) through the connecting box (3) respectively, the connecting box (3), the cross support unit I (1) and the cross support unit II (2) jointly constitute a horizontal straight rod, the end of the cross support unit II (2) is welded with a connecting steel plate III (15), the connecting steel plate III (15) is connected with a lining connecting steel plate (14) through a bolt (10), the connecting box (3) comprises a connecting box body (4), a connecting box body bottom plate (7) and a push plate (6), a spring (5) is assembled in a slot hole provided in the connecting box body (4), one end of the spring (5) is fixedly connected with the connecting box body bottom plate (7), the other end is fixedly connected with the push plate (6), a rectangular through hole (16) is provided on the push plate (6), the push plate (6) can freely move in the slot hole of the connecting box body (4) along with the spring (5), rectangular holes (8) are provided on the upper and lower sides of the connecting box body (4) along the length direction, the length and width of the rectangular holes (8) are same as those of the push plate rectangular through hole (16).

2. The temporary cross strut of a tunnel capable of adapting to different stress fields according to claim 1, characterized in that: The connecting box body (4) is the shell of the connecting box (3) and is made of steel material, and the wall thickness is 2-8 cm.

3. The temporary cross strut of a tunnel capable of adapting to different stress fields according to claim 1, characterized in that: A resistance plate (9) is inserted into the push plate rectangular through hole (16), the resistance plate (9) is a rectangular steel plate, the resistance plate (9) is inserted into the push plate rectangular through hole (16) from the rectangular holes (8) on the two sides of the connecting box body (4), the length of the resistance plate (9) is 10 cm longer than the thickness of the connecting box body (4), and one bolt (10) is arranged at each end of the resistance plate (9) to fix the resistance plate (9) on the two sides of the connecting box body (4).

4. The temporary cross strut of a tunnel capable of adapting to different stress fields according to claim 1, characterized in that: The other end of the cross support unit II (2) is welded with a connecting steel plate II (13), and the connecting steel plate II (13) is connected with the push plate (6) of the connecting box (3) through a bolt (10).

5. The temporary cross strut of a tunnel capable of adapting to different stress fields according to claim 1, characterized in that: The two ends of the cross support unit I (1) are welded with connecting steel plates I (12), and the connecting steel plates I (12) are connected with the connecting box body bottom plate (7) through bolts (10).

6. The method of using a temporary tunnel strut that can adapt to different stress fields according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step one, according to the cross section span of the tunnel, the lengths of the cross support unit I (1) and the cross support unit II (2) are determined, the two ends of the cross support unit I (1) are welded with the connecting steel plates I (12) respectively, the one end of the cross support unit II (2) is connected with the connecting steel plate III (15), and the other end is welded with the connecting steel plate II (13); Step two, the connecting steel plate III (15) at the one end of the cross support unit II (2) is connected with the lining connecting steel plate (14) through a bolt (10), and the connecting steel plate II (13) at the other end is connected with the push plate (6) through a bolt (10); Step three, the connecting box body bottom plate (7) is connected with the connecting steel plates I (12) of the cross support unit I (1) through bolts (10); Step four, according to actual requirements and actual conditions on site, it is determined whether the resistance plate (9) needs to be inserted and the position of the resistance plate (9) to be inserted, if the resistance plate (9) does not need to be inserted, the installation is completed. Step five, if the resistance plate (9) is needed to be inserted, insert the resistance plate (9) at the position where the rectangular through hole (16) of the push plate and the rectangular hole (8) on both sides of the connecting box (4) are completely aligned, then install the bolts (10) at both ends of the resistance plate (9) and tighten them, and the installation is completed.

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