Tunnel excavation support structure

Abstract

The present application relates to tunnel excavation technology, and discloses a tunnel excavation support structure, including a steel arch frame and a support part for supporting both ends of the steel arch frame; the support part includes a base and a support plate arranged at the lower end of the steel arch frame, a connecting piece is arranged between the base and the support plate, and the distance between the support plate and the surface of the base can be adjusted by the connecting piece; an extension plate extending upward is arranged on the base, and two auxiliary support assemblies are arranged on the extension plate, and the lower end of the steel arch frame is located between the two auxiliary support assemblies and supported by the auxiliary support assemblies. The present application can facilitate the height adjustment of the lower end of the steel arch frame.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel excavation, and in particular to a tunnel excavation support structure. Background Art

[0002] Tunnel excavation is a commonly used technical means in modern tunnel construction, and it is widely used in transportation, water conservancy and other fields. With the rapid development of my country's economy, the number of tunnel projects is increasing, and tunnel excavation and support technology is one of the key factors to ensure the quality and safety of tunnel construction, and has an important impact on improving the reliability and construction efficiency of tunnel projects. Therefore, research and improvement of tunnel excavation and support technology is of great significance to the development of the tunnel construction industry.

[0003] At present, in order to ensure the stability and construction safety of the tunnel during tunnel excavation, steel arches are often used for support. When installing the steel arch, a column foot platform or a concrete pad is usually set in the tunnel to provide a support position for the lower end of the steel arch.

[0004] During installation, the steel arch frame usually needs to be kept perpendicular to the centerline of the tunnel to improve the stability of the structure. Since the height of the tunnel ground may deviate, the height of the concrete pad needs to be adjusted to adjust the steel arch frame to a position perpendicular to the centerline of the tunnel. Therefore, in the current construction, more pads of different thicknesses are prefabricated to meet actual needs. However, even if pads of different thicknesses are combined, there may still be a certain deviation, and the concrete pads need to be cut on site. The above technical means have the problem of cumbersome operation and less than ideal adjustment effect on the steel arch frame. Summary of the invention

[0005] In order to adjust the steel arch frame, the present application provides a tunnel excavation support structure.

[0006] This application adopts the following technical solutions:

[0007] A tunnel excavation support structure, comprising a steel arch frame and a support portion for supporting both ends of the steel arch frame; the support portion comprises a base and a support plate arranged at the lower end of the steel arch frame, a connecting piece is arranged between the base and the support plate, and the distance between the support plate and the surface of the base can be adjusted by the connecting piece; an extension plate extending upward is arranged on the base, two auxiliary support assemblies are arranged on the extension plate, and the lower end of the steel arch frame is located between the two auxiliary support assemblies and supported by the auxiliary support assemblies;

[0008] The auxiliary support assembly includes a positioning column fixed on the extension plate and a support column slidably mounted on the outer wall of the positioning column, and a limiting structure is arranged between the support column and the positioning column to limit the rotation of the support column on the outer wall of the positioning column; a horizontal rod is arranged on the side wall of the steel arch frame, and an arc block is arranged on the outer wall of the support column, and the arc block can abut against the lower surface of the horizontal rod.

[0009] By adopting the above technical solution, when installing the steel arch frame, it is first hoisted to the predetermined position through the steel arch frame installation platform, and then the support column is rotated so that the side wall of the arc block abuts against the side wall of the horizontal rod and supports the horizontal rod. When the steel arch frame is adjusted to the ideal position, the support column is inserted into the positioning column so that the support column can no longer rotate, thereby allowing the support column to pre-support the steel arch frame; then the support plate and the base are connected together through the connecting piece, so that the steel arch frame and the supporting part are connected; through the cooperation of the auxiliary support member and the connecting member, the height of the lower end of the steel arch frame can be conveniently adjusted to a suitable position.

[0010] Optionally, an insertion groove for plugging the positioning column is formed at one end of the support column close to the positioning column, and the limiting structure includes a first limiting strip arranged on the side wall of the positioning column and a second limiting strip arranged on the inner wall of the insertion groove, and a plurality of first limiting strips are evenly arranged along the circumference of the side wall of the positioning column, and a space for plugging the second limiting strips is formed between adjacent first limiting strips.

[0011] By adopting the above technical solution, under the action of the first limiting strip and the second limiting strip, the support column cannot rotate on the outer wall of the positioning column, so that the arc block can support the horizontal rod.

[0012] Optionally, a connecting column is hinged on the positioning column, and the connecting column can move in a horizontal direction on the positioning column. One end of the connecting column extends into the plug-in slot and is slidably connected to the support column. When the support column and the positioning column are separated, the support column can rotate synchronously with the positioning column. When the support column is connected to the positioning column, the connecting column is accommodated in the plug-in slot.

[0013] By adopting the above technical solution, the connecting column is hinged on the positioning column, and the connecting column is located in the plug-in groove. When the supporting column supports the horizontal rod, the connecting column can improve the stability of the supporting column; and the supporting column can rotate synchronously with the connecting column, and the two supporting columns rotate to positions away from each other, so that the steel arch frame is easier to lift to the space between the two supporting columns, and then the supporting column is turned out and the position of the arc block is adjusted.

[0014] Optionally, the connecting member includes an adjusting column threadedly connected to the support plate, and a locking bolt slidably passed through the support plate and threadedly connected to the base, the base is provided with a positioning groove for the adjusting column to be inserted, and the base is provided with a threaded hole for the locking bolt to be threadedly connected; a positioning member is provided on the base, and when the locking bolt is connected to the threaded hole, the positioning member can be connected to the adjusting column to limit the adjusting column from sliding out of the positioning groove.

[0015] By adopting the above technical solution, the position of the adjusting column is adjusted so that the adjusting column is inserted into the positioning groove, so that the adjusting column can support the steel arch frame, and the locking bolt is then threaded into the threaded hole, thereby connecting the support plate and the base together, thereby improving the pull-out resistance of the support plate and the base; under the action of the positioning piece, the adjusting column is not easy to fall out of the positioning groove.

[0016] Optionally, a mounting hole is provided on the inner wall of the threaded hole, and the mounting hole passes through the adjacent positioning slot, and the positioning member includes a limiting rod slidably connected to the mounting hole and an elastic member arranged between the limiting rod and the inner wall of the mounting hole; a limiting slot is provided on the side wall of the adjusting column along the circumferential direction, and when the locking bolt is connected to the threaded hole, the limiting rod can be driven to slide into the positioning slot and be inserted into the limiting slot, and the elastic member provides a force for the limiting rod to slide out of the limiting slot.

[0017] By adopting the above technical solution, when the locking bolt is threadedly connected in the threaded hole, it can drive the limit rod to slide, and the end of the limit rod is inserted into the limit groove. Under the action of the limit rod, the adjustment column can be limited from detaching from the positioning groove, thereby improving the stability of the connection between the support plate and the base.

[0018] Optionally, a ring is provided on the outer wall of the support column, an extension column extending in the radial direction of the ring is provided on the side wall of the ring, and a threaded barrel is provided on the outer wall of the extension column, an abutment portion is provided at one end of the threaded barrel away from the ring, and the abutment portion abuts against the surface of the support plate.

[0019] By adopting the above technical solution, the support column is supported by the abutting portion, thereby further improving the stability of the support column and improving the supporting effect.

[0020] Optionally, a seating groove is provided on the upper surface of the support plate, and a through hole is provided on the side wall of the seating groove; the seating groove corresponds to the locking bolt; a reinforcement rod is slidably arranged in the through hole, and a second elastic member is arranged between the reinforcement rod and the side wall of the through hole, the abutment portion includes a rotating plate rotatably arranged at the end of the threaded cylinder and an insertion rod fixed at both ends of the rotating plate, and an annular groove is provided on the side wall of the locking bolt, the insertion rod can be inserted into the seating groove and drive the reinforcement rod to be inserted into the annular groove.

[0021] By adopting the above technical solution, when the insertion rod is inserted into the positioning groove, the insertion rod is inserted into the annular groove of the locking bolt, thereby connecting the locking bolt and the support plate together, thereby further improving the stability of the connection between the support plate and the base.

[0022] Optionally, the ring slides to a position where the first tooth and the second tooth are meshed, so that the ring cannot rotate. When the arc block supports the horizontal rod, the support column has a tendency to rotate. Therefore, under the action of the ring, the stability of the support column can be improved.

[0023] By adopting the above technical solution, the inner wall of the ring is evenly provided with first teeth, the outer wall of the support column is evenly provided with second teeth along the circumferential direction, the ring can be sleeved at the position of the second teeth, and the first teeth and the second teeth are meshed.

[0024] Optionally, a side wall of the connecting column is provided with a clearance groove, and an inner wall of the plug-in slot is provided with a limiting column, and the limiting column extends into the clearance groove.

[0025] By adopting the above technical solution, under the action of the limiting column, the supporting column is not easy to slide out from the connecting column, and is not easy to separate during normal storage and transportation, and can be used directly during construction.

[0026] Optionally, a through rod is passed through the support column, and the through rod passes through the support column, the connecting column, the positioning column and the extension plate at the same time, and is inserted into the side wall of the tunnel. One end of the through rod has a portion that exceeds the end of the support column, and a cross bar is connected between two adjacent through rods. The cross bar is threadedly connected to a positioning rod that is inserted into the side wall of the steel arch frame.

[0027] By adopting the above technical solution, the through rod is passed through the support column and the extension plate and inserted into the inner wall of the tunnel, thereby further improving the stability of the support column, and the positioning rod on the cross bar is inserted into the side wall of the steel arch frame, thereby connecting the steel arch frame and the support column more stably.

[0028] In summary, the present application includes at least one of the following beneficial effects:

[0029] 1. By rotating the support column, the contact position between the arc block and the horizontal rod is adjusted, so that the horizontal rod can be supported, so that the position of the steel arch frame can be adaptively adjusted, and then the base and the support plate are connected together through the connecting piece, and the distance between the base and the support plate can also be adjusted through the connecting piece, so as to adapt to the adjustment of the position of the steel arch frame;

[0030] 2. When the locking bolt is connected to the threaded hole, the positioning piece can position the adjusting column; when the insertion rod is inserted into the positioning groove, the reinforcement rod can be inserted into the ring groove, thereby positioning the locking bolt. The synergistic effect of the two further improves the stability of the connection between the support plate and the base, improves the supporting effect on the steel arch frame, and also improves the pull-out resistance between the steel arch frame and the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of an embodiment of the present application;

[0032] Figure 2 is a schematic diagram of a support portion in an embodiment of the present application;

[0033] Figure 3 is a schematic diagram of an auxiliary support assembly in an embodiment of the present application;

[0034] Figure 4 This is a schematic diagram of the explosion of the support column in the embodiment of the present application;

[0035] Figure 5 is a cross-sectional schematic diagram of a support column in an embodiment of the present application;

[0036] Figure 6 is a schematic cross-sectional view of the base in the embodiment of the present application;

[0037] Figure 7 yes Figure 6 Enlarged schematic diagram at point A in the middle.

[0038] Description of the accompanying drawings: 1. steel arch frame; 2. support part; 201. base; 202. support plate; 3. extension plate; 4. connecting piece; 41. adjustment column; 42. locking bolt; 5. auxiliary support assembly; 51. positioning column; 52. support column; 61. first limit bar; 62. second limit bar; 7. horizontal rod; 8. arc block; 9. plug-in groove; 10. connecting column; 11. positioning groove; 12. threaded hole; 13. round hole; 14. positioning piece; 1 41. Limit rod; 142. First elastic member; 15. Mounting hole; 16. Limit groove; 17. Ring; 18. Extension column; 19. Threaded tube; 20. Positioning groove; 21. Abutment portion; 211. Turn plate; 212. Insert rod; 22. Through hole; 23. Reinforcement rod; 24. Second elastic member; 25. Ring groove; 26. First tooth; 27. Second tooth; 28. Make way groove; 29. ​​Limit column; 30. Through rod; 31. Cross bar; 32. Positioning rod. DETAILED DESCRIPTION

[0039] The following is combined with Figure 1-7 This application is described in further detail.

[0040] The present application embodiment discloses a tunnel excavation support structure. Figure 1 The tunnel excavation support structure includes a steel arch frame 1 and a support portion 2 for supporting the two lower ends of the steel arch frame 1. The connection position between the support portion 2 and the lower end of the steel arch frame 1 can be adjusted in the vertical direction to facilitate the adjustment of the vertical height position of the steel arch frame 1. After the tunnel is excavated and supported, multiple steel arch frames 1 are arranged at intervals, and connecting bars are fixed between adjacent steel arch frames 1. The installation spacing of the steel arch frames is determined according to the stability of the surrounding rock after the tunnel excavation. And the steel arch frames should be erected in time after excavation or initial concrete spraying. After multiple steel arch frames 1 are installed, each steel arch frame support should be kept on the same plane and orthogonal to the tunnel axis.

[0041] The steel arch frame in this application is composed of multiple I-beams, which are bent at corresponding angles according to the size of the excavated tunnel and then spliced. When the tunnel width is between 2.5m-3m, the I-beam model is 14#, the diameter of the longitudinal connecting ribs is selected from Φ20mm, and the butt-connected steel plate (thickness×length×width) is 10mm×120mm×100mm; when the tunnel width is between 3m-4m, the I-beam model is 16#, the diameter of the longitudinal connecting ribs is selected from Φ20mm, and the butt-connected steel plate (thickness×length×width) is 10mm×140mm×120mm; when the tunnel width is between 4m-5m, the I-beam model is 18#, the diameter of the longitudinal connecting ribs is selected from Φ20mm, and the butt-connected steel plate (thickness×length×width) is 10mm×160mm×140mm.

[0042] Before installing the support, the waste and debris on the ground should be cleared and the support should be placed on a complete rock surface. Figure 1 and Figure 2 The support part 2 includes a support plate 202 fixed to the lower end of the steel arch frame 1 and a base 201 fixed to the ground of the tunnel. The base 201 can be fixed to the ground by bolts, casting, etc. The base 201 is prefabricated in the workshop, and the thickness and height are not less than 200mm. A connector 4 is installed between the base 201 and the support plate 202, and the support plate 202 can be supported by the connector 4. An extension plate 3 is fixed on the side of the base 201 close to the inner wall of the tunnel. The extension plate 3 extends vertically upward. Two auxiliary support components 5 are installed on the extension plate 3. When the steel arch frame 1 is installed on the base 201, it is located between the two auxiliary support components 5. During construction, the steel arch frame 1 is connected and installed to a predetermined position through the steel arch frame 1 installation stand, and then the lower end of the steel arch frame 1 is supported by the auxiliary support component 5, so that the height of the two ends of the steel arch frame 1 is at an ideal position, and then the base 201 and the support plate 202 are connected together by the connector 4.

[0043] Reference Figure 3 and Figure 4 The auxiliary support assembly 5 includes a positioning column 51 fixed on the extension plate 3 and a support column 52 installed on the positioning column 51. The support column 52 is slidably mounted on the outer wall of the positioning column 51, and a limiting structure is installed between the support column 52 and the positioning column 51. When the limiting structure rotates, the support column 52 is sleeved on the outer wall of the positioning column 51, which can limit the rotation of the support column 52. The support column 52 is a cylindrical structure, and an arc block 8 is fixed on the outer wall of the support column 52. Figure 2 , the side wall of the steel arch frame 1 is horizontally welded and fixed with a horizontal rod 7, and the horizontal rod 7 is located above the support column 52. By adjusting the position of the support column 52, the arc block 8 can abut against the lower surface of the horizontal rod 7, and the support column 52 is inserted into the positioning column 51, so that the support column 52 cannot rotate. In order to improve the supporting effect of the support column 52 on the arc block 8, two arc blocks 8 are fixed on each support column 52, and two horizontal rods 7 are symmetrically fixed on the side wall of the steel arch frame 1. After the steel arch frame 1 is adjusted to a suitable position, the support column 52 first pre-supports the steel arch frame 1, and then connects the base 201 and the support plate 202 together through the connecting piece 4.

[0044] Reference Figure 4 and Figure 5, an insertion groove 9 is provided at one end of the support column 52 close to the positioning column 51, and the positioning column 51 is inserted into the insertion groove 9. The limiting structure includes a first limiting strip 61 fixed to the outer wall of the positioning column 51 and a second limiting strip 62 fixed to the inner wall of the insertion groove 9. A plurality of first limiting strips 61 are evenly arranged along the circumference of the positioning column 51, and a plurality of second limiting strips 62 are evenly arranged along the circumference of the insertion groove 9. A space for the second limiting strip 62 to be inserted is formed between two adjacent first limiting strips 61. When the positioning column 51 is inserted into the insertion groove 9, the first limiting strip 61 and the second limiting strip 62 cooperate with each other, which can limit the rotation of the support column 52.

[0045] The end of the positioning column 51 away from the extension plate 3 is hinged with a connecting column 10, and the connecting column 10 is rotatably connected to the positioning column 51 by means of a pin shaft, and the connecting column 10 rotates in the horizontal direction. One end of the connecting column 10 is slidably inserted into the plug-in slot 9. When the support column 52 and the positioning column 51 are separated, the support column 52 can be rotated on the positioning column 51. After the steel arch frame 1 is located at the predetermined position, the two support columns 52 are rotated toward each other so that the support columns 52 abut against the side wall of the steel arch frame 1, and the support columns 52 are inserted into the positioning column 51. At this time, the lower end of the steel arch frame 1 is clamped by the two support columns 52, and the verticality of the steel arch frame 1 can be adjusted by installing the stand so that the lower end of the steel arch frame 1 corresponds to the base 201. Then pull the support column 52 out from the positioning column 51 , adjust the position of the arc block 8 so that the arc block 8 can abut against the lower surface of the horizontal rod 7 , and then insert the support column 52 into the positioning column 51 to support the horizontal rod 7 .

[0046] Further, see Figure 4 and Figure 5 In order to prevent the support column 52 from being separated from the connecting column 10, the outer wall of the connecting column 10 is provided with a clearance groove 28, which is arranged along the circumference of the side wall of the connecting column 10. The inner wall of the plug-in slot 9 is fixed with a limiting column 29, which extends in the clearance groove 28. When the support column 52 and the connecting column 10 slide relative to each other, the limiting column 29 moves in the clearance groove 28 and prevents the connecting column 10 from being separated from the plug-in slot 9.

[0047] In a further embodiment, referring to Figure 2 , Figure 6 and Figure 7The connecting member 4 includes an adjusting column 41 threadedly connected to the support plate 202, and a locking bolt 42 that slides through the support plate 202 and is threadedly connected to the base 201. The support plate 202 is provided with a circular hole 13 for the locking bolt 42 to pass through. Two adjusting columns 41 are symmetrically arranged, and a positioning groove 11 is arranged on the upper surface of the base 201. The lower end of the adjusting column 41 is inserted into the positioning groove 11, so that the support plate 202 is supported by the adjusting column 41. Four locking bolts 42 are arranged and are respectively located at the four corners of the support plate 202. The locking bolt 42 is threadedly connected to the threaded hole 12, and the upper end of the locking bolt 42 is pressed against the surface of the support plate 202. Under the action of the locking bolt 42, the pull-out resistance between the support plate 202 and the base 201 is improved. By adjusting the position of the adjusting column 41, the adjusting column 41 can be adapted to different distances between the support plate 202 and the base 201. The threaded hole 12 has a sufficient depth so that the locking bolt 42 can also adapt to different distances between the support plate 202 and the base 201 .

[0048] Reference Figure 6 and Figure 7 In order to improve the stability of the connection between the adjusting column 41 and the base 201, a mounting hole 15 is provided on the inner wall of the threaded hole 12, and the mounting hole 15 passes through the adjacent positioning groove 11. A positioning member 14 is installed in the mounting hole 15, and the positioning member 14 includes a limiting rod 141 that is slidably inserted in the mounting hole 15, and a first elastic member 142 that is sleeved on the outer wall of the limiting rod 141, and the first elastic member 142 is a spring. There is a portion of the expanded hole diameter in the middle position of the mounting hole 15, so as to provide space for the first elastic member 142. In order to facilitate the installation of the limiting rod 141, the base 201 can be connected in a splicing manner. Under the action of the first elastic member 142, one end of the limiting rod 141 extends into the threaded hole 12, and the other end is received in the mounting hole 15. A limiting groove 16 is provided on the side wall of the adjusting column 41, and the limiting groove 16 is arranged along the circumference of the adjusting column 41. When the lower end of the locking bolt 42 is threadedly connected to the threaded hole 12, it can push the limiting rod 141 to slide and be inserted into the limiting groove 16, thereby limiting the adjustment column 41 from being separated from the positioning groove 11. At this time, the first elastic member 142 is in a compressed state.

[0049] In a further embodiment, referring to Figure 5 , Figure 6 and Figure 7In order to improve the supporting effect of the support column 52 on the steel arch frame 1, the outer wall of the support column 52 is slidably sleeved with a collar 17, and the outer wall of the collar 17 is fixed with an extension column 18, and the extension column 18 extends in the radial direction of the support column 52. The outer wall of the extension column 18 is threadedly connected with a threaded barrel 19, and an abutment portion 21 is installed at one end of the threaded barrel 19 away from the collar 17. By adjusting the position of the threaded barrel 19, the abutment portion 21 is pressed against the support plate 202, thereby supporting the support column 52 and reducing the bending of the support column 52. The abutment portion 21 includes a rotating plate 211 rotatably connected to the outer wall of the threaded barrel 19 and an insertion rod 212 fixed to the lower surface of both ends of the rotating plate 211. A landing groove 20 is opened on the upper surface of the support plate 202. The threaded barrel 19 is rotated, and the insertion rod 212 can be inserted into the landing groove 20, thereby supporting the support column 52.

[0050] The side wall of the seating groove 20 is provided with a through hole 22, which passes through to the inner wall of the adjacent circular hole 13. A reinforcing rod 23 is slidably connected in the through hole 22, and a second elastic member 24 is sleeved on the outer wall of the reinforcing rod 23. The second elastic member 24 is a spring, and there is an enlarged diameter portion in the middle of the through hole 22, which is used to provide space for the installation of the second elastic member 24. One end of the spring is connected to the outer wall of the reinforcing rod 23, and the other end is connected to the inner wall of the through hole 22. In the natural state, one end of the reinforcing rod 23 extends into the seating groove 20, and the other end is received in the through hole 22. When the insertion rod 212 is inserted into the seating groove 20, it can drive the end of the reinforcing rod 23 to slide into the circular hole 13, and the second elastic member 24 is compressed. The side wall of the locking bolt 42 is provided with an annular groove 25 at the position of the circular hole 13, and the insertion rod 212 can drive the reinforcement rod 23 to be inserted into the annular groove 25, thereby connecting the locking bolt 42 and the support plate 202 together, further improving the supporting effect of the steel arch frame 1.

[0051] Reference Figure 5 The inner wall of the collar 17 is evenly provided with first teeth 26, and the outer wall of the support column 52 is evenly provided with second teeth 27. When the support column 52 is fixed at a predetermined position, the sliding collar 17 moves the collar 17 to the position of the second teeth 27, and the first teeth 26 and the second teeth 27 are meshed, that is, the collar 17 can no longer rotate, and then the insertion rod 212 is inserted into the positioning groove 20, so that the support column 52 is less likely to rotate.

[0052] Further, refer to Figure 2 and Figure 3, the two support columns 52 are each provided with a through rod 30, which passes through the connecting column 10 and the positioning column 51, and passes through the extension plate 3 and is plugged into the inner wall of the tunnel, thereby further improving the stability of the support column 52. The through rod 30 is selected from the structure of the anchor rod, and the length of the through rod 30 is adjusted according to the width of the tunnel. For example, when the tunnel width is ≥3.5m, the length L of the through rod 30 is 2.5m; when the tunnel width is <3.5m, the length L of the through rod 30 is 2.0m. And the two through rods 30 extend out of one end of the support column 52, and are fixed with a cross bar 31. The positioning rod 32 is threadedly connected to the cross bar 31, and the positioning rod 32 is plugged into the side wall of the steel arch frame 1, thereby further connecting the steel arch frame 1 and the support column 52 together.

[0053] The principle of a tunnel excavation support structure in an embodiment of the present application is described as follows: The technical requirements of the present application are suitable for the large water network projects in our province, where the diameter (or width) of the tunnel is 2.5m-5.0m and the pressure-free water supply tunnel is located in Class V surrounding rock. The primary support after excavation needs to adopt the rock tunnel section and the soil tunnel section supported by mesh spraying and steel arch frame; the use of steel arch frame support for other types of surrounding rock should be used with caution according to the actual geological conditions on site.

[0054] The steel arch frame 1 is installed by means of an installation stand, and is clamped and adjusted to a vertical state by means of two support columns 52, so that the support plate 202 and the base 201 correspond to each other, and then the position of the support column 52 is adjusted so that the arc block 8 abuts against the lower end of the horizontal rod 7 to support the steel arch frame 1. The support plate 202 and the base 201 are then connected together by means of a connector 4, so that the base 201 and the support column 52 can support the steel arch frame 1 synchronously. It is required that the rock mass where the steel arch frame is to be laid should be excavated strictly according to the contour line required by the design, and the steel arch frame should be installed close to the excavation surface along the actual excavation contour line, that is, in close contact with the wall surface of the cave, and the part with a larger gap should be supported on the rock surface with Φ25 steel bars or steel sections, and then concrete should be sprayed or poured in batches until it is filled up. After the steel arch frame of this application is installed, the steel mesh should be laid immediately and concrete should be sprayed, and the thickness of the sprayed concrete is 120mm. The steel arch frame must be covered with sprayed concrete and must not be exposed.

[0055] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A tunnel excavation support structure, comprising a steel arch frame (1) and a support portion (2) for supporting both ends of the steel arch frame (1); the support portion (2) comprises a base (201) and a support plate (202) arranged at the lower end of the steel arch frame (1), a connecting member (4) is arranged between the base (201) and the support plate (202), and the distance between the support plate (202) and the surface of the base (201) can be adjusted by the connecting member (4); an extension plate (3) extending upward is arranged on the base (201), two auxiliary support assemblies (5) are arranged on the extension plate (3), and the lower end of the steel arch frame (1) is located between the two auxiliary support assemblies (5) and is supported by the auxiliary support assemblies (5); The auxiliary support assembly (5) comprises a positioning column (51) fixed on the extension plate (3) and a support column (52) slidably mounted on the outer wall of the positioning column (51), and a limiting structure is arranged between the support column (52) and the positioning column (51) to limit the rotation of the support column (52) on the outer wall of the positioning column (51); a horizontal rod (7) is arranged on the side wall of the steel arch frame (1), and an arc block (8) is arranged on the outer wall of the support column (52), and the arc block (8) can abut against the lower surface of the horizontal rod (7); An insertion groove (9) for inserting the positioning column (51) is formed at one end of the support column (52) close to the positioning column (51); the limiting structure comprises a first limiting strip (61) arranged on the side wall of the positioning column (51) and a second limiting strip (62) arranged on the inner wall of the insertion groove (9); a plurality of the first limiting strips (61) are evenly arranged along the circumference of the side wall of the positioning column (51), and a space for inserting the second limiting strips (62) is formed between adjacent first limiting strips (61); A connecting column (10) is hinged on the positioning column (51), and the connecting column (10) can move on the positioning column (51) in a horizontal direction. One end of the connecting column (10) extends into the plug-in slot (9) and is slidably connected to the support column (52). When the support column (52) and the positioning column (51) are separated, the support column (52) can rotate on the positioning column (51) in a horizontal direction. When the support column (52) is connected to the positioning column (51), the connecting column (10) is accommodated in the plug-in slot (9).

2. A tunnel excavation support structure according to claim 1, characterized in that: The connecting member (4) comprises an adjusting column (41) threadedly connected to the supporting plate (202), and a locking bolt (42) slidably passing through the supporting plate (202) and threadedly connected to the base (201); the base (201) is provided with a positioning groove (11) for the adjusting column (41) to be inserted, and the base (201) is provided with a threaded hole (12) for the locking bolt (42) to be threadedly connected; a positioning member (14) is provided on the base (201); when the locking bolt (42) is connected to the threaded hole (12), the positioning member (14) can be connected to the adjusting column (41) to prevent the adjusting column (41) from sliding out of the positioning groove (11).

3. A tunnel excavation support structure according to claim 2, characterized in that: The inner wall of the threaded hole (12) is provided with a mounting hole (15), and the mounting hole (15) passes through the adjacent positioning slot (11); the positioning member (14) comprises a limiting rod (141) slidably connected to the mounting hole (15) and a first elastic member (142) arranged between the limiting rod (141) and the inner wall of the mounting hole (15); a limiting slot (16) is arranged on the side wall of the adjustment column (41) along the circumferential direction; when the locking bolt (42) is connected to the threaded hole (12), the limiting rod (141) can be driven to slide into the positioning slot (11) and be inserted into the limiting slot (16); the first elastic member (142) provides a force for the limiting rod (141) to slide out of the limiting slot (16).

4. A tunnel excavation support structure according to claim 3, characterized in that: The outer wall of the support column (52) is sleeved with a collar (17), the side wall of the collar (17) is provided with an extension column (18) extending in the radial direction of the collar (17), and the outer wall of the extension column (18) is provided with a threaded barrel (19), and an abutment portion (21) is provided at one end of the threaded barrel (19) away from the collar (17), and the abutment portion (21) abuts against the surface of the support plate (202).

5. A tunnel excavation support structure according to claim 4, characterized in that: The upper surface of the support plate (202) is provided with a seating groove (20), and the side wall of the seating groove (20) is provided with a through hole (22); the seating groove (20) corresponds to the locking bolt (42); a reinforcing rod (23) is slidably arranged in the through hole (22), and a second elastic member (24) is arranged between the reinforcing rod (23) and the side wall of the through hole (22); the abutment portion (21) comprises a rotating plate (211) rotatably arranged at the end of the threaded cylinder (19) and an insertion rod (212) fixed at both ends of the rotating plate (211); the side wall of the locking bolt (42) is provided with an annular groove (25); the insertion rod (212) can be inserted into the seating groove (20) and drive the reinforcing rod (23) to be inserted into the annular groove (25).

6. A tunnel excavation support structure according to claim 5, characterized in that: The inner wall of the collar (17) is evenly provided with first teeth (26), and the outer wall of the support column (52) is evenly provided with second teeth (27) along the circumferential direction; the collar (17) can be sleeved at the position of the second teeth (27), and the first teeth (26) and the second teeth (27) are meshed.

7. A tunnel excavation support structure according to claim 6, characterized in that: The side wall of the connecting column (10) is provided with a clearance groove (28), and the inner wall of the plug-in slot (9) is provided with a limiting column (29), and the limiting column (29) extends into the clearance groove (28).

8. A tunnel excavation support structure according to claim 7, characterized in that: A through rod (30) is inserted into the support column (52), and the through rod (30) simultaneously passes through the support column (52), the connecting column (10), the positioning column (51) and the extension plate (3), and is inserted into the side wall of the tunnel. One end of the through rod (30) has a portion that exceeds the end of the support column (52), and a cross rod (31) is connected between two adjacent through rods (30). The cross rod (31) is threadedly connected to a positioning rod (32) inserted into the side wall of the steel arch frame (1).

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