Multi-layer primary support arch frame for large-span tunnel double-side-wall pilot tunnel method construction

Abstract

The utility model relates to the technical field of underground tunnels, in particular to a multi-layer primary support arch frame for large-span tunnel double-side-wall pilot tunnel method construction, and aims to solve the problem that in the prior art, a temporary side support and a side arch are directly connected in a welded mode, so that the strength of a connecting point is not high. A second connecting plate is arranged on the side wall of the inner side of the first-layer steel arch, and the second connecting plate is connected with the first connecting plate through a bolt, so that effective connection between the side support and the first-layer steel arch is achieved; third connecting plates are arranged on the two end walls, close to the side supports, of the second-layer steel arch correspondingly, and the two third connecting plates are connected with the side walls of the two sides of the side supports through bolts correspondingly, so that effective connection between the side supports and the second-layer steel arch is achieved. The connecting structure has the effect of improving the connecting stability of the side supports and the side arches.

Description

Technical Field

[0001] The present application relates to the technical field of underground tunnels, and particularly to a multi-layer primary support arch frame for the construction of a large-span tunnel by the double-side drift method. Background Art

[0002] The double-side drift method is a common construction method for excavating and supporting a large-section underground tunnel while excavating. The entire large section of the tunnel is divided into three small sections, namely left, middle, and right, by two middle partitions. Following the excavation construction sequence of the left and right pilot tunnels first and the middle section closely following, side arches are installed in the left and right pilot tunnels, and the pressure received by the side arches is supported by temporary side supports. After the construction of the left and right side arches is completed, the excavation of the middle pilot tunnel and the installation of the inverted arch are carried out. After the primary support inverted arch forms a ring, the temporary supports on both sides of the arch are removed to form a complete force-bearing system for the entire section.

[0003] In the existing construction technology, the temporary side support is connected to the side arch by welding. When welding, it is necessary to first grind the two welding surfaces, then align the two welding surfaces for welding, and sometimes additional welding is required to enhance the connection strength. However, the connection points where the surfaces are connected by welding have low strength; if the situation occurs that the temporary support is not perpendicular to the tangent of the side arch during welding, then during subsequent support, the internal stress generated between the temporary support and the side arch will cause the welding connection to fail, resulting in the failure of the support and affecting the stability of the side arch, so it needs to be improved. Utility Model Content

[0004] In order to improve the stability of the connection between the side support and the side arch, the present application provides a multi-layer primary support arch frame for the construction of a large-span tunnel by the double-side drift method.

[0005] The multi-layer primary support arch frame for the construction of a large-span tunnel by the double-side drift method provided by the present application adopts the following technical solutions:

[0006] A multi-layer primary support arch frame for the construction of a large-span tunnel by the double-side drift method includes a first-layer steel arch frame arranged on the outside, a second-layer steel arch frame arranged on the inside, and a side support. The second-layer steel arch frame is disconnected on the extension line of the side support. The first-layer steel arch frame and the second-layer steel arch frame enclose a support installation position with an open bottom, and the side support is inserted into the support installation position; a first connecting plate is arranged on the end wall of the side support close to the first-layer steel arch frame, a second connecting plate is arranged on the inner side wall of the first-layer steel arch frame, and the second connecting plate is connected to the first connecting plate by bolts to realize the effective connection between the side support and the first-layer steel arch frame; third connecting plates are arranged on both end walls of the second-layer steel arch frame close to the side support, and the two third connecting plates are respectively connected to the side walls on both sides of the side support by bolts to realize the effective connection between the side support and the second-layer steel arch frame.

[0007] By adopting the above technical solution, before construction, the first connecting plate is pre-welded to the side support, the second connecting plate is pre-welded to the first-layer steel arch, and the third connecting plate is pre-welded to the second-layer steel arch. When installing the first-layer steel arch, the construction worker aligns the first connecting plate with the second connecting plate and effectively connects the first connecting plate, the second connecting plate, and the first-layer steel arch with high-strength bolts. The side support provides a supporting force for the first-layer steel arch. Subsequently, when installing the second-layer steel arch, the construction worker first connects the third connecting plate located below to the side support with high-strength bolts, and then connects the third connecting plate located above to the side support with high-strength bolts, so that the second-layer steel arch transfers its own force to the side support, forming a complete force system. The connection between the side support and the first-layer steel arch is assisted by the first connecting plate and the second connecting plate, which improves the stability and accuracy of the connection compared with the direct welding in the prior art.

[0008] Optionally, two positioning blocks are installed on the end wall of the first connecting plate close to the side support. The two positioning blocks are arranged side by side. First inclined grooves are formed on the side walls of the two positioning blocks facing each other. The first inclined grooves are used to guide the side support to be inserted between the two positioning blocks.

[0009] Optionally, second inclined grooves are respectively formed on the two end walls in the length direction of the positioning block. The two second inclined grooves on each positioning block are respectively communicated with the two ends of the first inclined groove. The second inclined grooves are used to guide the side support to be inserted between the two positioning blocks.

[0010] Optionally, the side wall of the positioning block is attached to the side wall of the side support. A V-shaped groove is formed between the first inclined groove and the side wall of the side support, and a V-shaped groove is also formed between the second inclined groove and the side wall of the side support; the positioning block and the side support are connected by welding and welded along the V-shaped groove.

[0011] By adopting the above technical solution, when installing the first connecting plate, the operator first welds the positioning block to the first connecting plate, then aligns the positioning block with the end wall of the side support, controls the first connecting plate to approach the side support, and the first inclined groove and the second inclined groove guide the positioning block to be clamped on both sides of the transverse plate of the side support. Subsequently, the operator uses a welding torch to weld at the first inclined groove and the second inclined groove to weld and fix the positioning block and the side support, completing the installation of the first connecting plate and the side support, and improving the stability of the connection between the first connecting plate and the side support. The positioning block can assist the first connecting plate to align with the side support, improve the accuracy of positioning the first connecting plate and the side support, and further improve the accuracy of positioning the side support and the first-layer steel arch.

[0012] Optionally, two wedge blocks are installed on the end wall of the first connecting plate close to the second connecting plate, and the length direction of the wedge block is perpendicular to the length direction of the positioning block; a receiving seat is installed on the end wall of the second connecting plate close to the first connecting plate, and two square grooves for accommodating the wedge blocks are opened on the side wall of the receiving seat; six opposite screw holes are opened on the first connecting plate, the second connecting plate and the first-layer steel arch, and the screw holes are arranged at the edge of the second connecting plate, and the receiving seat is located between the six screw holes.

[0013] Optionally, the materials of the wedge block and the receiving seat are both selected as cork, and the inner walls of the wedge block and the receiving seat at the square groove are in interference fit.

[0014] Optionally, a concave relief groove is provided on the end wall of the receiving seat close to the first connecting plate, so as to form an annular protrusion at the edge of the receiving seat, and the end wall of the annular protrusion abuts against the end wall of the first connecting plate.

[0015] Optionally, a groove is opened on the first connecting plate, the wedge block is embedded in the groove, and the wedge block and the inner wall of the groove are adhesively connected; a groove is opened on the second connecting plate, the receiving seat is embedded in the groove, and the receiving seat and the inner wall of the groove are adhesively connected.

[0016] By adopting the above technical solution, when installing the side support, the construction personnel hoist the top of the side support installed on the first connecting plate to be close to the second connecting plate by a crane, and manually adjust to align the wedge block with the square groove. At this time, the bottom end of the side support is temporarily fixed first, and the construction personnel use a tool to hammer the side support to insert the wedge block to the bottom of the square groove, so that the axis in the length direction of the side support is aligned with the center line of the first-layer steel arch, realizing the first positioning of the side support; at this time, the screw holes on the first connecting plate, the second connecting plate and the first-layer steel arch are aligned with each other, and the construction personnel use the strengthening bolts to connect the first connecting plate, the second connecting plate and the first-layer steel arch, but do not tighten the bolts. After rechecking the bottom end of the side support and finally fixing the bottom end of the side support, then tighten all the strengthening bolts until the annular protrusion is crushed and damaged, indicating that the first connecting plate and the second connecting plate are firmly connected, forming an effective connection between the side support and the first-layer steel arch. Improve the accuracy and firmness of the side support installation.

[0017] In summary, the present application includes at least one of the following beneficial technical effects:

[0018] 1. Before construction, the first connecting plate is pre-welded to the side support, the second connecting plate is pre-welded to the first-layer steel arch, and the third connecting plate is pre-welded to the second-layer steel arch. When installing the first-layer steel arch, the construction workers align the first connecting plate with the second connecting plate and effectively connect the first connecting plate, the second connecting plate, and the first-layer steel arch with high-strength bolts. The side support provides a supporting force for the first-layer steel arch. Subsequently, when installing the second-layer steel arch, the construction workers first connect the third connecting plate located below to the side support with high-strength bolts, and then connect the third connecting plate located above to the side support with high-strength bolts, so that the second-layer steel arch transfers its own force to the side support, forming a complete force system. The connection between the side support and the first-layer steel arch is assisted by the first connecting plate and the second connecting plate. Compared with direct welding in the prior art, the stability and accuracy of the connection are improved;

[0019] 2. When installing the first connecting plate, the operator first welds the positioning block to the first connecting plate, then aligns the positioning block with the end wall of the side support, controls the first connecting plate to approach the side support, and the first inclined groove and the second inclined groove guide the positioning block to be clamped on both sides of the middle plate of the side support. Subsequently, the operator uses a welding torch to weld at the first inclined groove and the second inclined groove to weld and fix the positioning block to the side support, completing the installation of the first connecting plate and the side support, and improving the stability of the connection between the first connecting plate and the side support. The positioning block can assist the first connecting plate to align with the side support, improve the accuracy of positioning the first connecting plate and the side support, and further improve the accuracy of positioning the side support and the first-layer steel arch;

[0020] 3. When installing the side support, the construction workers hoist the top of the side support where the first connecting plate is installed to be close to the second connecting plate by a crane, and manually adjust to align the wedge block with the square groove. At this time, first temporarily fix the bottom end of the side support. The construction workers use a tool to hammer the side support to insert the wedge block to the bottom of the square groove, and align the axis in the length direction of the side support with the center line of the first-layer steel arch to achieve the first positioning of the side support; at this time, the screw holes on the first connecting plate, the second connecting plate, and the first-layer steel arch are aligned with each other. The construction workers connect the first connecting plate, the second connecting plate, and the first-layer steel arch with reinforcing bolts but do not tighten the bolts. After re-measuring the bottom of the side support and finally fixing the bottom end of the side support, then tighten all the reinforcing bolts until the annular protrusion is flattened and damaged, indicating that the first connecting plate and the second connecting plate are firmly connected, forming an effective connection between the side support and the first-layer steel arch. Improve the accuracy and firmness of the side support installation. Brief Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of a multi-layer primary support arch for the construction of a large-span tunnel by the double-side drift method in an embodiment of the present application.

[0022] Figure 2It is a schematic explosion structure diagram of the support arch frame in the embodiment of the present application.

[0023] Figure 3 It is a schematic structure diagram of the first connecting plate in the embodiment of the present application.

[0024] Figure 4 It is a schematic structure diagram of the second connecting plate in the embodiment of the present application.

[0025] Explanation of reference numerals: 1, the first layer of steel arch frame; 2, the second layer of steel arch frame; 3, side support; 4, the first connecting plate; 41, positioning block; 42, the first inclined groove; 43, the second inclined groove; 44, wedge block; 5, the second connecting plate; 51, receiving seat; 52, square groove; 53, annular protrusion; 6, the third connecting plate; 7, strengthening bolt; 8, screw hole. Detailed implementation manners

[0026] The following further elaborates on the present application in conjunction with the attached Figures 1-4 drawings.

[0027] The embodiment of the present application discloses a multi-layer primary support arch frame for the construction of a large-span tunnel by the double-side drift method. Referring to Figure 1 , a multi-layer primary support arch frame for the construction of a large-span tunnel by the double-side drift method includes a first layer of steel arch frame 1 arranged on the outer side and a second layer of steel arch frame 2 arranged on the inner side. The arch ribs of both the first layer of steel arch frame 1 and the second layer of steel arch frame 2 are made of I-beams. Side supports 3 are arranged on the first layer of steel arch frame 1 and the second layer of steel arch frame 2, and the side supports 3 are also made of I-beams. The second layer of steel arch frame 2 is disconnected on the extension line of the side support 3. The first layer of steel arch frame 1 and the second layer of steel arch frame 2 enclose a support installation position with an open bottom, and the side support 3 is inserted into the support installation position.

[0028] Referring to Figure 1 and Figure 2 , a first connecting plate 4 is arranged on the end wall of the side support 3 close to the first layer of steel arch frame 1, and a second connecting plate 5 is arranged on the inner side wall of the first layer of steel arch frame 1. Six screw holes 8 are penetrated and opened on the first connecting plate 4, the second connecting plate 5 and the first layer of steel arch frame 1. The six screw holes 8 are arranged in pairs at the edge of the second connecting plate 5. The first connecting plate 4 is connected to the side support 3 by welding, the second connecting plate 5 is connected to the first layer of steel arch frame 1 by welding, and the second connecting plate 5 is connected to the first connecting plate 4 by bolts, so as to realize the effective connection between the side support 3 and the first layer of steel arch frame 1. Third connecting plates 6 are arranged on both end walls of the second layer of steel arch frame 2 close to the side support 3, and the third connecting plates 6 are connected to the second layer of steel arch frame 2 by welding; Six screw holes 8 are penetrated and opened on the third connecting plates 6 and the side support 3, and the two third connecting plates 6 are respectively connected to the side walls on both sides of the side support 3 by bolts, so as to realize the effective connection between the side support 3 and the second layer of steel arch frame 2.

[0029] Before construction, the first connecting plate 4 is pre-welded on the side support 3, the second connecting plate 5 is pre-welded on the first-layer steel arch 1, and the third connecting plate 6 is pre-welded on the second-layer steel arch 2. When installing the first-layer steel arch 1, the construction workers align the first connecting plate 4 with the second connecting plate 5 and effectively connect the first connecting plate 4, the second connecting plate 5 and the first-layer steel arch 1 with high-strength bolts. The side support 3 provides a supporting force for the first-layer steel arch 1. Subsequently, when installing the second-layer steel arch 2, the construction workers first connect the third connecting plate 6 located below to the side support 3 with high-strength bolts, and then connect the third connecting plate 6 located above to the side support 3 with high-strength bolts, so that the second-layer steel arch 2 transfers its own force to the side support 3, forming a complete force system. The connection between the side support 3 and the first-layer steel arch 1 is assisted by the first connecting plate 4 and the second connecting plate 5, which improves the stability and accuracy of the connection compared with direct welding in the prior art.

[0030] Referring to Figure 2 and Figure 3 , two positioning blocks 41 are installed on the end wall of the first connecting plate 4 close to the side support 3. The positioning blocks 41 are connected to the first connecting plate 4 by welding. The two positioning blocks 41 are arranged side by side. First inclined grooves 42 are formed on the opposite side walls of the two positioning blocks 41. Second inclined grooves 43 are formed on the two end walls in the length direction of the positioning blocks 41. The two second inclined grooves 43 on each positioning block 41 communicate with the two ends of the first inclined groove 42 respectively. The first inclined groove 42 and the second inclined groove 43 are used to guide the side support 3 to be inserted between the two positioning blocks 41.

[0031] The side wall of the positioning block 41 is attached to the side wall of the side support 3. A V-shaped groove is formed between the first inclined groove 42 and the side wall of the side support 3, and a V-shaped groove is also formed between the second inclined groove 43 and the side wall of the side support 3. The positioning block 41 is connected to the side support 3 by welding, and the weld seam is arranged in the V-shaped groove.

[0032] When installing the first connecting plate 4, the operator first welds the positioning blocks 41 on the first connecting plate 4, then aligns the positioning blocks 41 with the end wall of the side support 3, controls the first connecting plate 4 to approach the side support 3, and the first inclined groove 42 and the second inclined groove 43 guide the positioning blocks 41 to be clamped on both sides of the transverse plate of the side support 3. Subsequently, the operator uses a welding torch to weld at the first inclined groove 42 and the second inclined groove 43 to weld and fix the positioning blocks 41 to the side support 3, completing the installation of the first connecting plate 4 and the side support 3, and improving the stability of the connection between the first connecting plate 4 and the side support 3. The positioning blocks 41 can assist the first connecting plate 4 to align with the side support 3, improve the positioning accuracy of the first connecting plate 4 and the side support 3, and further improve the positioning accuracy of the side support 3 and the first-layer steel arch 1.

[0033] Similarly, two positioning blocks 41 are also installed on the side wall of the third connecting plate 6. The installation method of the third connecting plate 6 is the same as that of the first connecting plate 4.

[0034] Refer to Figure 3 and Figure 4 , two wedge-shaped blocks 44 are installed on the end wall of the first connecting plate 4 close to the second connecting plate 5. Grooves are formed on the first connecting plate 4, and the wedge-shaped blocks 44 are embedded in the grooves. The wedge-shaped blocks 44 are adhesively connected to the inner walls of the grooves; the length direction of the wedge-shaped blocks 44 is perpendicular to the length direction of the positioning blocks 41. A receiving seat 51 is installed on the end wall of the second connecting plate 5 close to the first connecting plate 4. Grooves are formed on the second connecting plate 5, and the receiving seat 51 is embedded in the grooves. The receiving seat 51 is adhesively connected to the inner walls of the grooves. Two square grooves 52 for accommodating the wedge-shaped blocks 44 are formed on the side wall of the receiving seat 51. The materials of the wedge-shaped blocks 44 and the receiving seat 51 are both selected as cork, and the inner walls of the wedge-shaped blocks 44 and the receiving seat 51 at the square grooves 52 are in interference fit. A concave relief groove is provided on the end wall of the receiving seat 51 close to the first connecting plate 4 to form an annular protrusion 53 at the edge of the receiving seat 51, and the end wall of the annular protrusion 53 abuts against the end wall of the first connecting plate 4.

[0035] When installing the side support 3, the construction worker hoists the top of the side support 3 installed on the first connecting plate 4 close to the second connecting plate 5 by a crane, and manually adjusts to align the wedge-shaped block 44 with the square groove 52. At this time, first temporarily fix the bottom end of the side support 3, and the construction worker uses a tool to hammer the side support 3 to insert the wedge-shaped block 44 to the bottom of the square groove 52, and align the axis in the length direction of the side support 3 with the center line of the first-layer steel arch 1 to achieve the first positioning of the side support 3; at this time, the screw holes 8 on the first connecting plate 4, the second connecting plate 5 and the first-layer steel arch 1 are aligned with each other, and the construction worker uses the reinforcing bolts 7 to connect the first connecting plate 4, the second connecting plate 5 and the first-layer steel arch 1, but does not tighten the bolts. After rechecking the side support 3 and finally fixing the bottom end of the side support 3, then tighten all the reinforcing bolts 7 until the annular protrusion 53 is crushed and damaged, indicating that the first connecting plate 4 and the second connecting plate 5 are firmly connected, forming an effective connection between the side support 3 and the first-layer steel arch 1. Improve the accuracy and firmness of the installation of the side support 3.

[0036] The implementation principle of the multi-layer primary support arch in the double-side drift method for large-span tunnel construction in the embodiment of the present application is as follows: The first connecting plate 4 is welded and installed at the top of the side support 3 through the positioning block 41 to improve the stability of the connection between the first connecting plate 4 and the side support 3. When installing the side support 3, the first positioning of the side support 3 is carried out through the interference fit between the wedge block 44 and the square groove 52, so that the screw holes 8 are aligned with each other; after rechecking, the bolts are tightened, and the first connecting plate 4 and the first connecting plate 4 clamp the receiving seat 51 and the annular protrusion 53 is flattened, realizing the effective connection between the side support 3 and the first-layer steel arch 1 and improving the stability of the connection. Subsequently, when installing the second-layer side support 3, the third connecting plate 6 pre-welded on the second-layer steel arch 2 is aligned with the side support 3 and is also connected through the strengthening bolt 7.

[0037] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited hereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A multi-layer primary support arch for the construction of a large-span tunnel by the double-side drift method, characterized in that: It includes a first-layer steel arch frame (1) arranged on the outside, a second-layer steel arch frame (2) arranged on the inside, and side supports (3). The second-layer steel arch frame (2) is disconnected on the extension line of the side supports (3). The first-layer steel arch frame (1) and the second-layer steel arch frame (2) enclose a support installation position with an open bottom, and the side supports (3) are inserted into the support installation position; a first connecting plate (4) is arranged on the end wall of the side support (3) close to the first-layer steel arch frame (1), and a second connecting plate (5) is arranged on the inner side wall of the first-layer steel arch frame (1). The second connecting plate (5) is bolted to the first connecting plate (4) to effectively connect the side support (3) with the first-layer steel arch frame (1); third connecting plates (6) are arranged on both end walls of the second-layer steel arch frame (2) close to the side supports (3), and the two third connecting plates (6) are respectively bolted to the side walls on both sides of the side support (3) to effectively connect the side support (3) with the second-layer steel arch frame (2).

2. The multi-layer primary support arch for construction by the double-side drift method in a long-span tunnel according to claim 1, wherein: Two positioning blocks (41) are installed on the end wall of the first connecting plate (4) close to the side support (3). The two positioning blocks (41) are arranged side by side. First inclined grooves (42) are opened on the opposite side walls of the two positioning blocks (41). The first inclined grooves (42) are used to guide the side support (3) to be inserted between the two positioning blocks (41).

3. The multi-layer primary support arch used in the construction of a large-span tunnel by the double-side drift method according to claim 2, characterized in that: Second inclined grooves (43) are respectively opened on the two end walls in the length direction of the positioning block (41). The two second inclined grooves (43) on each positioning block (41) are respectively communicated with the two ends of the first inclined groove (42). The second inclined grooves (43) are used to guide the side support (3) to be inserted between the two positioning blocks (41).

4. A multi-layer primary support arch for construction of a large-span tunnel by the double-side drift method according to claim 3, characterized in that: The side wall of the positioning block (41) is attached to the side wall of the side support (3). A V-shaped groove is formed between the first inclined groove (42) and the side wall of the side support (3), and a V-shaped groove is also formed between the second inclined groove (43) and the side wall of the side support (3); the positioning block (41) and the side support (3) are connected by welding and welded along the V-shaped groove.

5. The multi-layer primary support arch for construction of a large-span tunnel by the double-side drift method according to claim 2, characterized in that: Two wedge blocks (44) are installed on the end wall of the first connecting plate (4) close to the second connecting plate (5). The length direction of the wedge block (44) is perpendicular to the length direction of the positioning block (41); a receiving seat (51) is installed on the end wall of the second connecting plate (5) close to the first connecting plate (4). Two square grooves (52) for accommodating the wedge blocks (44) are opened on the side wall of the receiving seat (51); six opposite screw holes (8) are opened on the first connecting plate (4), the second connecting plate (5), and the first-layer steel arch frame (1). The screw holes (8) are arranged at the edge of the second connecting plate (5), and the receiving seat (51) is located between the six screw holes (8).

6. The multi-layer primary support arch for the construction of a large-span tunnel by the double-side drift method according to claim 5, characterized in that: The materials of the wedge block (44) and the receiving seat (51) are both selected as cork, and the inner walls of the wedge block (44) and the receiving seat (51) at the square groove (52) are in interference fit.

7. A multi-layer primary support arch for construction of a large-span tunnel by the double-side drift method according to claim 6, characterized in that: A concave relief groove is provided on the end wall of the receiving seat (51) close to the first connecting plate (4), so as to form an annular protrusion (53) at the edge of the receiving seat (51), and the end wall of the annular protrusion (53) abuts against the end wall of the first connecting plate (4).

8. The multi-layer primary support arch for the construction of a large-span tunnel by the double-side drift method according to claim 5, characterized in that: A groove is formed on the first connecting plate (4), the wedge-shaped block (44) is embedded in the groove, and the wedge-shaped block (44) is adhesively connected to the inner wall of the groove; a groove is formed on the second connecting plate (5), the receiving seat (51) is embedded in the groove, and the receiving seat (51) is adhesively connected to the inner wall of the groove.

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