Primary support structure of underground chamber traffic tunnel

Abstract

The utility model discloses a primary support structure of an underground chamber traffic tunnel, which is used for an initial chamber after blasting, the initial chamber comprises an arc-shaped wall and a bottom wall, and the primary support structure comprises a plurality of anchor rods annularly inserted into the arc-shaped wall; the arch frame is in an arch shape, the two ends of the arch frame are fixedly connected with the bottom wall, and the ends, away from the arc-shaped wall, of the anchor rods are fixedly connected with the arch frame; wherein a plurality of arch frames are arranged in the length direction of the initial chamber, and every two adjacent arch frames are fixedly connected through steel bars. Through the arrangement of the primary supporting structure, the situation that surrounding rock overall deformation, rock stratum collapse and scattered rock block falling are caused by the fact that underground chamber surrounding rock is soft can be avoided, and then the stability of the underground chamber traffic tunnel is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of underground chamber support, in particular to a primary support structure of an underground chamber traffic tunnel. Background Art

[0002] In the new energy storage industry, compressed air energy storage has the advantages of large capacity, long cycle and low investment, and is considered to be the new large-scale energy storage with the broadest development prospects. Compared with salt cavern energy storage and small gas storage tanks, the gas storage system using fully artificial underground gas storage has better geological adaptability and promotion.

[0003] However, at present, the 100-megawatt compressed air energy storage system using a fully artificial underground gas storage has an underground chamber surrounding rock composed mainly of slightly weathered calcareous siltstone, with a small amount of slightly weathered marlstone and slightly weathered siltstone, and locally developed faults or fracture zones. The rock mass has low hardness and strong crushing properties after blasting. There is no mature construction plan for the construction of traffic tunnels in the muddy siltstone geological environment. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art or related technology.

[0005] In view of this, the utility model provides a primary support structure for an underground cavern traffic tunnel, wherein the setting of the primary support structure can prevent the overall deformation of the surrounding rock, rock layer collapse, and falling of scattered rock blocks caused by the soft surrounding rock of the underground cavern, thereby improving the stability of the underground cavern traffic tunnel.

[0006] Specifically, the following technical solutions are included:

[0007] The utility model provides a primary support structure of an underground chamber traffic tunnel, which is used for an initial chamber after blasting. The initial chamber includes an arc-shaped wall and a bottom wall. The primary support structure includes:

[0008] Anchor rods, a plurality of said anchor rods are circumferentially inserted into the arc-shaped wall;

[0009] An arch frame is in an arch shape, both ends of the arch frame are fixedly connected to the bottom wall, and one end of the anchor rod away from the arc-shaped wall is fixedly connected to the arch frame;

[0010] Wherein, a plurality of the arch frames are arranged along the length direction of the initial chamber, and two adjacent arch frames are fixedly connected by steel bars.

[0011] Optionally, a steel mesh is further provided between the arc-shaped wall and the arch frame, the steel mesh is provided close to one end of the arc-shaped top wall, and the steel mesh is fixedly connected to the anchor rod and the arch frame respectively.

[0012] Optionally, a concrete layer is further provided on the arc-shaped wall, and the concrete layer is arranged in close contact with the arc-shaped wall.

[0013] Optionally, the primary branch structure further comprises:

[0014] An advance small conduit, a plurality of the advance small conduits are circumferentially inserted into the surrounding rock on the side of the arc-shaped wall away from the bottom wall, the advance small conduits and the contour line of the arc-shaped wall form a first insertion angle, and a plurality of first grouting holes are evenly arranged on the outer wall of the advance small conduits.

[0015] Optionally, a plurality of rows of the advance small ducts are arranged along the length direction of the initial chamber, and the overlapping length of the projections of two adjacent rows of the advance small ducts on the bottom wall is not less than a set length.

[0016] Optionally, the insertion end of the advance small catheter is conical, and a stirrup is provided on the end of the advance small catheter away from the insertion end.

[0017] Optionally, the primary branch structure further comprises:

[0018] A pipe rack, wherein a plurality of the pipe racks are annularly inserted into the surrounding rock on the side of the arc-shaped wall away from the bottom wall, the pipe rack and the contour line of the arc-shaped wall form a second insertion angle, both ends of the pipe rack are provided with external threads, and the initial chamber includes a plurality of sections of the pipe rack along the length direction, and two adjacent sections of the pipe rack are connected by a connecting ring, and the connecting ring is provided with an internal thread.

[0019] Optionally, the pipe rack includes: seamless steel pipes and steel flower pipes, the seamless steel pipes and the steel flower pipes are spaced apart in the annular direction of the arc-shaped wall, and the steel flower pipes are evenly provided with a plurality of second grouting holes.

[0020] Optionally, the connecting rings of two adjacent pipe racks in the annular direction are arranged in different sections.

[0021] Optionally, locking foot anchor tubes are provided at both ends of the arch frame that are in contact with the bottom wall, and two locking foot anchor tubes are provided in the width direction of each end.

[0022] The embodiment of the utility model provides a primary support structure for an underground cavern traffic tunnel, wherein the primary support structure includes anchor rods and arch frames, multiple anchor rods are inserted into the arc wall in an annular direction, one end of the anchor rods away from the arc wall is fixedly connected to the arch frame, multiple arch frames are arranged along the length direction of the initial cavern, and two adjacent arch frames are fixedly connected by steel bars. Arranging multiple arch frames at different distances according to the type of surrounding rock can improve the stability and reliability of the primary support structure, avoid the occurrence of deformation and collapse of the surrounding rock, and improve the reliability and safety of subsequent traffic tunnel use.

[0023] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic diagram of a primary support structure according to an embodiment of the utility model;

[0026] Figure 2 A schematic diagram of the connection of multiple arches according to an embodiment of the utility model;

[0027] Figure 3 is a schematic diagram of a primary support structure according to another embodiment of the utility model;

[0028] Figure 4 This is a schematic diagram of inserting an advanced small catheter according to another embodiment of the utility model;

[0029] Figure 5 is a schematic diagram of an advanced small catheter according to another embodiment of the utility model;

[0030] Figure 6 is a schematic diagram of a primary support structure according to another embodiment of the utility model;

[0031] Figure 7 It is a schematic diagram of inserting a pipe rack according to another embodiment of the utility model;

[0032] Figure 8 The figure is a top view of a pipe rack according to another embodiment of the utility model.

[0033] in, Figures 1 to 8 The corresponding relationship between the reference numerals and the component names is as follows:

[0034] 100 primary support structure, 110 anchor rod, 120 arch frame, 130 steel bars, 140 steel mesh, 150 concrete layer, 160 advance small guide tube, 161 insertion end, 162 stirrups, 163 first grouting hole, 170 pipe shed, 171 seamless steel pipe, 172 steel flower pipe, 1721 second grouting hole, 173 connecting ring, 180 locking foot anchor pipe, 191 first insertion angle, 192 second insertion angle, 193 overlapping length. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] Before further describing the embodiments of the present invention in detail, the directional terms involved in the embodiments of the present invention, such as "upper part", "lower part" and "side part", do not have the meaning of limiting the protection scope of the present invention.

[0037] In order to make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0038] Figure 1 A schematic diagram of a primary support structure according to an embodiment of the utility model; Figure 2 The figure is a schematic diagram of connecting a plurality of arches according to an embodiment of the utility model.

[0039] like Figure 1 and Figure 2 As shown, an embodiment of the utility model provides a primary support structure 100 of an underground chamber traffic tunnel, which is used for an initial chamber after blasting. The initial chamber includes an arc wall and a bottom wall. The primary support structure 100 includes:

[0040] Anchor rods 110, a plurality of anchor rods 110 are circumferentially inserted into the arc-shaped wall;

[0041] The arch frame 120 is in an arch shape, and both ends of the arch frame 120 are fixedly connected to the bottom wall, and one end of the anchor rod 110 away from the arc wall is fixedly connected to the arch frame 120;

[0042] Among them, a plurality of arch frames 120 are arranged along the length direction of the initial chamber, and two adjacent arch frames 120 are fixedly connected by steel bars 130 .

[0043] The primary support structure includes anchor rods 110 and arches 120. Multiple anchor rods 110 are inserted into the arc wall in an annular direction. One end of the anchor rod 110 away from the arc wall is fixedly connected to the arch 120. Multiple arches 120 are arranged along the length direction of the initial chamber, and two adjacent arches 120 are fixedly connected by steel bars 130. Arranging multiple arches 120 at different distances according to the type of surrounding rock can improve the stability and reliability of the primary support structure 100, avoid deformation and collapse of the surrounding rock, and improve the reliability and safety of subsequent traffic tunnel use.

[0044] It should be noted that the primary support structure 100 using only anchor rods 110 and arches 120 is suitable for underground chambers with Class III, Class II and Class I surrounding rocks. Specifically, the anchor rod 110 is driven into the rock layer above the arc-shaped wall by a pneumatic drill, and the anchor rod 110 needs to be exposed by 15cm to 30cm, and the exposed end is connected to the arch 120 by welding. Among them, in actual applications, it can be based on the provisions of the "Technical Specifications for Geotechnical Anchor Rods and Sprayed Concrete Support Engineering" GB50086-2015: The length of the anchor rod body inserted into the borehole "prestressed anchor rods shall not be less than 97% of the design strength, and non-prestressed anchor rods shall not be less than 98% of the design strength", without other restrictions.

[0045] It can be understood that since the length of the arch frame 120 is relatively long, the arch frame 120 can be divided into multiple arc segments, and the multiple arc segments are fixed by bolts to form an arch frame 120. Along the length direction of the initial chamber, multiple arch frames 120 are included, and two adjacent arch frames 120 are welded and fixedly connected by multiple steel bars 130. The multiple steel bars 130 are evenly arranged on the arch frame 120 to ensure the uniformity of the support of the arch frame 120, thereby ensuring the firmness of the arch frame 120.

[0046] Among them, the diameter of the anchor rod 110 is 25mm, the length is 2.5 meters, and the allowable deviation of the length of the anchor rod 110 is -30mm to 100mm. When supporting the surrounding rock of Class III, Class II and Class I, the anchor rod 110 is set within a range of 60° on both sides of the central axis of the initial chamber to meet the support requirements. The distance or number of adjacent anchor rods 110 needs to be set according to the surrounding rock level and the excavation span, and is not limited here. The arch frame 120 can be made of I-beams or steel. When the surrounding rock of Class III, Class II and Class I is good, the arch frame 120 may not be set, or fewer arch frames 120 may be set along the length direction of the initial chamber, such as 2 to 3 arch frames 120, to meet the support requirements. The installation allowable error of the distance between adjacent arch frames 120 is ±100mm. Usually, the distance between adjacent arch frames 120 is calculated and designed according to the distribution of the surrounding rock.

[0047] In a possible implementation, Figure 1As shown, a steel mesh 140 is further provided between the arc-shaped wall and the arch frame 120 . The steel mesh 140 is provided close to one end of the arc-shaped top wall. The steel mesh 140 is fixedly connected to the anchor rod 110 and the arch frame 120 , respectively.

[0048] Among them, the steel mesh is also located between two adjacent arch frames 120, that is, the steel mesh covers the arc wall of the initial chamber. It can be understood that a concrete layer needs to be sprayed on the steel mesh. The setting of the steel mesh is beneficial to improve the shear and bending strength of the sprayed concrete, improve the shear resistance and bending resistance of the concrete, improve the integrity of the sprayed concrete, reduce shrinkage cracks of the sprayed concrete, prevent local block falling, improve the strength of the initial chamber, and avoid the occurrence of safety accidents.

[0049] In a possible implementation, Figure 1 As shown, a concrete layer 150 is further provided on the arc-shaped wall, and the concrete layer 150 is arranged in close contact with the arc-shaped wall.

[0050] It should be noted that before installing the anchor rod 110, a layer of concrete 150 is first sprayed on the curved wall of the initial chamber after blasting. Usually, the thickness of the sprayed concrete layer 150 is not less than 4 cm, and can be selected from 4 cm to 6 cm. The concrete compressive strength of the concrete layer 150 must reach above 25 MPa, and the water-resistance grade must be above P8. At the same time, the concrete should also meet the requirements of 3h strength of not less than 1.5 MPa, 8h strength of not less than 2 MPa, and 24h strength of not less than 10 MPa. The bonding strength between the sprayed concrete layer 150 and the surrounding rock is not less than 8 MPa. Alkali-free quick-setting agent is added to the sprayed concrete layer 150 to ensure that the initial setting time of the cement paste should not be more than 3 minutes, and the final setting time should not be more than 12 minutes, thereby ensuring the reinforcement of the surrounding rock by the concrete layer 150, controlling the deformation of the surrounding rock, and improving the stability and reliability of the initial chamber. After the concrete layer 150 is sprayed, the stability of the surrounding rock can be ensured. At this time, the anchor rod 110 is drilled in and the anchor rod 110 and the arch frame 120 are fixed, thereby improving the support strength of the anchor rod 110 and the arch frame 120 for the initial chamber.

[0051] Figure 3 is a schematic diagram of a primary support structure according to another embodiment of the utility model; Figure 4 This is a schematic diagram of inserting an advanced small catheter according to another embodiment of the utility model;

[0052] like Figure 3 and Figure 4 As shown, the primary support structure 100 also includes:

[0053] The advance small conduit 160, multiple advance small conduits 160 are circumferentially inserted into the surrounding rock on the side of the arc wall away from the bottom wall, the advance small conduit 160 and the contour line of the arc wall form a first insertion angle 191, and multiple first grouting holes 163 are evenly arranged on the outer wall of the advance small conduit 160.

[0054] It should be noted that when the surrounding rock of the underground chamber is Class IV surrounding rock, the support requirements cannot be met only by the anchor rods 110 and the arch frame 120. At this time, it is necessary to insert an advance small guide tube 160 into the surrounding rock.

[0055] Specifically, the outer diameter of the advance small duct 160 is usually 42 mm, and the wall thickness is 3.5 mm of the hot-rolled seamless steel pipe. The length of the advance small duct 160 is 3.5 m to 4.1 m. The distance between the centers of two adjacent advance small ducts 160 is 300 mm to 500 mm, and the allowable error range of the distance between two adjacent advance small ducts 160 is ±50 mm. The arrangement angle of the advance small duct 160 can be calculated and selected according to the strength of the surrounding rock, which will not be repeated here. It is understandable that the multiple advance small pipes 160 are inserted circumferentially into the surrounding rock on the side of the arc wall away from the bottom wall, which will inevitably form an angle between the advance small pipe 160 and the contour line of the arc wall, that is, the first insertion angle 191, and the first insertion angle 191 is 10° to 15°. At the same time, multiple first grouting holes 163 are evenly arranged on the outer wall of the advance small pipe 160. By injecting cement slurry into the advance small pipe 160, the cement slurry in the advance small pipe 160 enters the surrounding rock through the first grouting holes 163, thereby achieving the reinforcement of the Class IV soft surrounding rock, avoiding the deformation and collapse of the surrounding rock of the underground chamber, and ensuring the safety and reliability of the subsequent use of the traffic tunnel. Among them, the diameter of the first grouting hole 163 is 8mm to 10mm, the first grouting hole 163 is arranged along the axial direction of the advance small pipe 160, and the first grouting holes 163 of two adjacent rows are staggered, and the distance between the first grouting holes 163 of two adjacent rows is 100mm.

[0056] In a feasible implementation, cement slurry is injected into the advance small conduit 160 through the first grouting hole 163. The cement slurry is composed of water, cement, admixtures and external admixtures. After grouting, the advance small conduit 160 is sealed with plastic mud to block the hole and surrounding gaps. If necessary, concrete is sprayed near the advance small conduit 160 and the working surface to prevent the working surface from collapsing, improve the stability of the initial chamber and the reliability of subsequent use, and avoid collapse accidents.

[0057] Among them, when the surrounding rock is Class IV surrounding rock, the anchor rods 110 are evenly arranged on the entire arc wall. At this time, the circumferential distance between adjacent anchor rods 110 is 1.2m, and the allowable error is ±10cm. It can be calculated based on the distribution of Class IV surrounding rock without additional restrictions; at the same time, along the length direction of the initial chamber, the spacing between adjacent arch frames 120 is 1.2m, and the allowable error of the distance between adjacent arch frames is ±10cm.

[0058] It is understandable that when supporting Class IV surrounding rock, the advance small guide tube 160 is constructed first, and then the anchor rod 110 and the arch frame 120 are constructed and installed, so as to ensure the stability of the installation of the anchor rod 110 and the arch frame 120.

[0059] In a possible implementation, Figure 4 As shown, a plurality of rows of advance small ducts 160 are arranged along the length direction of the initial chamber, and the overlapping length 193 of the projections of two adjacent rows of advance small ducts 160 on the bottom wall is not less than a set length.

[0060] Among them, in order to ensure the stability of Class IV surrounding rock, it is necessary to set multiple rows of advance small pipes 160 along the length direction of the initial chamber to ensure that cement slurry is filled into the surrounding rock, thereby ensuring the stability of the surrounding rock. This is because the overlapping length 193 of the projection of two adjacent rows of advance small pipes 160 on the bottom wall is not less than the set length, which is 1000mm. The larger the overlapping length 193, the more cement slurry is filled in, and the better the stability of the surrounding rock, but the construction cost will increase. Therefore, it is selected according to needs, but the overlapping length 193 cannot be less than 1000mm, so that the reinforcement requirements of Class IV surrounding rock can be met.

[0061] Figure 5 It is a schematic diagram of an advanced small catheter according to another embodiment of the utility model.

[0062] In a possible implementation, Figure 5 As shown, the insertion end 161 of the advance small catheter 160 is conical, and a stirrup 162 is provided on the end of the advance small catheter 160 away from the insertion end.

[0063] Among them, in order to facilitate the insertion of the advance small guide tube 160 into the surrounding rock, the insertion end 161 of the advance small guide tube 160 is cone-shaped to ensure the feasibility of the advance small guide tube 160 being inserted into the surrounding rock. A stirrup 162 is provided on the end of the advance small guide tube 160 away from the insertion end 161. The setting of the stirrup 162 is convenient for connection with the grouting equipment on the one hand, and on the other hand, it can also enhance the strength of the tail end of the advance small guide tube 160 to prevent the advance small guide tube 160 from being damaged or broken due to vibration, impact and other factors during operation, thereby ensuring the reliability of the support of the advance small guide tube 160.

[0064] Figure 6 is a schematic diagram of a primary support structure according to another embodiment of the utility model; Figure 7 It is a schematic diagram of inserting a pipe rack according to another embodiment of the utility model.

[0065] like Figure 6 and Figure 7 As shown, the primary support structure 100 also includes:

[0066] Pipe rack 170, multiple pipe racks 170 are circumferentially inserted into the surrounding rock on the side of the arc wall away from the bottom wall, the pipe rack 170 and the contour line of the arc wall form a second insertion angle 192, both ends of the pipe rack 170 are provided with external threads, and along the length direction of the initial chamber, multiple sections of pipe rack 170 are included, and two adjacent sections of pipe rack 170 are connected by a connecting ring 173, and the connecting ring 173 is provided with an internal thread.

[0067] It should be noted that when the surrounding rock of the underground chamber is Class V surrounding rock, the support requirements cannot be met only by the advance small guide tube 160, anchor rod 110 and arch frame 120. At this time, it is necessary to insert a pipe roof 170 into the surrounding rock. Usually, the pipe roof 170 is located below the advance small guide tube 160.

[0068] Specifically, the outer diameter of the pipe shed 170 is usually 89 mm, the wall thickness is 5 mm, the total length of the pipe shed is 10 m to 40 m, and the length of a single pipe shed is usually 4 m to 6 m. The multiple sections of the pipe shed 170 along the length direction of the initial chamber are connected by a connecting ring 173, the length of the connecting ring 173 is not less than 3 m, to ensure the stability of the connection between the two sections of the pipe shed 170. If the length of the connecting ring 173 is too small, it is easy to cause the sinking of the rear section of the pipe shed 170, affecting the stability and reliability of the support of the pipe shed 170. It can be understood that the multiple pipe sheds 170 are inserted circumferentially into the surrounding rock on the side of the arc wall away from the bottom wall, which will inevitably form an angle between the pipe shed 170 and the contour line of the arc wall, that is, the second insertion angle 192, and the second insertion angle 192 is 1.5° to 3°. In the circumferential direction, the centers of two adjacent pipe sheds 170 are 400 mm apart, and the allowable error range is ±30 mm. Among them, the radial error of the pipe-roof construction is no more than 20cm, and the circumferential error is no more than 10cm.

[0069] Among them, when supporting Class V surrounding rock, the distance between the centers of two adjacent advance small guide tubes 160 is 400mm, the allowable error range is ±50mm, and the advance small guide tubes 160 are evenly distributed along the tunnel arch; at the same time, the anchor rods 110 are evenly arranged on the entire arc wall. At this time, the distance between adjacent anchor rods 110 is 1.2m, and the allowable error is ±10cm. It can be calculated according to the distribution of Class V surrounding rock without additional restrictions; along the length direction of the initial chamber, the spacing between adjacent arch frames 120 is 1.0m, and the construction allowable error between adjacent arch frames 120 is ±10cm.

[0070] It is understandable that when supporting Class V surrounding rock, the construction of the advance small guide tube 160 and the pipe rack 170 is carried out in sequence, and then the anchor rod 110 and the arch frame 120 are constructed and installed, which can ensure the stability of the installation of the anchor rod 110 and the arch frame 120.

[0071] In a feasible implementation, the pipe rack 170 includes: a seamless steel pipe 171 and a steel flower pipe 172 , which are spaced apart in the annular direction of the arc wall, and a plurality of second grouting holes 1721 are evenly arranged on the steel flower pipe 172 .

[0072] Among them, the pipe rack 170 includes a seamless steel pipe 171 and a steel flower pipe 172, and a plurality of second grouting holes 1721 are evenly arranged on the outer wall of the steel flower pipe 172. By injecting cement slurry into the steel flower pipe 172, the cement slurry in the steel flower pipe 172 enters the surrounding rock through the second grouting holes 1721, thereby realizing the reinforcement of Class V softer surrounding rock, avoiding deformation and collapse of the surrounding rock of the underground chamber, and ensuring the safety and reliability of subsequent use of the traffic tunnel.

[0073] In a feasible implementation, the second grouting holes 1721 are arranged in a plum blossom shape on the outer wall of the steel tube 172. The plum blossom shape means that multiple rows of second grouting holes 1721 are arranged along the axial direction of the steel tube 172, and two adjacent rows of second grouting holes 1721 are staggered, and the distance between two adjacent rows of second grouting holes 1721 is 50mm, and the diameter of the second grouting holes 1721 is 10mm to 16mm. It can be understood that the insertion end of the pipe rack 170 is also conical, which is convenient for the insertion of the pipe rack 170 into the surrounding rock; the tail of the steel tube 1721 should be left with a grouting stop section where the second grouting holes 1721 are not drilled, and the grouting stop section is usually 1m to 2m.

[0074] It should be noted that the grouting liquid in the steel tube 172 is cement slurry, the water-cement ratio in the cement slurry is 1:1 (weight ratio), and the grouting pressure is 0.5MPa to 2.0MPa. Before grouting, a field grouting test should be carried out, and the grouting parameters should be adjusted according to the actual situation to obtain the grouting construction experience of the steel tube 172. After the grouting is completed, the steel tube 172 is filled with M10 cement mortar to enhance the strength of the steel tube 172.

[0075] It is understandable that the seamless steel pipe 171 also needs to be filled with M10 cement mortar to increase the overall rigidity of the pipe roof, thereby increasing the supporting strength for Class V surrounding rock and ensuring the safety of the initial chamber.

[0076] Figure 8 The figure is a top view of a pipe rack according to another embodiment of the utility model.

[0077] In a possible implementation, Figure 8 As shown, the connecting rings 173 of two adjacent pipe racks 170 in the annular direction are arranged in different sections.

[0078] It should be noted that the connecting rings 173 of two adjacent pipe racks 170 in the annular direction are arranged in different sections, that is, the number of connecting rings 173 in the same section shall not exceed 50% of the total number of pipe racks 170, that is, the connecting rings 173 should be staggered, which can ensure that the cement slurry penetrates into the surrounding rock more evenly, improve the firmness of the surrounding rock, and thus improve the reliability of the primary support structure 100.

[0079] In a possible implementation, Figure 1 As shown, locking foot anchor tubes 180 are provided at both ends of the arch frame 120 that contact the bottom wall, and two locking foot anchor tubes 180 are provided in the width direction of each end.

[0080] It should be noted that the locking foot anchor pipe 180 can be made of threaded steel or steel pipe. When using a steel pipe, it is necessary to fill the steel pipe with mortar to increase the strength of the locking foot anchor pipe 180. The locking foot anchor pipe 180 is inserted into the surrounding rock on the side of the arc wall away from the bottom wall, and a section of the locking foot anchor pipe 180 extending out of the surrounding rock is welded and fixed to the arch frame 120.

[0081] It is understandable that, since the arch frame 120 is a steel section or an I-beam, a U-shaped steel bracket can be welded at the connection between the locking foot anchor pipe 180 and the arch frame 120 to achieve auxiliary welding, thereby ensuring the stability of the welding between the locking foot anchor pipe 180 and the arch frame 120, and further ensuring the reliability and safety of the use of the arch frame 120. Among them, the outer diameter of the locking foot anchor pipe 180 is 42 mm, and two locking foot anchor pipes 180 are set in the width direction at both ends of the arch frame 120. In order to ensure the stability of the arch frame 120, a pair of locking foot anchor pipes 180 can also be set within a certain height range from the lower end of the arch frame 120. The setting method is as described above, which can further ensure the support stability and reliability of the arch frame 120.

[0082] According to different types of surrounding rock, different primary support structures 100 are selected, which can effectively avoid deformation and collapse of the initial chamber, thereby ensuring the stability and reliability of the primary support structure 100, and improving the reliability and safety of subsequent traffic tunnel use. On the other hand, it can also reduce the primary support cost 100 and improve the economy of the primary support structure 100. It can be understood that the schematic diagrams of this application are all schematic in nature and are not actual construction conditions.

[0083] It should be noted that the drawings of this application are all schematic diagrams, which only show the positional relationship of the various components. The arrangement angles of the wire mesh, the advance small guide tube 160 and the pipe rack annular 170 are calculated based on the grade of the surrounding rock and will not be repeated here.

[0084] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0085] Those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the present invention disclosed herein. The present invention is intended to cover any variation, use, or adaptation of the present invention that follows the general principles of the present invention and includes common knowledge or customary technical means in the art that are not disclosed in the present invention. The specification and examples are to be regarded as exemplary only.

[0086] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A primary support structure of an underground chamber traffic tunnel, used for an initial chamber after blasting, the initial chamber comprising an arc wall and a bottom wall, characterized in that: The primary support structure comprises: Anchor rods, a plurality of said anchor rods are circumferentially inserted into the arc-shaped wall; An arch frame is in an arch shape, both ends of the arch frame are fixedly connected to the bottom wall, and one end of the anchor rod away from the arc-shaped wall is fixedly connected to the arch frame; Wherein, a plurality of the arch frames are arranged along the length direction of the initial chamber, and two adjacent arch frames are fixedly connected by steel bars.

2. The primary support structure of the underground traffic tunnel according to claim 1 is characterized in that: A steel mesh is further provided between the arc-shaped wall and the arch frame. The steel mesh is arranged close to one end of the arc-shaped top wall. The steel mesh is fixedly connected to the anchor rod and the arch frame respectively.

3. The primary support structure of the underground traffic tunnel according to claim 2 is characterized in that: A concrete layer is also provided on the arc-shaped wall, and the concrete layer is arranged in close contact with the arc-shaped wall.

4. The primary support structure of the underground traffic tunnel according to claim 1 is characterized in that: The primary support structure also includes: An advance small conduit, a plurality of the advance small conduits are circumferentially inserted into the surrounding rock on the side of the arc-shaped wall away from the bottom wall, the advance small conduits and the contour line of the arc-shaped wall form a first insertion angle, and a plurality of first grouting holes are evenly arranged on the outer wall of the advance small conduits.

5. The primary support structure of the underground traffic tunnel according to claim 4 is characterized in that: A plurality of rows of the advance small conduits are arranged along the length direction of the initial chamber, and the overlapping length of the projections of two adjacent rows of the advance small conduits on the bottom wall is not less than a set length.

6. The primary support structure of the underground traffic tunnel according to claim 4, characterized in that: The insertion end of the advance small catheter is conical, and a stirrup is arranged on the end of the advance small catheter away from the insertion end.

7. The primary support structure of the underground traffic tunnel according to claim 4, characterized in that: The primary support structure also includes: A pipe rack, wherein a plurality of the pipe racks are annularly inserted into the surrounding rock on the side of the arc-shaped wall away from the bottom wall, the pipe rack and the contour line of the arc-shaped wall form a second insertion angle, both ends of the pipe rack are provided with external threads, and the initial chamber includes a plurality of sections of the pipe rack along the length direction, and two adjacent sections of the pipe rack are connected by a connecting ring, and the connecting ring is provided with an internal thread.

8. The primary support structure of the underground traffic tunnel according to claim 7, characterized in that: The pipe shed comprises: seamless steel pipes and steel flower pipes, the seamless steel pipes and the steel flower pipes are arranged at intervals in the circumferential direction of the arc-shaped wall, and a plurality of second grouting holes are evenly arranged on the steel flower pipes.

9. The primary support structure of the underground traffic tunnel according to claim 7, characterized in that: The connecting rings of two adjacent pipe racks in the ring direction are arranged in different sections.

10. The primary support structure of an underground traffic tunnel according to any one of claims 1 to 9, characterized in that: The two ends of the arch frame contacting the bottom wall are provided with locking foot anchor pipes, and two locking foot anchor pipes are provided in the width direction of each end.

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