A support system and construction method for dealing with the collapse of the arch of a layered tunnel.

Abstract

This invention provides a support system and construction method for handling the collapse of the arch of a layered tunnel, relating to the field of tunnel engineering. It includes a top rock reinforcement unit and a main tunnel structure located within the tunnel collapse zone. The system further includes arched I-beam units within the main tunnel structure to form initial support, and reinforced support structure units on these arched I-beam units to resist rock pressure in the collapse zone and enhance support strength. Through the coordination of these structures, the following beneficial effects are achieved: First, by using grouting anchors for asymmetric reinforcement of the layered rock mass, the integrity and self-supporting capacity of the top rock are maximized; second, by using spring rod support components to support and reinforce the surrounding rock, secondary collapses caused by excessive backfill concrete weight or poor rock adhesion are avoided, and a 10cm thick concrete sealing layer is laid on the surface of the surrounding rock using shotcrete technology.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering, and in particular to a support system and construction method for dealing with the collapse of the arch of a layered tunnel. Background Technology

[0002] Due to the special nature of tunnel engineering, the construction process inevitably disturbs the rock mass, which often leads to many engineering disasters during tunnel excavation. Among them, tunnel collapse is the most serious, often resulting in a large number of casualties and economic losses.

[0003] During tunnel construction, site conditions often limit comprehensive exploration, leading to significant variations in the geological environment ahead and unpredictable adverse geological conditions. This increases the risk of tunnel collapse, impacting construction progress and costs. For layered rock tunnels, the main characteristics are well-developed bedding and relatively poor interlayer cohesion, making the tunnel arch prone to collapse along bedding planes during construction. Once a collapse occurs, the volume is often substantial. Since tunnel collapses are unavoidable during construction, in addition to strengthening prevention, appropriate mitigation measures must be implemented.

[0004] Existing methods for managing tunnel collapses primarily involve concrete backfilling, but these methods fail to consider the weight of the concrete and the bonding with the surrounding rock, potentially leading to secondary collapses. Therefore, it is necessary to provide a method for handling tunnel arch collapses and a reinforcement support device to ensure safety during tunnel construction. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, the technical problem to be solved by this invention is to provide a support system and construction method for dealing with the collapse of the arch of a layered tunnel. This system can improve the integrity and stability of the surrounding rock of the arch of a layered rock tunnel through asymmetric grouting and anchor reinforcement, spring rod support, and steel arch frame sealing, effectively preventing the collapse of the surrounding rock and secondary collapse, and ensuring construction safety and efficiency.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: The present invention provides a support system and construction method for dealing with the collapse of the arch of a layered tunnel, including a top surrounding rock reinforcement unit and a tunnel main structure located in the tunnel collapse zone. The tunnel main structure is further provided with an arched I-beam unit located in the tunnel main structure to form initial support. A support structure reinforcement unit is provided on the arched I-beam unit to resist the rock pressure in the tunnel collapse zone and strengthen the support force.

[0007] In a preferred embodiment, the tunnel collapse zone includes the surrounding rock of the collapse zone arch, the collapse zone of the arch, and the surrounding rock of the tunnel.

[0008] The top surrounding rock reinforcement unit includes grouting anchors installed inside the arch crown surrounding rock in the collapse zone and distributed asymmetrically, as well as spring support rods asymmetrically installed in the arch crown collapse zone;

[0009] Grouting anchors are used to reinforce the surrounding rock in the arch collapse area. A layer of concrete is sprayed onto the surface of the surrounding rock in the arch collapse area to form a protective barrier.

[0010] In a preferred embodiment, multiple arched I-beam units are laid inside the surrounding rock of the tunnel. These arched I-beam units are equidistantly arranged along the axis of the main tunnel structure. The arch axis of the arched I-beam units matches the contour of the main tunnel structure. The ends of the spring support rods are placed on the arched I-beam units, and the tops are embedded in the concrete layer to abut against the surrounding rock in the arch collapse zone. Shotcreting is used to form an arched initial support structure between the I-beam units and the concrete layer inside the main tunnel structure to provide initial support.

[0011] In a preferred embodiment, the support structure reinforcement unit includes a first connecting rod group and a steel mesh respectively disposed on the outer diameter surface of the arched I-beam unit to form an outer protective structure for resisting the rock pressure of the surrounding rock at the top of the collapse zone.

[0012] The arched I-beam unit is also provided with a second connecting rod group at its center, as well as a supporting rod group that is symmetrically arranged on both sides of the inner diameter surface of the arched I-beam unit.

[0013] The second connecting rod group consists of multiple second guide pipes, and the first connecting rod group consists of multiple first guide pipes. The multiple first guide pipes and multiple second guide pipes are arranged at equal intervals along the arch axis of the arched I-beam unit.

[0014] In a preferred embodiment, the first guide pipe is located between the outer diameter surfaces of multiple arched I-beam units, and the second guide pipe passes through multiple arched I-beam units in sequence. The combination of the first guide pipe and the second guide pipe forms an integrated arched structure.

[0015] Steel mesh is laid over multiple first guide pipes to cover the outer surface of multiple arched I-beam units.

[0016] In the preferred embodiment, the support rod assembly includes a convex base, a threaded rod, a support top bracket, and a threaded sleeve;

[0017] The top of the support bracket is connected to the inner diameter surface of the arched I-beam unit, and one end of the threaded rod is embedded in the support bracket, while the other end extends into the interior of the internal threaded sleeve and is threadedly connected to the internal threaded sleeve. The threaded rod can rotate relative to the internal threaded sleeve and move axially along the internal threaded sleeve to adjust the extension and retraction length of the threaded rod within the internal threaded sleeve. The end of the internal threaded sleeve is connected to a convex base that abuts against the ground.

[0018] In a preferred embodiment, the present invention provides a construction method for a support system applied to the above-described treatment of layered tunnel arch collapse, comprising the following steps:

[0019] S1. Shotcrete and Grouting Anchor Reinforcement: When the tunnel collapse zone is encountered during the excavation of the main tunnel structure, shotcrete is first applied to the collapse zone of the arch crown to seal the surface. Then, grouting anchors are installed inside the surrounding rock of the arch crown in the collapse zone for reinforcement.

[0020] S2. Steel arch frame installation and initial support structure formation: After the top surrounding rock is reinforced with grouting anchors, steel arch frames are installed below. Each section of the steel arch frame is composed of multiple arched I-beam units to form a closed support structure.

[0021] S3. Layout of support rods and installation of spring support rods: In order to protect the unclosed steel arch support structure, support rod assemblies are arranged on the left and right sides of the steel arch to support the steel arch.

[0022] S4. Welding of connecting rods and steel mesh (9): The first connecting rod group is welded along the arch axis above the arch I-beam unit located at the arch top, connecting multiple sets of steel arch frames in front and behind to jointly bear the load. In addition, fine-hole steel mesh (9) is welded above multiple first connecting rod groups, and a closed initial support structure is formed by spraying concrete.

[0023] S5. Removal of Support Rod Assembly and Final Closure: Before the initial support is shotcreted, the support rod assembly is removed. At this time, the steel arch frame that is closed in front and not closed in the rear is connected by the second connecting rod assembly and the first connecting rod assembly, which plays an auxiliary support role.

[0024] In the preferred embodiment, in step S1, based on the layered rock mass characteristics of the surrounding rock of the arch in the collapse area, the grouting anchors are asymmetrically distributed, including in-layer anchors, out-of-layer anchors and bottom anchors, and are arranged differently according to the different characteristics of the in-layer anchors, out-of-layer anchors and bottom anchors.

[0025] Among them, the reinforcement angle of the bedding-parallel anchor bolts is arranged parallel to the bedding plane of the surrounding rock at the top of the collapse zone;

[0026] The reinforcement angle of the reverse-layer anchor bolts is perpendicular to the bedding plane of the surrounding rock at the top of the collapse zone;

[0027] The bottom anchor bolts are arranged at a certain angle to intersect the bedding planes of the surrounding rock at the top of the collapse zone.

[0028] In the preferred embodiment, in step S4, a second row of connecting rods is welded at the center of the arched I-beam unit to connect the multiple sets of steel arch frames in front and behind again.

[0029] In the preferred embodiment, in step S4, the stability of the structure can be determined by a specific algorithm for the arched I-beam unit and its corresponding second and first connecting rod groups. The formula calculation process is as follows:

[0030] S41, Input parameters;

[0031] S42. Calculation process:

[0032] Calculation of the distance from the centroid to the outermost edge of an arched I-beam unit section:

[0033] The centroid coordinates of the arched I-beam element are The radius of curvature is Then from the centroid to the outermost edge of the arc The distance formula is:

[0034] ;

[0035] Through the radius of curvature Calculate the degree of arch curvature and the expected maximum bearing capacity threshold, then the bending moment... The formula:

[0036] ;

[0037] in, It is a force. It refers to the span, and the simplified representation of the arch support is... ;

[0038] For an arched I-beam element, the bending moment The section modulus, calculated using structural mechanics methods, can be determined based on the load distribution and the shape of the arch axis. Therefore, the formula for the section modulus is:

[0039] ;

[0040] in, For the moment of inertia, This is the distance from the centroid of the cross section to the outermost edge;

[0041] According to the bending stress formula in mechanics of materials, and substituting into the formula... and The maximum bending stress of the arched I-beam unit is:

[0042] ;

[0043] in, For bending moment, The section modulus is the bending section modulus.

[0044] The tensile strength of the steel selected for the arched I-beam unit is obtained as follows: Then a safety factor is introduced. To calculate the allowable bending stress for:

[0045] ;

[0046] Among them, the safety factor The value ranges from 1.5 to 3.0;

[0047] After comparing the maximum bending stress and allowable bending stress The values ​​between these ranges are used to ensure structural safety, i.e., the maximum load-bearing capacity threshold. The following conditions must be met:

[0048] ;

[0049] Among them, if Exceed If necessary, adjust the cross-sectional dimensions and change the material parameters until the safety requirements are met.

[0050] Therefore, the maximum bearing capacity threshold The calculation formula is as follows:

[0051] ;

[0052] Substitution ,available:

[0053] ;

[0054] Next, based on factors such as steel strength and load distribution, the optimal diameter of the first guide pipe in the first connecting rod group is determined by an algorithm. ,quantity and layout;

[0055] Obtain the yield strength of the material selected for the first guide pipe and load Then the cross-sectional area of ​​the first guide tube member is:

[0056] ;

[0057] Next, based on the diameter of the rod in the first guide pipe... The calculation formula is determined as follows:

[0058] ;

[0059] Finally, quantity It can be determined based on the span of the structure, load distribution, and connection requirements;

[0060] The layout can be uniform or optimized according to areas of concentrated load.

[0061] Therefore, the maximum bearing capacity of the first connecting member group can be calculated using the following formula:

[0062] ;

[0063] in, The yield strength of the material is selected for the first guide pipe. For the cross-sectional area of ​​a single first conductor pipe, The number of the first-stage take-off;

[0064] Based on the number and layout of the first guide pipes in the first connecting rod group, the coverage area of ​​the steel mesh is adjusted accordingly. ;

[0065] The width of the steel mesh is , length is The coverage area Determined by the following formula:

[0066] ;

[0067] The width of the reinforcing mesh can be determined based on the spacing and distribution of the first guide pipes in the first connecting member group. and length ;

[0068] If the spacing between each first guide tube in the first connecting rod group is The width of the steel mesh is... It can be taken as:

[0069] ;

[0070] in, The number of the first-stage take-off;

[0071] Tensile strength of steel mesh The enhancement effect on the overall load-bearing capacity can be calculated using the following formula:

[0072] ;

[0073] in, The yield strength of the steel reinforcement. This represents the cross-sectional area of ​​the steel mesh.

[0074] A second row of connecting rods was welded at the center of the arched I-beam unit. This second connecting rod group consists of... It consists of two second guide pipes, each with a cross-sectional area of ​​[missing information]. The yield strength of the material selected for the second guide pipe is... ;

[0075] For the cross-sectional area of ​​the rod Its diameter is ,but:

[0076] ;

[0077] Among them, the diameter here ,quantity and yield strength The maximum bearing capacity of the second connecting member group can be determined based on the steel properties used in the actual construction project. The formula for calculating the maximum bearing capacity of the second connecting member group is as follows:

[0078] ;

[0079] Comprehensive analysis shows that the maximum load-bearing capacity of the arched I-beam unit is The maximum bearing capacity of the first connecting rod group is The maximum bearing capacity of the second connecting rod group is The tensile strength of the steel mesh is The interaction coefficients between the parts are ,and Then the comprehensive bearing capacity threshold The formula is:

[0080] ;

[0081] S43. Output result:

[0082] The predicted comprehensive carrying capacity threshold Output to achieve relevant safety performance indicators.

[0083] This invention provides a support system and construction method for dealing with the collapse of the arch of a layered tunnel. Through the cooperation between the above structures, the following beneficial effects can be achieved:

[0084] First, by using grouting anchors to asymmetrically reinforce the layered rock mass, the integrity and self-supporting capacity of the top surrounding rock were maximized, preventing further loosening and collapse of the surrounding rock.

[0085] Secondly, by using spring rod support components to support and reinforce the surrounding rock, the traditional method of backfilling concrete is replaced, avoiding secondary collapse caused by excessive weight of backfill concrete or poor adhesion of the surrounding rock. This method is safer and more reliable. At the same time, a 10cm thick concrete sealing layer is laid on the surface of the surrounding rock using shotcrete technology, and the top of the spring rod is embedded in it. The bottom is connected to the double-layer internal steel frame of the support by bolts and welded steel plates, ensuring the firmness and stability of the support components.

[0086] Third, steel arch frames, in conjunction with the first and second connecting rods, are used to completely seal the collapsed cavity, providing effective support and load-bearing capacity. In particular, temporary jacking devices can be used in the roof collapse area to ensure the safety and stability of the initial support structure during the collapse control period, and to protect the safety of construction personnel and equipment. Attached Figure Description

[0087] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0088] Figure 1 This is a schematic diagram of the grouting anchor structure of the present invention;

[0089] Figure 2 This is a schematic diagram of the asymmetric support structure of the tunnel main structure of the present invention;

[0090] Figure 3 This is the present invention. Figure 2 A three-dimensional diagram;

[0091] Figure 4 This is a schematic diagram of the construction method of the present invention.

[0092] In the diagram: 1. Tunnel collapse zone; 11. Cavity rock of the collapse zone arch; 12. Cavity collapse zone; 13. Tunnel surrounding rock; 2. Grouting anchor; 3. Spring support rod; 4. Concrete layer; 5. Initial support structure; 6. Arch-shaped I-beam unit; 7. Second connecting rod group; 8. First connecting rod group; 9. Steel mesh; 10. Support rod group; 11. Convex base; 12. Threaded rod; 13. Support top support; 14. Threaded sleeve. Detailed Implementation

[0093] To better understand the purpose, structure, and function of this invention, the embodiments and features described herein can be combined with each other without conflict. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0094] Example 1

[0095] like Figures 1 to 3 As shown, a support system for dealing with the collapse of the arch of a layered rock tunnel includes a top rock reinforcement unit and a main tunnel structure located within the tunnel collapse zone 1. The system also includes an arched I-beam unit 6 located within the main tunnel structure to form initial support. A support structure reinforcement unit is installed on the arched I-beam unit 6 to resist rock pressure in the tunnel collapse zone 1 and enhance support. The top rock is reinforced using methods such as anchor bolts and grouting to prevent further rock slippage or collapse and ensure construction safety.

[0096] In the preferred scheme, such as Figure 1As shown, the tunnel collapse zone 1 includes the surrounding rock of the collapse zone arch 11, the arch collapse zone 12, and the surrounding rock of the tunnel 13;

[0097] Specifically, the collapsed arch surrounding rock 11 is located at the top of the tunnel main structure and is a key pressure-bearing area of ​​the tunnel structure. The arch collapse zone 12 refers to the arch area with potential collapse risk. The tunnel surrounding rock 13 is the rock mass surrounding the tunnel main structure, providing natural support to the tunnel main structure.

[0098] The top surrounding rock reinforcement unit includes grouting anchors 2 asymmetrically distributed inside the arch-top surrounding rock 11 in the collapse zone, and spring support rods 3 asymmetrically arranged in the arch-top collapse zone 12, used to provide immediate support force and prevent further collapse of the surrounding rock. The spring support rods 3 have a certain elastic deformation capacity and can automatically adjust under pressure to maintain the support effect.

[0099] Specifically, by injecting cement grout into the grouting anchor 2 under high pressure, the grouting anchor 2 is tightly bonded to the surrounding rock of the arch collapse zone 12, thereby improving the integrity and shear strength of the surrounding rock of the arch collapse zone 12 and effectively reinforcing the surrounding rock of the arch collapse zone 12.

[0100] Furthermore, the grouting anchor 2 is used to reinforce the surrounding rock of the arch collapse zone 12. A concrete layer 4 is sprayed onto the surface of the surrounding rock of the arch collapse zone 12 to form a protective barrier and further reinforce the surface of the surrounding rock of the arch collapse zone 12, preventing weathering, spalling and other phenomena, and improving the safety of the overall structure to protect and reinforce the surface of the surrounding rock of the arch collapse zone 12.

[0101] In the preferred scheme, such as Figure 1 , 2 As shown, multiple arched I-beam units 6 are laid inside the tunnel surrounding rock 13. The multiple arched I-beam units 6 are equidistantly arranged along the axis of the main tunnel structure and customized according to the shape of the tunnel cross section. Their arch axis matches the tunnel outline to provide uniform pressure distribution and effective structural support. The ends of the spring support rods 3 are set on the arched I-beam units 6, and the tops are embedded in the concrete layer 4 to abut against the surrounding rock on the arch collapse zone 12. By spraying grout, the I-beam units 6 and the concrete layer 4 form an arched initial support structure 5 inside the main tunnel structure to provide initial support.

[0102] In the preferred scheme, such as Figure 2 , 3As shown, the support structure reinforcement unit includes a first connecting rod group 8 and a steel mesh 9 respectively located on the outer diameter surface of the arched I-beam unit 6, forming an outer protective structure to resist the rock pressure from the surrounding rock 11 of the arch crown in the collapse zone, thereby enhancing the stability and bearing capacity of the overall structure and ensuring that the tunnel can maintain safety and stability even under complex geological conditions. The arched I-beam unit 6 is provided with a second connecting rod group 7 at its center position, as well as a support rod group 10 located on both sides of the inner diameter surface of the arched I-beam unit 6 and arranged symmetrically.

[0103] Among them, the second connecting rod group 7, as the core part of the internal support system, ensures that the arch structure will not buckle or deform when subjected to high pressure, thereby improving the reliability and safety of the overall structure. In addition, the support rod group 10 provides necessary lateral support for the internal structure, ensuring that the arch structure remains stable when under stress, and avoiding displacement or tilting caused by lateral forces.

[0104] It should be noted that the second connecting rod group 7 is composed of multiple second guide pipes, and the first connecting rod group 8 is composed of multiple first guide pipes. The multiple first guide pipes and multiple second guide pipes are arranged at equal intervals along the arch axis of the arched I-beam unit 6, which ensures that the structure is subjected to uniform stress and avoids the occurrence of stress concentration.

[0105] Specifically, the first connecting rod group 8 not only enhances the rigidity of the external structure, but also effectively transmits and disperses the rock pressure from the surrounding rock 11 of the arch in the collapse zone. The main function of the second connecting rod group 7 is to provide internal support and enhance the compressive strength and overall rigidity of the arched I-beam unit 6.

[0106] Furthermore, the first guide pipes are located between the outer diameter surfaces of multiple arched I-beam units 6, serving as lateral connectors to ensure a tight connection between adjacent units. These first guide pipes are equidistantly arranged along the arch axis, providing necessary lateral support and helping to evenly distribute external loads. The second guide pipes sequentially penetrate multiple arched I-beam units 6, serving as another lateral connector to achieve continuous connection between multiple units. The second guide pipes not only enhance the overall rigidity of the structure but also ensure the stability and compressive strength of the structure under complex geological conditions. Through the combined use of the first and second guide pipes, multiple arched I-beam units 6 can be tightly connected to form an integrated arch structure, effectively improving the overall strength and stability of the structure. The reinforcing mesh 9 is laid above the multiple first guide pipes to cover the outer surface of the multiple arched I-beam units 6. The reinforcing mesh 9 increases the integrity and shear resistance of the surface, further enhancing the overall integrity and compressive strength of the structure. Together with the multiple first guide pipes, it forms a robust protective barrier to prevent the direct impact of surrounding rock pressure on the arch structure.

[0107] Specifically, through the dual connection of the first and second guide pipes, and the coverage of the steel mesh 9, the entire arch structure not only has strong compressive strength, but also effectively resists the rock pressure from the surrounding rock 11 of the arch crown in the collapse zone. Even under complex geological conditions, it can maintain the safety and stability of the tunnel. In addition, under the synergistic effect of the first and second guide pipes, the external load can be evenly distributed on each arch I-beam unit 6, avoiding the problem of local stress concentration, so as to extend the service life of the structure.

[0108] In this embodiment, the support rod assembly 10 includes a convex base 101, a threaded rod 102, a support top 103, and a threaded sleeve 104.

[0109] The top of the support 103 is connected to the inner diameter surface of the arched I-beam unit 6, and one end of the threaded rod 102 is embedded in the support 103, while the other end extends into the inner threaded sleeve 104 and is threadedly connected to the threaded sleeve 104. The threaded rod 102 can rotate relative to the inner threaded sleeve 104 and move axially along the threaded sleeve 104 to adjust the extension length of the threaded rod 102 within the inner threaded sleeve 104. The end of the threaded sleeve 104 is connected to the convex base 101 that abuts against the ground, providing a stable support foundation. Its convex structure can increase the contact area between the convex base 101 and the ground, improving its anti-slip capability.

[0110] In practice, the support top 103 is firmly connected to the arched I-beam unit 6. By rotating the threaded rod 102, its extension length within the threaded sleeve 104 can be changed, thereby fine-tuning the overall height of the support rod assembly 10. This allows the support rod assembly 10 to adapt to different geological conditions and construction requirements, ensuring the best support effect. In addition, the support force is transmitted from the ground to the threaded sleeve 104 through the convex base 101, and then to the support top 103 through the threaded rod 102, ultimately acting on the arched I-beam unit 6. This ensures that the threaded rod 102 can stably transmit the support force from the ground to the arched I-beam unit 6.

[0111] Example 2

[0112] Further explanation based on Example 1, such as Figure 4 The construction method for the support system used to handle the collapse of the arch of a layered tunnel, as shown, includes the following steps:

[0113] S1. Concrete spraying and grouting anchor 2 reinforcement: When the tunnel collapse zone 1 is encountered during the excavation of the main tunnel structure, the surface of the collapse zone 12 of the arch is first sprayed with concrete to seal it. Then, grouting anchor 2 is installed inside the surrounding rock 11 of the arch in the collapse zone for reinforcement.

[0114] Specifically, in step S1, based on the layered rock mass characteristics of the surrounding rock 11 of the arch in the collapse area, the grouting anchor bolts 2 are asymmetrically distributed, including the bedding anchor bolts, the reverse bedding anchor bolts and the bottom anchor bolts, and are arranged differently according to the different characteristics of the bedding anchor bolts, the reverse bedding anchor bolts and the bottom anchor bolts.

[0115] Among them, the reinforcement angle of the bedding-parallel anchor bolts is arranged parallel to the bedding plane of the surrounding rock 11 in the collapse zone, which means that they directly pass through the bedding plane, effectively preventing slippage along the bedding plane and enhancing interlayer bonding.

[0116] The reinforcement angle of the reverse-bedding anchor is arranged perpendicular to the bedding plane of the surrounding rock 11 in the collapse zone, which helps to provide lateral support, prevents the rock mass from moving in the horizontal direction, and facilitates installation.

[0117] The bottom anchor rods are arranged at a certain angle to intersect the bedding plane of the surrounding rock 11 in the collapsed area to ensure convenient installation.

[0118] The asymmetrical arrangement ensures ease of installation, especially since the layered anchor bolts are easier to construct, and maximizes the support effect of the anchor bolts in the main structure of the layered surrounding rock tunnel, thereby enhancing the stability and safety of the overall structure.

[0119] S2. Steel arch frame installation and initial support structure 5 formation: After the top surrounding rock is reinforced by grouting anchor rods 2, steel arch frames are installed below. Each section of the steel arch frame is composed of multiple arched I-beam units 6 to form a closed support structure.

[0120] Specifically, the initial closed support structure 5 can only be formed after all the excavation from top to bottom is completed, and this process requires multiple excavation advances.

[0121] S3. Layout of support rod assembly 10 and installation of spring support rod 3: In order to protect the unclosed steel arch support structure, support rod assembly 10 is arranged on the left and right sides of the steel arch to support the steel arch.

[0122] In step S3, a spring support rod 3 is installed between the steel arch frame and the arch collapse zone 12. One end is welded to the top of the steel arch frame, and the other end is pressed against the concrete sprayed on the surface of the surrounding rock. Then, a 10cm thick layer of arch collapse zone 12 is sprayed to fix the top of the spring support rod 3.

[0123] S4. Welding of connecting rods and steel mesh (9): The first connecting rod group 8 is welded above the arch I-beam unit 6 located at the arch top along the arch axis to connect multiple sets of steel arch frames in front and behind to jointly bear the load. In addition, fine-hole steel mesh (9) is welded above multiple first connecting rod groups 8 to prevent subsequent collapse and facilitate subsequent top sprayed concrete to form a closed initial support structure 5. This can avoid uneven spraying and uneven distribution of top concrete, which can cause structural hollowing and leave safety hazards.

[0124] It should be noted that in step S4, a row of second connecting rods 7 is welded at the center of the arched I-beam unit 6 to weld the multiple sets of steel arch frames together again, which serves as a secondary reinforcement.

[0125] In the preferred embodiment, in step S4, the stability of the structure can be determined by a specific algorithm for the arched I-beam unit 6 and its cooperating second connecting rod group 7 and first connecting rod group 8. The formula calculation process is as follows:

[0126] S41. Input parameters:

[0127] The geometric dimensions of arched I-beam unit 6.

[0128] The shape and radius of curvature of the arch axis.

[0129] Material properties (such as steel strength).

[0130] S42. Calculation process:

[0131] Calculation of moment of inertia for arched I-beam element 6:

[0132] When the cross-section of arched I-beam element 6 is curved, the calculation of the moment of inertia is more complex than that of a regular straight I-beam. For curved cross-sections, the integral method can be used to calculate the moment of inertia. Therefore, the equation of the cross-sectional curve of arched I-beam element 6 is:

[0133] ;

[0134] in, and These are points on the coordinate axes within the cross-sectional plane, and the arc is rotated around a certain axis to form the cross-section.

[0135] In the calculation of moment of inertia, for a planar cross-section, the moment of inertia is calculated around the cross-section. Calculate the moment of inertia of the axis Then the moment of inertia The defining formula is:

[0136] ;

[0137] in, Let the area be the infinitesimal element. for the area of ​​the infinitesimal element arrive For curved cross-sections, the distance between axes cannot be simply calculated using the area formulas for rectangles or other regular shapes to determine the moment of inertia. Therefore, the curved cross-section needs to be divided into countless tiny area units. and will use and Show it.

[0138] That is, let the thickness of the arc be... And thickness If the cross-section is uniform, then the formula is:

[0139] ;

[0140] in, yes The first derivative, Indicates in A small length increment in the axial direction, In the arc curve Above, due to Incremental length along the axis The resulting increase in arc length, when multiplied by the other two, yields the area of ​​the infinitesimal element enclosed by this tiny increase in length and thickness. Then the moment of inertia Determined by the following formula:

[0141] ;

[0142] The above integral needs to be calculated based on the specific functional expression of the arc, and the formula for arched I-beam element 6 is as follows:

[0143] ;

[0144] in, If it is one of the following: minor arc, major arc, semicircle, or quadrant arc, then Substitute the moment of inertia From the formula, we can obtain:

[0145] ;

[0146] The value of the moment of inertia can be obtained through a series of complex integral operations.

[0147] Calculation of the centroid position of section 6 of the arched I-beam unit:

[0148] Calculating the centroid position of an arc-shaped I-beam cross-section is also quite complex. For a planar curved cross-section, the centroid coordinates... The calculation formulas are as follows:

[0149] ;

[0150] ;

[0151] in, It is the cross-sectional area. The representation method is the same as the previous moment of inertia. The calculations are the same.

[0152] Taking the arched I-beam unit 6 in this embodiment as an example, the cross-sectional area is first calculated using the following formula:

[0153] ;

[0154] Thickness is Then, by integration... and ,for ,but:

[0155] ;

[0156] Substitution and We can obtain:

[0157] ;

[0158] The centroid is determined by integration. coordinate.

[0159] Calculation of the distance from the centroid to the outermost edge of section 6 of the arched I-beam unit:

[0160] After calculating the centroid position using the above formula, the calculation of the distance from the centroid to the outermost edge needs to take into account the geometry of the arc.

[0161] For arched I-beam element 6, if the distance from a point within the cross-section to the centroid is taken as the outermost edge distance, it needs to be determined through geometric relationships.

[0162] Using the centroid coordinates of the arched I-beam unit 6 in this embodiment as The radius of curvature is Then from the centroid to the uppermost edge of the semicircle The distance formula is:

[0163] ;

[0164] Degree of bending and load-bearing capacity estimation:

[0165] The degree of arch bending and the expected maximum bearing capacity threshold are calculated by using the radius of curvature. Then the bending moment... The formula:

[0166] ;

[0167] in, It is a force. It refers to the span; a simply supported arch is simplified as... .

[0168] For arched I-beam element 6, bending moment The section modulus, calculated using structural mechanics methods, can be determined based on the load distribution and the shape of the arch axis. Therefore, the formula for the section modulus is:

[0169] ;

[0170] in, For the moment of inertia, This is the distance from the centroid of the cross section to the outermost edge.

[0171] According to the bending stress formula in mechanics of materials, and substituting into the formula... and The maximum bending stress of arched I-beam unit 6 is:

[0172] ;

[0173] in, For bending moment, This is the section modulus for bending resistance.

[0174] The tensile strength of the steel selected for arched I-beam unit 6 is obtained as follows: Then a safety factor is introduced. To calculate the allowable bending stress for:

[0175] ;

[0176] Among them, the safety factor The value ranges from 1.5 to 3.0.

[0177] After comparing the maximum bending stress and allowable bending stress The values ​​between these ranges are used to ensure structural safety, i.e., the maximum load-bearing capacity threshold. The following conditions must be met:

[0178] ;

[0179] Among them, if Exceed If so, the design parameters need to be adjusted, such as increasing the cross-sectional dimensions or changing the materials, until the safety requirements are met.

[0180] Therefore, the maximum bearing capacity threshold The calculation formula is as follows:

[0181] ;

[0182] Substitution ,available:

[0183] ;

[0184] Next, based on factors such as steel strength and load distribution, the optimal diameter of the first guide pipe in the first connecting rod group 8 is determined by an algorithm. ,quantity and layout.

[0185] Obtain the yield strength of the material selected for the first guide pipe and load Then the cross-sectional area of ​​the first guide tube member is:

[0186] ;

[0187] Next, based on the diameter of the rod in the first guide pipe... The calculation formula is determined as follows:

[0188] ;

[0189] Finally, quantity It can be determined based on the span of the structure, load distribution, and connection requirements.

[0190] Specifically, quantity The higher the value, the better the connection stability, but this also increases the cost and construction difficulty.

[0191] The layout can be uniform or optimized based on areas of concentrated load.

[0192] Therefore, the maximum bearing capacity of the first connecting member group 8 can be calculated using the following formula:

[0193] ;

[0194] in, The yield strength of the material is selected for the first guide pipe. For the cross-sectional area of ​​a single first conductor pipe, This refers to the number of units taken over by the first leader.

[0195] In addition, it is necessary to determine the coverage area of ​​the steel mesh 9:

[0196] Based on the number and layout of the first guide pipes in the first connecting rod group 8, the coverage area of ​​the steel mesh 9 is adjusted accordingly. .

[0197] The width of the steel mesh 9 is... , length is The coverage area Determined by the following formula:

[0198] ;

[0199] The width of the reinforcing mesh can be determined based on the spacing and distribution of the first guide pipes in the first connecting member group 8. and length .

[0200] If the spacing between each first guide tube in the first connecting rod group 8 is Then the width of the steel mesh 9 It can be taken as:

[0201] ;

[0202] in, This refers to the number of first guide pipes in the above formula.

[0203] Tensile strength of steel mesh 9 The enhancement effect on the overall load-bearing capacity can be calculated using the following formula:

[0204] ;

[0205] in, The yield strength of the steel reinforcement. This represents the cross-sectional area of ​​the steel mesh 9.

[0206] A row of second connecting rod groups 7 was welded at the center of the arched I-beam unit 6, wherein the second connecting rod group 7 consists of... It consists of two second guide pipes, each with a cross-sectional area of ​​[missing information]. The yield strength of the material selected for the second guide pipe is... .

[0207] For the cross-sectional area of ​​the rod Its diameter is ,but:

[0208] ;

[0209] Among them, the diameter here ,quantity and yield strength The maximum bearing capacity of the second connecting member group 7 can be determined based on the steel properties in the actual construction project. The formula for calculating the maximum bearing capacity of the second connecting member group 7 is as follows:

[0210] ;

[0211] Based on the above formulas, the maximum load-bearing capacity of the arched I-beam unit 6 is: The maximum bearing capacity of the first connecting rod group 8 is The maximum bearing capacity of the second connecting rod group 7 is The tensile strength of steel mesh 9 is .

[0212] Considering that the entire structure works collaboratively, the comprehensive load-bearing capacity threshold It's not a simple addition; the interaction coefficients between the parts need to be considered. ,and Generally less than 1, then the comprehensive bearing capacity threshold is... The formula is:

[0213] ;

[0214] This comprehensive bearing capacity threshold The formula takes into account the combined bearing capacity of the arched I-beam unit 6 itself, the first connecting rod group 8, the second connecting rod group 7, and the steel mesh 9. In actual engineering design, it can be used to evaluate the safety of the structure under various loads.

[0215] S43. Output result:

[0216] The predicted comprehensive carrying capacity threshold Output to achieve relevant safety performance indicators.

[0217] S5. Removal of support rod assembly 10 and final closure: Before the initial support is shotcreted, the support rod assembly 10 is removed. At this time, the steel arch frame that is closed in front and not closed in the rear is connected by the second connecting rod assembly 7 and the first connecting rod assembly 8, which plays a role in auxiliary support.

[0218] Example 3

[0219] To further illustrate, in conjunction with Examples 1 and 2, the electronic equipment used in the construction method for a support system applied to handle the collapse of the arch of a layered tunnel includes:

[0220] Memory, processor, and computer programs stored in memory and capable of running on the processor.

[0221] When the processor executes the program, it implements the construction method of the support system for handling the collapse of the arch of a layered tunnel provided in the above embodiments.

[0222] Furthermore, electronic devices also include:

[0223] A communication interface used for communication between the memory and the processor.

[0224] Memory is used to store computer programs that can run on the processor.

[0225] The memory may include high-speed RAM, and may also include non-volatile memory, such as at least one disk drive.

[0226] If the memory, processor, and communication interface are implemented independently, they can be interconnected via a bus to communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0227] A processor may include one or more processing units, such as an application processor (AP), an application-specific integrated circuit (ASIC), a modem processor, a central processing unit (CPU), an image signal processor (ISP), a controller, memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors. The controller may serve as a central nervous system and command center. The controller generates operation control signals based on instruction opcodes and timing signals to control instruction fetching and execution. The processor may also include memory for storing instructions and data. In some embodiments, the memory in the processor is a cache memory. This memory can store instructions or data that the processor has recently used or that is used repeatedly. If the processor needs to reuse the instruction or data, it can directly retrieve it from the memory. This avoids repeated access, reduces processor waiting time, and thus improves system efficiency.

[0228] Alternatively, in a specific implementation, if the memory, processor, and communication interface are integrated on a single chip, then the memory, processor, and communication interface can communicate with each other through an internal interface.

[0229] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described construction method for a support system to handle the collapse of a layered tunnel arch.

[0230] This application also provides a computer program product that can run computer instructions, which, when executed by a processor, implement the above-described construction method for a support system to handle the collapse of the arch of a layered tunnel.

[0231] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0232] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0233] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0234] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0235] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0236] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0237] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0238] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A construction method for a support system for dealing with the collapse of the arch of a layered tunnel, characterized in that, Includes the following steps: S1. Concrete spraying and grouting anchor (2) reinforcement: When the tunnel collapse zone (1) is encountered during the excavation of the main tunnel structure, the surface of the collapse zone (12) of the arch is first sprayed with concrete to seal the surface, and then grouting anchor (2) is installed inside the surrounding rock (11) of the arch in the collapse zone for reinforcement. S2, Steel arch frame installation and initial support structure (5) formation: After the top surrounding rock is reinforced by grouting anchor rods (2), steel arch frames are installed below. Each section of the steel arch frame is composed of multiple arched I-beam units (6) to form a closed support structure. S3, Layout of support rod group (10) and installation of spring support rod (3): In order to protect the unclosed steel arch support structure, support rod group (10) is laid out on the left and right sides of the steel arch to support the steel arch. S4. Welding of connecting rods and steel mesh (9): The first connecting rod group (8) is welded above the arch I-beam unit (6) located at the arch top along the arch axis to connect multiple sets of steel arch frames in front and behind to jointly bear the load. In addition, fine-hole steel mesh (9) is welded above multiple first connecting rod groups (8) and a closed initial support structure (5) is formed by spraying concrete. S5. Removal of support rod group (10) and final closure: Before the initial support is shotcreted, the support rod group (10) is removed. At this time, the steel arch frame that is closed in front and not closed in the back is connected by the second connecting rod group (7) and the first connecting rod group (8) to play the role of auxiliary support. The invention includes a top rock reinforcement unit and a tunnel main structure located in the tunnel collapse zone (1). The invention is characterized by the presence of an arched I-beam unit (6) located within the tunnel main structure to form initial support. A support structure reinforcement unit is provided on the arched I-beam unit (6) to resist the rock pressure in the tunnel collapse zone (1) and strengthen the support force. The tunnel collapse zone (1) includes the surrounding rock of the collapse zone arch (11), the arch collapse zone (12), and the surrounding rock of the tunnel (13). The top surrounding rock reinforcement unit includes grouting anchors (2) installed inside the arch surrounding rock (11) in the collapse area and distributed asymmetrically, and spring support rods (3) installed asymmetrically in the arch collapse area (12). Grouting anchors (2) are used to reinforce the surrounding rock of the collapsed area (12) of the arch. A layer of concrete (4) is sprayed on the surface of the surrounding rock of the collapsed area (12) of the arch to form a protective barrier. Multiple arched I-beam units (6) are laid inside the surrounding rock (13) of the tunnel. The multiple arched I-beam units (6) are arranged at equal intervals along the axis of the main tunnel structure. The arch axis of the arched I-beam unit (6) matches the outline of the main tunnel structure. The end of the spring support rod (3) is placed on the arched I-beam unit (6), and the top is embedded in the concrete layer (4) to abut against the surrounding rock in the arch collapse zone (12). The arched I-beam unit (6) and the concrete layer (4) are sprayed to form an arched initial support structure (5) inside the main tunnel structure to provide initial support.

2. The construction method of the support system for treating the collapse of the arch of a layered tunnel according to claim 1, characterized in that, In step S1, based on the layered rock mass characteristics of the surrounding rock (11) of the arch in the collapse area, the grouting anchors (2) are asymmetrically distributed, including the layered anchors, the reverse layer anchors and the bottom anchors, and are arranged differently according to the different characteristics of the layered anchors, the reverse layer anchors and the bottom anchors. Among them, the reinforcement angle of the bedding anchor is arranged parallel to the bedding plane of the surrounding rock (11) of the arch in the collapse area; The reinforcement angle of the reverse layer anchor is perpendicular to the bedding plane of the surrounding rock (11) of the arch in the collapse area; The bottom anchor rods are arranged at a certain angle to intersect the bedding plane of the surrounding rock (11) at the top of the collapsed area.

3. The construction method of the support system for treating the collapse of the arch of a layered tunnel according to claim 1, characterized in that, In step S4, a second connecting rod group (7) is welded at the center of the arched I-beam unit (6) to connect the multiple sets of steel arch frames in front and behind again.

4. The construction method of the support system for treating the collapse of the arch of a layered tunnel according to claim 1, characterized in that, In step S4, the stability of the structure is determined by the following calculation process for the arched I-beam unit (6) and its corresponding second connecting rod group (7) and first connecting rod group (8): S41, Input parameters; S42. Calculation process: Calculation of the distance from the centroid of the section to the outermost edge of the arched I-beam unit (6): The centroid coordinates of the arched I-beam unit (6) are: The radius of curvature is Then from the centroid to the outermost edge of the arc The distance formula is: ； Through the radius of curvature Calculate the degree of arch curvature and the expected maximum bearing capacity threshold, then the bending moment... The formula: ； in, It is a force. It refers to the span, and the simplified representation of the arch support is... ; For the arched I-beam unit (6), the bending moment The section modulus is calculated using structural mechanics methods and determined based on load distribution and the shape of the arch axis. Therefore, the formula for the section modulus is: ； in, For the moment of inertia, This is the distance from the centroid of the cross section to the outermost edge; According to the bending stress formula in mechanics of materials, and substituting into the formula... and Then the maximum bending stress of the arched I-beam unit (6) is: ； in, For bending moment, The section modulus is the bending section modulus. The tensile strength of the steel selected for the arched I-beam unit (6) is: Then a safety factor is introduced. To calculate the allowable bending stress for: ； Among them, the safety factor The value ranges from 1.5 to 3.0; After comparing the maximum bending stress and allowable bending stress The values ​​between these ranges are used to ensure structural safety, i.e., the maximum load-bearing capacity threshold. The following conditions must be met: ； Among them, if Exceed If necessary, adjust the cross-sectional dimensions and change the material parameters until the safety requirements are met. Therefore, the maximum bearing capacity threshold The calculation formula is as follows: ； Substitution ,get: ； Next, based on the steel strength and load distribution factors, the optimal diameter of the first guide pipe in the first connecting rod group (8) is determined by algorithm. ,quantity and layout; Obtain the yield strength of the material selected for the first guide pipe and load Then the cross-sectional area of ​​the first guide tube member is: ； Next, based on the diameter of the rod in the first guide pipe... The calculation formula is determined as follows: ； Finally, quantity Determined based on the structure's span, load distribution, and connection requirements; The layout can be uniformly distributed or optimized according to areas of concentrated load. Then, the maximum bearing capacity of the first connecting rod group (8) is calculated by the following formula: ； in, The yield strength of the material to be selected for the first guide pipe is... For the cross-sectional area of ​​a single first conductor pipe, The number of the first-stage take-off; Based on the number and layout of the first guide pipes in the first connecting rod group (8), the coverage area of ​​the steel mesh (9) is adjusted accordingly. ; The width of the steel mesh (9) is , length is The coverage area Determined by the following formula: ； The width of the steel mesh is determined based on the spacing and distribution of the first guide pipe in the first connecting rod group (8). and length ; If the spacing of each first guide tube in the first connecting rod group (8) is The width of the steel mesh (9) Take as: ； in, The number of the first-stage take-off; Tensile strength of steel mesh (9) The enhancement effect on the overall load-bearing capacity is calculated using the following formula: ； in, The yield strength of the steel reinforcement. The cross-sectional area of ​​the steel mesh (9) is given. A second connecting rod group (7) was welded at the center of the arched I-beam unit (6), wherein the second connecting rod group (7) consists of... It consists of two second guide pipes, each with a cross-sectional area of ​​[missing information]. The yield strength of the material selected for the second guide pipe is... ; For the cross-sectional area of ​​the rod Its diameter is ,but: ； Among them, the diameter here ,quantity and yield strength Based on the actual steel properties in the construction project, the formula for calculating the maximum bearing capacity of the second connecting member group (7) is as follows: ； Comprehensive analysis shows that the maximum bearing capacity of the arched I-beam unit (6) is The maximum bearing capacity of the first connecting rod group (8) is The maximum bearing capacity of the second connecting rod group (7) is The tensile strength of the steel mesh (9) is The interaction coefficients between the parts are ,and Then the comprehensive bearing capacity threshold The formula is: ； S43. Output result: The predicted comprehensive carrying capacity threshold Output to achieve relevant safety performance indicators.

5. The construction method of the support system for treating the collapse of the arch of a layered tunnel according to claim 1, characterized in that, The support structure reinforcement unit includes a first connecting rod group (8) and a steel mesh (9) respectively located on the outer diameter surface of the arched I-beam unit (6) to form an outer protective structure to resist the rock pressure of the surrounding rock (11) of the arch in the collapse zone; The arched I-beam unit (6) is also provided with a second connecting rod group (7) at the center position, and a support rod group (10) is provided on both sides of the inner diameter surface of the arched I-beam unit (6) and arranged symmetrically. The second connecting rod group (7) consists of multiple second guide pipes, and the first connecting rod group (8) consists of multiple first guide pipes. The multiple first guide pipes and multiple second guide pipes are arranged at equal intervals along the arch axis of the arched I-beam unit (6).

6. The construction method of the support system for treating the collapse of the arch of a layered tunnel according to claim 5, characterized in that, The first guide pipe is located between the outer diameter surfaces of multiple arched I-beam units (6), and the second guide pipe passes through multiple arched I-beam units (6) in sequence, and forms an integrated arched structure through the combination of the first guide pipe and the second guide pipe; The steel mesh (9) is laid above multiple first guide pipes to cover the outer surface of multiple arched I-beam units (6).

7. The construction method of the support system for treating the collapse of the arch of a layered tunnel according to claim 5 or 6, characterized in that, The support rod assembly (10) includes a convex base (101), a threaded rod (102), a support top (103), and a threaded sleeve (104). The top of the support top (103) is connected to the inner diameter surface of the arched I-beam unit (6), and one end of the threaded rod (102) is embedded in the support top (103), while the other end extends into the inner threaded sleeve (104) and is threadedly connected to the threaded sleeve (104). The threaded rod (102) rotates relative to the inner threaded sleeve (104) and moves axially along the threaded sleeve (104) to adjust the extension length of the threaded rod (102) in the inner threaded sleeve (104). The end of the threaded sleeve (104) is connected to the convex base (101) that abuts against the ground.

Images