A modular elastic tunnel support system and its construction method

Abstract

This invention provides a modular elastic tunnel support system and its construction method. The tunnel support system includes a slope retaining wall structure adjacent to the mountain slope, an external support structure located at the road edge, and a canopy structure located on top of the slope retaining wall structure and the external support structure. The slope retaining wall structure includes a slope retaining sidewall, a horizontal retaining wall, and a retaining wall base. A first magnetic expanded-head anchor rod is driven from the slope retaining sidewall toward the mountain slope, and a second magnetic expanded-head anchor rod is driven from the retaining wall base toward the surrounding mountain. The external support structure includes a roadbed retaining wall and multiple support columns. The canopy structure includes multiple parallel main beams and modular support plates installed between adjacent main beams. This invention is convenient to construct, greatly improves the stability of the mountain, has high load-bearing capacity, and allows for rapid repair and replacement in case of damage. It is suitable for tunnel sections in steep mountainous areas.

Description

Technical Field

[0001] This invention relates to the field of slope management, and to a modular elastic tunnel support system and its construction method. The tunnel structure is used in steep slope sections in plateau and mountainous areas, and can be quickly constructed and repaired in tunnel sections. Background Technology

[0002] Steep slopes in high-altitude mountainous regions make them prone to natural disasters such as torrential rains, floods, landslides, and earthquakes. The complex geological structures further exacerbate the instability of steep slopes, increasing the risk of collapses and landslides. Snowstorms and avalanches are also common in winter, posing significant challenges to road operation and construction. Existing tunnel structures mostly require on-site casting, which, while effective in resisting disasters, results in high material transportation costs, low work efficiency, and relatively insufficient disaster protection capabilities. These structures are susceptible to damage, and if damaged, cannot be repaired promptly, leading to difficult repair cycles and construction procedures, slow progress, and extended construction periods, indirectly increasing construction costs. Therefore, there is an urgent need for a tunnel structure with strong protective capabilities, rapid construction, and short repair cycles. Summary of the Invention

[0003] This invention addresses the problems of cumbersome and time-consuming existing tunnel repair procedures by providing a modular and flexible tunnel structure and its construction method suitable for steep slopes in plateau and mountainous areas. The road system modularizes the tunnel structure, facilitating rapid on-site construction and quick repair and replacement after tunnel damage. Furthermore, the entire road system enhances the stability of the mountain, improves slope stability, and mitigates the impact of falling rocks from above.

[0004] To achieve the above-mentioned technical objectives, the present invention provides a modular elastic shed support system, which includes a slope retaining wall structure adjacent to the mountain slope, an external support structure located at the road edge, and a shed structure located on top of the slope retaining wall structure and the external support structure.

[0005] The slope retaining wall structure includes a slope retaining sidewall, a horizontal retaining wall located at the bottom of the slope retaining sidewall, and a retaining wall base. The retaining wall base is a trapezoidal retaining structure formed by excavating from the bottom of the mountain slope and pouring concrete. The horizontal retaining wall is a horizontal retaining structure poured on top of the retaining wall base. A first magnetic expanded head anchor is installed from the slope retaining sidewall toward the inside of the mountain slope, and a second magnetic expanded head anchor is installed from the retaining wall base toward the surrounding mountain.

[0006] The external support structure includes a roadbed retaining wall and multiple support columns. The roadbed retaining wall is a retaining structure composed of multiple bearing piles driven into the bearing layer of the foundation from the ground. The tops of the multiple bearing piles are connected as one unit through a bearing pile platform. The multiple support columns are set in a straight line on the bearing pile platform, and their tops are connected as one unit through a connecting beam. A third magnetic expanded head anchor rod is driven from the bearing pile platform toward the underground bearing layer.

[0007] The scaffolding structure includes multiple parallel main beams, modular support plates installed between adjacent main beams, and a steel cage filled with expanded clay aggregate located above the main beams and modular support plates; one end of each main beam is connected to the connecting beam of the external support structure through a spring damping support, and the other end is connected to the top of the slope retaining wall through a rotating support.

[0008] A further technical solution of the present invention: The first, second, and third magnetic expanded-head anchor bolts have the same structure, each including a main steel anchor bolt, a tension steel anchor bolt, an expansion anchor bolt, a first support steel disc, and a magnetic anchor bolt expansion head; the first support steel disc is welded to one end of the main steel anchor bolt near the anchor head, the tension steel anchor bolt passes through the main steel anchor bolt and connects to the magnetic anchor bolt expansion head, the magnetic anchor bolt expansion head includes a second support steel disc fixed to the end of the tension steel anchor bolt and a magnet block welded to the side of the second support steel disc away from the tension steel anchor bolt, the diameter of the second support steel disc is larger than that of the first support steel disc, and the first... The two supporting steel discs have multiple radially distributed slotted holes on their surfaces, arranged in a ring around the connection point between the tension steel anchor and the second supporting steel disc. A connecting spring is provided between the first and second supporting steel discs, sleeved on the outside of the main steel anchor and the tension steel anchor, with one end connected to the first supporting steel disc and the other end connected to the second supporting steel disc. Multiple expansion anchors are provided, distributed around the tension steel anchor as the center. One end of each expansion anchor is movably connected to the first supporting steel disc, and the other end passes through the corresponding slotted hole in the second supporting steel disc and extends to the outside of the magnet block.

[0009] The preferred technical solution of this invention is as follows: Each main beam has a beam armhole on both sides in the width direction, and beam side pads on both ends in the length direction. Each main beam has cable fixing supports at the top of both ends in the length direction. Multiple beam bottom pads are distributed at the bottom of each main beam, with the multiple beam bottom pads parallel to each other and the length of each beam bottom pad equal to the width of the main beam. Multiple cables are arranged parallel to each other at the bottom of the beam bottom pads. Rope holes are correspondingly provided on the spring damping supports, swivel supports, and cable fixing supports. Each cable is laid along the length direction of the main beam, with both ends passing through the corresponding rope holes on the spring damping supports and swivel supports, and then running along the two beam sides. The cushion layer extends upward to the top of the main beam and is anchored and locked after passing through the expansion holes on the corresponding cable fixing supports. The front and rear sides of the modular support plate are respectively erected on the beam armholes of the adjacent two main beams. The thickness of the main beam is greater than the thickness of the modular support plate. Multiple support springs are provided between the modular support plate and the side of the main beam and the beam armhole. Spring grooves are opened at corresponding positions on the modular support plate, the main beam and the beam armhole. The two ends of each support spring are fixed in the corresponding spring groove. The steel cage is also provided with an installation groove at the position corresponding to the main beam. The part of the main beam that is higher than the modular support plate is embedded in the installation groove of the steel cage.

[0010] A preferred technical solution of the present invention: The spring damping support includes a convex support disposed at the bottom of the main beam and a spring damping device installed at the top of the connecting beam. The spring damping device includes a frame structure and damping springs. The frame structure consists of an outer frame and an inner support frame. The outer frame is a concave frame with an open bottom surface, and its concave area matches the convex support. The inner support frame is a square frame with an open top surface. The inner support frame is fixed to the top surface of the connecting beam. Multiple sets of vertical damping springs are provided inside the inner support frame. The outer frame is fitted onto the open surface of the inner support frame, and the tops of the multiple sets of damping springs are connected to the outer frame. A lateral buffer spring is provided between the side baffle of the inner pier frame and the side baffle of the recessed area of ​​the outer frame. The side baffle of the inner pier frame and the side baffle of the outer frame are connected by a snap-fit ​​assembly. The snap-fit ​​assembly includes an upper snap-fit ​​component welded to the inner pier frame, a lower snap-fit ​​component welded to the outer frame, and a bolt component connecting the two snap-fit ​​components. The upper snap-fit ​​component has multiple bolt holes evenly distributed, and the lower snap-fit ​​component has a vertical adjustment hole. The bolt component is fixed in the corresponding bolt hole, and the other end extends into the vertical adjustment hole. Under the action of the shock-absorbing spring, when the outer frame moves up and down, the bolt component moves up and down along the vertical adjustment hole.

[0011] The preferred technical solution of this invention is as follows: the third magnetic expanded-head anchor rod is driven into the bearing layer at an angle of 30 to 60 degrees, and the outer end of the third magnetic expanded-head anchor rod is connected to the bearing pile platform; a steel mesh is suspended on the slope surface of the suspended side of the bearing pile platform, and foam fiber concrete is sprayed; the rotating support is a support with an arc-shaped cross-section, fixed to the bottom of the main beam, and a corresponding rotating support is provided on the top surface of the retaining wall of the slope, with an arc-shaped groove opened in the rotating support, and an arc-shaped fitting matching the rotating support is installed in the groove.

[0012] The concave steel plate has a rotating support seat that is embedded in the corresponding groove and can rotate within the groove.

[0013] The preferred technical solution of this invention is as follows: There are 3 to 5 expansion anchor rods. An anchor rod through hole is opened at the center of the first support steel plate. Multiple pull holes are distributed in a ring around the anchor rod through hole on the annular surface of the first support steel plate. The pull steel anchor rod passes through the anchor rod through hole, and the other end is fixedly welded to the center of the second support steel plate or fixedly inserted into the center hole of the second support steel plate. The number of pull holes and strip holes is the same as the number of expansion anchor rods. Each expansion anchor rod has a connecting ring at one end, and the connecting ring is sleeved at the pull hole. The magnet block is frustum-shaped or I-shaped, and the diameter of the end of the magnet block near the second support steel plate is smaller than the diameter of the end away from the second support steel plate. During the process of inserting the magnetic expansion anchor rod into the hole, the connecting spring is in an extended state, and the elastic force provided keeps the expansion anchor rod in a non-open state. At this time, the end of the expansion anchor rod away from the first support steel plate is located outside the large diameter end of the magnet block and contacts the outer edge of the large diameter end of the magnet block.

[0014] The preferred technical solution of the present invention is as follows: the modular support plate is a rectangular reinforced concrete structural plate, on which ribbed beams are arranged, and reinforcing steel bars and reinforcing stirrups are arranged inside; the left and right sides of the modular support plate are respectively provided with side beams at the beam armholes, and the support springs set on the modular support plate are respectively opened at the bottom and side of the side beams; each modular support plate has matching splicing slots on the front and rear sides, and the protruding part of the outer edge of the splicing slot is set in an arc.

[0015] A further technical solution of the present invention: The slope retaining sidewall is constructed by splicing precast retaining wall panels of reinforced concrete structure. Each precast retaining wall panel has matching splicing interfaces on both sides. Adjacent precast retaining wall panels are spliced ​​and fixed together through the splicing interfaces. A rotating support is provided at the top of the precast retaining wall panel, and a lower protrusion is provided at the bottom. A magnet is embedded at the bottom of the lower protrusion. The horizontal retaining wall has an installation groove that matches the lower protrusion. Multiple retaining wall bases are provided, all of which are cast with magnetic concrete. The installation grooves on the horizontal retaining wall lead to the corresponding retaining wall bases. Multiple second magnetic expanded head anchors are installed around each retaining wall base. The first magnetic expanded head anchor, the second magnetic expanded head anchor, and the third magnetic expanded head anchor are all filled and cast with magnetic concrete.

[0016] The magnetic concrete is composed of the following materials by mass percentage: 25-35% iron ore crushed stone with a particle size of 5-10mm, 15-25% iron powder, 20-30% cement, 2-4% SBS modifier, 6-8% glass fiber with a length of 15-20mm, and 12-17% water.

[0017] The construction method specifically includes the following steps: S1. Prepare prefabricated main beams, modular support slabs, and prefabricated retaining wall slabs;

[0018] S2. Construct the retaining wall structure on the inner side of the road according to the design drawings; first, excavate a trapezoidal cross-section retaining wall base pouring hole at the design location, and drill and install multiple second magnetic enlarged head anchor rods through the retaining wall base pouring hole. After the installation of multiple second magnetic enlarged head anchor rods, pour magnetic concrete into the retaining wall base pouring hole. After the concrete solidifies, the retaining wall base is formed; then, pour a horizontal retaining wall on the upper part of the retaining wall base, and connect the horizontal retaining wall to the retaining wall base. The horizontal retaining wall is then constructed using formwork. During construction, installation slots for the retaining walls on the slope are reserved. The position, shape, and size of the installation slots are matched with the protruding parts of the precast retaining wall panels. The precast retaining wall panels are spliced ​​and installed, and the protruding parts at the bottom of each precast retaining wall panel are inserted into the corresponding installation slots. Magnetic concrete is poured into the grooves and gaps of the horizontal retaining wall. Finally, multiple first magnetic expanded head anchors are drilled into the mountain through the anchor installation holes reserved on the precast retaining wall panels. A rotating support matching the rotating support seat is provided on the top of the retaining wall.

[0019] S3. Construct the external support structure on the outer side of the road according to the design drawings; first, drill multiple bearing piles from the ground, each bearing pile is driven into the bearing layer of the foundation, and the tops of the bearing piles are connected to each other with a bearing pile platform; then, construct multiple third magnetic expanded head anchor rods, which are driven into the bearing layer from a 30-60 degree inclined hole drilled from the bearing pile platform, and the outer end of the third magnetic expanded head anchor rod is anchored to the bearing pile platform; after that, hang steel mesh on the outer slope of the road and spray foam fiber concrete for protection; finally, vertically install support columns and connecting beams on the bearing pile platform;

[0020] S4. Install the main beams and modular support plates. One end of each main beam is rotatably connected to the rotating support at the top of the slope retaining wall via a rotating support seat, and the other end is connected to the connecting beam of the external support structure via a spring damping support seat. After the main beams are installed, assemble the modular support plates between two adjacent main beams. After completing the installation of the modular support plates, place the steel cage on the top of the installed main beams and modular support plates and fill it with ceramsite.

[0021] S5. When a vehicle exceeding the height limit inside the tunnel needs to pass, lift the steel cage containing expanded clay, modular support plate and main beam to the side. After the vehicle passes, repeat step S4 to install them.

[0022] A further technical solution of the present invention: The first magnetic expanded head anchor rod, the second magnetic expanded head anchor rod, and the third magnetic expanded head anchor rod used in the construction method have the same structure, each including a main steel anchor rod, a tension steel anchor rod, an expansion anchor rod, a first support steel plate, and a magnetic anchor rod expansion head. The magnetic anchor rod expansion head includes a second support steel plate fixed to the end of the tension steel anchor rod and a magnet block welded to the side of the second support steel plate away from the tension steel anchor rod. A connecting spring is provided between the first support steel plate and the second support steel plate.

[0023] The installation process for each second magnetic expanded head anchor rod is as follows: Drill holes at the designed anchor rod positions within the casting holes of the retaining wall base, and continue drilling at the deepest point of the anchor rod hole using a reaming drill bit. Insert the second magnetic expanded head anchor rod into the anchor rod hole, pull the steel anchor rod to stretch the magnetic anchor rod expansion head, causing the magnetic anchor rod expansion head to press against the expansion anchor rod and expand it in all directions. The connecting spring is compressed, and the expansion anchor rod will expand to the maximum diameter of the anchor rod hole, fixing the position of the steel anchor rod. Then, inject magnetic concrete into the anchor rod hole, and use a magnet to attract the magnetic concrete to fill the gaps in the hole. Wait for the magnetic concrete to solidify to complete the installation of the second magnetic expanded head anchor rod.

[0024] The installation process for each first magnetic expanded head anchor rod is as follows: drill holes in the mountain through the anchor rod installation holes reserved on the retaining wall precast slab, and continue drilling at the deepest part of the anchor rod hole using a hole-enlarging drill bit, and put the first magnetic expanded head anchor rod into the anchor rod hole. The rest of the process is the same as the installation process for the second magnetic expanded head anchor rod.

[0025] The installation process for each third magnetic reamer is as follows: drill anchor holes from the outside of the bearing pile platform towards the foundation at an angle, and continue drilling at the deepest point of the anchor hole using a reamer. Insert the third magnetic reamer into the anchor hole. The remaining process is the same as the installation process for the second magnetic reamer.

[0026] The retaining wall base in the slope retaining wall structure of this invention is made of magnetic concrete. Magnetic concrete is also poured at the connection between the slope retaining sidewall and the horizontal retaining wall. This facilitates rapid assembly and installation, saving on-site construction steps and increasing speed. The retaining wall base is designed as a trapezoidal cone-shaped retaining wall to improve its load-bearing capacity. Magnetic anchor rods with enlarged heads are driven into the mountainside around the base and cast integrally with magnetic concrete. It is then cast together with the horizontal retaining wall at the top, further enhancing its load-bearing capacity and anchoring ability to the mountainside, thus increasing the load-bearing capacity provided to other structures. The horizontal retaining wall serves as a foundation for rapid repair of the slope retaining sidewall and provides a supportive mounting base, transferring the load-bearing capacity of the retaining wall base to the slope retaining sidewall.

[0027] In this invention, a first supporting steel disc is welded in the middle of the magnetic expansion head anchor rod, and a connecting ring of the expansion anchor rod is inserted into the hole of the first supporting steel disc. The purpose is to provide reinforcing steel for the expansion head of the main steel anchor rod. A magnet is welded to the front end of the magnetic expansion head anchor rod. The purpose is to attract the expansion anchor rod to the magnet, making it easier for the device to extend into the hole of the magnetic expansion head anchor rod. When the bottom is opened by tensioning, the front magnet also helps to attract the magnetic concrete to gather. The magnetic concrete in this invention helps to make the magnetic concrete more dense and displace air by utilizing the mutual attraction between magnetic forces.

[0028] The side retaining wall of this invention is designed as a precast component with a convex lower end reinforced concrete structure. A magnet is embedded at the bottom of the convex shape, which is intended to attract magnetic concrete material during rapid installation on the construction site and also facilitates quick maintenance and replacement later. Magnetic anchor rods are passed through pre-drilled holes in the wall body and connected to the conical retaining wall for magnetic concrete pouring, which is intended to improve the lateral support of the side retaining wall. A rotating support is set at the top of the side retaining wall to facilitate its connection with the rotating support of the main beam. The modular prefabrication and installation facilitate faster and more convenient maintenance later.

[0029] In the external support structure of this invention, precast bearing piles are driven into the bearing layer of the foundation, and the top is connected to the bearing pile platform roadbed. This aims to better and more evenly transfer the vertical load to the bearing layer of the foundation. Magnetic expanded head anchors are driven into the bearing layer of the foundation at an angle of 30 to 60 degrees, and the other end of the magnetic expanded head anchors is connected to the bearing pile platform roadbed. This aims to improve the lateral bearing capacity of the bearing pile platform roadbed. A steel mesh is suspended on the suspended side of the bearing pile platform roadbed, and foam fiber concrete is sprayed for protection. This aims to protect the slope from rainwater erosion and provide a certain lateral bearing capacity to the slope. The foam fiber concrete is composed of foaming agent, water, ordinary Portland cement, fine sand, and steel fibers.

[0030] The snap-fit ​​assembly of the spring damping device of the present invention can be divided into upper and lower parts, which is beneficial to provide displacement distance for vertical movement; the lower end of the pressure spring is placed on the spring support of the outer frame and the upper end is snapped on the spring support of the inner support frame, so that the spring can move up and down when the entire device is subjected to vertical load by utilizing the elastic force of the spring; the side buffer spring is placed on the side position, which is beneficial to buffer the lateral movement of the device. The main beam of this invention has a rotating support at the lower part and a cable-fixed support at the upper part at one end, which is intended to provide a certain rotational displacement when the main beam is displaced; the other end has a spring support at the lower part and a cable-fixed support at the upper part, which is intended to provide a certain vertical buffer displacement when the main beam is subjected to vertical load, so as to reduce the impact force on the structure; the steel reinforcement skeleton of the module flip beam is intended to reduce the impact on the clearance of the opening; the installation of the beam bottom pad and cable at the bottom of the beam is intended to improve the bending resistance of the main beam; the cable passes through the reserved hole in the beam bottom pad, and then passes through the beam side pad and around to the cable-fixed support at the beam end, and is fixed by the clamps, which is intended to improve the load-bearing capacity of the main beam.

[0031] The beneficial effects of this invention are:

[0032] (1) The present invention adopts a modular design, which facilitates rapid construction on the construction site, and also facilitates rapid repair and replacement after the tunnel is damaged. It can also be quickly replaced and repaired using prepared spare parts when the tunnel is damaged; it is suitable for tunnel sections in plateau and mountainous areas with steep slopes.

[0033] (2) This invention innovatively proposes a slope retaining wall structure, which greatly improves the stability of the mountain. The designed main beam structure has a great load-bearing capacity and can alleviate the impact of falling rocks from above. This invention innovatively designs a spring shock absorption device, which provides energy reduction and buffering for the tunnel, and also facilitates rapid repair and replacement after the tunnel is damaged. Moreover, the modular tunnel structure can remove the top when needed, without height restrictions, to allow road passage.

[0034] (3) This invention innovatively proposes the combined use of roadbed retaining walls and magnetic expansion magnetic head anchor structures, which greatly improves the stability of road slopes and enhances the road's resistance to landslide settlement.

[0035] (4) The present invention innovatively designs a magnetic expansion head anchor rod. A magnet is welded to the front end of the expansion head of the magnetic expansion head anchor rod, which is conducive to attracting the expansion anchor rod to the magnet and making it convenient for the device to be inserted into the magnetic expansion head anchor rod hole. When the bottom is opened by tensioning, the front end magnet is also conducive to attracting magnetic concrete to gather more densely and displacing excess air.

[0036] (5) The magnetic concrete mix proportions and the addition of modifiers and glass fibers of the present invention are beneficial to make the concrete more dense and displace air by utilizing the mutual attraction between magnets.

[0037] (6) The slope protection formed by the steel mesh and foam fiber concrete of the present invention helps to reduce the pressure on the concrete slope, improve the strength of the foam concrete, protect the slope, prevent the slope from being impacted by rainwater and causing soil erosion, and greatly improve the slope stability.

[0038] The invention has a simple overall structure, low cost, and easy operation, and can easily repair damaged spring canopy holes and design and construct special road sections. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the overall longitudinal cross-section of the present invention;

[0040] Figure 2 This is a side view of the main beam in this invention;

[0041] Figure 3 This is a bottom view of the main beam in this invention;

[0042] Figure 4 This is a schematic diagram of the installation plan of the main beam and the modular support plate in this invention;

[0043] Figure 5 This is a schematic diagram of the installation cross-section of the main beam and the modular support plate in this invention;

[0044] Figure 6 This is a cross-sectional schematic diagram of the modular support plate in this invention;

[0045] Figure 7 This is a schematic diagram of the modular support plate assembly in this invention;

[0046] Figure 8 This is a schematic diagram of the magnetic expansion head anchor rod in the unexpanded state in this invention;

[0047] Figure 9This is a schematic diagram of the expansion state of the magnetic expansion head anchor bolt in this invention;

[0048] Figure 10 This is a plan view of the first supporting steel disc in this invention;

[0049] Figure 11 This is a plan view of the second supporting steel disc in this invention;

[0050] Figure 12 This is a schematic diagram of the connection between the main beam and the spring damping support in this invention.

[0051] Figure 13 This is a schematic diagram of the connection between the main beam and the rotating support in this invention.

[0052] Figure 14 This is a schematic diagram of the spring damping support in this invention;

[0053] Figure 15 This is a schematic diagram of the upper snap fastener structure in the snap fastener assembly of the present invention;

[0054] Figure 16 This is a schematic diagram of the lower snap fastener structure in the snap fastener assembly of the present invention;

[0055] Figure 17 This is a schematic diagram of the structure of the precast retaining wall slab in this invention;

[0056] Figure 18 This is a cross-sectional schematic diagram of the precast retaining wall slab in this invention;

[0057] Figure 19 This is a schematic diagram of the horizontal retaining wall in this invention;

[0058] Figure 20 This is a cross-sectional schematic diagram of the connection between the horizontal retaining wall and the retaining wall base in this invention;

[0059] Figure 21 This is a schematic diagram of the connection between the horizontal retaining wall and the precast retaining wall slab in this invention.

[0060] In the diagram: 1. Slope retaining wall, 100. Rotary bearing, 101. Groove, 102. Concave steel plate, 103. Precast retaining wall slab, 104. Joint, 105. Lower protrusion, 106. Magnet, 107. Anchor bolt mounting hole; 2. Horizontal retaining wall, 200. Mounting groove; 3. Retaining wall base; 4. Mountain slope; 5. First magnetic expanded head anchor bolt, 500. Main steel anchor bolt, 501. Pull steel anchor bolt, 502. Expansion anchor bolt, 503. First support steel plate, 504. Second support steel plate, 505. Magnet block, 506. Connecting spring, 507. Pull hole, 508. Strip hole, 509. Connecting ring; 6. Spring damping bearing, 600. Protruding bearing, 601. Frame structure, 602. Damping spring, 6021. Outer frame. 6022, Inner bearing frame; 603, Lateral buffer spring; 604, Clip assembly; 6041, Upper clip; 6042, Lower clip; 6043, Bolt hole; 6044, Vertical adjustment hole; 7, Roadbed retaining wall; 8, Rotary support seat; 9, Main beam; 900, Beam axle; 901, Beam side cushion layer; 902, Beam bottom cushion layer; 903, Cable; 904, Cable fixing support; 905, Rope hole; 10, Third magnetic expanded head anchor rod; 11, Modular support plate; 1100, Side beam; 1101, Splicing groove; 1102, Outer side retaining edge; 12, Second magnetic expanded head anchor rod; 13, Bearing pile platform; 14, Support column; 15, Connecting beam; 16, Third magnetic expanded head anchor rod; 17, Support spring; 18, Spring groove. Detailed Implementation

[0061] The present invention will be further described below with reference to the accompanying drawings and embodiments. Figures 1 to 21 All accompanying drawings are simplified versions of embodiments and are intended only to clearly and concisely illustrate the embodiments of the present invention. The technical solutions shown in the drawings below are specific solutions of embodiments of the present invention and are not intended to limit the scope of the claimed invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0062] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0063] A modular elastic tunnel support system is provided in the embodiments, such as Figures 1 to 21 As shown, the shed support system includes a slope retaining wall structure adjacent to the mountain slope 4, an external support structure located at the road edge, and a shed structure located on top of the slope retaining wall structure and the external support structure; the slope retaining wall structure includes a slope retaining side wall 1, a horizontal retaining wall 2 located at the bottom of the slope retaining side wall 1, and a retaining wall base 3. The retaining wall base 3 is a trapezoidal retaining structure formed by excavating and pouring concrete from the bottom of the mountain slope 4. The horizontal retaining wall 2 is a horizontal retaining structure poured on top of the retaining wall base 3; a first magnetic expanded head anchor 5 is installed from the slope retaining side wall 1 toward the mountain slope 4, and a second magnetic expanded head anchor 12 is installed from the retaining wall base 3 toward the surrounding mountain.

[0064] The external support structure includes a roadbed retaining wall 7 and multiple support columns 14. The roadbed retaining wall 7 is a retaining structure composed of multiple bearing piles driven into the bearing layer from the ground. The tops of the multiple bearing piles are connected as one unit through a bearing pile platform 13. The multiple support columns 14 are arranged in a straight line on the bearing pile platform 13, and their tops are connected as one unit through a connecting beam 15. A third magnetic expanded head anchor rod 10 is driven from the bearing pile platform 13 toward the underground bearing layer. The third magnetic expanded head anchor rod 16 is driven into the bearing layer at an angle of 30 to 60 degrees, and the outer end of the third magnetic expanded head anchor rod 16 is connected to the bearing pile platform 13. A steel mesh 16 is suspended on the slope of the suspended side of the bearing pile platform 13, and foam fiber concrete is sprayed for protection. The purpose is to protect the slope from rainwater erosion and provide a certain lateral bearing capacity to the slope. The foam fiber concrete is made of foaming agent, water, ordinary silicate cement, fine sand and steel fiber in a certain proportion.

[0065] The scaffolding structure includes multiple parallel main beams 9, modular support plates 11 installed between adjacent main beams 9, and a steel cage 12 filled with expanded clay aggregate located above the main beams 9 and the modular support plates 11. One end of each main beam 10 is connected to the connecting beam 15 of the external support structure via a spring damping support 6, and the other end is connected to the top of the slope retaining wall 1 via a rotating support 8. The modular support plate 11 is a rectangular reinforced concrete structural slab, with ribbed beams arranged on the modular support plate 11, and reinforcing steel bars and stirrups arranged inside; for example... Figures 4 to 7As shown, the modular support plate 11 has side beams 1100 on the left and right sides corresponding to the beam armpits 900. Each modular support plate 11 has matching splicing slots 1101 on the front and back sides. The protruding part of the outer edge 1102 of the splicing slot 1101 is arc-shaped. The purpose of the arc-shaped treatment is to facilitate the displacement of the main beam 9 when it is displaced. The modular support plate 11 is erected on the front and rear sides of the beam armholes 900 of two adjacent main beams 9. The thickness of the main beam 9 is greater than the thickness of the modular support plate 11. Multiple support springs 17 are provided between the modular support plate 11 and the sides of the main beams 9 and the beam armholes 900. Spring grooves 18 are provided at corresponding positions on the modular support plate 11, the main beams 9, and the beam armholes 900. The two ends of each support spring 17 are fixed in the corresponding spring groove 18. The support springs 17 on the modular support plate 11 are respectively provided at the bottom and sides of the side beams 1100. The spring grooves 18 and support springs 17 are designed to allow the plate to generate a certain elastic displacement when the main beam 9 is subjected to load, thus preventing damage to the plate and facilitating replacement in case of future damage. The reinforcing cage 12 is also provided with an installation groove corresponding to the position of the main beam 9. The portion of the main beam 9 that extends above the modular support plate 11 is embedded in the installation groove of the reinforcing cage 12.

[0066] like Figure 2 , Figure 3 , Figure 12 and Figure 13 As shown in the embodiment, each main beam 9 has beam armholes 900 on both sides in the width direction, beam side pads 901 on both ends in the length direction, cable fixing supports 904 on the top of both ends in the length direction, and multiple beam bottom pads 902 distributed at the bottom of each main beam 9. The multiple beam bottom pads 902 are parallel to each other, and the length of each beam bottom pad 902 is equal to the width of the main beam 9. Multiple cables 903 are arranged parallel to each other at the bottom of the beam bottom pads 902. Rope holes 905 are opened on the spring damping support 6, the rotating support 8, and the cable fixing supports 904 respectively. Each cable 903 is laid along the length direction of the main beam 9, and its two ends pass through the corresponding rope holes on the spring damping support 6 and the rotating support 8 respectively, and then extend upward along the two beam side pads 901 to the top of the main beam 9. After passing back through the expansion holes on the corresponding side cable fixing supports 904, they are anchored and locked. Figure 13 As shown, the rotating support 8 is a support with an arc-shaped cross section, fixed to the bottom of the main beam 9. A rotating support 100 is provided on the top surface of the slope retaining wall 1. An arc-shaped groove 101 is opened in the rotating support 100, and an arc-shaped concave steel plate 102 matching the rotating support 8 is installed in the groove 101. The rotating support 8 is embedded in the corresponding groove 101 and can rotate in the groove 101.

[0067] In the embodiments, such as Figures 8 to 11 As shown, the first magnetic expansion head anchor bolt 5, the second magnetic expansion head anchor bolt 12, and the third magnetic expansion head anchor bolt 10 have the same structure, each including a main steel anchor bolt 500, a tension steel anchor bolt 501, an expansion anchor bolt 502, a first support steel plate 503, and a magnetic anchor bolt expansion head; the magnetic anchor bolt expansion head includes a second support steel plate 504 fixed to the end of the tension steel anchor bolt 501 and a magnet block 505 welded to the side of the second support steel plate 504 away from the tension steel anchor bolt 501, the diameter of the second support steel plate 504 is... The first support steel plate 503 is larger than the second support steel plate 504. Four expansion anchor rods 502 are provided. The first support steel plate 503 is welded to the end of the main steel anchor rod 500 near the anchor head. An anchor rod through hole is opened at the center of the first support steel plate 503. Four pull holes 507 are distributed in a ring around the anchor rod through hole on the annular surface of the first support steel plate 503. The pull steel anchor rod 501 passes through the anchor rod through hole, and its other end is fixedly welded to or inserted into the center of the second support steel plate 504. At the hole; four strip-shaped holes 508 are radially distributed on the surface of the second support steel plate 504, and the four strip-shaped holes 508 are arranged in a ring with the connection point between the tension steel anchor rod 501 and the second support steel plate 504 as the center; a connecting spring 506 is provided between the first support steel plate 503 and the second support steel plate 504, the connecting spring 506 is sleeved on the outside of the main steel anchor rod 500 and the tension steel anchor rod 501, one end is connected to the first support steel plate 503 and the other end is connected to the second support steel plate 504; each One end of the expansion anchor 502 is provided with a connecting ring 509, which is sleeved on the pull hole 507 and is movable. The other end passes through the corresponding strip hole 508 of the second support steel plate 504 and extends to the outside of the magnet block 505. The magnet block 505 is frustum-shaped or I-shaped. Setting it as I-shaped saves costs, and the diameter of the end of the magnet block 505 near the second support steel plate 504 is smaller than the diameter of the end away from the second support steel plate 504. During the process of inserting the magnetic expansion anchor into the hole, if... Figure 8 As shown, the connecting spring 506 is in the extended state, and the elastic force it provides keeps the expansion anchor 502 in the non-open state. At this time, the end of the expansion anchor 502 away from the first support steel plate 503 is located outside the large-diameter end of the magnet block 505 and contacts the outer edge of the large-diameter end of the magnet block 505. The purpose of setting the magnet in the magnetic anchor expansion head is to facilitate the attraction of the expansion anchor 502 to the magnet, making it easier for the device to be inserted into the magnetic expansion head anchor hole. When the bottom is opened by tensioning, the front magnet also helps to attract magnetic concrete to gather. The designed spring helps to give the magnetic expansion head anchor a spring force during the insertion process, generate a rebound force when encountering resistance, and spring back when there is no resistance, ensuring that the magnetic expansion head anchor is placed in the designed position of the hole.

[0068] In the embodiments, such as Figures 14 to 16As shown, the spring damping support 6 includes a convex support 600 disposed at the bottom of the main beam 9 and a spring damping device installed on the top of the connecting beam 15. The spring damping device includes a frame structure 601 and damping springs 602. The frame structure 601 consists of an outer frame 6021 and an inner support frame 6022. The outer frame 6021 is a concave frame with an open bottom surface, and its concave area matches the convex support 600. The convex support 600 is embedded in the concave area of ​​the outer frame 6021. The inner support frame 6022 is a square frame with an open top surface. The inner support frame 6022 is fixed to the top surface of the connecting beam 15. Multiple sets of vertical damping springs 602 are provided inside the inner support frame 6022. The outer frame 6021 is fitted onto the open surface of the inner support frame 6022, and the tops of the multiple sets of damping springs 602 are connected to the outer frame 6021. A lateral buffer spring 603 is provided between the side baffle of the inner support frame 6022 and the side baffle of the recessed area of ​​the outer frame 6021. The side baffle of the inner support frame 6022 and the side baffle of the outer frame 6021 are connected by a buckle assembly 604. The buckle assembly 604 includes an upper buckle 6041 welded to the inner support frame 6022, a lower buckle 6042 welded to the outer frame 6021, and a bolt connecting the two buckles. The upper buckle 6041 has multiple bolt holes 6043 evenly distributed, and the lower buckle 6042 has a vertical adjustment hole 6044. The bolt is fixed in the corresponding bolt hole 6043, and the other end extends into the vertical adjustment hole 6044. Under the action of the damping spring 602, when the outer frame 6021 moves up and down, the bolt moves up and down along the vertical adjustment hole 6044.

[0069] In the embodiments, such as Figures 17 to 21 As shown, the slope retaining wall 1 is constructed by splicing precast retaining wall panels 103 of reinforced concrete structure. Each precast retaining wall panel 103 has matching splicing interfaces 104 on both sides. Adjacent precast retaining wall panels 103 are spliced ​​and fixed together through the splicing interfaces 104. A rotating support 100 is provided at the top of the precast retaining wall panel 103, and a lower protrusion 105 is provided at the bottom. A magnet 106 is embedded at the bottom of the lower protrusion 105, and multiple anchor bolt mounting holes 107 are provided on the precast retaining wall panel 103. The horizontal retaining wall 103 is constructed by splicing precast retaining wall panels 103. The earth wall 2 has an installation groove 200 that matches the lower protrusion 105. There are multiple retaining wall bases 3, all of which are made of magnetic concrete. The installation grooves 200 on the horizontal retaining wall 2 lead to the corresponding retaining wall bases 3. Multiple second magnetic expanded head anchors 12 are installed around each retaining wall base 3. The first magnetic expanded head anchor 5, the second magnetic expanded head anchor 12 and the third magnetic expanded head anchor 10 are all filled with magnetic concrete. The first magnetic expanded head anchor 5 is driven into the anchor installation hole 107.

[0070] The magnetic concrete being implemented is composed of the following materials by mass percentage: 30% iron ore crushed stone with a particle size of 5-10mm, 20% iron powder, 25% cement, 3% SBS modifier, 7% 19mm long glass fiber and 15% water.

[0071] This case study focuses on constructing tunnels on steep mountain slopes in high-altitude mountainous regions and rapidly repairing and constructing damaged sections. The specific construction process is as follows:

[0072] S1. Prepare prefabricated main beams, modular support plates, and retaining wall prefabricated plates; all these components are processed in the factory and then transported directly to the construction site for assembly. The main beams are constructed according to design requirements, with reinforcing bars and stirrups tied as per design specifications. Reinforcing bars are added to the cable fixing supports, followed by compaction. The poured modular plates are a*b in size, constructed according to the design drawings, with reinforcing bars and stirrups arranged inside. After pouring, the long side beams of the plate are rounded and polished. Prestressed reinforcement devices are installed on the poured main beams 9. The bottom and side bedding layers are placed in the designed positions. Cables are passed through pre-drilled holes in the bottom bedding layer, then through the side bedding layer, and around to the cable fixing supports at the beam ends. The cables are anchored using clamps. Prestressing is applied to the cables according to the beam's load-bearing requirements.

[0073] S2. Construct the retaining wall structure on the inner side of the road according to the design drawings; first, excavate a trapezoidal cross-section retaining wall base pouring hole at the design location, and drill and install multiple second magnetic enlarged head anchor rods through the retaining wall base pouring hole. After the installation of multiple second magnetic enlarged head anchor rods, pour magnetic concrete into the retaining wall base pouring hole. After the concrete solidifies, the retaining wall base 3 is formed; then, pour a horizontal retaining wall 2 on the upper part of the retaining wall base 3, and connect the horizontal retaining wall 2 to the retaining wall base 3. When the horizontal retaining wall 2 is erected and poured, a slope retaining side is reserved. The installation groove of the wall 1 is set in a position and shape that matches the lower protrusion 105 of the precast retaining wall slab 103. The precast retaining wall slab 103 is spliced ​​and installed, and the lower protrusion 105 at the bottom of each precast retaining wall slab 103 is inserted into the installation groove. Magnetic concrete is poured into the groove of the horizontal retaining wall 2. Finally, multiple first magnetic expanded head anchor rods 5 are drilled into the mountain through the anchor rod installation holes 107 reserved on the precast retaining wall slab 103. A rotating support matching the rotating support seat 8 is provided on the top of the slope retaining side wall 1.

[0074] S3. Construct the external support structure on the outer side of the road according to the design drawings; first, drill multiple bearing piles from the ground, each bearing pile is driven into the bearing layer of the foundation, and the tops of the bearing piles are connected to each other with a bearing pile platform; then, construct multiple third magnetic expanded head anchor rods 10, which are driven into the bearing layer from a 30-60 degree inclined hole drilled from the bearing pile platform, and the outer end of the third magnetic expanded head anchor rod 10 is anchored to the bearing pile platform; after that, suspend steel mesh on the outer slope of the road and spray foam fiber concrete for protection; finally, vertically install support columns and connecting beams on the bearing pile platform;

[0075] S4. Install the main beams and modular support plates. One end of each main beam is rotatably connected to the rotating support at the top of the slope retaining wall 1 via the rotating support seat 8, and the other end is connected to the connecting beam 15 of the external support structure via the spring damping support. After the main beams are installed, the modular support plates are assembled between two adjacent main beams. After the installation of the modular support plates is completed, a steel cage is placed on the top of the installed main beams and modular support plates and filled with ceramsite.

[0076] S5. When a vehicle exceeding the height limit inside the tunnel needs to pass, lift the steel cage containing expanded clay, modular support plate and main beam to the side. After the vehicle passes, repeat step S4 to install them.

[0077] S6. When a section of a tunnel or retaining wall is damaged and needs repair, clean up the damaged area, excavate the damaged area, and repeat steps S2 to S5.

[0078] The first magnetic expanded head anchor rod 5, the second magnetic expanded head anchor rod 12, and the third magnetic expanded head anchor rod 10 used in the embodiment have the same structure and the same construction method. The installation process of each second magnetic expanded head anchor rod is as follows: Drill holes at the anchor rod positions designed in the casting holes of the retaining wall base, and continue drilling at the deepest part of the anchor rod hole using a hole-expanding drill bit. Place the second magnetic expanded head anchor rod into the anchor rod hole, pull the steel anchor rod 501 to drive the magnetic anchor rod expansion head to stretch, so that the magnetic anchor rod expansion head pushes against the expansion anchor rod 502 and expands it in all directions. The connecting spring 506 is compressed, and the expansion anchor rod 502 will expand to the maximum diameter of the anchor rod hole. Fix the position of the steel anchor rod 501, and then inject magnetic concrete into the anchor hole. The magnetic concrete is attracted by the magnet block 505 to fill the gaps in the hole. Wait for the magnetic concrete to solidify to complete the installation of the second magnetic expanded head anchor rod.

[0079] The installation process of each first magnetic expanded head anchor rod 5 is as follows: drill holes in the mountain through the anchor rod installation holes 107 reserved on the retaining wall precast plate 103, and continue drilling at the deepest part of the anchor rod hole using a hole enlarging drill bit, and put the first magnetic expanded head anchor rod into the anchor rod hole. The rest of the process is the same as the installation process of the second magnetic expanded head anchor rod.

[0080] The installation process for each third magnetic expanded head anchor rod 10 is as follows: drill anchor rod holes inclined from the outside of the bearing pile platform toward the foundation, and continue drilling at the deepest point of the anchor rod hole using a reaming drill bit, and insert the third magnetic expanded head anchor rod 10 into the anchor rod hole. The remaining process is the same as the installation process for the second magnetic expanded head anchor rod.

[0081] The above description is merely one embodiment of the present invention, and while it is detailed and specific, it should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A modular elastic tunnel support system, characterized in that: The tunnel support system includes a slope retaining wall structure on the side adjacent to the mountain slope (4), an external support structure located at the edge of the road, and a canopy structure located on top of the slope retaining wall structure and the external support structure; the slope retaining wall structure includes a slope retaining side wall (1), a horizontal retaining wall (2) located at the bottom of the slope retaining side wall (1), and a retaining wall base (3). The retaining wall base (3) is a trapezoidal retaining structure formed by excavating and pouring concrete from the bottom of the mountain slope (4). The horizontal retaining wall (2) is a horizontal retaining structure poured on top of the retaining wall base (3); a first magnetic expanded head anchor rod (5) is installed from the slope retaining side wall (1) toward the mountain slope (4), and a second magnetic expanded head anchor rod (12) is installed from the retaining wall base (3) toward the surrounding mountain; the external support structure includes a roadbed retaining wall (7) and multiple supports. The roadbed retaining wall (7) is a retaining structure composed of multiple bearing piles driven into the bearing layer from the ground. The tops of the multiple bearing piles are connected together through the bearing pile platform (13). Multiple support columns (14) are set in a straight line on the bearing pile platform (13), and the tops are connected together through the connecting beam (15). A third magnetic expansion head anchor rod (10) is driven from the bearing pile platform (13) toward the underground bearing layer. The canopy structure includes multiple parallel main beams (9), modular support plates (11) installed between adjacent main beams (9), and a steel cage (12) filled with ceramsite located above the main beams (9) and the modular support plates (11). One end of each main beam (10) is connected to the connecting beam (15) of the external support structure through a spring damping support (6), and the other end is connected to the top of the slope retaining side wall (1) through a rotating support (8). The first magnetic expansion head anchor rod (5), the second magnetic expansion head anchor rod (12), and the third magnetic expansion head anchor rod (10) have the same structure, each including a main steel anchor rod (500), a tension steel anchor rod (501), an expansion anchor rod (502), a first support steel plate (503), and a magnetic anchor rod expansion head; the first support steel plate (503) is welded to one end of the main steel anchor rod (500) near the anchor head, the tension steel anchor rod (501) passes through the main steel anchor rod (500) and connects to the magnetic anchor rod expansion head, the magnetic anchor rod expansion head includes a second support steel plate (504) fixed to the end of the tension steel anchor rod (501) and a magnet block (505) welded to the side of the second support steel plate (504) away from the tension steel anchor rod (501), the diameter of the second support steel plate (504) is larger than that of the first support steel plate (503), and the disc surface of the second support steel plate (504) is radially... Multiple strip holes (508) are distributed in a ring around the connection point between the steel anchor rod (501) and the second support steel plate (504). A connecting spring (506) is provided between the first support steel plate (503) and the second support steel plate (504). The connecting spring (506) is sleeved on the outside of the main steel anchor rod (500) and the steel anchor rod (501), with one end connected to the first support steel plate (503) and the other end connected to the second support steel plate (504). Multiple expansion anchor rods (502) are provided, distributed around the steel anchor rod (501) with the steel anchor rod (501) as the center. One end of each expansion anchor rod (502) is movably connected to the first support steel plate (503), and the other end passes through the corresponding strip hole (508) of the second support steel plate (504) and extends to the outside of the magnet block (505).

2. The modular elastic tunnel support system according to claim 1, characterized in that: Each main beam (9) has a beam armhole (900) on both sides in the width direction and a beam side pad (901) on both ends in the length direction. Each main beam (9) has a cable fixing support (904) at the top of both ends in the length direction. Each main beam (9) has multiple beam bottom pads (902) distributed at the bottom. The multiple beam bottom pads (902) are parallel to each other, and the length of each beam bottom pad (902) is equal to the width of the main beam (9). Multiple cables (903) are arranged parallel to each other at the bottom of the beam bottom pads (902). Rope holes (905) are opened on the spring damping support (6), the rotating support (8) and the cable fixing support (904). Each cable (903) is laid along the length direction of the main beam (9), and its two ends pass through the corresponding rope holes on the spring damping support (6) and the rotating support (8) and then run upward along the two beam side pads (901). Extending to the top of the main beam (9), and after passing through the expansion holes on the corresponding side cable fixing support (904), it is anchored and locked; the front and rear sides of the modular support plate (11) are respectively erected on the beam armholes (900) of the adjacent two main beams (9), the thickness of the main beam (9) is greater than the thickness of the modular support plate (11), and multiple support springs (17) are respectively provided between the modular support plate (11) and the side of the main beam (9) and the beam armhole (900). Spring grooves (18) are opened at the corresponding positions on the modular support plate (11), the main beam (9) and the beam armhole (900), and the two ends of each support spring (17) are respectively fixed in the corresponding spring groove (18); the steel cage (12) is also provided with an installation groove at the position corresponding to the main beam (9), and the part of the main beam (9) that is higher than the modular support plate (11) is embedded in the installation groove of the steel cage (12).

3. The modular elastic tunnel support system according to claim 1, characterized in that: The spring damping support (6) includes a convex support (600) set at the bottom of the main beam (9) and a spring damping device installed on the top of the connecting beam (15). The spring damping device includes a frame structure (601) and a damping spring (602). The frame structure (601) consists of an outer frame (6021) and an inner support frame (6022). The outer frame (6021) is a concave frame with an open bottom surface, and its concave area is connected to the convex support (600). 00) Matching, the inner bearing frame (6022) is a square frame with an open top surface. The inner bearing frame (6022) is fixed to the top surface of the connecting beam (15). Multiple sets of vertical damping springs (602) are provided inside the inner bearing frame (6022). The outer frame (6021) is fitted onto the open surface of the inner bearing frame (6022). The top of the multiple sets of damping springs (602) is connected to the outer frame (6021). On the side of the inner bearing frame (6022) A lateral buffer spring (603) is provided between the baffle and the side baffle of the recessed area of ​​the outer frame (6021). The side baffle of the inner support frame (6022) and the side baffle of the outer frame (6021) are connected by a snap-fit ​​assembly (604). The snap-fit ​​assembly (604) includes an upper snap-fit ​​member (6041) welded to the inner support frame (6022), a lower snap-fit ​​member (6042) welded to the outer frame (6021), and a connecting element for the two sides. The upper snap fastener (6041) has multiple bolt holes (6043) evenly distributed, and the lower snap fastener (6042) has a vertical adjustment hole (6044). The bolt is fixed in the corresponding bolt hole (6043), and the other end extends into the vertical adjustment hole (6044). Under the action of the shock-absorbing spring (602), when the outer frame (6021) moves up and down, the bolt moves up and down along the vertical adjustment hole (6044).

4. The modular elastic tunnel support system according to claim 1, characterized in that: The third magnetic expanded head anchor rod (16) is driven into the bearing layer at an angle of 30 to 60 degrees. The outer end of the third magnetic expanded head anchor rod (16) is connected to the bearing pile platform (13). A steel mesh (16) is suspended on the slope of the suspended side of the bearing pile platform (13), and foam fiber concrete is sprayed. The rotating support seat (8) is a support with an arc-shaped cross section, fixed at the bottom of the main beam (9). A rotating support seat (100) is provided on the top surface of the slope retaining side wall (1). An arc-shaped groove (101) is opened in the rotating support seat (100), and an arc-shaped concave steel plate (102) matching the rotating support seat (8) is installed in the groove (101). The rotating support seat (8) is embedded in the corresponding groove (101) and can rotate in the groove (101).

5. The modular elastic tunnel support system according to claim 1, characterized in that: The expansion anchor rods (502) are provided in groups of 3 to 5. An anchor rod through hole is opened at the center of the first support steel plate (503). The annular surface of the first support steel plate (503) is provided with multiple pull holes (507) arranged in a ring around the anchor rod through hole. The pull steel anchor rod (501) passes through the anchor rod through hole, and the other end is fixedly welded to the center of the second support steel plate (504) or fixedly inserted into the center hole of the second support steel plate (504). The number of pull holes (507) and strip holes (508) is the same as the number of expansion anchor rods (502). Each expansion anchor rod (502) is provided with a connecting ring (509) at one end. The connecting ring (509) is sleeved at the pull hole (507); the magnet block (505) is frustum-shaped or I-shaped, and the diameter of the end of the magnet block (505) near the second support steel plate (504) is smaller than the diameter of the end away from the second support steel plate (504); during the process of inserting the magnetic expansion anchor rod into the hole, the connecting spring (506) is in an extended state, and the elastic force provided keeps the expansion anchor rod (502) in a non-open state. At this time, the end of the expansion anchor rod (502) away from the first support steel plate (503) is located outside the large diameter end of the magnet block (505) and contacts the outer edge of the large diameter end of the magnet block (505).

6. The modular elastic tunnel support system according to claim 3, characterized in that: The modular support plate (11) is a rectangular reinforced concrete structural plate. Ribbed beams are arranged on the modular support plate (11), and reinforcing bars and stirrups are arranged inside. Side beams (1100) are provided on the left and right sides of the modular support plate (11) at the positions corresponding to the beam armholes (900). Support springs (17) set on the modular support plate (11) are respectively opened at the bottom and side of the side beams (1100). Each modular support plate (11) has matching splicing slots (1101) on the front and rear sides, and the protruding part of the outer edge (1102) of the splicing slot (1101) is set in an arc.

7. The modular elastic tunnel support system according to claim 4, characterized in that: The slope retaining sidewall (1) is made of precast retaining wall panels (103) of reinforced concrete structure spliced ​​together. Each precast retaining wall panel (103) has matching splicing interfaces (104) on both sides. Adjacent precast retaining wall panels (103) are spliced ​​and fixed together by splicing interfaces (104). A rotating support (100) is provided at the top of the precast retaining wall panel (103), and a lower protrusion (105) is provided at the bottom. A magnet (106) is embedded at the bottom of the lower protrusion (105), and multiple anchor bolt installation holes (107) are opened on the precast retaining wall panel (103); the horizontal retaining wall (2) An installation groove (200) matching the lower protrusion (105) is provided on the upper part. The retaining wall base (3) is provided in multiple ways, all of which are made of magnetic concrete. The installation groove (200) on the horizontal retaining wall (2) leads to the corresponding retaining wall base (3). Multiple second magnetic expansion head anchor rods (12) are installed around each retaining wall base (3). The first magnetic expansion head anchor rod (5), the second magnetic expansion head anchor rod (12) and the third magnetic expansion head anchor rod (10) are all filled and poured with magnetic concrete. The first magnetic expansion head anchor rod (5) is driven into the anchor rod installation hole (107). The magnetic concrete is composed of the following materials by mass percentage: 25-35% iron ore crushed stone with a particle size of 5-10mm, 15-25% iron powder, 20-30% cement, 2-4% SBS modifier, 6-8% glass fiber with a length of 15-20mm, and 12-17% water.

8. A construction method for a modular elastic tunnel support system according to any one of claims 1 to 7, characterized in that, The slope retaining sidewall (1) is made of precast retaining wall panels (103) of reinforced concrete structure. The bottom of the precast retaining wall panel (103) is provided with a lower protrusion (105) that is spliced ​​with the horizontal retaining wall (2), and an embedded magnet (106) is provided at the bottom of the lower protrusion (105). Multiple anchor bolt installation holes (107) are reserved on the precast retaining wall panel (103). The construction method specifically includes the following steps: S1. Prepare prefabricated main beams, modular support slabs, and prefabricated retaining wall slabs; S2. Construct the retaining wall structure on the inner side of the road according to the design drawings; first, excavate a trapezoidal cross-section retaining wall base pouring hole at the design location, and drill and install multiple second magnetic enlarged head anchor rods through the retaining wall base pouring hole. After the installation of multiple second magnetic enlarged head anchor rods, pour magnetic concrete into the retaining wall base pouring hole. After the concrete solidifies, the retaining wall base is formed; then, pour a horizontal retaining wall on the upper part of the retaining wall base, and connect the horizontal retaining wall to the retaining wall base. The horizontal retaining wall is then constructed using formwork. During construction, installation slots for the retaining walls on the slope are reserved. The position, shape, and size of the installation slots are matched with the protruding parts of the precast retaining wall panels. The precast retaining wall panels are spliced ​​and installed, and the protruding parts at the bottom of each precast retaining wall panel are inserted into the corresponding installation slots. Magnetic concrete is poured into the grooves and gaps of the horizontal retaining wall. Finally, multiple first magnetic expanded head anchors are drilled into the mountain through the anchor installation holes reserved on the precast retaining wall panels. A rotating support matching the rotating support seat is provided on the top of the retaining wall. S3. Construct the external support structure on the outer side of the road according to the design drawings; first, drill multiple bearing piles from the ground, each bearing pile is driven into the bearing layer of the foundation, and the tops of the bearing piles are connected to each other with a bearing pile platform; then, construct multiple third magnetic expanded head anchor rods, which are driven into the bearing layer from a 30-60 degree inclined hole drilled from the bearing pile platform, and the outer end of the third magnetic expanded head anchor rod is anchored to the bearing pile platform; after that, hang steel mesh on the outer slope of the road and spray foam fiber concrete for protection; finally, vertically install support columns and connecting beams on the bearing pile platform; S4. Install the main beams and modular support plates. One end of each main beam is rotatably connected to the rotating support at the top of the slope retaining wall via a rotating support seat, and the other end is connected to the connecting beam of the external support structure via a spring damping support seat. After the main beams are installed, assemble the modular support plates between two adjacent main beams. After completing the installation of the modular support plates, place the steel cage on the top of the installed main beams and modular support plates and fill it with ceramsite. S5. When a vehicle exceeding the height limit inside the tunnel needs to pass, lift the steel cage containing expanded clay, modular support plate and main beam to the side. After the vehicle passes, repeat step S4 to install them.

9. The construction method of a modular elastic tunnel support system according to claim 8, characterized in that: The first, second, and third magnetic expanded head anchor bolts used in the construction method have the same structure, each including a main steel anchor bolt, a tension steel anchor bolt, an expansion anchor bolt, a first support steel plate, and a magnetic anchor bolt expansion head. The magnetic anchor bolt expansion head includes a second support steel plate fixed to the end of the tension steel anchor bolt and a magnet block welded to the side of the second support steel plate away from the tension steel anchor bolt. A connecting spring is provided between the first support steel plate and the second support steel plate. The installation process for each second magnetic expanded head anchor rod is as follows: Drill holes at the designed anchor rod positions within the casting holes of the retaining wall base, and continue drilling at the deepest point of the anchor rod hole using a reaming drill bit. Insert the second magnetic expanded head anchor rod into the anchor rod hole, pull the steel anchor rod to stretch the magnetic anchor rod expansion head, causing the magnetic anchor rod expansion head to press against the expansion anchor rod and expand it in all directions. The connecting spring is compressed, and the expansion anchor rod will expand to the maximum diameter of the anchor rod hole, fixing the position of the steel anchor rod. Then, inject magnetic concrete into the anchor rod hole, and use a magnet to attract the magnetic concrete to fill the gaps in the hole. Wait for the magnetic concrete to solidify to complete the installation of the second magnetic expanded head anchor rod. The installation process for each first magnetic expanded head anchor rod is as follows: drill holes in the mountain through the anchor rod installation holes reserved on the retaining wall precast slab, and continue drilling at the deepest part of the anchor rod hole using a hole-enlarging drill bit, and put the first magnetic expanded head anchor rod into the anchor rod hole. The rest of the process is the same as the installation process for the second magnetic expanded head anchor rod. The installation process for each third magnetic reamer is as follows: drill anchor holes from the outside of the bearing pile platform towards the foundation at an angle, and continue drilling at the deepest point of the anchor hole using a reamer. Insert the third magnetic reamer into the anchor hole. The remaining process is the same as the installation process for the second magnetic reamer.

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