A tunnel protection structure resistant to gypsum rock

Abstract

The present invention relates to the technical field of tunnel protection structures, and provides a tunnel protection structure resistant to gypsum rock, comprising an arched arch wall and a base plate cast from reinforced concrete, further comprising a fixing rod fixed within the arch wall and the base plate, a hard material protective tube fixed to the fixing rod, the protective tube passing through the arch wall and the base plate and extending into the rock wall, a heating tube fixed within the protective tube; and a base plate having a triangular cross-section along the radial direction of the tunnel, an I-shaped reinforcing rib fixed within the base plate, and both ends of the base plate fixedly connected to the arch foot of the arch wall. The present invention controls the moisture in the rock wall where gypsum rock is buried by providing fixing rods, a protective tube, a heating tube, a triangular base plate, and reinforcing ribs, thereby preventing the gypsum rock from corroding the concrete after swelling and dissolution in water. Furthermore, the triangular base plate and reinforcing ribs further enhance the compressive strength of the protection structure itself, greatly increasing the protection effect and service life of the protection structure.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel protection structures, and in particular to a gypsum rock resistant tunnel protection structure. Background Art

[0002] Tunnel protection structures are permanent concrete support structures constructed along the tunnel perimeter to prevent surrounding rock deformation or collapse. They are essential for ensuring the normal and safe operation of tunnels. However, during tunnel excavation, tunnels may pass through gypsum strata. In their natural state, gypsum rock has a certain strength, but when exposed to water, the anhydrite (primarily composed of CaSO4) hydrates into gypsum (primarily composed of CaSO4·2H2O), causing volume expansion. In underground projects, this expansive nature of anhydrite generates expansion pressure, which acts on structures within it and significantly affects project stability. Especially in tunnel projects, expansion can lead to disasters such as tunnel floor heave, surrounding rock intrusion, and support failure. Furthermore, gypsum dissolves when exposed to water. The resulting water is rich in sulfates, which are highly corrosive to concrete, further compromising the safety of the protection structure. Therefore, when gypsum strata are present near tunnels, the tunnel protection structure must further consider its ability to resist the stress effects of gypsum expansion and the corrosion of the gypsum-containing water.

[0003] However, in the existing technology, for gypsum hornfels with low gypsum content and main damage manifestation of sulfate corrosion, drainage, sulfate-resistant cement and other treatment suggestions are adopted. For hard gypsum rocks and gypsum rocks with high gypsum content, which are mainly damaged by expansion, the arch wall shape is optimized to improve the resistance to expansion stress. Although the above research results have achieved phased results, they are very limited. Whether it is drainage, sulfate-resistant cement, or optimization of arch wall shape, they are only improvements to the concrete wall protection structure itself. The fundamental reason for the damage of the protection structure, that is, the water absorption and expansion of the external gypsum rock, always exists and is uncontrollable. The protection structure is being damaged by chemical erosion and physical extrusion every day, and it is bound to not last long.

[0004] In view of this, the present invention proposes a tunnel protection structure that is resistant to gypsum rock. Considering that the corrosion of gypsum rock to the concrete protection structure by environmental water after water dissolution is caused by water, a method is provided to solve the problem of damage caused by gypsum rock encountering water from the source. Summary of the Invention

[0005] In order to make up for the shortcomings of the existing technology and solve the problems that the existing technology, whether it is drainage, resistance to sulfate cement, or optimization of arch wall shape, only improves the concrete wall protection structure itself, but cannot solve the problem of expansion stress caused by gypsum rock when it comes into contact with water and erosion of gypsum rock by environmental water after dissolution from the source, the present invention proposes a tunnel protection structure that is resistant to gypsum rock.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A tunnel protection structure for resisting gypsum rock, comprising an arched arch wall and a bottom plate cast by reinforced concrete, and further comprising:

[0008] A fixing rod, wherein the fixing rod is fixed in the arch wall and the bottom plate, a protective tube made of a hard material is fixed on the fixing rod, the protective tube passes through the arch wall and the bottom plate and extends into the rock wall, and a heating tube is fixed in the protective tube;

[0009] The bottom plate has a triangular cross-section along the radial direction of the tunnel, an I-shaped reinforcement rib is fixed inside the bottom plate, and both ends of the bottom plate are fixedly connected to the arch feet of the arch wall.

[0010] Preferably, an insulating gap is provided inside the arch wall and the bottom plate, and the fixing rod is fixed in the insulating gap. The insulating gap divides the arch wall into an inner wall and an outer wall, and divides the bottom plate into an inner plate and an outer plate.

[0011] Preferably, a No. 1 connecting column and a No. 2 connecting column are fixed on the outer wall and the fixed rod respectively, the No. 1 connecting column and the No. 2 connecting column are slidably connected, a No. 1 spring is fixedly connected between the No. 1 connecting column and the No. 2 connecting column, the fixed rod is fixedly connected to the inner wall, and the protective tube is slidably connected to the outer wall.

[0012] Preferably, a slot is provided in the No. 1 connecting column, and a plug is provided in the No. 2 connecting column. The plug and the slot cooperate with each other, and the plug and the slot are connected in parallel in the heating tube control circuit.

[0013] Preferably, the other end of the protective tube is fixedly connected to a fixed shell, a pressure plate is slidably connected inside the fixed shell, a fixed claw is rotatably connected to the pressure plate, a through hole is provided on the side of the fixed shell, the fixed claw is slidably connected to the through hole, a No. 2 spring is provided between the pressure plate and the bottom surface of the fixed shell near the protective tube, a pull rope made of flexible material is fixedly connected to the pressure plate, and the other end of the pull rope passes through the fixed shell and the protective tube and is fixed in the insulation gap.

[0014] Preferably, a mounting seat is fixed to the other end of the fixed shell, a conical drill bit is fixedly connected to the other end of the mounting seat, a power rod is provided in the protective tube and is slidably connected to the bottom of the fixed shell, and the fixed shell is rotatably connected to the protective tube.

[0015] Preferably, the projection point of the tip of the conical drill bit vertically projected onto the circular surface of its bottom is not the center of the circular surface.

[0016] Preferably, a protective plate is fixed between the No. 1 connecting column and the outer wall or outer panel, and the protective plate fits tightly against the outer wall or outer panel.

[0017] Preferably, a coil is fixed in the heating tube, and the portion of the protective tube extending into the rock wall is made of iron material.

[0018] Preferably, a magnetron is fixed in the heating tube, and the heating tube and the protective tube are made of non-metallic materials.

[0019] The present invention has at least the following advantages and beneficial effects:

[0020] 1. The tunnel protection structure for gypsum rock described in the present invention controls moisture in the rock wall where gypsum rock is buried by providing fixing rods, protective pipes, heating pipes, triangular base plates, and reinforcing ribs. This prevents the gypsum rock from corroding concrete due to its expansion and dissolution when exposed to water. The triangular base plates and reinforcing ribs further enhance the compressive strength of the protection structure itself, greatly increasing its protective effect and service life.

[0021] 2. The tunnel protection structure for gypsum rock resistance described in the present invention, by providing a fixed shell, a fixed base and a conical drill bit, can more easily deliver the protection pipe into a larger range of rock walls, expand the range of influence on the heating pipe, and affect the gypsum rock in a larger range, thereby better controlling the expansion of underground gypsum rock and the stress generated on the protection structure. At the same time, the protection pipe is fixed to the rock wall by the fixed claws in the fixed shell, which also generates an outward pulling force on the outer wall, further improving the effect of the outer wall in resisting stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 is a perspective view of the present invention;

[0024] Figure 2 This is a schematic diagram of the local structure of spring No. 1;

[0025] Figure 3 This is the structural view of the protective pipe;

[0026] Figure 4 Schematic diagram of the internal structure of the fixed shell;

[0027] Figure 5 It is a schematic diagram of the structure of a tapered drill bit;

[0028] In the figure: 1. Exterior wall; 11. Interior wall; 12. Insulation gap; 2. Exterior panel; 21. Interior panel; 22. Reinforcement rib; 3. Fixing rod; 31. Connecting column No. 1; 32. Connecting column No. 2; 33. Spring No. 1; 34. Slot; 35. Plug; 4. Protective tube; 42. Heating tube; 5. Fixed shell; 51. Pressing plate; 52. Fixing claw; 53. Through hole; 54. Spring No. 2; 55. Pull rope; 6. Mounting base; 61. Conical drill bit; 62. Power rod; 7. Protective plate. DETAILED DESCRIPTION

[0029] like Figures 1 to 5 As shown, a tunnel protection structure for resisting gypsum rock, comprising an arched arch wall and a bottom plate cast by reinforced concrete, further comprising:

[0030] A fixing rod 3 is fixed in the arch wall and the bottom plate. A protective tube 4 is fixedly connected to the fixing rod 3. The other end of the protective tube 4 passes through the arch wall and the bottom plate and extends into the rock wall. A heating tube 42 is fixed in the protective tube 4.

[0031] The bottom plate has a triangular cross-section along the radial direction of the tunnel. An I-shaped reinforcement rib 22 is fixed inside the bottom plate, and both ends of the bottom plate are fixedly connected to the arch feet of the arch wall.

[0032] When in use, a bottom plate with a triangular cross-section along the radial direction of the tunnel is fixed to the bottom of the arch wall, and both ends of the bottom plate are fixedly connected to the arch feet of the arch wall respectively. An "I"-shaped reinforcing rib 22 is fixed in the bottom plate, and a fixing rod 3 is fixed in the arch wall and the bottom plate. A protective pipe 4 is fixedly connected to the fixing rod 3, and the protective pipe 4 passes through the arch wall and the bottom plate and extends into the rock wall. The protective pipe 4 is slidably connected to the arch wall and the bottom plate, and a heating pipe 42 is fixed in the protective pipe 4. When the gypsum rock undergoes plastic deformation due to excessive pressure from the surrounding rock and squeezes the arch wall and the bottom plate, or when the gypsum rock absorbs water and expands and squeezes the arch wall and the bottom plate, pressure will be generated on the arch wall and the bottom plate. When the pressure is greater than the bearing capacity of the arch wall and the bottom plate, the structure of the arch wall and the bottom plate will be damaged. At this time, in order to solve this situation, In this case, the heating pipe 42 is started to heat the surrounding gypsum rock. The strength of the gypsum rock gradually weakens with increasing temperature, and the strength of the gypsum rock is reduced, thereby reducing the stress of the gypsum rock on the arch wall and the bottom plate, so as to achieve the purpose of protecting the arch wall and the bottom plate from being damaged and ensure the normal use of the tunnel. When the gypsum rock absorbs water and expands due to the increase of moisture in the environment, the heating pipe 42 is started to heat the gypsum rock, which can further evaporate the crystallization water in the gypsum rock, reduce the expansion volume of the gypsum rock, and evaporate the moisture in the environment around the gypsum rock from the source, making the environment drier and preventing the gypsum rock from absorbing moisture in the environment and expanding, thereby avoiding the gypsum rock absorbing water and generating stress on the arch wall and the bottom plate.

[0033] In addition, the bottom plate will be crushed by vehicles running on the bottom plate, causing the upper surface of the bottom plate to be subjected to downward pressure, and the compressive stress of the gypsum rock will cause the bottom plate to be subjected to upward stress. The arched bottom plate in the existing technology can only have a certain resistance to the compressive stress of the gypsum rock, and cannot effectively cope with the pressure on the bottom plate, so that the structure of the bottom plate is destroyed under the action of the upper stress, thereby weakening the bottom plate's resistance to the stress from the gypsum rock below, and eventually resulting in the bottom plate being destroyed, the road surface being arched, and the arch foot being destroyed. Therefore, a triangular cross-section is adopted, and the stability of the triangle is utilized to effectively resist the stress on each side. At the same time, "I"-shaped reinforcement ribs 22 are fixed in the three sides of the cross-section. The shear stress resistance characteristics of the "I"-shaped reinforcement ribs 22 can be utilized to further enhance the resistance of the triangular bottom plate.

[0034] That is, the present invention uses the structure of the fixing rod 3, the protective tube 4 and the heating tube 42 to evaporate the moisture in the gypsum rock, thereby solving the problem of physical damage and chemical corrosion to the concrete protective structure caused by the expansion and dissolution of the gypsum rock when it comes into contact with water. The structural change of the bottom plate further enhances the stress resistance of the protective structure. Through the combination of the two, the overall strength of the anti-gypsum rock tunnel protective structure is effectively enhanced.

[0035] An insulating gap 12 is provided inside the arch wall and the bottom plate, and the fixing rod 3 is fixed in the insulating gap 12. The insulating gap 12 divides the arch wall into an inner wall 11 and an outer wall 1, and divides the bottom plate into an inner plate 21 and an outer plate 2.

[0036] During use, an insulating gap 12 is provided inside the arch wall and the bottom plate, and the fixing rod 3 is fixed on the inner wall 11 or the inner plate 21. When the heating tube 42 is started, the surrounding gypsum rock will be heated, and the heat of the heating tube 42 will also be radiated to the arch wall to heat the arch wall, thereby causing the heat on the arch wall to be transferred into the tunnel, causing the temperature inside the tunnel to rise. When this heat cannot be discharged in time, the temperature in the tunnel will rise rapidly. When it exceeds the tolerance limit of the human body and the vehicle, it will cause human discomfort and affect the normal use of the instruments and meters in the vehicle, affecting the normal driving of vehicles and personnel in the tunnel. By utilizing the insulating gap 12 between the inner wall 11 and the outer wall 1, when heat passes through the still air in the insulating gap 12, due to the very low thermal conductivity of the still air, the heat is almost completely lost when it is transferred to the inner wall 11, so that the tunnel temperature inside the inner wall 11 remains constant, protecting the vehicles and personnel in the tunnel from being affected by the heat transferred from the heating tube 42, thereby ensuring the safety of personnel and vehicles.

[0037] A No. 1 connecting column 31 and a No. 2 connecting column 32 are fixed on the outer wall 1 and the fixed rod 3 respectively. The No. 1 connecting column 31 and the No. 2 connecting column 32 are slidably connected. A No. 1 spring 33 is fixedly connected between the No. 1 connecting column 31 and the No. 2 connecting column 32. The fixed rod 3 is fixedly connected to the inner wall 11, and the protective tube 4 is slidably connected to the outer wall 1.

[0038] When in use, a No. 1 connecting column 31 and a No. 2 connecting column 32 are fixed on the outer wall 1 and the fixing rod 3 respectively, and the No. 1 connecting column 31 and the No. 2 connecting column 32 are slidably connected. A No. 1 spring 33 is fixedly connected between the No. 1 connecting column 31 and the No. 2 connecting column 32. The fixing rod 3 is fixedly connected to the inner wall 11, and the protective tube 4 is slidably connected to the outer wall 1. When the outer wall 1 is subjected to the pressure of the gypsum rock, and when the pressure on the outer wall 1 exceeds the bearing capacity of the outer wall 1, the outer wall 1 will be deformed, so that the No. 1 connecting column 31 fixedly connected to the outer wall 1 will compress the No. 1 spring 33. 3. The elastic force of the No. 1 spring 33 will help the outer wall 1 resist the pressure of the gypsum rock. On the other hand, when the gypsum rock squeezes the outer wall 1, the heating tube 42 starts to reduce the strength of the gypsum rock, thereby gradually reducing the pressure of the gypsum rock on the wall. At this time, the balance between the elastic force of the No. 1 spring 33 and the pressure of the gypsum rock is broken, and the No. 1 spring 33 stretches, which will gradually eliminate the deformation on the outer wall 1, thereby protecting the outer wall 1 from deformation accumulation due to repeated expansion of the gypsum rock, which will eventually cause the outer wall 1 to be damaged, thereby extending the service life of the outer wall 1.

[0039] The No. 1 connecting column 31 is provided with a slot 34 , and the No. 2 connecting column 32 is provided with a plug 35 . The plug 35 and the slot 34 cooperate with each other, and the plug 35 and the slot 34 are connected in parallel in the control circuit of the heating tube 42 .

[0040] When in use, a slot 34 is provided in the No. 1 connecting column 31, and a plug 35 is provided in the No. 2 connecting column 32. The plug 35 and the slot 34 cooperate with each other, and the plug 35 and the slot 34 are connected in parallel in the control circuit of the heating tube 42. When the outer wall 1 does not deform, there is a gap between the plug 35 and the slot 34, and the heating tube 42 is not powered and does not heat. When the expansion or plastic deformation of the gypsum rock produces pressure on the outer wall 1, when the pressure exceeds the bearing capacity of the outer wall 1, the outer wall 1 is deformed inward, which will cause the No. 1 connecting column 31 to compress the No. 1 spring 33, and the plug in the No. 1 connecting column 31 will compress the No. 1 spring 33. The groove 34 will move toward the plug 35, thereby cooperating with the slot 34, so that the heating pipe 42 is energized, heating the gypsum rock, reducing the strength of the gypsum rock and thereby reducing its pressure on the outer wall 1. Afterwards, the outer wall 1 recovers its deformation under the action of the elastic force of the No. 1 spring 33, and the plug 35 is disengaged from the slot 34, thereby cutting off the power to the heating pipe 42, so that the heating pipe 42 can respond to the pressure of the gypsum rock in time, preventing personnel from failing to respond to the pressure of the gypsum rock on the outer wall 1 in time due to inadequate personnel monitoring or other faults, thereby eliminating the defect of requiring personnel to monitor at all times.

[0041] The other end of the protective tube 4 is rotatably connected to a fixed shell 5, and a pressure plate 51 is slidably connected inside the fixed shell 5. A fixing claw 52 is rotatably connected to the pressure plate 51. A through hole 53 is provided on the side of the fixed shell 5, and the fixing claw 52 is slidably connected to the through hole 53. A No. 2 spring 54 is provided between the pressure plate 51 and the bottom surface of the fixed shell 5 close to the protective tube 4, and an inclined surface is provided on the inner side of the bottom surface. A pull rope 55 is fixedly connected to the pressure plate 51. The pull rope 55 is made of flexible material, and the other end of the pull rope 55 passes through the fixed shell 5 and the protective tube 4 and is fixed in the insulation gap 12.

[0042] When in use, the other end of the protective tube 4 is fixedly connected to the fixed shell 5, and a pressure plate 51 is slidably connected to the fixed shell 5. A fixed claw 52 is rotatably connected to the pressure plate 51. A through hole 53 is provided on the side of the fixed shell 5. A pull rope 55 is fixedly connected to the pressure plate 51. The other end of the pull rope 55 passes through the fixed shell 5 and the protective tube 4 and is fixed in the heat-insulating gap 12. When the protective tube 4 is extended into the specified position inside the gypsum rock, the end of the pull rope 55 located in the heat-insulating gap 12 is pulled to make the pressure plate 51 slide along the inner wall of the fixed shell 5. The spring 54 is compressed. Since the fixed shell 5 is provided with an inclined surface at a position corresponding to the fixed clamping claw 52 on the bottom surface close to the protective tube 4, when the fixed claw 52 originally retracted in the fixed shell 5 slides toward the bottom surface driven by the pressure plate 51, it will slide out from the through hole 53 along the inclined surface of the bottom plate, and as the pressure plate 51 approaches the bottom surface, the fixed claw 52 gradually opens and inserts into the nearby rock wall (it is easy to understand that the end of the fixed claw can be designed to be pointed to facilitate insertion into the rock wall), and then the pull is pulled. The end of the rope 55 located in the heat-insulating gap 12 is fixed (for example, bolted to the fixing rod 3, or a pull ring is provided on the inner wall 11 and the inner plate 21, and the pull rope is bolted to the pull ring), so that the fixing claw 52 remains in an open state, thereby fixing the protective tube 4 in the rock wall. When the protective tube 4 needs to be retracted, the pull rope 55 is released, and the No. 2 spring 54 loses the restriction of the pressure of the pressure plate 51 and begins to recover its deformation and stretch under the action of the elastic force. Under the elastic force of the compressed No. 2 spring 54, the pressure plate 51 moves away from the protective tube in the fixed shell 5. One end of the protective tube 4 slides and drives the fixing claw 52 to slide in the through hole 53. When the pressure plate 51 is squeezed to the bottom surface away from the end of the protective tube 4 by the spring force, the fixing claw 52 is finally retracted into the fixed shell 5, and then the protective tube 4 can be withdrawn. Moreover, since the protective tube 4 is fixedly connected to the fixing rod 3, a No. 1 spring 33 is provided between the fixing rod 3 and the outer wall 1. When the fixing claw 52 is fixed in the rock wall, the protective tube 4 is tightened on the outer wall 1, further improving the bearing limit of the outer wall 1 to the stress of gypsum rock.

[0043] The other end of the fixed shell 5 is fixed with a mounting base 6, and the other end of the mounting base 6 is fixedly connected to a conical drill bit 61. A power rod 62 is provided in the protective tube 4 and is slidably connected to the bottom of the fixed shell 5. The fixed shell 5 is rotatably connected to the protective tube 4.

[0044] When in use, the other end of the fixed shell 5 is fixed with a mounting seat 6, and the other end of the mounting seat 6 is fixedly connected with a conical drill bit 61. The fixed shell 5 is rotatably connected to the protective tube 4, and the bottom of the fixed shell 5 is slidably connected to a power rod 62. The cylindrical power rod 62 is fixed with a cylindrical protrusion on the side of the sliding part of the fixed shell 5. After the outer wall 1 and the outer plate 2 are installed, when the protective tube 4 is installed into the rock wall, it is difficult to directly push the protective tube 4 into the rock layer due to the resistance of the rock layer or soil. At this time, the power rod 62 is fixed to the motor, and the power rod 62 is slidably inserted into the hole that matches the bottom surface of the fixed shell 5. The motor is started to rotate the power rod 62. Due to the restriction of the cylindrical protrusion fixedly connected to the power rod 62, the power rod 62 will not rotate with the rock layer. The fixed shell 5 rotates relative to each other, which will drive the fixed shell 5 connected to one end of the protective tube 4 to rotate. The rotation of the fixed shell 5 drives the conical drill bit 61 fixedly connected to it to rotate, and applies a force to the other end of the protective tube 4 to push the protective tube 4 into the rock wall, so that the conical drill bit 61 drills the soil or rock layer in front, and the protective tube 4 extends into the rock layer, expanding the influence range of the heating tube 42 and the protective tube 4, so that the moisture inside the rock layer can be evaporated better and more widely, reducing the damage to the protective structure caused by water on the gypsum rock from the source, and improving the overall service life of the tunnel protective structure. After reaching the designated position, the motor can be removed and reused. On the other hand, the power rod 62 slidably connected to the fixed shell 5 can be pulled out for reuse, saving costs.

[0045] The projection point of the tip of the conical drill bit 61 on the circular surface at its bottom is not the center of the circular surface.

[0046] When in use, the projection point of the tip of the conical drill bit 61 on the circular surface at its bottom is not the center of the circular surface. At this time, the length of the generatrix formed by the tip of the conical drill bit 61 and the circumference of the circular surface of its bottom surface is no longer equal everywhere, but changes regularly around the circumference of the circular surface. When the motor connected to the conical drill bit 61 is not started, the conical drill bit 61 will not rotate. At this time, during the advancement of the drill bit, since the pressure in the soil and rock wall can be regarded as roughly unchanged, the bottom surface of the cone is divided into small line segments of equal distance, forming small triangles with the generatrix, and the length of the generatrix is ​​approximately equal to the height of the triangle. Therefore, the longer the generatrix, the larger the area of ​​the triangle, and the greater the pressure it withstands when the pressure remains unchanged. Therefore, the pressure at the position where the generatrix of the conical drill bit 61 is long is greater than that at the position where the generatrix is ​​short, which will cause the conical drill bit 61 to advance. When the conical drill bit 61 rotates one circle, the long side of the busbar and the short side of the busbar both rotate one circle, and the average pressure on each direction during this time is equal. Moreover, since it takes time for the conical drill bit 61 to rotate one circle, the trajectory of the conical drill bit 61 during this circle is approximately a spiral line, and the cross-sectional area of ​​the drilled hole will be larger than the area of ​​the circular surface of the bottom surface of the conical drill bit 61, which is more conducive to the subsequent protection tube 4 entering the soil and rock wall deep layer. When the protection tube 4 reaches the specified position, the motor is stopped, and then the pull rope 55 is pulled to open and fix the fixed claw 52 in the rock wall. By using the conical drill bit 61 with this structure, the protection tube 4 can be extended into the rock formation, so that the protection tube 4 can extend over a wider range.

[0047] A rigid protective plate 7 is fixed between the No. 1 connecting column 31 and the outer wall 1 or outer panel 2 , and the protective plate 7 is tightly fitted to the outer wall 1 or outer panel 2 .

[0048] When in use, a rigid protective plate 7 that fits tightly with the outer wall 1 or outer panel 2 is fixed between the No. 1 connecting column 31 and the outer wall 1 or outer panel 2, so that the pressure of the No. 1 spring 33 is first transmitted to the rigid protective plate 7 through the No. 1 connecting column 31, and then transmitted to the outer wall 1 or outer panel 2, and the original point contact between the No. 1 connecting column 31 and the outer wall 1 or outer panel 2 is changed to a surface contact between the protective plate 7 and the outer wall 1 or outer panel 2. When the outer wall 1 or outer panel 2 is deformed and concave due to the expansion stress of the gypsum rock, the protective plate 7 will be translated as a whole toward the inner wall 11 or inner panel 21, and because the protective plate 7 is rigid, the stress and deformation away from the No. 1 connecting column 31 but within the coverage of the protective plate 7 can also be transmitted to the No. 1 connecting column 31, thereby causing the No. 1 connecting column 31 to move inward. The heating tube 42 is activated, thereby expanding the sensing range of the No. 1 connecting column 31. When the heating tube 42 is activated, the stress is eliminated. When the protective plate 7 begins to recover to the position in contact with the outer wall 1 or the outer panel 2 under the action of the No. 1 spring 33, the contact between the protective plate 7 and the outer wall 1 or the outer panel 2 changes from point contact with the wall to surface contact in a fitted state. Since the force-bearing area of ​​the protective plate 7 increases, the pressure exerted on the wall is reduced. Therefore, after the outer wall 1 or the outer panel 2 returns to its original state, the protective plate 7 no longer continues to move, effectively preventing the situation where the No. 1 connecting column 31 is in full point contact with the outer wall 1 or the outer panel 2, the wall is concave due to stress and the strength is reduced, and the pressure from the No. 1 spring 33 on the No. 1 connecting column 31 causes the wall to bulge outward, thereby further reducing the strength of the wall.

[0049] In this embodiment, a coil is fixed in the heating tube 42, and the portion of the protective tube 4 extending into the rock wall is made of iron material.

[0050] During use, a coil is fixed inside the heating tube 42, and the part of the protective tube 4 extending into the rock wall is made of iron material. When the heating tube 42 needs to be started, high-frequency alternating current is passed through the coil to generate an alternating magnetic field with constantly changing direction. According to Faraday's law of electromagnetic induction, eddy currents will be generated inside the conductor in the alternating magnetic field, and the eddy currents will promote the movement of electrons in the conductor. According to the Joule heating effect, the movement of electrons will cause the conductor to heat up, thereby heating the iron protective tube 4. The heat of the iron protective tube 4 is then radiated into the surrounding rock wall, heating the gypsum rock and reducing the strength of the gypsum rock. At the same time, the heat can be used to evaporate the moisture in the surrounding environment and the crystallized water in the gypsum rock, thereby controlling the humidity field and temperature field in the surrounding rock wall.

[0051] In other embodiments of the present invention, a magnetron is fixed in the heating tube 42 , and the heating tube 42 and the protective tube 4 are made of non-metallic materials.

[0052] During use, a magnetron is fixed in the heating tube 42. The heating tube 42 and the protective tube 4 are made of non-metallic materials. When the heating tube 42 needs to be started for heating, current is passed into the magnetron in the prior art, and the magnetron is used to convert the current into microwaves. The microwave radiation causes the polar molecules in the rock wall to oscillate, and the collision between the molecules generates a large amount of friction heat, thereby increasing the temperature inside the rock wall, heating the gypsum rock, and reducing the strength of the gypsum rock. At the same time, the heat can be used to evaporate the moisture in the surrounding environment and the crystallized water in the gypsum rock, thereby realizing the control of the humidity field and temperature field in the surrounding rock wall. In addition, the microwave radiation range is wider and can cover a larger range.

[0053] The specific workflow is as follows:

[0054] Before pouring the protective structure, I-shaped reinforcement bars 22 are laid, followed by the installation of the fixing rods 3, protective tubes 4, and protective plates 7. The exterior wall 1 and exterior plate 2 are then poured, followed by the installation of the No. 1 spring 33. Finally, the interior wall 11 and interior plate 21 are poured. During the installation of the protective tube 4, the motor is started, rotating the power rod 62 and ultimately the conical drill bit 61. This forces the protective tube 4 inward into the rock wall, and the steering function of the conical drill bit 61 is utilized to position the protective tube 4 in the desired location. Once the desired location is reached, the pull cord 55 is pulled to secure the protective tube 4. After installation, when the gypsum rock absorbs water and expands due to the increase of moisture in the surrounding environment, or when it undergoes plastic deformation due to excessive confining pressure, stress will be generated on the outer wall 1. At this time, the tension of the protective tube 4, the resistance of the outer wall 1 itself and the elastic force of the No. 1 spring 33 will resist the stress outside the outer wall 1. Once the stress exceeds the bearing limit of the outer wall 1, the outer wall 1 will deform inward, thereby pushing the protective plate 7 and driving the No. 1 connecting column 31 to move inward, so that the plug 35 contacts the slot 34, thereby starting the heating tube 42 to heat the surrounding rock wall. When the heat is transferred to the gypsum After the gypsum rock is heated, the stress of the gypsum rock on the outer wall 1 decreases due to the characteristic that the strength of the gypsum rock decreases with increasing temperature, and the heating pipe 42 also evaporates the moisture in the surrounding environment and the crystallization water in the gypsum rock, so that the volume of the gypsum rock decreases, thereby further reducing the stress on the outside of the outer wall 1. Through the above structure, the stress resistance of the protective structure itself is increased. At the same time, the heating pipe 42 evaporates the moisture in the environment, solving the problem of damage to the protective structure caused by water absorption and expansion and water dissolution of the gypsum rock from the source, thereby comprehensively improving the protective performance of the protective structure.

[0055] Front, back, left, right, up and down are all based on the Figure 1 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0057] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

Claims

1. A tunnel protection structure for gypsum rock, comprising an arched wall and a base plate cast from reinforced concrete, characterized by: Also includes; A fixing rod (3), wherein the fixing rod (3) is fixed in the arch wall and the bottom plate, a protective tube (4) made of a hard material is fixed on the fixing rod (3), the protective tube (4) passes through the arch wall and the bottom plate and extends into the rock wall, and a heating tube (42) is fixed in the protective tube (4); A bottom plate, wherein the bottom plate has a triangular cross section along the radial direction of the tunnel, an I-shaped reinforcement rib (22) is fixed inside the bottom plate, and both ends of the bottom plate are fixedly connected to the arch feet of the arch wall; A heat-insulating gap (12) is provided inside the arch wall and the bottom plate, and the fixing rod (3) is fixed in the heat-insulating gap (12). The heat-insulating gap (12) divides the arch wall into an inner wall (11) and an outer wall (1), and divides the bottom plate into an inner plate (21) and an outer plate (2). The other end of the protective tube (4) is rotatably connected to a fixed shell (5), a pressure plate (51) is slidably connected inside the fixed shell (5), a fixed claw (52) is rotatably connected to the pressure plate (51), a through hole (53) slidably connected to the fixed claw (52) is provided on the side of the fixed shell (5), a second spring (54) is provided between the pressure plate (51) and the bottom surface of the fixed shell (5) near the protective tube (4), a pull rope (55) made of flexible material is fixedly connected to the pressure plate (51), and the other end of the pull rope (55) passes through the fixed shell (5) and the protective tube (4) and is fixed in the heat-insulating gap (12).

2. The tunnel protection structure for gypsum rock according to claim 1, characterized in that: A No. 1 connecting column (31) and a No. 2 connecting column (32) are fixed on the outer wall (1) and the fixing rod (3), respectively. The No. 1 connecting column (31) and the No. 2 connecting column (32) are slidably connected. A No. 1 spring (33) is fixedly connected between the No. 1 connecting column (31) and the No. 2 connecting column (32). The fixing rod (3) is fixedly connected to the inner wall (11), and the protective tube (4) is slidably connected to the outer wall (1).

3. The tunnel protection structure for gypsum rock according to claim 2, characterized in that: A slot (34) is provided in the first connecting column (31), a plug (35) is provided in the second connecting column (32), the plug (35) and the slot (34) cooperate with each other, and the plug (35) and the slot (34) are connected in parallel in the control circuit of the heating tube (42).

4. The tunnel protection structure for resisting gypsum rock according to claim 1, characterized in that: The other end of the fixed housing (5) is fixed with a mounting seat (6), the other end of the mounting seat (6) is fixedly connected to a conical drill bit (61), a power rod (62) slidably connected to the bottom of the fixed housing (5) is provided in the protective tube (4), and the fixed housing (5) is rotatably connected to the protective tube (4).

5. The tunnel protection structure for resisting gypsum rock according to claim 4, characterized in that: The projection point of the tip of the tapered drill bit (61) vertically projected onto the circular surface at its bottom is not the center of the circular surface.

6. The tunnel protection structure for resisting gypsum rock according to claim 3, characterized in that: A protective plate (7) is fixed between the No. 1 connecting column (31) and the outer wall (1) or the outer plate (2), and the protective plate (7) and the outer wall (1) or the outer plate (2) are tightly fitted.

7. The tunnel protection structure for resisting gypsum rock according to claim 1, characterized in that: A coil is fixed inside the heating tube (42), and the portion of the protective tube (4) extending into the rock wall is made of iron material.

8. The tunnel protection structure for resisting gypsum rock according to claim 1, characterized in that: A magnetron is fixed in the heating tube (42), and the heating tube (42) and the protective tube (4) are made of non-metallic materials.

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