High steep wall rolling stone buffer protection device and protection method

Abstract

The invention provides a high steep wall rolling stone buffer protection device and method, and the device comprises a broken stone buffer layer which is embedded in a protection platform; the insertion positioning devices are inserted in the gravel buffer layer side by side and incline towards the slope body direction of the high steep wall; the extension supporting device comprises an extension cylinder and an extension rod, the lower end of the extension cylinder is fixedly mounted at the upper end of the insertion positioning device, the lower end of the extension rod is coaxially inserted into the extension cylinder in a sliding manner, and an elastic supporting piece is fixedly mounted in the extension cylinder; the protective blocking net faces the falling direction of the rolling stones, the lower edge of the protective blocking net is located on the surface of the gravel buffer layer, the two ends of the lower edge of the protective blocking net are fixedly installed at the upper ends of the two adjacent insertion positioning devices, and the two ends of the upper edge of the protective blocking net are fixedly installed at the upper ends of the two adjacent extension supporting devices. Through cooperation of the rubble buffer layer, the elastic supporting piece, the protective blocking net and other components, multiple buffer protection on rolling stones is achieved, the impact effect of the rolling stones on the protective wall is weakened, and the threat of the rolling stones on a road or a railway is reduced.

Description

Technical Field

[0001] This invention relates to the field of road or railway protection technology, specifically to a rockfall buffer and protection device and method for steep cliffs. Background Technology

[0002] When constructing roads or railways in mountainous areas, it is usually necessary to excavate tunnels into the mountains and construct viaducts in valleys to maintain the road's smoothness. This ensures the overall straightness of the road or railway and reduces elevation differences, thereby improving the comfort of travel. Therefore, during tunnel excavation, unstable rocks inevitably encounter the tunnel entrance. If these rocks are not cleared in time, they can collapse after the road or railway is opened to traffic, endangering its safety. Furthermore, when clearing unstable rocks, it is also necessary to reinforce and protect steeper sections of the mountainside to prevent falling rocks from impacting bridge piers or entering the tunnel entrance or road area, thus affecting safe operation.

[0003] In general, dangerous rocks are protected by constructing retaining walls. However, with this method, falling rocks will directly impact the retaining wall, and the massive kinetic energy carried by the rocks will be entirely borne by the retaining wall. Therefore, this method requires a high strength for the retaining wall. Furthermore, the impact of rocks on the retaining wall will generate significant vibrations, which will affect the stability of the retaining wall and the mountain. Since the retaining wall is usually close to the bridge piers, the vibrations will also be transmitted to the bridge piers, affecting their safety. In addition, the retaining wall's protective effect is poor. When rocks hit the retaining wall, they will also generate flying debris. This debris will also carry some kinetic energy and impact the bridge piers, or fall into tunnel entrances or roads, further expanding the damage to roads or railways and threatening traffic safety or train safety.

[0004] Therefore, it is necessary to provide a buffer protection device and method for rockfall protection on steep cliffs to buffer and protect against falling rocks and reduce their impact on roads or railways. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a boulder buffer and protection device and method for steep cliffs, solving the problems of poor protective effect of retaining walls, high requirements for structural strength, and the potential for further damage to roads or railways caused by flying debris upon impact.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a boulder buffer and protection device for steep cliffs, comprising:

[0008] Crushed stone buffer layer, buried on a protective platform above a road or railway;

[0009] At least two plug-in positioning devices are inserted side by side into the gravel buffer layer and tilted toward the slope of the steep cliff, with their upper ends exposed on the surface of the gravel buffer layer.

[0010] At least two extension support devices, each extension support device includes an extension cylinder and an extension rod. The lower end of the extension cylinder is fixedly installed on the upper end of the insertion positioning device. The lower end of the extension rod is coaxially and slidably inserted into the extension cylinder. An elastic support member is fixedly installed inside the extension cylinder. The upper end of the elastic support member is connected to the lower end of the extension rod.

[0011] The protective barrier net is set facing the direction of the falling stones. Its lower edge is located on the surface of the gravel buffer layer and its two ends are fixedly installed on the upper ends of two adjacent plug-in positioning devices. Its two ends are fixedly installed on the upper ends of two adjacent extension rods.

[0012] Based on the above technical solution, after being impacted by rolling stones, the protective barrier net itself will bend and deform along the direction of the rolling stones' movement. The protective barrier net will wrap around the rolling stones, constraining their movement. The upper edges of the protective barrier net will cause the extended support devices to compress axially. Part of the impact of the rolling stones will be borne by the elastic support components, which will act as the first layer of buffering. The constraint of the crushed stone buffer layer on the insertion positioning device installed within it is not an absolutely fixed constraint, but allows the insertion positioning device to undergo a certain degree of deformation. The extended support device and the insertion positioning device are rigidly connected. When the rolling stones impact the protective barrier net, the protective barrier net and the… The extended support device will deform around the plug-in positioning device, and the plug-in positioning device will also undergo a certain degree of rotational deformation. Part of the impact of the rolling stones will be transferred to the crushed stone buffer layer, which will act as a second layer of buffering. After some rolling stones impact the protective barrier, they will have an upward trajectory, putting the protective barrier under the rolling stones into a tensile state. This will cause the plug-in positioning device to have a pull-out tendency. The crushed stone buffer layer will generate an anti-pull-out friction force on the plug-in positioning device, thus acting as a third layer of buffering. The multi-layer buffering can effectively buffer the impact energy of rolling stones and significantly reduce the impact of rolling stones on roads or railways.

[0013] Preferably, the upper end of the extension cylinder is provided with a limiting ring, the lower end of the extension rod is provided with a limiting shoulder, the cavity inside the extension cylinder matches the limiting shoulder, and the through hole inside the limiting ring matches the extension rod; thus, the extension rod is always in the extension cylinder.

[0014] Preferably, the extension support device further includes an elastic limiting member, which is inserted into a transverse hole in the wall of the extension cylinder or the limiting ring. A limiting groove is provided in the middle of the extension rod. When the limiting groove slides with the extension rod to the elastic limiting member, the elastic limiting member springs into the limiting groove to limit the extension rod.

[0015] Preferably, the elastic limiting component includes a crimping bolt, a pressing spring, and a limiting block, all of which are installed in the transverse holes on the extension cylinder wall or the limiting ring. The limiting block is located inside the through hole, the crimping bolt is threaded to the outside of the through hole, and the two ends of the pressing spring are fixedly connected to the crimping bolt and the limiting block, respectively, so that the limiting block abuts against the surface of the extension rod. The extension support device can perform axial extension and contraction to ensure the support height when not in a supported state. When subjected to the impact of rolling stones, it wraps the rolling stones by contraction to prevent the rolling stones from flying after breaking due to impact.

[0016] Preferably, the outer wall of each of the plug-in positioning devices is formed with a plurality of protrusions, which can increase the frictional resistance between the plug-in positioning device and the gravel buffer layer and improve the pull-out resistance of the plug-in positioning device.

[0017] Preferably, the insertion and installation device includes an insertion positioning tube, an adjusting threaded shaft, an adjusting screw sleeve, an installation groove, and a resistance side bracket. The insertion positioning tube has several through-hole installation grooves on its wall, the upper surface of which is an outer bevel, and the bottom of the insertion positioning tube has a closed conical tip. The adjusting threaded shaft is rotatably mounted inside the insertion positioning tube via a bearing. The adjusting screw sleeve is threaded onto the adjusting threaded shaft and located in the installation groove. The resistance side bracket is installed in the installation groove, its bottom end connected to the outer wall of the adjusting screw sleeve via a hinge, and its top end forming an inner bevel matching the upper surface of the installation groove. Rotating the adjusting threaded shaft moves the resistance side bracket along the installation groove and expands it outward from the insertion positioning tube, forming the protrusion. By setting the above structure, the tube wall of the insertion positioning tube remains smooth when inserted into the gravel buffer layer, reducing frictional resistance during insertion. After the insertion positioning tube is inserted into place, the formation of the tube wall protrusion can be controlled by adjusting the threaded shaft, improving the pull-out resistance of the insertion positioning tube.

[0018] Preferably, the top end of the insertion positioning tube has a threaded hole coaxial with the inner cavity of the tube, the diameter of the threaded hole is not less than the inner diameter of the insertion positioning tube, and the lower end of the extension tube has an external thread that matches the threaded hole; the top end of the adjusting threaded shaft is provided with a nut, and the nut is located in the threaded hole.

[0019] Preferably, the upper and lower edges of the protective barrier net are respectively equipped with horizontal tie chains. The two ends of the upper edge tie chain are respectively hinged to the upper ends of the extension rods in the two adjacent extension support devices, and the two ends of the lower edge tie chain are respectively hinged to the upper ends of the two adjacent insertion positioning devices.

[0020] Preferably, the elastic support is a support spring or a support rubber pad.

[0021] Preferably, the top end of the insertion positioning tube is also provided with a first connecting ear that is hinged to the horizontal tie chain at the lower edge of the protective barrier net, and a positioning plate is provided on the outer wall of the top end of the insertion positioning tube, preferably a hexagonal positioning plate.

[0022] Secondly, the present invention provides a method for buffering and protecting against falling rocks on steep cliffs, comprising the following steps:

[0023] Construct a protective platform on a high and steep cliff above a road or railway, excavate a buffer pit extending along the contour of the cliff slope inside the protective platform, fill the buffer pit with a gravel buffer layer, and construct a protective wall on the outer edge of the protective platform.

[0024] At least two rows of insertion positioning devices are inserted in the gravel buffer layer along the contour of the mountain slope, with no less than two in each row. An extension support device is installed on the upper end of each insertion positioning device, and the insertion positioning device is inclined toward the mountain slope.

[0025] A protective barrier net is installed between two adjacent plug-in positioning devices in the same row (facing the direction of the rolling stones on the slope); the lower two ends of the protective barrier net are hinged to the upper end of the plug-in positioning device, and the upper two ends of the upper edge are hinged to the upper end of the extension rod.

[0026] Preferably, the tilt angle of the insertion positioning device relative to the vertical direction is 15-30 degrees.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) When the boulders roll down the slope, some of them will fall into the buffer pit first. After the boulders fall into the gravel buffer layer, they will sink down. The gravel buffer layer will buffer the boulders, allowing the boulders carrying a huge amount of kinetic energy to land softly. Then, the buffer protection device will protect them. The buffer protection device will also provide multiple layers of buffering for the boulders. The impact force will only collide with the protective wall after multiple layers of buffering. The protection is provided by multiple buffering methods, which improves the ability to block and protect against the impact of boulders.

[0029] (2) By combining the crushed stone buffer layer, the plug-in positioning device, the extension support device and the protective barrier net, the kinetic energy of the rolling stone is consumed in advance, the vibration generated when the rolling stone hits the protective wall is reduced, and the vibration is prevented from causing damage to the bridge pier.

[0030] (3) When the rolling stone rolls to the position of the protective barrier net, it will pull the upper end of the protective barrier net downward and compress the extension support device, so that the protective barrier net surrounds the rolling stone from the top and bottom sides. By wrapping the rolling stone, it prevents the subsequent rolling stone from being hit and causing the stone fragments to fly, thereby preventing the rolling stone from expanding the damage range and preventing the rolling stone from threatening the safety of the railway and road.

[0031] (4) The installation and fixing methods of the plug-in positioning device, extension support device and protective barrier net are simple, which makes it easy to install and replace the enclosure, thus making it easy for maintenance personnel to carry out maintenance and replacement work and easy to use.

[0032] (5) After being impacted, the plug-in positioning device and the extension support device will go through three processes: being pressed down, tilting away from the slope, and being pulled out away from the slope. They can be buffered by the elastic support inside the extension support device and by the resistance provided by the crushed stone buffer layer, thus continuously providing a buffering effect on the rolling stone, improving the deceleration and buffering effect, accelerating the kinetic energy consumption of the rolling stone, and enabling the rolling stone to stop quickly and stably, thus achieving the blocking effect. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the rolling stone buffer protection device of the present invention; wherein, the resistance side frame is in the unfolded state;

[0034] Figure 2 For the present invention Figure 1 Enlarged view of the structure at point A in the middle;

[0035] Figure 3 For the present invention Figure 1 Enlarged view of the structure at point B in the middle;

[0036] Figure 4 This is a schematic diagram of the plug-in installation device and the extension support device of the present invention;

[0037] Figure 5 This is a cross-sectional view of the plug-in installation device of the present invention;

[0038] Figure 6 For the present invention Figure 5 Enlarged view of the structure at point C;

[0039] Figure 7 This is a cross-sectional view of the extended support device of the present invention;

[0040] Figure 8 For the present invention Figure 7 Enlarged view of the structure at point D.

[0041] The components include: 1. Protective platform; 2. Slope; 3. Protective wall; 4. Buffer pit; 5. Crushed stone buffer layer; 7. Insertion positioning device; 71. Insertion positioning tube; 72. Adjusting threaded shaft; 73. Adjusting screw sleeve; 74. Mounting groove; 75. Resistance side frame; 76. Screw hole; 77. Cone tip; 78. Positioning plate; 8. Extension support device; 81. Extension cylinder; 82. Limiting shoulder; 83. Support spring; 84. Extension rod; 85. Press bolt; 86. Pressing spring; 87. Limiting block; 88. Limiting slot; 89. Limiting ring; 91. Protective barrier net; 92. Upper edge horizontal pull chain; 93. First connecting ear; 94. Lower edge horizontal pull chain; 95. Second connecting ear. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0043] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] Example 1;

[0046] Please see Figure 1-8 This embodiment provides a boulder buffer and protection device for steep cliffs, including:

[0047] A gravel buffer layer 5 is buried on a protective platform 1 above a road or railway; the protective platform 1 is located on a high and steep cliff.

[0048] At least two plug-in positioning devices 7 are inserted side by side into the gravel buffer layer 5 and tilted toward the slope 2 of the high and steep cliff, with their upper ends exposed on the surface of the gravel buffer layer 5.

[0049] At least two extension support devices 8, each extension support device 8 includes an extension cylinder 81 and an extension rod 84. The lower end of the extension cylinder 81 is fixedly installed on the upper end of the insertion positioning device 7. The lower end of the extension rod 84 is coaxially and slidably inserted into the extension cylinder 81. An elastic support member is fixedly installed inside the extension cylinder 81. The upper end of the elastic support member is connected to the lower end of the extension rod 84.

[0050] The protective barrier net 91 is set facing the direction of the falling stones. Its lower edge is located on the surface of the gravel buffer layer 5 and its two ends are fixedly installed on the upper ends of two adjacent plug-in positioning devices 7. Its two ends are fixedly installed on the upper ends of two adjacent extension rods 84.

[0051] Specifically, the upper end of the extension cylinder 81 is provided with a limiting ring 89, and the lower end of the extension rod 84 is provided with a limiting shoulder 82. The cavity inside the extension cylinder 81 matches the limiting shoulder 82 (preferably with a transition fit), and the through hole inside the limiting ring 89 matches the extension rod 84 (preferably with a transition fit). In this way, the extension rod 84 is always in the extension cylinder 81.

[0052] Specifically, the extension support device 8 also includes an elastic limiting member, which is inserted into a transverse hole opened on the wall of the extension cylinder 81 or the limiting ring 89. A limiting groove 88 is opened in the middle of the extension rod 84. When the limiting groove 88 slides with the extension rod 84 to the elastic limiting member, the elastic limiting member springs into the limiting groove 88 to limit the extension rod 84.

[0053] Specifically, the elastic limiting components include a crimping bolt 85, a pressing spring 86, and a limiting block 87. All three are installed in the transverse hole on the wall of the extension cylinder 81 or the limiting ring 89. The limiting block 87 is located inside the through hole, and the crimping bolt 85 is threaded to the outside of the through hole. The two ends of the pressing spring 86 are fixedly connected to the crimping bolt 85 and the limiting block 87, respectively, so that the limiting block 87 abuts against the surface of the extension rod 84. The extension support device 8 can perform axial extension and contraction to ensure the support height when not in a supported state. When impacted by rolling stones, it wraps the rolling stones by contraction to prevent them from flying after breaking due to impact.

[0054] Specifically, the elastic support is preferably a support spring 83 or a support rubber pad, with support spring 83 being more preferred. The two ends of the support spring 83 are fixedly connected to the bottom of the extension cylinder 81 and the lower end of the extension rod 84, respectively. The support rubber pad is filled inside the extension cylinder 81 and supports the lower end of the extension rod 84. Generally, the elastic support supports the extension rod 84, with its upper part protruding outside the extension cylinder 81, ensuring the support height of the protective barrier net 91; when a rolling stone impacts the protective barrier net 91, the elastic support is compressed. It is recommended that the support spring 83 or the support rubber pad be made of a material with high elasticity, so that the elastic support has a large compression amount, allowing the extension rod 84 to produce a large elastic displacement. The height of the limiting groove 88 on the extension rod 84 is no greater than the compression amount of the elastic support.

[0055] Specifically, each insertion positioning device 7 has several protrusions on its outer wall. These protrusions increase the frictional resistance between the insertion positioning device 7 and the gravel buffer layer 5, thereby improving the pull-out resistance of the insertion positioning device 7. Ideally, the protrusions should be arranged in a ring along the outer wall of the insertion positioning device 7 and uniformly distributed along its length. While protrusions on the outer wall of the insertion positioning device 7 would provide good pull-out resistance when inserted into the gravel buffer layer 5, they would also be inconvenient to install and replace. Therefore, the protrusions are ultimately designed for selective activation.

[0056] Specifically, the insertion positioning device 7 includes an insertion positioning tube 71, an adjusting threaded shaft 72, an adjusting screw sleeve 73, a mounting groove 74, and a resistance side bracket 75. The insertion positioning tube 71 has several through mounting grooves 74 formed on its wall, with the upper surface of each groove being an outwardly inclined surface. The bottom of the insertion positioning tube 71 has a closed conical tip 77. The adjusting threaded shaft 72 is rotatably mounted inside the insertion positioning tube 71 via bearings. The adjusting screw sleeve 73 is threaded onto the adjusting threaded shaft 72 and is located within the mounting groove 74. The resistance side bracket 75 is mounted on the mounting groove 74. In the groove 74, its bottom end is connected to the outer wall of the adjusting screw sleeve 73 via a hinge, and its top end forms an inner inclined surface that matches the upper surface of the mounting groove 74. Rotating the adjusting threaded shaft 72 causes the resistance side bracket 75 to move along the mounting groove 74 and expand outwards towards the insertion positioning tube 71, forming a protrusion. By setting the above structure, the tube wall of the insertion positioning tube 71 remains smooth when it is inserted into the gravel buffer layer 5, reducing the frictional resistance during insertion. After the insertion positioning tube 71 is inserted into place, the formation of the tube wall protrusion can be controlled by adjusting the threaded shaft 72, thereby improving the pull-out resistance of the insertion positioning tube 71. The top end of the insertion positioning tube 71 forms a screw hole 76 coaxial with the inner cavity of the tube. The diameter of the screw hole 76 is not less than the inner diameter of the insertion positioning tube 71. The lower end of the extension tube 81 forms an external thread that matches the screw hole 76. The top end of the adjusting threaded shaft 72 is provided with a nut, which is located in the screw hole 76.

[0057] More specifically, at least two sets of mounting slots 74 are provided along the length of the insertion positioning tube 71. The same set of mounting slots 74 are located on the same cross-section of the insertion positioning tube 71. Each set of mounting slots 74 has 2-3 slots, and they are preferably evenly arranged in a ring. The radial angle occupied by each mounting slot 74 should not exceed 60°. The upper surface of the mounting slot 74 is an outward inclined surface, meaning that the inclined surface is inclined outward towards the insertion positioning tube 71. The inner inclined surface at the top of the resistance side bracket 75 means that the inclined surface is inclined inward towards the insertion positioning tube 71. When the resistance side bracket 75 moves upward with the adjusting screw sleeve 73, due to the cooperation of the inner and outer inclined surfaces, the top of the resistance side bracket 75 will tilt outward towards the insertion positioning tube 71 to form a protrusion. The number of protrusions corresponds to the number of resistance side brackets 75. The protrusions of different resistance side brackets 75 are controlled by adjusting the threaded shaft 72. Two bearings are typically installed inside the insertion positioning tube 71, located at the bottom and top of the insertion positioning tube 71 respectively, and connected to both ends of the adjusting threaded shaft 72, while ensuring that the nut at the top of the adjusting threaded shaft 72 extends into the threaded hole 76.

[0058] Specifically, the upper and lower edges of the protective barrier net 91 are each equipped with a horizontal tie chain. The two ends of the upper edge tie chain 92 are hinged to the upper ends of the extension rods 84 in two adjacent extension support devices 8, respectively. The two ends of the lower edge tie chain 94 are hinged to the upper ends of two adjacent insertion positioning devices 7, respectively. More specifically, the top end of the insertion positioning tube 71 is also provided with a first connecting ear 93 that is hinged to the lower edge tie chain 94, and the top end of the extension rod 84 is also provided with a second connecting ear 95 that is hinged to the upper edge tie chain 92.

[0059] Specifically, the first horizontal tie chain 92 is inserted and installed at the bottom of the barrier net 91, supporting the bottom of the protective barrier net 91. The first connecting ear 93 is installed at the top of the insertion positioning tube 71, and the first horizontal tie chain 92 is connected to the first connecting ear 93 through the connecting component. The second connecting ear 95 is installed at the top of the extension rod 84, and the second horizontal tie chain 94 is inserted and installed at the top of the barrier net 91. The second horizontal tie chain 94 is fixedly connected to the second connecting ear 95 through the connector. The protective barrier net 91 is used to protect and block rolling stones. The barrier net 91 is made of prefabricated ring net and wire rope mesh. Ring net and wire rope mesh are widely used in mountain protection work. After installation, the first horizontal tie chain 92 hangs on the surface of the gravel buffer layer 5.

[0060] Specifically, the first horizontal tie chain 92 and the first connecting ear 93, and the second horizontal tie chain 94 and the second connecting ear 95 are all connected by connecting components. The connecting components include a pressure-reducing ring and a connecting ring sleeved on the outside of the pressure-reducing ring. When subjected to a huge impact, the pressure-reducing ring deforms and elongates to absorb energy, acting as an "energy-absorbing fuse." It buffers the impact through deformation. When the impact energy of the rolling stone is small, only the pressure-reducing ring deforms and dissipates energy. When the impact energy exceeds the design energy dissipation capacity of the pressure-reducing ring, the pressure-reducing ring elongates to its limit state, and the force is borne by the connecting ring. The connecting ring is made of high-strength alloy steel, and the inner diameter of the connecting ring is larger than the outer diameter of the pressure-reducing ring. Thus, when subjected to tension, the pressure is first released through the pressure-reducing ring. After the pressure-reducing ring deforms and expands, the protective barrier net 91 contacts the connecting ring, and then a rigid connection is made through the connecting ring. This achieves both a buffering effect and prevents breakage after buffering. Alternatively, the pressure-reducing ring can be omitted, and the connecting ring can be used directly for direct connection. There are two connection methods.

[0061] Specifically, the outer wall of the top end of the insertion positioning tube 71 is also provided with a positioning plate 78, preferably a hexagonal positioning plate 78. When the insertion positioning tube 71 is inserted into the gravel buffer layer 5, the lower surface of the positioning plate 78 contacts the gravel buffer layer 5, so that the top end of the insertion positioning tube 71 remains exposed on the upper surface of the gravel buffer layer 5, which facilitates the installation of the extension support device.

[0062] Example 2;

[0063] Please see Figure 1-8 This embodiment provides a method for buffering and protecting against falling rocks at the entrance of a mountain tunnel, including the following steps:

[0064] Construct a protective platform 1 on a high and steep cliff above a road or railway. Excavate a buffer pit 4 extending along the outline of the cliff slope 2 inside the protective platform 1. Fill the buffer pit 4 with a gravel buffer layer 5. Construct a protective wall 3 on the outer edge of the protective platform 1.

[0065] At least two rows of insertion positioning devices 7 are inserted in the gravel buffer layer 5 along the contour direction of the mountain slope 2, with no less than two in each row. An extension support device 8 is installed on the upper end of each insertion positioning device 7, and the insertion positioning device 7 is inclined toward the direction of the mountain slope 2.

[0066] A protective barrier net 91 (facing the direction of the rolling stones on the slope 2) is installed between two adjacent plug-in positioning devices 7 in the same row; wherein, the lower two ends of the protective barrier net 91 are hinged to the upper end of the plug-in positioning device 7, and the upper two ends are hinged to the upper end of the extension rod 84.

[0067] Specifically, the tilt angle of the insertion positioning device 7 relative to the vertical direction is 15-30 degrees. This angle range allows the buffer protection device to achieve the best buffer protection effect against rolling stones.

[0068] Specifically, the installation angle of the insertion positioning device 7 and the extension support device 8 is inclined towards the slope 2. This inclined installation method allows the rolling stones to exert downward pressure on the protective barrier net 91 after falling onto its surface. This compresses the extension support device 8 through the protective barrier net 91, bringing the upper and lower ends of the net closer together and creating a wrapping effect on the rolling stones. Simultaneously, when the protective barrier net 91 initially applies downward pressure to the insertion positioning device 7 and the extension support device 8, it pushes the insertion positioning device 7 further downward into the gravel buffer layer 5, converting the impact force of the rolling stones into a downward force for stress relief. Furthermore, as the rolling stones continue to roll downwards, the protective barrier net 91 drives the insertion positioning device... 7 and the extension support device 8 are tilted in the direction of the rolling stone movement, so that the insertion positioning device 7 changes from tilting towards the slope 2 to tilting towards the protective wall 3. When the insertion positioning device 7 is inserted into the gravel buffer layer 5 and changes its tilt angle, the gravel buffer layer 5 blocks and buffers the insertion positioning device 7, thereby achieving the effect of buffering the protective barrier net 91. After the insertion positioning device 7 is tilted to the direction of the protective wall 3, if the rolling stone continues to move, it will be pulled upward from the gravel buffer layer 5 by the protective barrier net 91. In the process of pulling the extension support device 8 upward, the resistance during the pull-out is increased by the cooperation of the outwardly extended resistance side frame 75 and the gravel buffer layer 5, thereby achieving the effect of force relief and buffering.

[0069] In addition, when the rocks roll down the slope 2, some of them will first fall into the buffer pit 4. After falling into the gravel buffer layer 5, the rocks will sink downwards, and the gravel buffer layer 5 will cushion the rocks, allowing the rocks carrying a huge amount of kinetic energy to land softly. Then the rocks will rebound and continue to impact the buffer protection device, which will provide protection. The buffer protection device will further provide multiple layers of cushioning for the rocks. Some rocks may also directly impact the buffer protection device after rolling down the slope 2, and the buffer protection device will directly cushion and protect the rocks.

[0070] Specifically, the adjusting threaded shaft 72 is rotatably mounted inside the insertion positioning tube 71 via a bearing, and the adjusting screw sleeve 73 is threaded onto the outside of the adjusting threaded shaft 72. Rotating the adjusting threaded shaft 72 drives the adjusting screw sleeve 73 to move upward. The mounting groove 74 is formed on the outer surface of the insertion positioning tube 71. The bottom end of the resistance side bracket 75 is connected to the outer wall of the adjusting screw sleeve 73 via a hinge. Before installation, the resistance side bracket 75 is retracted into the mounting groove 74. The insertion positioning tube 71 is inserted into the gravel buffer layer 5, and is inserted at an angle. A sleeve that matches the top of the insertion positioning tube 71 is fitted onto the top of the insertion positioning tube 71. The top of the sleeve has a first connecting lug. The 93-phase matching notch, during hammer installation, protects the top of the insertion positioning tube 71 and the first connecting ear 93 with a sleeve. Then, by hammering the top of the sleeve, the insertion positioning tube 71 is inserted into the gravel buffer layer 5. After being inserted into the gravel buffer layer 5, the adjusting threaded shaft 72 is rotated with a wrench. The adjusting threaded shaft 72 drives the adjusting screw sleeve 73 to move upward. The adjusting screw sleeve 73 drives the resistance side bracket 75 to move upward. When the resistance side bracket 75 moves upward, its top will open outward and insert into the gravel inside the gravel buffer layer 5. The resistance side bracket 75 increases the resistance when the insertion positioning tube 71 is pulled out, thereby realizing the installation and fixing of the insertion positioning device 7.

[0071] Specifically, the limiting slot 88 is formed on the surface of the extension rod 84. The extension support device 8 can extend and retract to increase the support height of the protective barrier net 91 in the non-supported state. When subjected to the impact of rolling stones, the protective barrier net 91 wraps around the rolling stones by retracting to prevent the rolling stones from flying after breaking due to the impact. When the top of the extension rod 84 is under pressure, it will retract downward into the interior of the extension cylinder 81 and compress the support spring 83. When the extension rod 84 retracts, it will drive the limiting slot 88 to move downward. When the limiting slot 88 moves to the inner position of the limiting block 87, the elastic force of the pressing spring 86 will push the limiting block 87 to move inward, so that the limiting block 87 is locked into the interior of the limiting slot 88, thereby fixing the extension length of the extension rod 84. This reduces the support distance between the insertion positioning device 7 and the extension support device 8 on the protective barrier net 91, making the protective barrier net 91 arc-shaped, which can wrap the rolling stones inside the protective barrier net 91.

[0072] Specifically, the top end of the adjusting threaded shaft 72 extends into the interior of the threaded hole 76, and a nut for turning is provided at the top end of the adjusting threaded shaft 72. A hexagonal positioning plate 78 for fixing the insertion positioning tube 71 is provided on the outer wall of the insertion positioning tube 71. A hexagonal wrench is sleeved onto the nut at the top of the adjusting threaded shaft 72 through the threaded hole 76, thereby controlling the rotation of the adjusting threaded shaft 72.

[0073] Specifically, the top of the mounting groove 74 is formed by an outer slope, and the top of the resistance side frame 75 is formed by an inner slope. When the resistance side frame 75 moves upward, it extends outward with the cooperation of the two slopes. When the resistance side frame 75 moves upward, its top inner slope is supported by the outer slope of the inner wall of the top of the mounting groove 74, which causes the resistance side frame 75 to unfold outward, so that the upper end of the resistance side frame 75 is inserted into the interior of the gravel buffer layer 5, thereby achieving the effect of fixing the insertion positioning device 7 and improving the pull-out resistance of the insertion positioning device 7.

[0074] When unstable rocks appear above the tunnel entrance or near bridge piers, they cannot be left to exist and need to be removed. However, removing unstable rocks inevitably generates falling rocks. Based on the aforementioned method for buffering and protecting against falling rocks at mountain tunnel entrances, this embodiment also provides a construction method for reducing the risk of falling rocks at tunnel entrances, specifically including the following steps.

[0075] Step 1: When constructing the protective facilities, a buffer pit 4 is reserved at the top of the protective platform 1. The buffer pit 4 is located below the slope 2, and the interior of the buffer pit 4 is filled with a gravel buffer layer 5. The protective platform 1 is usually set on a high and steep cliff above a road or railway and is made of concrete.

[0076] When there are falling rocks, the rocks on the surface of slope 2 will fall onto the gravel buffer layer 5. The gravel buffer layer 5 buffers the vibration generated when the rocks fall. The gravel buffer layer 5 is filled with gravel. When the falling rocks fall into the gravel-filled buffer pit 4, they will compress the gravel to achieve a buffering effect. Through the huge and continuous frictional resistance and plastic deformation resistance of the granular medium, the kinetic energy of the falling rocks is efficiently and irreversibly dissipated into heat energy. Through a uniform and gradual plastic deceleration process, the instantaneous huge impact force (high deceleration) of rigid collision is avoided, and the falling rocks come to a smooth stop, protecting the structures below from vibration damage. Meanwhile, the crushed stone itself has hardness, which can fix the insertion positioning device 7. Due to its size, and because the rolling stone is in a rolling state when it falls on the crushed stone buffer layer 5, the depth it sinks into when rolling on the crushed stone buffer layer 5 will not be too deep, and it will not affect the rolling stone from rolling into the inner side of the protective barrier net 91. The bottom of the protective barrier net 91 extends downward to the surface of the crushed stone buffer layer 5, which makes it easy for the rolling stone to enter the interior of the protective barrier net 91. Furthermore, the protective barrier net 91 is set near the edge of the buffer pit 4, so that the rolling stone has already entered the inner side of the protective barrier net 91 and been wrapped before it sinks in.

[0077] Step 2: Insert at least two rows of insertion positioning devices 7 into the gravel buffer layer 5, with no less than two in each row. Install an extension support device 8 on the upper end of each insertion positioning device 7. The insertion positioning device 7 is inclined towards the mountain slope 2. Install a protective barrier net 91 on the insertion positioning device 7 and the extension support device 8. There are two rows of protective barrier nets 91, and there is a certain distance between the two rows of protective barrier nets 91.

[0078] When a boulder hits the protective barrier 91 at the front and cannot be effectively buffered, it will pass over the front barrier and strike the rear barrier 91. The protective barrier 91 then buffers and stops the boulder, reducing its rolling distance. Furthermore, the protective barrier 91 encloses the boulder. After blocking the boulder, the top of the protective barrier 91 compresses the top of the extension support device 8, causing the top of the protective barrier 91 to move downwards. This brings the top and bottom of the protective barrier 91 closer together, forming a groove that encloses the boulder inside, preventing it from breaking apart and flying beyond the barrier area, causing harm.

[0079] Step 3: Construct a protective wall 3 on the side of the protective platform 1 located away from the slope 2, in the buffer pit 4.

[0080] The protective wall 3 blocks the falling rocks that haven't completely stopped after being buffered by the gravel buffer layer 5. The road and bridge piers to be protected are located on the left side of the protective wall 3 (the side away from the slope 2). Through the cooperation of the gravel buffer layer 5, the protective barrier net 91, and the protective wall 3, layered buffering and blocking protection is achieved to prevent the falling rocks from the slope 2 from landing on the bridge piers, tunnel entrances, or roads. This multi-layered blocking allows the falling rocks to achieve a soft landing. Compared to directly using the protective wall 3, this method reduces the problem of falling rocks breaking apart upon impact and causing widespread damage, and also reduces the damage to the bridge piers caused by the vibrations. After all the unstable rock masses are removed, a completely new slope will be formed. This new slope needs to undergo an immediate geological assessment. Based on the assessment results, a permanent active protection system (or a covering guide net) will be installed on the new slope.

[0081] Step 4: Before breaking up the dangerous rock, the area below the construction site should be sealed off in advance. An active protective net should be laid on the surface of slope 2 to reinforce the rock mass above (top of the slope) and on both sides of the work area. The active protective net will reinforce the areas where rock collapse may occur during the breaking up of the dangerous rock. By covering and securing the active protective net to the slope, a certain pre-pressure will be applied to the rock or soil on the slope, "binding" the loose and unstable rock and soil into a whole and anchoring it to the deep stable rock layer to prevent weathering and erosion, suppress the occurrence of local collapses, and control the occurrence of small landslides.

[0082] Step 5: Drill holes at a distance above the dangerous rock that needs to be broken up and install safety stakes in the holes. When workers are carrying out the rock breaking work, they are connected to the safety stakes by safety ropes to prevent the workers from falling with the dangerous rock in case of sudden collapse, thus protecting the safety of the workers.

[0083] Step Six: When workers carry out the work of breaking up dangerous rocks, they first clear away the trees and weeds above the dangerous rocks, and then use shovels and pneumatic picks to clear the soil and broken rock mass on top of the dangerous rocks.

[0084] Step Seven: After the preliminary cleaning work is completed, a hole is drilled at the top of the unstable rock using a pneumatic drill. After drilling, the water and rock debris inside the hole are thoroughly blown away using a high-pressure air hose. Debris or water inside the hole will severely affect the expansion effect of the expanding agent and may even cause it to fail. After drilling, the expanding agent is injected into the hole, and then the hole is sealed. The expanding agent expands, breaking the unstable rock and separating it from the mountainside.

[0085] Prepare the slurry according to the designed water-cement ratio (e.g., a common weight ratio of 1:3 to 1:3.3, i.e., 1 part water and 3 parts expanding agent). Add water first, then powder, and quickly stir with a machine or wooden stick until a uniform paste is formed. Do not stir too much at once, and the grouting should be completed within 5-10 minutes. Otherwise, the slurry mixture will begin to heat up and solidify, reducing its fluidity. Quickly pour the stirred slurry into the hole. Vertical holes are generally filled completely, while horizontal or inclined holes need to be compacted with special tools or plugs to prevent overflow. Grouting should be carried out continuously to avoid the presence of voids in the hole.

[0086] The diameter of the expansion agent injection holes is 50mm, the depth is 1-2m, the hole spacing is 20-40cm, and the row spacing is 30-90cm. The specific drilling depth and spacing are determined based on the properties of the rock being investigated. The harder and stronger the rock (such as granite), the smaller the required hole spacing is usually to generate sufficient breaking force. The drilling depth may also need to be appropriately increased to ensure anchoring force. Rocks with good toughness may require a denser hole network. When the rock mass itself has well-developed fractures and many primary or secondary fractures, the hole spacing can be appropriately increased because fractures facilitate stress propagation and penetration. However, it is important to ensure that the drilling depth exceeds the main fracture zone or weak surface to ensure that the expansion force can be effectively applied.

[0087] Step 8: The separated dangerous rocks fall downwards under the action of gravity, thereby realizing the removal of the dangerous rocks. After the removal is completed, the fallen rocks are cleaned up; the rolling stones generated by the fall are buffered and blocked by the buffer protection device and the protective wall 3.

[0088] The buffer protection device provided by this invention can effectively protect against falling rocks generated during the removal of unstable rocks, as well as falling rocks generated by natural rockfalls during road or railway operation. This invention improves the ability to block falling rocks through multiple buffer protection measures, and also avoids the need for excessively thick or large protective walls.

[0089] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mountain tunnel portal rockfall buffering protection device, characterized in that: The invention relates to a protection platform (1) for protecting the road or railway above the high and steep cliff (2) from the rockfall, comprising: a gravel cushion (5) buried on the protection platform (1) above the road or railway; at least two plug-in positioning devices (7) inserted side by side in the gravel cushion (5) and inclined towards the slope body (2) of the high and steep cliff, with the upper end exposed on the surface of the gravel cushion; at least two extension support devices (8), each of which comprises an extension cylinder (81) and an extension rod (84), the lower end of the extension cylinder (81) is fixedly installed on the upper end of the plug-in positioning device (7), the lower end of the extension rod (84) is coaxially and slidably inserted in the extension cylinder (81), an elastic support member is fixedly installed inside the extension cylinder (81), and the upper end of the elastic support member is connected with the lower end of the extension rod (84); a protection barrier net (91) arranged facing the direction of the rockfall, with the lower edge located on the surface of the gravel cushion (5) and the lower edge fixedly installed on the upper end of the adjacent two plug-in positioning devices (7), and the upper edge fixedly installed on the upper end of the adjacent two extension rods (84).

2. The mountain tunnel portal rockfall buffering protection device according to claim 1, characterized in that: The upper end of the extension cylinder (81) is provided with a limiting ring (89), the lower end of the extension rod (84) is provided with a limiting shaft shoulder (82), the cavity in the extension cylinder (81) is matched with the limiting shaft shoulder (82), and the through hole in the limiting ring (89) is matched with the extension rod (84).

3. The mountain tunnel portal rockfall buffering protection device according to claim 2, characterized in that: The extension support device (8) further comprises an elastic limiting member inserted in the transverse hole formed in the cylinder wall of the extension cylinder (81) or the limiting ring (89), a limiting clamping groove (88) is formed in the middle of the extension rod (84), and when the limiting clamping groove (88) slides with the extension rod (84) to the elastic limiting member, the elastic limiting member is elastically inserted into the limiting clamping groove (88) to limit the extension rod (84).

4. The mountain tunnel portal rockfall buffering protection device according to claim 3, characterized in that: The elastic limiting member comprises a press-fit bolt (85), a pressing spring (86), and a limiting clamping block (87), which are all installed in the transverse hole in the cylinder wall of the extension cylinder (81) or the limiting ring (89), the limiting clamping block (87) is located on the inner side of the through hole, the press-fit bolt (85) is threadedly connected with the outer side of the through hole, and the pressing spring (86) is fixedly connected with the press-fit bolt (85) and the limiting clamping block (87) at both ends, so that the limiting clamping block (87) abuts against the surface of the extension rod (84).

5. The mountain tunnel portal rockfall buffering protection device according to claim 4, characterized in that: The outer wall of each plug-in positioning device (7) is formed with a plurality of protrusions.

6. The mountain tunnel portal rockfall buffering protection device according to claim 5, characterized in that: The plug-in positioning device (7) comprises a plug-in positioning tube (71), an adjusting screw shaft (72), a regulating sleeve (73), a mounting groove (74) and a resistance side frame (75), the plug-in positioning tube (71) is provided with a plurality of internally and externally through mounting grooves (74) on the tube wall, the upper surface of the mounting groove (74) is an outer inclined surface, and the bottom of the plug-in positioning tube (71) is provided with a closed tapered tip (77); the adjusting screw shaft (72) is rotatably mounted in the plug-in positioning tube (71) through a bearing, the regulating sleeve (73) is mounted on the adjusting screw shaft (72) through a thread, and the regulating sleeve (73) is located in the mounting groove (74); the resistance side frame (75) is mounted in the mounting groove (74), the bottom end of the resistance side frame (75) is connected with the outer wall of the regulating sleeve (73) through a hinge, and the top end of the resistance side frame (75) is provided with an inner inclined surface matched with the upper surface of the mounting groove (74); the adjusting screw shaft (72) is rotated to move the resistance side frame (75) along the mounting groove (74) and expand the resistance side frame (75) outwardly from the plug-in positioning tube (71), thereby forming the protrusion.

7. The mountain tunnel portal rockfall buffering protection device according to claim 6, characterized in that: The upper edge and the lower edge of the protective barrier net (91) are respectively provided with horizontal pull chains, the upper edge horizontal pull chain (92) is hingedly connected with the upper ends of the extension rods (84) of the adjacent two extension support devices (8), and the lower edge horizontal pull chain (94) is hingedly connected with the upper ends of the adjacent two plug-in positioning devices (7).

8. The mountain tunnel portal rockfall buffering protection device according to claim 7, characterized in that: The elastic support member is a supporting spring (83) or a supporting rubber pad.

9. A mountain tunnel portal rockfall buffering protection method, characterized in that: The mountain tunnel portal rockfall buffering protection device comprises the following steps: A protection platform (1) is constructed on a high and steep cliff above a road or a railway, a buffering pit (4) extending along the contour direction of the cliff slope (2) is dug in the protection platform (1), a gravel buffering layer (5) is filled in the buffering pit (4), and a protection wall (3) is constructed at the outer edge of the protection platform (1); At least two rows of plug-in positioning devices (7) are inserted into the gravel buffering layer (5) along the contour direction of the mountain slope (2), and each row has not less than two plug-in positioning devices (7), the extension support device (8) is mounted at the upper end of each plug-in positioning device (7), and the plug-in positioning device (7) is inclined towards the mountain slope (2); The protective barrier net (91) is mounted between the adjacent two plug-in positioning devices (7) in the same row, the lower ends of the protective barrier net (91) are hingedly connected with the upper ends of the plug-in positioning devices (7), and the upper ends of the protective barrier net (91) are hingedly connected with the upper ends of the extension rods (84).

10. The mountain tunnel portal rockfall buffering protection method according to claim 9, characterized in that: The inclination angle of the plug-in positioning device (7) relative to the vertical direction is 15-30 degrees.

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