A wellhead flyrock protection device and method for pile foundation blasting

Abstract

This invention belongs to the field of pile foundation blasting safety protection technology. Addressing the problems of prominent blind spots and cumbersome disassembly and assembly in existing protective devices, it discloses a wellhead flyrock protection device and method for pile foundation blasting, including a mounting frame, a protective body, and a ground nail shell. The protective body is located in the middle of the mounting frame and is filled with a filling layer that hardens rapidly under the action of the blasting shock wave. It has a protective cavity, a transmission slide rod, a piston plate, and a slide rail. The inner wall of the protective cavity is fitted with the blasting material, and the outer wall is made of aramid fiber. The ground nail shell is detachably connected to the mounting frame. Its internal reinforcement structure, through a linkage assembly, drives a claw structure to embed into the ground, improving stability. The bottom baffle of the mounting frame is equipped with a steel mesh, and the outer side is hinged to a side plate. The side plate is linked to the transmission slide rod through an angle adaptive adjustment mechanism, allowing dynamic adjustment of the protection angle. This invention, through graded protection and deep reinforcement design, achieves interception of blasting flyrock under different working conditions, effectively ensuring the safety of pile foundation blasting operations.

Description

Technical Field

[0001] This invention belongs to the field of safety protection technology for pile foundation blasting, specifically relating to a wellhead rock protection device and method for pile foundation blasting. Background Technology

[0002] Pile foundation blasting is a commonly used construction technique in building foundation engineering. Its key characteristic is that the impact force and flyrock generated by the blasting can only be directionally discharged through the wellhead of the pile shaft. Therefore, wellhead protection becomes a crucial aspect of ensuring construction safety. Compared to ordinary blasting operations, pile foundation blasting results in a higher concentration of flyrock and greater impact energy. Furthermore, the angle and distance of flyrock projection are significantly affected by geological conditions (such as the development of rock joints and fissures), well depth, and charge quantity, placing stringent demands on the reliability, adaptability, and dynamic protection capabilities of protective devices.

[0003] Currently, various technologies for pile foundation blasting protection have emerged in the industry, but many shortcomings still need to be addressed. Traditional protection measures often employ methods such as sandbag stacking, iron plate covering, or wooden formwork sealing. These devices are simple in structure but have extremely poor stability: under the strong impact force generated by blasting in shallow pile wells (depth not exceeding 20 meters), sandbags are easily blown away, and iron plates are prone to displacement or damage, causing flying rocks to directly break through the protection, seriously threatening the safety of surrounding personnel and equipment. At the same time, these fixed structures cannot adjust the protection range according to the dynamic changes in the angle of flying rock projection, easily creating blind spots. Especially under complex geological conditions, blasting vibrations may cause the rock mass around the wellhead to loosen, further exacerbating the risk of flying rocks escaping.

[0004] With technological advancements, some improved protective devices have emerged, such as the pile foundation blasting protection device disclosed in patent number CN210533200U. This device achieves a certain degree of buffering and pressure relief through a combination of a shell, shock-absorbing springs, a mesh, and a rotatable sheet. However, this type of device still has significant limitations: First, the protective core relies on the elastic buffering of the shock-absorbing springs and the interception of a single mesh, lacking a composite protective structure for high-intensity impacts. After repeated use, structural fatigue can easily lead to a decrease in protective effectiveness. Second, the use of anchor bolts for fixing lacks a deep reinforcement structure with the ground, making it prone to loosening under blasting vibrations and resulting in insufficient stability.

[0005] In summary, existing pile foundation blasting wellhead protection devices are inadequate in terms of protection reliability and ease of installation. Developing a wellhead flyrock protection device with composite protection capabilities, adaptive adjustment function, and convenient disassembly and assembly structure has become an urgent technical challenge to be solved in this field. Summary of the Invention

[0006] To address the aforementioned issues of prominent blind spots and cumbersome installation and maintenance, this invention aims to provide a comprehensive, adaptable, and reliable wellhead fly rock protection device for pile foundation blasting. Through the coordinated design of a composite filling layer protective body, a retractable reinforced ground nail structure, and a linked angle adaptive adjustment mechanism, it achieves graded interception and dynamic protection against blasting fly rocks under different pile diameters, hole depths, and complex geological conditions. Simultaneously, it simplifies the disassembly and assembly process, reduces usage costs, and ensures the safety of personnel and equipment surrounding pile foundation blasting operations.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On the one hand, a flyrock protection device for wellheads in pile foundation blasting is proposed, including a mounting frame and also including: The central protective body is located in the middle of the mounting frame and is filled with a filling layer that hardens rapidly under the action of the blast shock wave. Multiple sets of lateral protection mechanisms are disposed on the outer periphery of the central protection body and are movably connected to the central protection body; The ground stake housing is detachably connected to the mounting bracket and has an internal retractable reinforcement structure.

[0008] Furthermore, the central protective body includes: The protective cover is fixed at the bottom to the mounting bracket and has a filling cavity inside. The piston cylinder is located inside the protective cover and communicates with the filling cavity; The transmission slide rod is connected to the wellhead baffle at one end and passes through the mounting frame at the other end, where it is connected to a piston plate. The piston plate slides in cooperation with the inner wall of the piston cylinder.

[0009] Furthermore, the mounting bracket includes: The top plate, located above the central protective body, has a through hole communicating with the piston cylinder; The bottom baffle, connected to the reinforcement structure via a connecting rod, is installed at the bottom of the central protective body.

[0010] Furthermore, the bottom baffle includes: The mounting holes are adapted to the bottom opening of the central protective body and are fitted with steel mesh. The connecting sleeve corresponds to each of the connecting rods and is bolted to the top of the ground nail housing.

[0011] Furthermore, the protective device also includes: The guide plate is located at the center of the steel mesh, connected to the outer periphery of the steel mesh, and slidably connected to the transmission slide rod.

[0012] Furthermore, the reinforcement structure includes: Several linkage components, with the fixed end hinged to the inner wall of the ground nail housing and the free end sliding through the ground nail housing; An internal fixing bolt is inserted at one end through the top of the ground nail shell and threadedly connected to the connecting rod. A horizontally set extrusion plate is connected to the bottom end.

[0013] Furthermore, the lateral protection mechanism includes: Side panels are circumferentially hinged to the outside of the bottom baffle. The angle adjustment component is connected to the side plate at one end and is movably engaged with the transmission slide rod at the other end via a short transmission rod.

[0014] Furthermore, the angle adjustment component includes: A pulley system is rotatably mounted on the top plate and the bottom baffle. A rigid rope, one end of which is connected to the transmission rod, and the other end of which passes around the pulley block and is connected to the side plate.

[0015] On the other hand, a method for protecting wellheads from flyrock during pile foundation blasting is proposed, employing the aforementioned wellhead flyrock protection device for pile foundation blasting, and including the following steps: The outer shell of the ground nail is pre-embedded in the strata around the wellhead, and a solid connection is formed with the strata through a reinforcement structure; The mounting bracket and the ground nail housing can be detachably fixed so that the central protective body is positioned directly opposite the wellhead; During blasting, the shock wave sequentially drives the filling layer inside the central protective body to harden and form rigid protection. The protection range is dynamically adjusted by the transmission short rod, rigid rope and pulley block linked to the side plate. The greater the intensity of the shock wave, the greater the rotation angle of the side plate, so as to achieve the appropriate interception of the flying stone throwing range.

[0016] Furthermore, during blasting, the shock wave acts on the wellhead baffle, driving the transmission slide rod to move the piston plate. The transmission slide rod is linked to the rigid rope through the transmission short rod. The rigid rope passes around the pulley block and pulls the side plate to rotate around the hinge point. The intensity of the shock wave is positively correlated with the rotation angle of the side plate. After the blasting is completed, the side plate automatically resets.

[0017] The beneficial effects of this invention are: 1. This invention forms a three-dimensional interception system through a three-level protection design consisting of a steel mesh, a central protective body, and side plates: the steel mesh can accurately intercept large pieces of debris generated by blasting, preventing them from impacting the core protective structure; the central protective body adopts a composite structure of a shear-thickening fluid filling layer and an aramid fiber protective cover, combined with a blasting cover that fits the inner wall, to achieve dual protection of flexible buffering and rigid interception, efficiently absorbing the impact energy of small and medium-sized debris; the side plates cover the outer perimeter of the wellhead through angle adaptive adjustment, which can dynamically adapt to the range of flying rocks, solving the defect of blind spots easily formed by traditional fixed protective structures, and can effectively intercept flying rocks of different sizes and different projection angles.

[0018] 2. This invention utilizes a linkage design between the transmission slide rod and the angle adjustment component. The intensity of the blast shock wave directly determines the rotation angle of the side plate—the stronger the shock wave (e.g., in shallow pile well blasting), the larger the rotation angle of the side plate, thus expanding the protection range; when the shock wave weakens (e.g., in deep pile well blasting), the torsion spring drives the side plate to automatically reset, ensuring the interception effect on small-angle projectiles. It can adapt to blasting operations with different pile diameters, hole depths, and geological conditions without manual intervention, significantly improving the versatility and ease of use of the device, and solving the problem of poor adaptability of traditional protective devices.

[0019] 3. The reinforcement structure of this invention adopts a transmission system of internal fixing bolts, extrusion plates, connecting rod assemblies, and barbed claw structures. The barbed claw structure is driven to embed into the ground by rotating the bolts, achieving initial reinforcement. During blasting, the shock wave thrust on the top plate is transmitted to the internal fixing bolts through the connecting rods, further driving the extrusion plate to push the connecting rod assembly, causing the barbed claw structure to penetrate deeper into the ground. The embedding force increases synchronously with the impact force, ensuring that the device does not loosen or shift under strong vibration. Compared to traditional anchor bolt fixing methods, the deep embedding design significantly improves the vibration resistance of the device, avoiding the risk of flying rocks escaping due to displacement of the protective device. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the main structure of the protective device of the present invention; Figure 2 This is a schematic diagram of the bottom structure of the protective device of the present invention; Figure 3 This is a cross-sectional view of the central axis of the protective device of the present invention; Figure 4 This is a schematic diagram of the central protective body and side plate protective structure of the protective device of the present invention; Figure 5 This is a schematic diagram of the transmission slide bar-side plate protective structure of the protective device of the present invention; Figure 6 For the present invention Figure 5 Bottom structure diagram; Figure 7 This is a schematic diagram of the baffle-steel mesh structure of the present invention; Figure 8 This is an exploded view of the transmission slide bar-transmission short rod of the present invention; Figure 9 This is a schematic diagram of the top plate structure of the present invention; Figure 10 For the present invention Figure 9 Partial view at point M in the middle; Figure 11 This is a schematic diagram of the bottom baffle structure of the present invention; Figure 12 This is a cross-sectional view of the connecting rod-ground nail housing of the present invention; Figure 13 For the present invention Figure 12 Partial view at point N in the middle; Figure 14 This is an exploded view of the connecting rod-reinforcement structure-ground nail shell of the present invention; Figure 15 This is an exploded view of the internal fixing bolt-extrusion plate of the present invention; Figure 16 This is a schematic diagram of the internal fixing bolt structure of the present invention; Figure 17 This is a schematic diagram of the protective cover structure of the present invention; Figure 18 This is a cross-sectional view of the protective cover-piston cylinder of the present invention; Figure 19 This is a schematic diagram of the central protective body - top plate structure of the present invention; Figure 20 For the present invention Figure 19 Cross-sectional view along the central axis; Figure 21 For the present invention Figure 20 Partial view at point Y; Figure 22 This is a schematic diagram of the protective device of the present invention in use.

[0021] Among them: 100, protective netting; 200, sandbags; 300, blasting covers; 1. Mounting bracket; 101. Top plate; 1011. Slide rail; 102. Bottom baffle; 1021. Mounting hole; 1022. Connecting sleeve; 1023. Mounting component; 1024. Central shaft; 2. Central protective body; 201. Protective cover; 202. Transmission slide rod; 203. Piston cylinder; 3. Ground nail shell; 301. Partition plate one; 4. Reinforcing structure; 401. Linkage assembly; 4011. First link; 4012. Second link; 402. Internal fixing bolts ; 403, Extrusion plate; 4031, Connecting short rod; 404, Partition plate II; 405, Perforated limiting plate; 5, Baffle; 6, Piston plate; 7, Connecting rod; 8, Reinforcing steel mesh; 9, Guide plate; 10, Side plate; 11, Transmission short rod; 1101, Transmission base plate; 1102, Transmission top plate; 12, Pulley block; 13, Rigid rope; 14, Torsion spring; 15, Elastic component I; 16, Elastic component II; 17, Ultrasonic generator; 18, Sealing mounting plate; 19, Filling layer. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] Example 1: See attached document Figure 1-22This invention proposes a flyrock protection device for pile foundation blasting, comprising a mounting frame 1, a central protective body 2, multiple sets of lateral protective mechanisms, and a ground nail shell 3. The central protective body 2 is located in the center of the mounting frame 1 and is used to absorb the energy of the blast shock wave and buffer and intercept small-to-medium diameter gravel. The lateral protective mechanisms are arranged circumferentially around the outer periphery of the central protective body 2 and can dynamically adjust the protective angle according to the shock wave intensity to intercept residual flyrock. The ground nail shell 3 is detachably connected to the mounting frame 1, and its internal reinforcing structure 4 can be embedded in the stratum to ensure that the device does not loosen or shift during blasting. The device as a whole achieves comprehensive protection against flyrock from pile foundation blasting under different working conditions through a three-level protection design of steel mesh 8, protective cover 201, and side plate 10, combined with an adaptive angle adjustment component and reinforcing structure 4.

[0024] The central protective body 2 is bowl-shaped and includes a protective cover 201, a piston cylinder 203, a transmission slide rod 202, and a piston plate 6. The bottom of the protective cover 201 is fixed to the mounting bracket 1 with bolts, and it has a filling cavity inside. In the initial state, the filling cavity of the protective cover 201 and the piston cylinder 203 are filled with only a small amount of filling layer 19 (the filling amount is 1 / 3 to 1 / 2 of the cavity volume). The filling layer 19 is a shear-thickening fluid, which is soft and easily deformable under normal conditions, but can harden rapidly under impact. The inner wall of the protective cover 201 is fitted with a blasting blanket 300 near the wellhead for initial buffering of the impact of gravel. The protective cover 201 is made of aramid fiber, which can enhance the structural strength and synergistically absorb impact energy. The piston cylinder 203 is located at the inner center of the protective cover 201 and communicates with the filling cavity of the protective cover 201. Its sidewall is a rigid structure, which can limit the movement trajectory of the piston plate 6. One end of the transmission slide rod 202 is welded and fixed to the wellhead baffle 5, and the other end passes through the mounting frame 1 in sequence, extends into the piston cylinder 203 and is bolted to the piston plate 6. The piston plate 6 slides with the inner wall of the piston cylinder 203. When subjected to force, it can move along the piston cylinder 203 towards the filling cavity, squeezing the filling layer 19 from the piston cylinder 203 into the filling cavity, causing the filling layer 19 to harden quickly and form a rigid protection.

[0025] Specifically, the shock wave generated by the blast first acts on the wellhead baffle 5, which transmits the impact force to the transmission slide rod 202, driving it to move upward in a straight line. Simultaneously, the transmission slide rod 202 drives the piston plate 6 to slide within the piston cylinder 203. The piston plate 6, through compression, pushes the filling layer 19 within the piston cylinder 203 into the filling cavity of the protective cover 201. Under instantaneous compression and impact, the shear-thickening fluid in the filling layer 19 rapidly aggregates nano-silicon particles to form a rigid structure. Simultaneously, the protective cover 201, made of aramid fiber, forms a composite protective layer of fluid hardening and fiber protection, efficiently absorbing impact energy. The inner wall of the protective cover, protected by a blasting device 300, first provides flexible buffering against the high-speed splashing of small- and medium-sized gravel, weakening its kinetic energy. Then, the hardened filling layer 19 and the outer wall of the aramid fiber provide rigid interception. This dual action prevents gravel from breaching the protection, achieving a secondary protection effect.

[0026] Mounting bracket 1 includes a top plate 101, a bottom baffle 102, and several connecting rods 7. The top plate 101 is horizontally positioned above the central protective body 2, and a through hole 1011 communicating with the piston cylinder 203 is opened at its center. Mounting components 1023 are provided on the lower surface of the top plate 101 and the upper surface of the bottom baffle 102 for rotatably mounting the pulley block 12. The mounting component 1023 is an L-shaped angle iron. One side of the angle iron is fixed to the top plate 101 or the bottom baffle 102 by bolts, and the other side has a round hole for mounting the shaft of the pulley block 12. This is a conventional existing mounting structure and will not be described in detail here.

[0027] The bottom baffle 102 is horizontally positioned at the bottom of the central protective body 2 and is detachably connected to the top plate 101 via a connecting rod 7. The connecting rod 7 is vertically arranged and slides into the through hole two in the top plate 101. Its bottom end is slidably connected to the bottom baffle 102, together forming the frame structure of the mounting bracket 1. The bottom end of the connecting rod 7 has an internal thread adapted to the reinforcing structure 4 for threaded connection. Near the bottom of the through hole two in the top plate 101, the outer peripheral wall of the connecting rod 7 has an external thread, on which a limit nut is screwed. By tightening the limit nut, the top plate 101 is fixed, preventing it from sliding axially along the connecting rod 7. The bottom baffle 102 has a mounting hole 1021 at its center. The size of the mounting hole 1021 is adapted to the bottom opening of the protective cover 201. A steel mesh 8 is fixedly installed in the mounting hole 1021. The mesh size of the steel mesh 8 is 5-10cm, used to intercept large pieces of gravel generated by blasting. The lower surface of the bottom baffle 102 is provided with connecting sleeves 1022 corresponding to the connecting rods 7. The connecting sleeves 1022 are hollow tubular structures that nest with the top of the ground nail shell 3 and are fixed by bolts, realizing the detachable connection between the mounting frame 1 and the ground nail shell 3, which is convenient for disassembly and installation. In this embodiment, the protective device also includes a guide plate 9 located at the center of the reinforcing mesh 8. Its outer periphery is welded and fixed to the reinforcing mesh 8. A sliding hole is opened in the center of the guide plate 9, and the transmission slide rod 202 slides through the sliding hole to provide guidance for the transmission slide rod 202 and prevent it from tilting during movement.

[0028] Specifically, the connecting rod 7 firmly connects the top plate 101 and the bottom baffle 102, forming a stable support structure. This provides an installation reference for the central protective body 2 and the lateral protective mechanism, while also withstanding the longitudinal impact force during blasting, preventing deformation of the mounting frame 1. The bottom baffle 102 provides bottom support for the protective cover 201 and fixes the steel mesh 8 through the mounting holes 1021. The steel mesh 8 uses a grid structure to intercept large pieces of gravel (particle size greater than 5-10cm) generated by the blast, preventing them from impacting the central protective body 2 and causing structural damage, thus achieving a first-level protection effect. The guide plate 9 radially limits the transmission slide rod 202 through sliding holes, ensuring that the transmission slide rod 202 always moves in the vertical direction, preventing it from tilting and causing the piston plate 6 to jam against the inner wall of the piston cylinder 203, thus ensuring the stable operation of the central protective body 2.

[0029] The lateral protection mechanism includes side plates 10 and an angle adjustment assembly. In this embodiment, four sets of side plates 10 are arranged circumferentially and evenly hinged to the outside of the bottom baffle 102. The lower surface of the bottom baffle 102 is provided with a horizontal central shaft 1024. The side plates 10 are sleeved on the central shaft 1024 through bearings and can rotate around the central shaft 1024. A torsion spring 14 is also sleeved on the outer periphery of the central shaft 1024. One end of the torsion spring 14 is connected to the side wall of the stop block provided on the bottom baffle 102, and the other end is connected to the end of the side plate 10, which is used to provide a reset torque for the side plate 10. The angle adjustment assembly includes a pulley block 12, a rigid rope 13, and a transmission short rod 11. The pulley block 12 includes a top pulley and a bottom pulley. The top pulley is rotatably mounted on the mounting part 1023 of the top plate 101, and the bottom pulley is rotatably mounted on the mounting part 1023 of the bottom baffle 102, which is used to change the transmission direction of the rigid rope 13. A transmission rod 11 is vertically positioned between the top plate 101 and the central protective body 2. It has a transmission top plate 1102 at its top and a transmission bottom plate 1101 at its bottom. The transmission rod 11 is movably engaged with the piston plate 6 via the transmission bottom plate 1101 (either through contact or by a linkage block). A matching sealing mounting plate 18 is provided at the top of the through hole 1011, and a through hole 3 for sliding the transmission rod 11 is provided at the center of the sealing mounting plate 18. The sealing mounting plate 18 is located between the transmission bottom plate 1101 and the transmission top plate 1102. An elastic element 16 is provided between the transmission bottom plate 1101 and the sealing mounting plate 18. The elastic element 16 is sleeved on the outside of the transmission rod 11 to buffer the impact force of the transmission rod 11's movement and assist in resetting. One end of the rigid rope 13 is fixedly connected to the transmission top plate 1102, and the other end passes around the pulley block 12 and is fixedly connected to the side of the side plate 10 away from the hinge end. The rigid rope 13 and the side plate 10 are set one-to-one to ensure that the side plate 10 is subjected to uniform force.

[0030] It should be noted that an ultrasonic generator 17 is fixedly installed on the upper surface of the sealing mounting plate 18. The output end of the ultrasonic generator 17 abuts against the top of the protective cover 201. After the explosion, it can transmit low-frequency vibration to the protective cover 201, causing the hardened filling layer 19 to quickly return to a fluid state so that the device can be reused.

[0031] Specifically, during the blast, the transmission slide rod 202 moves upward, causing the piston plate 6 to contact the transmission base plate 1101 of the transmission short rod 11, pushing the transmission short rod 11 to move upward synchronously. The elastic element 16 is compressed and stores elastic potential energy. The transmission short rod 11 pulls the rigid rope 13 through the transmission top plate 1102. The pulley block 12 converts the vertical tension of the rigid rope 13 into a horizontal tension, acting on the side of the side plate 10 away from the hinge end, driving the side plate 10 to rotate around the central axis 1024. The torsion spring 14 is twisted and stores energy. The greater the shock wave intensity, the greater the displacement of the transmission slide rod 202, the stronger the tension of the rigid rope 13, and the greater the rotation angle of the side plate 10, thereby expanding the protection range and adapting to the projectile angle of the flying stones. After the blasting is completed, the transmission slide bar 202 is reset under the action of the elastic element 15, the transmission short rod 11 loses its thrust, the elastic element 2 16 releases its potential energy to drive the transmission short rod 11 to reset, the tension of the rigid rope 13 disappears, the torsion spring 14 releases its torsional potential energy, and drives the side plate 10 to rotate in the opposite direction around the central axis 1024, returning to the initial protection angle.

[0032] The ground stake shell 3 is a hollow cylindrical structure. Its top end is nested with the connecting sleeve 1022 of the bottom baffle 102. A partition 301 is welded and fixed at the upper opening. A through hole 4 is provided on the outer peripheral wall for the connecting rod assembly 401 to extend outward. The ground stake shell 3 has a reinforcing structure 4 inside. The reinforcing structure 4 includes several connecting rod assemblies 401, internal fixing bolts 402, a pressing plate 403, and a connecting short rod 4031, a partition 404, and a perforated limiting plate 405, which are arranged with the central axis of the pressing plate 403. The perforated limiting plate 405 is fixedly connected to the top end of the connecting short rod 4031, the pressing plate 403 is located at the bottom end of the connecting short rod 4031, and the partition 404 is located between the pressing plate 403 and the perforated limiting plate 405, and its center is fixedly connected to the connecting short rod 4031. All three move synchronously with the connecting short rod 4031. Both ends of the internal fixing bolt 402 are provided with external threads. One end has a through groove that matches the perforated limiting plate 405 (i.e., this end is the male end). The limiting hole of the perforated limiting plate 405 is the female end. After the two are plugged in, they are tightened with a nut that matches the external thread of the internal fixing bolt 402, so that the connecting short rod 4031 and the internal fixing bolt 402 form a whole. The distance between the connecting short rod 4031 and the internal fixing bolt 402 can be changed by adjusting the fixing position of the perforated limiting plate 405 on the connecting short rod 4031. The connecting rod assembly 401 is evenly distributed on the outer periphery of the extrusion plate 403 and is located below the partition plate 404. Each linkage assembly 401 includes a first linkage 4011 and a second linkage 4012. The fixed end of the first linkage 4011 is hinged to the inner wall of the ground nail housing 3, and the free end is hinged to one end of the second linkage 4012. The other end of the second linkage 4012 passes through the side wall through hole four of the ground nail housing 3, and its free end is set as a pointed tip, which can be embedded into the rock layer to enhance the embedding force. The extrusion plate 403 is located above the first linkage 4011 near the fixed end. When the extrusion plate 403 rises, it can abut against the first linkage 4011 and drive it to swing around the hinge point, thereby causing the second linkage 4012 to extend outward.

[0033] It should be noted that a spring is installed between partition 301 and partition 404 to provide a buffering force when the extrusion plate 403 is subjected to the tension of the connecting short rod 4031. A damping structure is also provided between the perforated limiting plate 405 and the bottom baffle 102, specifically, a gasket is provided on each of the two on opposite sides, and a buffer spring is abutting between the gaskets to enhance the vibration resistance during blasting.

[0034] Specifically, rotating the internal fixing bolt 402, which is threadedly connected to the connecting rod 7, drives the extrusion plate 403 to move upward along the inside of the ground nail shell 3. The extrusion plate 403 abuts against the first connecting rod 4011 and pushes it to swing around the hinge point, thereby driving the second connecting rod 4012 to extend outward from the ground nail shell 3. The barbed claw structure at the free end of the second connecting rod 4012 embeds into the surrounding rock layer, achieving initial reinforcement of the device through mechanical engagement. The shock wave generated by the blast is transmitted to the top plate 101, forming an upward thrust. This thrust is transmitted through the connecting rod 7 to the internal fixing bolt 402 and the connecting short rod 4031, further driving the extrusion plate 403 to move upward, causing the second connecting rod 4012 to penetrate deeper into the strata. The barbed claw structure engages more tightly with the strata, and the embedding force increases synchronously with the increase of the impact force, ensuring that the device does not loosen or shift under blast vibration.

[0035] In other embodiments, see Appendix Figure 22 To enhance the redundancy of lateral protection, a protective net 100 can be added to the outside of the side plate 10. The lower edge of the protective net 100 is pressed firmly to the ground by sandbags 200. The protective net 100 is made of high-strength polyester fiber with a mesh size of 3-5cm, used to intercept residual debris that still splashes outward after rebounding from the side plate 10. The sandbags 200 are continuously arranged around the circumference of the protective net 100, providing a bottom counterweight to prevent the protective net 100 from being overturned by the shock wave, and absorbing the residual kinetic energy of flying rocks, further ensuring the safety of the area around the wellhead.

[0036] The working principle of the protective device of the present invention is as follows: During blasting operations, large pieces of rock are intercepted by the steel mesh 8 and fall back into the well, achieving primary protection. The shock wave generated by the blast first acts on the wellhead baffle 5, which compresses the elastic element 15 and drives the transmission slide rod 202 to move upward in a straight line along the sliding hole of the guide plate 9. The transmission slide rod 202 simultaneously drives the piston plate 6 to slide inside the piston cylinder 203. The piston plate 6 squeezes a small amount of filler layer 19 from the piston cylinder 203 into the filling cavity of the protective cover 201. The shear-thickening fluid of the filler layer 19 hardens rapidly under the instantaneous impact, forming a composite protective layer with the aramid fiber material of the protective cover 201. At the same time, the blasting device 300 buffers the impact force of small-diameter rock fragments, achieving secondary protection.

[0037] Simultaneously, the transmission slide rod 202 drives the piston plate 6 to move upward, and the piston plate 6 pushes the transmission short rod 11 to compress the elastic element 16 to move upward. The transmission short rod 11 pulls the side plate 10 to rotate around the central axis 1024 through the rigid rope 13. The torsion spring 14 stores force. The greater the intensity of the shock wave, the greater the rotation angle of the side plate 10, expanding the protection range to adapt to the angle of the flying rock. The shock wave generated by the blast is transmitted to the top plate 101, generating an upward thrust. The thrust is transmitted to the internal fixing bolt 402 through the connecting rod 7, driving the connecting short rod 4031 and the extrusion plate 403 to move upward. The extrusion plate 403 pushes the first connecting rod 4011 to swing, causing the second connecting rod 4012 to extend further and embed into the stratum. The embedding force increases with the increase of the impact force, ensuring that the device does not loosen.

[0038] After the blasting is completed, elastic element 15 and elastic element 2 16 release their elastic potential energy, driving the transmission slide rod 202 and transmission short rod 11 to reset, and the torsion spring 14 drives the side plate 10 to return to its initial angle. The ultrasonic generator 17 is activated, and low-frequency vibration causes the hardened filling layer 19 to return to a fluid state. The connecting rod 7 is rotated in the opposite direction, causing the internal fixing bolt 402 to rotate in the opposite direction, driving the extrusion plate 403 to move downward. The first connecting rod 4011 resets, causing the second connecting rod 4012 to retract into the ground nail shell 3, releasing the formation embedment. Loosen the bolts and limit nuts of the connecting sleeve 1022, separate the mounting frame 1 from the ground nail shell 3, and clean the gravel at the wellhead for reuse.

[0039] Example 2 This embodiment provides a method for protecting the wellhead from flyrock during pile foundation blasting, employing the wellhead flyrock protection device for pile foundation blasting described in Embodiment 1, specifically including the following steps: Step 1: The outer shell of the ground nail 3 is pre-embedded in the stratum around the wellhead, and a solid connection is formed with the stratum through the reinforcement structure 4; Specifically, based on the wellhead size and geological conditions, multiple sets of ground nail housings 3 are evenly arranged at predetermined positions around the wellhead. The internal fixing bolt 402, threadedly connected to the connecting rod 7, is rotated using a wrench. This rotation drives the pressing plate 403 to move upwards along the interior of the ground nail housing 3. The pressing plate 403 abuts against the first connecting rod 4011 and pushes it to swing around the hinge point, thereby causing the second connecting rod 4012 to extend outwards from the ground nail housing 3. The claw structure at the free end of the second connecting rod 4012 embeds into the surrounding rock layer, achieving initial reinforcement of the device through mechanical engagement. The reinforcement depth can be adjusted by the number of rotations to adapt to the embedding requirements of different strata.

[0040] Step 2: Detachably fix the mounting bracket 1 to the ground nail shell 3 so that the central protective body 2 is positioned facing the wellhead; The bottom baffle 102 of the mounting bracket 1 is nested with the top of the ground nail housing 3 via the connecting sleeve 1022, and the bolts on the connecting sleeve 1022 are tightened to achieve detachable fixation. At this time, the central protective body 2 is positioned directly opposite the wellhead, the wellhead baffle 5 is attached to the top of the wellhead, and the steel mesh 8 covers the wellhead area. By adjusting the limiting nut on the connecting rod 7, the top plate 101 and the bottom baffle 102 are kept parallel to each other, ensuring that the transmission slide rod 202 is in a vertical state.

[0041] Step 3: Graded protection during the blasting process; After the explosion is detonated, the shockwave and flying debris trigger the three levels of protection in sequence: Level 1 protection: Large pieces of gravel (particle size greater than 5-10cm) are first intercepted by the steel mesh 8 and fall back into the well under the action of gravity, avoiding direct impact on the central protective body 2.

[0042] Secondary protection: The shock wave acts on the wellhead baffle 5, compressing the elastic element 15 and driving the transmission slide rod 202 to move upward in a straight line along the sliding hole of the guide plate 9. Simultaneously, the transmission slide rod 202 drives the piston plate 6 to slide within the piston cylinder 203, compressing the filling layer 19 (shear-thickening fluid) from the piston cylinder 203 into the filling cavity of the protective cover 201. The filling layer 19 hardens rapidly under the instantaneous compression impact, forming a composite rigid protective layer with the aramid fiber protective cover 201. Simultaneously, the 300 blasting bushings adhering to the inner wall of the protective cover 201 provide flexible buffering for small and medium-sized gravel. After the dual action of "flexible buffering - rigid interception," the kinetic energy of the small and medium-sized gravel is fully absorbed.

[0043] Level 3 protection: When the transmission slide rod 202 moves upward, the piston plate 6 contacts the transmission base plate 1101 of the transmission short rod 11, pushing the transmission short rod 11 to move upward synchronously, compressing the elastic element 16. The transmission short rod 11 pulls the rigid rope 13 through the transmission top plate 1102. After passing around the pulley block 12, the rigid rope 13 acts on the side of the side plate 10 away from the hinge end, driving the side plate 10 to rotate around the central axis 1024, and the torsion spring 14 stores force. The greater the shock wave intensity, the greater the displacement of the transmission slide rod 202, the stronger the tension of the rigid rope 13, and the greater the rotation angle of the side plate 10, thereby dynamically adapting to the projectile range of the flying stone and intercepting the residual flying stone.

[0044] Step 4: Resetting and disassembling after the explosion; After the blasting is completed, the elastic element 15 releases its elastic potential energy to drive the transmission slide bar 202 to reset, the elastic element 26 releases its potential energy to drive the transmission short rod 11 to reset, the tension of the rigid rope 13 disappears, and the torsion spring 14 releases its torsional potential energy to drive the side plate 10 to rotate in the opposite direction around the central axis 1024, returning to the initial protection angle.

[0045] The ultrasonic generator 17 is activated, and low-frequency vibrations are transmitted to the protective cover 201, causing the hardened filling layer 19 to return to a fluid state so that the device can be reused.

[0046] Reverse rotation of connecting rod 7 causes internal fixing bolt 402 to rotate in the opposite direction, driving extrusion plate 403 to move downward. First connecting rod 4011 resets, causing second connecting rod 4012 to retract into ground nail housing 3, releasing the formation from embedment. Loosen bolts and limit nuts on connecting sleeve 1022, separate mounting frame 1 from ground nail housing 3, and after clearing debris from the wellhead, the next blasting operation can proceed.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A wellhead rockfall protection device for pile foundation blasting, comprising a mounting frame (1), characterized in that, Also includes: The central protective body (2) is located in the middle of the mounting frame (1) and is filled with a filling layer (19) that hardens rapidly under the action of the blast shock wave. Multiple sets of lateral protection mechanisms are disposed on the outer periphery of the central protection body (2) and are movably connected to the central protection body (2); The ground nail shell (3) is detachably connected to the mounting bracket (1) and has a retractable reinforcement structure (4) inside.

2. The wellhead flyrock protection device for pile foundation blasting according to claim 1, characterized in that, The central protective body (2) includes: The protective cover (201) is fixed at the bottom to the mounting bracket (1) and has a filling cavity inside; The piston cylinder (203) is located inside the protective cover (201) and communicates with the filling cavity; The transmission slide rod (202) is connected to the wellhead baffle (5) at one end and passes through the mounting frame (1) at the other end and is connected to the piston plate (6). The piston plate (6) slides in cooperation with the inner wall of the piston cylinder (203).

3. The wellhead flyrock protection device for pile foundation blasting according to claim 2, characterized in that, The mounting bracket (1) includes: The top plate (101) is located above the central protective body (2) and has a through hole (1011) communicating with the piston cylinder (203). The bottom baffle (102) is connected to the reinforcement structure (4) via a connecting rod (7) and is installed at the bottom of the central protective body (2).

4. The wellhead flyrock protection device for pile foundation blasting according to claim 3, characterized in that, The bottom baffle (102) includes: The mounting hole (1021) is adapted to the bottom of the opening of the central protective body (2) and is fitted with a steel mesh (8). The connecting sleeve (1022) corresponds one-to-one with the connecting rod (7) and is bolted to the top of the ground nail shell (3).

5. The wellhead flyrock protection device for pile foundation blasting according to claim 4, characterized in that, The protective device also includes: The guide plate (9) is located at the center of the steel mesh (8), and its outer periphery is connected to the steel mesh (8) and slidably connected to the transmission slide rod (202).

6. The wellhead flyrock protection device for pile foundation blasting according to claim 3, characterized in that, The reinforced structure (4) includes: Several linkage components (401) have their fixed ends hinged to the inner wall of the ground nail shell (3) and their free ends sliding through the ground nail shell (3). An internal fixing bolt (402) is inserted at one end through the top of the ground nail shell (3) and threadedly connected to the connecting rod (7). A horizontally arranged extrusion plate (403) is connected at the bottom end.

7. The wellhead flyrock protection device for pile foundation blasting according to claim 6, characterized in that, The lateral protection mechanism includes: Side plate (10) is circumferentially hinged to the outside of bottom baffle (102); Angle adjustment assembly, one end of which is connected to the side plate (10), and the other end of which is movably engaged with the transmission slide rod (202) via the transmission short rod (11).

8. The wellhead flyrock protection device for pile foundation blasting according to claim 7, characterized in that, The angle adjustment component includes: The pulley block (12) is rotatably mounted on the top plate (101) and the bottom baffle (102); A rigid rope (13) is connected at one end to the transmission rod (11) and at the other end to the side plate (10) after passing over the pulley block (12).

9. A method for protecting wellheads from flyrock during pile foundation blasting, characterized in that, The wellhead flyrock protection device according to any one of claims 1-8 is used for protection, comprising the following steps: The outer shell of the ground nail (3) is pre-embedded in the strata around the wellhead, and a solid connection is formed with the strata through the reinforcement structure (4); The mounting bracket (1) and the ground nail shell (3) are detachably fixed so that the central protective body (2) is positioned directly opposite the wellhead; During the blast, the shock wave drives the filling layer (19) inside the central protective body (2) to harden and form a rigid protection. The protection range is dynamically adjusted by the transmission short rod (11), rigid rope (13) and pulley block (12) linked to the side plate (10). The greater the intensity of the shock wave, the greater the rotation angle of the side plate (10), thus achieving the adaptation and interception of the flying stone throwing range.

10. The method for protecting wellhead debris from falling rocks during pile foundation blasting according to claim 9, characterized in that, During the blast, the shock wave acts on the wellhead baffle (5), driving the transmission slide rod (202) to move the piston plate (6). The transmission slide rod (202) is linked to the rigid rope (13) through the transmission short rod (11). The rigid rope (13) passes around the pulley block (12) and pulls the side plate (10) to rotate around the hinge point. The intensity of the shock wave is positively correlated with the rotation angle of the side plate (10). After the blast ends, the side plate (10) automatically resets.

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