A blasting flyrock protection structure

Abstract

The application discloses a blasting flyrock protection structure and belongs to the technical field of geotechnical engineering and blasting safety protection. The structure comprises an NPR protection net, a shape memory alloy module and an integrated heating and spraying auxiliary system. The NPR protection net is used for initially intercepting large-diameter flyrocks with high kinetic energy; the shape memory alloy module absorbs the impact energy of small and medium-diameter flyrocks that pass through the protection net through plastic deformation; the heating system can heat the shape memory alloy module after blasting, so that the structure returns to the original state and realizes the self-recovery function. The spraying system is intelligently started according to the blasting noise or the structure deflection feedback, and is used for dust reduction, temperature reduction and auxiliary noise reduction. The application solves the problems of large rigidity, poor energy absorption, non-recovery and incapability of coping with flyrocks with multiple diameters of the traditional protection structure through hierarchical interception and self-recovery design, significantly improves the protection efficiency, the reuse rate and the environmental adaptability, and is especially suitable for multi-cycle blasting engineering such as urban subway foundation pits.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering and blasting safety protection technology, specifically to a blasting flyrock protection structure. Background Technology

[0002] In the development of underground spaces such as subway foundation pits in cities, blasting is widely used due to its high efficiency. However, the flyrock produced by blasting has a wide range of particle size distribution (from centimeter-sized debris to meter-sized rock fragments), high initial kinetic energy, and strong randomness in flight direction. It can easily pose a serious safety threat to surrounding buildings, municipal facilities, construction workers, and machinery and equipment, and induce secondary disasters.

[0003] Currently, common methods for protecting against flying rocks from blasting in engineering projects are mainly divided into two categories: rigid protection and flexible protection. Rigid protection, such as reinforced concrete retaining walls and steel plates, offers high protective strength, but its structure is bulky, inconvenient to construct, has limited energy absorption capacity, and is prone to brittle failure after impact, resulting in irreversible damage and extremely low reusability. Flexible protection, such as wire rope nets and flexible protective curtains, while possessing a certain degree of deformation capability, typically suffers from the following inherent drawbacks: 1. The structural design is simplistic, with a fixed mesh size, making it difficult to effectively intercept fly stones with vastly different particle sizes simultaneously. For small-diameter, high-speed fly stones, an excessively large mesh will allow some to slip through; for large-diameter fly stones, an excessively small mesh will lead to localized overload and structural tearing.

[0004] 2. Material fatigue and irreversibility: Most flexible materials will undergo plastic deformation or damage accumulation after being subjected to high-energy impacts. The protective performance decreases with the number of uses, requiring frequent inspection, repair or replacement, resulting in high maintenance costs.

[0005] 3. Limited functionality: Traditional protective structures mainly focus on mechanical interception and lack the ability to comprehensively manage secondary pollution such as dust, noise, and high temperatures that accompany blasting.

[0006] 4. Poor environmental adaptability: In the confined spaces of the city, the installation and dismantling of traditional protective structures are often complicated procedures, affecting construction efficiency.

[0007] Therefore, there is an urgent need to develop a high-efficiency, economical, and reusable blasting fly rock protection structure that can intelligently respond to the impact of fly rocks of different particle sizes, has self-recovery capabilities to be suitable for multiple rounds of blasting, and can integrate environmental management functions. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a protective structure for blasting flying rocks, so as to solve the technical problems of traditional protective structures, such as inability to intercept flying rocks of different particle sizes in a graded manner, non-recovery after impact, low reusability, and single function.

[0009] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A protective structure for blasting debris is provided, comprising: an NPR protective net, a shape memory alloy module disposed behind the NPR protective net, and an auxiliary system; the NPR protective net is used to intercept large-diameter blasting debris; the shape memory alloy module is used to absorb the impact energy of small- to medium-diameter blasting debris; the auxiliary system includes at least a heating device for restoring the shape memory alloy module to its original shape.

[0010] The basic principle of a blasting flyrock protection structure is as follows: During blasting operations, when the NPR (Non-Particle Recognition) protective net is impacted by flyrock, the pore size shrinks and the mesh deforms, effectively intercepting large-diameter, high-kinetic-energy flyrock. For small- to medium-diameter high-speed flyrock, the impact shape memory alloy modules of the NPR protective net bear the load and buffer the impact. Through controllable plastic deformation, they absorb the impact kinetic energy, significantly reducing the risk of flyrock damage to the structure. The shape memory alloy modules have the ability to undergo a reverse phase transition after heating, thus restoring their shape. The heating device can accelerate the shape memory alloy modules' recovery. The entire blasting flyrock protection structure has graded interception and self-recovery capabilities, significantly improving the overall interception efficiency and reliability. It solves the technical problems of traditional protective structures, such as the inability to grade and intercept flyrock of different sizes, lack of recovery after impact, low reusability, and limited functionality.

[0011] Furthermore, the shape memory alloy module comprises multiple shape memory alloy blocks assembled by detachable connectors; each shape memory alloy block has internal pores filled with sound-absorbing material. This modular design significantly improves construction convenience, maintainability, and transportation efficiency; the introduction of sound-absorbing material enables the entire blasting debris protection structure to not only intercept flying debris but also provide significant noise pollution control, achieving multi-functional integration.

[0012] Furthermore, the heating device includes multiple resistance heating elements and a control switch electrically connected by wires; each shape memory alloy block has a resistance heating element disposed within its hole. The independent placement of resistance heating elements within each shape memory alloy block, connected in series with the control switch via wires, forms a distributed yet centrally controlled electrothermal network. This ensures that heat is directly and uniformly transferred to each shape memory alloy block body requiring recovery, resulting in high energy utilization efficiency and direct recovery drive. This achieves reliable, uniform, and controllable triggering of the self-recovery process. Centralized control simplifies operation, and distributed heating ensures the consistency of the overall module recovery, avoiding problems of uneven recovery stress or deformation caused by uneven local heating.

[0013] Furthermore, each of the shape memory alloy blocks has a cylindrical channel inside; the auxiliary system also includes a spray system, which comprises a water pump, a controller, a main water pipe, and multiple spray pipes; the water pump is electrically connected to the controller, the main water pipe is connected to the water pump outlet, and the multiple spray pipes are respectively arranged in the cylindrical channels inside the multiple shape memory alloy blocks, with a spray outlet at the bottom of each spray pipe; the controller is used to control the water pump to supply water to the spray outlets. The main functions of the spray system are dust suppression, cooling, and auxiliary noise reduction.

[0014] Furthermore, the spraying system is a sound-controlled spraying system. The controller is configured to automatically start the water pump to spray when the detected blasting noise reaches a preset threshold. Utilizing the inherent characteristic that blasting inevitably generates high-intensity instantaneous noise, this is used as a natural and reliable trigger signal for automatically starting the spraying. The comparison circuit or program within the controller determines whether the noise exceeds a safety or activation threshold, achieving full automation of the environmental management function of the protective structure. No manual intervention is required; dust suppression can be initiated simultaneously with the blast, with extremely fast response speed, improving the automation level and safety of the operation and ensuring timely dust suppression.

[0015] Furthermore, the NPR protective net uses metal materials as the main and fine reinforcing bars, and is processed through drawing and cross-weaving processes to form a stable triangular mesh structure; the spacing between the main reinforcing bars... D Designed to satisfy the following relation:

[0016] in, R This represents the radius of the maximum spherical flying stone to be intercepted. This setting allows the design of NPR protective nets to move from experience-based to scientifically quantified. Based on the maximum expected flying stone size in the project, the mesh size can be accurately calculated and manufactured, ensuring the reliability and effectiveness of intercepting large-diameter flying stones and avoiding protective failures due to improper mesh design.

[0017] Furthermore, the protective structure is also equipped with a fiber Bragg grating sensor for monitoring the impact deformation of the NPR protective net. The fiber Bragg grating sensor measures the deflection of the main ribs. The controller is signal-connected to the fiber Bragg grating sensor and configured to dynamically adjust the spray duration of the spray system based on the deflection signal fed back by the fiber Bragg grating sensor. The fiber Bragg grating sensor monitors the deflection of the NPR main ribs in real time with high precision and in a distributed manner by measuring the change in the grating period due to strain. This deflection value directly reflects the magnitude and location of the impact of the flying stone. The controller uses this physical signal as input to adjust the spray strategy, upgrading the spray control from event-based (voice-controlled) to state-based (impact consequences) control, achieving an intelligent leap from "spraying when the explosion occurs" to "determining how to spray based on the severity of the impact."

[0018] Furthermore, the spray system includes multiple zoned spray units, each corresponding to a monitoring area. The controller is configured to independently control the spray duration of the corresponding zoned spray unit based on the maximum deflection value fed back by the fiber optic grating sensor within each monitoring area. By dividing the protective surface into zones and independently monitoring the maximum deflection and controlling the spray duration for each zone, a differentiated response strategy is achieved, solving the resource waste problem of "one-size-fits-all" spraying. Areas with severe impact receive more adequate dust suppression and cooling, while areas with minor impact experience reduced resource consumption, thus improving water resource utilization efficiency.

[0019] Furthermore, the entire blasting flyrock protection structure also includes two mounting blocks, which are used to fix the entire protection structure to the edge of the pit. Both the NPR protective net and the shape memory alloy module are detachably connected to the mounting blocks. As a standardized interface and load-bearing transfer component connecting the main protective structure to the engineering foundation, the mounting blocks greatly improve the deployment speed, ease of assembly and disassembly, and connection reliability of the entire protection system on site. The mounting blocks can be reliably fixed to a stable foundation in advance, and the NPR protective net and the shape memory alloy module can be quickly attached or bolted together, meeting the needs of efficient on-site operations.

[0020] Furthermore, the plurality of shape memory alloy blocks include a central shape memory alloy block and a plurality of general shape memory alloy blocks evenly distributed on both sides of the central shape memory alloy block, with the central shape memory alloy block protruding from the general shape memory alloy blocks; the NPR protective net is fixedly connected to the two mounting blocks, the central shape memory alloy block, and the general shape memory alloy blocks via edge hooks; the impact surface of each shape memory alloy block is a curved concave shape. The arrangement of the central shape memory alloy block and the plurality of general shape memory alloy blocks strengthens the core area most likely to withstand frontal impact, improving the overall impact robustness and reliability of the blasting debris protection structure. Simultaneously, the impact surface is designed as a curved concave shape to utilize the mechanical properties of curved surfaces to disperse impact stress, reduce localized concave damage, and potentially guide the deflection of the flying debris.

[0021] Compared with traditional protective structures, the beneficial effects of this invention are as follows: 1. This invention provides a protective structure for blasting debris, which, through the combination of an NPR (Non-Particle Removal) protective mesh and a shape memory alloy module, achieves the ability to classify and process blasting debris according to its particle size. The NPR mesh, with its large deformation characteristics, effectively "screens" large pieces of debris; the shape memory alloy module focuses on absorbing the kinetic energy of small and medium-sized high-speed fragments that penetrate the mesh, solving the problem of blind spots in single-structure protection and significantly improving the overall interception efficiency and reliability.

[0022] 2. The blasting debris protection structure provided by this invention utilizes the unique shape memory effect of shape memory alloys. After the protective structure deforms due to impact, it can be almost completely restored to its initial shape and performance by heating it through an integrated heating device. This fundamentally changes the traditional "one-time use" or "limited-use" mode of protective structures, realizing the structure's self-repair and long-term reuse, greatly reducing material consumption, replacement frequency, and total life cycle cost, and conforming to the concept of green construction.

[0023] 3. The blasting debris protection structure provided by this invention integrates an intelligent spray system that can automatically start, stop, and adjust spray parameters based on blasting noise or real-time structural stress and deformation (deflection) information. This not only achieves rapid dust reduction and cooling after blasting, improving the working environment, but also assists in absorbing noise and a small amount of shock wave energy through the additional damping effect of water mist, demonstrating an upgrade of the protection structure from passive interception to active intelligent response and comprehensive environmental management.

[0024] 4. The blasting fly rock protection structure provided by the present invention adopts a modular design. The components (such as NPR mesh, shape memory alloy blocks, and mounting blocks) are connected by standardized interfaces (such as bolts and hooks), which facilitates rapid assembly, disassembly, transportation and maintenance on site. It is adapted to the characteristics of narrow sites and overlapping processes in urban foundation pit engineering, and improves construction flexibility and efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a structure for protecting against flying debris from blasting.

[0026] Figure 2 This is a schematic diagram of the NPR protective net structure.

[0027] Figure 3 This is a schematic diagram of the heating device.

[0028] Figure 4 This is a schematic diagram of the structure of a single shape memory alloy block.

[0029] Among them, 1. NPR protective net; 2. Shape memory alloy block; 201. Intermediate shape memory alloy block; 202. General shape memory alloy block; 3. Hole; 4. Resistance heating element; 5. Control switch; 6. Wire; 7. Cylindrical channel; 8. Water pump; 9. Controller; 10. Main water pipe; 11. Spray pipe; 12. Spray outlet; 13. Mounting block; 14. Main rib; 15. Fine rib. Detailed Implementation

[0030] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0031] refer to Figures 1-4 As shown, this invention provides a basic structure for protecting against flying debris during blasting. This structure is horizontally erected on the side of the blasting operation face in a subway foundation pit. It mainly consists of an NPR protective net 1 at the front end, a shape memory alloy module, and an auxiliary system. The entire structure is firmly anchored to the side wall of the foundation pit or a stable support frame via two mounting blocks 13 on the left and right sides.

[0032] The NPR protective net 1 uses metal materials as the main ribs 14 and thin ribs 15, and is processed through drawing and cross-weaving processes to form a stable triangular mesh structure; the spacing of the main ribs 14 is... D Designed to satisfy the following relation:

[0033] in, RThis represents the radius of the maximum spherical flying stone to be intercepted. This setting allows the design of the NPR protective net 1 to move from experience-based to scientifically quantified. Based on the maximum expected flying stone diameter, the mesh size can be accurately calculated and manufactured, ensuring the reliability and effectiveness of intercepting large-diameter flying stones and avoiding protective failures due to improper mesh design.

[0034] The shape memory alloy module is assembled from multiple independent shape memory alloy blocks 2 (such as NiTi alloy blocks) connected end-to-end with high-strength bolts to form a continuous, integral barrier, located approximately 10-50 cm directly behind the NPR protective net 1. Each shape memory alloy block 2 has internally machined holes 3, which are filled with sound-absorbing material, such as flame-retardant sound-absorbing cotton. The introduction of sound-absorbing material enables the entire blast debris protection structure to not only intercept blast debris but also significantly reduce noise pollution.

[0035] Preferably, the plurality of shape memory alloy blocks 2 include a central shape memory alloy block 201 and a plurality of general shape memory alloy blocks 202 evenly distributed on both sides of the central shape memory alloy block 201, with the central shape memory alloy block 201 protruding from the general shape memory alloy blocks 202; the NPR protective net 1 is fixedly connected to the two mounting blocks 13, the central shape memory alloy block 201, and the general shape memory alloy blocks 202 via edge hooks; the impact surface of each shape memory alloy block 2 is a curved concave shape. The arrangement of the central shape memory alloy block 201 and the plurality of general shape memory alloy blocks 202 strengthens the core area most likely to withstand frontal impact, improving the overall impact resistance robustness and reliability of the blasting debris protection structure. At the same time, the impact surface is designed as a curved concave shape to utilize the mechanical properties of curved surfaces to disperse impact stress, reduce local concave damage, and may guide the deflection of the blasting debris.

[0036] The auxiliary system includes at least a heating device. The heating device consists of a resistance heating element 4 embedded in the cavity of each shape memory alloy block 2, a wire 6 connected in series with the resistance heating element 4, and a control switch 5. After the blasting operation, the control switch 5 is closed, causing the resistance heating element 4 to heat the shape memory alloy block 2. When the temperature exceeds its austenitic phase transformation initiation temperature, the shape memory alloy block 2 will gradually recover to its shape before the impact.

[0037] Each shape memory alloy block 2 has a cylindrical channel 7 inside. The auxiliary system also includes a spray system, which includes a water pump 8, a controller 9, a main water pipe 10, and multiple spray pipes 11. The water pump 8 is electrically connected to the controller 9, the main water pipe 10 is connected to the outlet of the water pump 8, and the multiple spray pipes 11 are respectively arranged in the cylindrical channels 7 inside the multiple shape memory alloy blocks 2, and each spray pipe 11 has a spray outlet 12 at its bottom. The controller 9 is used to control the water pump 8 to supply water to the spray outlets 12. The spray pipes 11 are made of high-temperature and pressure resistant miniature plastic water pipes.

[0038] Specifically, the spray system is a sound-controlled spray system. The controller 9 is configured to automatically activate the water pump 8 to spray when the detected explosion noise reaches a preset threshold. When an explosion occurs, if the spray system detects that the noise intensity exceeds a preset safety threshold (e.g., 120 decibels), the controller 9 activates the water pump 8 to pressurize water into the spray pipe 11, from which a fine water mist is sprayed out from each spray outlet 12. The spraying lasts for a base time T (e.g., 30 seconds) to achieve the effects of dust suppression, cooling, and auxiliary absorption of explosion noise. This design makes the protective structure not only a physical barrier but also an active environmental purification device.

[0039] Specifically, to achieve more precise and adaptive spray control, multiple fiber Bragg grating sensors are attached or welded to the main ribs of the NPR protective net 1. These fiber Bragg grating sensors transmit the real-time deflection signals (corresponding to the intensity and location of the flying stone impact) to the controller 9. The controller 9 has a preset control algorithm that defines a functional relationship between the spray duration ΔT and the deflection δ detected by the fiber Bragg grating sensors, for example, ΔT = k * f(δ), where k is a proportionality coefficient and f(δ) is a function of the deflection δ, for example, taking the maximum deflection value within the monitoring area.

[0040] When a flying rock impacts the NPR protective netting 1, fiber optic grating sensors in different areas measure different deflection values ​​δ1, δ2, δ3... Upon receiving these signals, the controller 9 first logically partitions the protected area (e.g., each partition corresponds to 2-3 adjacent spray outlets 12). For each partition, the controller 9 selects the maximum deflection value fed back by all sensors within that partition. Then, based on the aforementioned functional relationship, it calculates the required spray extension time for that partition. After triggering the basic spray time T, the controller 9 independently controls the water pump 8 branches or solenoid valves (branch solenoid valves can be installed on the main water supply pipe to achieve partition control) of each partition, ensuring that the spray in each partition operates according to the calculated extension time. For example, in areas severely impacted and with large deflections, the spray time is automatically extended to provide more sufficient dust suppression and cooling; areas with minor impacts are sprayed for a shorter time. This "on-demand allocation" mode, while ensuring protective effectiveness, maximizes water conservation and embodies intelligent and refined control.

[0041] The assembly and protection process of the blasting flyrock protection structure in this invention is as follows: Assembly includes: Step 1, Positioning and fixing the mounting block 13: On the stable base at the outer edge of the blasting area of ​​the foundation pit, fix the two mounting blocks 13 by pre-embedded bolts or expansion bolts.

[0042] Step 2: Assemble the shape memory alloy module: Connect multiple shape memory alloy blocks 2 sequentially with high-strength bolts to form an integral module, and connect and fix the two ends of the module to the mounting block 13.

[0043] Step 3: Install internal components: Before assembling each shape memory alloy block 2, fill its cavity with sound insulation cotton and pre-position the resistance heating element 4 and water spray pipe 11 in the designed position.

[0044] Step 4: Connect the auxiliary system: Connect the wires 6 of all resistance heating elements 4 in series to the control switch 5. Connect all water spray pipes 11 to the main water pipe 10, and connect the main water pipe 10 to the water pump 8. Connect the signal line of the fiber optic grating sensor to the controller 9.

[0045] Step 5: Install NPR protective netting 1: Securely attach the edge of NPR protective netting 1 to the connection point of mounting block 13 and the front end of shape memory alloy module using special hooks or connecting rings, ensuring that it is taut and covers the front of shape memory alloy module.

[0046] The protective workflow includes: Step 1: During the blast, high-speed flying rocks first impact the NPR protective netting 1. Large-diameter flying rocks are directly intercepted by the netting, and their kinetic energy is absorbed and dissipated through the large deformation of the netting. The negative Poisson's ratio effect of the NPR material causes the netting around the impact point to tighten, enhancing local penetration resistance.

[0047] Step 2: Some small- to medium-sized flying stones may pass through the mesh pores and then impact the shape memory alloy module behind them. The shape memory alloy module undergoes controllable plastic deformation, converting the kinetic energy of the flying stones into the internal energy of the material (mainly phase transition energy), causing the flying stones to decelerate, stop, or be bounced away.

[0048] Step 3: The loud noise generated by the blast triggers the sound-controlled spray system, and water mist is automatically sprayed out to reduce dust and cool the air.

[0049] Step 4: The fiber optic grating sensor monitors grid deformation in real time and feeds the data back to the controller 9. The controller 9 dynamically adjusts the spray duration of each zone according to the algorithm to achieve precise dust suppression.

[0050] Step 5: After a single blasting operation, shut down the spray system. Activate control switch 5 of the heating device to heat the shape memory alloy module as a whole or in sections. After heating to the set temperature and maintaining it for a period of time, the shape memory alloy essentially returns to its initial flat shape due to phase transformation recovery, completing the self-recovery process.

[0051] Step 6: Inspect NPR safety net 1 for irreparable damage or breakage, and repair or replace it if necessary. Check that all system connections are normal.

[0052] Step 7: After the structure is restored, it can be prepared for the next round of blasting operations, thus achieving reuse.

Claims

1. A structure for protecting against flying debris from blasting, characterized in that, include: The system comprises an NPR protective net, a shape memory alloy module disposed behind the NPR protective net, and an auxiliary system; the NPR protective net is used to intercept large-diameter blasting debris; the shape memory alloy module is used to absorb the impact energy of small- to medium-diameter blasting debris; and the auxiliary system includes at least a heating device for restoring the shape memory alloy module to its original shape.

2. The blasting flyrock protection structure according to claim 1, characterized in that, The shape memory alloy module includes multiple shape memory alloy blocks that are spliced ​​together by detachable connectors; the multiple shape memory alloy blocks have holes inside, and the holes are filled with sound-absorbing material.

3. The blasting flyrock protection structure according to claim 2, characterized in that, The heating device includes multiple resistance heating elements and a control switch electrically connected by wires; each shape memory alloy block has a resistance heating element installed in its hole.

4. The blasting flyrock protection structure according to any one of claims 1-3, characterized in that, Each of the shape memory alloy blocks has a cylindrical channel inside; The auxiliary system also includes a spray system, which includes a water pump, a controller, a main water pipe, and multiple spray pipes; The water pump is electrically connected to the controller, the main water pipe is connected to the water outlet of the water pump, and multiple spray pipes are respectively set in the cylindrical channels inside multiple shape memory alloy blocks, and each spray pipe has a spray outlet at its bottom. The controller is used to control the water pump to supply water to the spray outlet.

5. The blasting flyrock protection structure according to claim 4, characterized in that, The spray system is a sound-controlled spray system, and the controller is configured to automatically start the water pump to spray when the detected explosion noise reaches a preset threshold.

6. The blasting flyrock protection structure according to claim 4, characterized in that, The NPR protective net uses metal materials as the main and secondary reinforcing bars, and is processed through drawing and cross-weaving techniques to form a stable triangular mesh structure; the spacing between the main reinforcing bars... D Designed to satisfy the following relation: in, R The radius of the largest spherical flying stone expected to be intercepted.

7. The blasting flyrock protection structure according to claim 6, characterized in that, The protective structure is also equipped with a fiber Bragg grating sensor for monitoring the impact deformation of the NPR protective net. The fiber Bragg grating sensor measures the deflection of the main rib. The controller is connected to the fiber Bragg grating sensor and configured to dynamically adjust the spray duration of the spray system based on the deflection signal fed back by the fiber Bragg grating sensor.

8. The blasting flyrock protection structure according to claim 7, characterized in that, The spray system includes multiple zoned spray units, each zoned spray unit corresponding to a monitoring area; the controller is configured to independently control the spray extension time of the corresponding zoned spray unit based on the maximum deflection value fed back by the fiber optic grating sensor in each monitoring area.

9. The blasting flyrock protection structure according to claim 1, characterized in that, It also includes two mounting blocks, which are used to fix the entire protective structure to the edge of the pit; the NPR protective net and the shape memory alloy module are both detachably connected to the mounting blocks.

10. The blasting flyrock protection structure according to claim 1, characterized in that, The plurality of shape memory alloy blocks include a central shape memory alloy block and a plurality of general shape memory alloy blocks evenly distributed on both sides of the central shape memory alloy block, wherein the central shape memory alloy block protrudes from the general shape memory alloy blocks; the NPR protective net is fixedly connected to the two mounting blocks, the central shape memory alloy block and the general shape memory blocks via edge hooks; the impact surface of each shape memory alloy block against blasting debris is a curved concave shape.

Images