Steel plate protection statically determinate blasting construction method

Abstract

The invention discloses a steel plate protection statically determinate blasting construction method, which relates to a construction blasting method, and comprises the following steps: survey lofting, drilling, blast hole acceptance inspection, charging, blocking, cotton quilt covering and steel plate laying, networking, warning, detonation and post-detonation inspection. Compared with the prior art, through the combined protection measures of covering the cotton quilt and laying the steel plates, blasting shock waves are effectively reduced, flying stones and flying dust are restrained, meanwhile, the construction process is simplified, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to a construction blasting method. Background Art

[0002] With the rapid development of infrastructure construction in China, the demand for blasting engineering in fields such as mining, transportation, and water conservancy is increasing day by day. Especially in large-scale infrastructure projects, such as highways, ports, tunnels, etc., blasting technology, as a key construction means, directly affects the project efficiency and quality. However, the blasting operation itself has a high degree of danger and involves flammable and explosive items such as explosives. Therefore, there are high safety risks during the operation process. At the same time, traditional blasting technologies have problems such as large vibration, many flying stones, and serious dust pollution, posing a threat to the surrounding environment and the safety of residents.

[0003] In recent years, national environmental protection policies have become stricter, and regulations such as the "Safety Regulations for Blasting" (GB6722-2014) have put forward higher requirements for the safety and environmental protection of blasting operations. In this context, the static blasting technology, with its advantages of low vibration, low noise, high precision, etc., has become an important development direction in the field of blasting engineering. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the present invention provides a construction method for static blasting with steel plate protection. This method effectively reduces the blasting shock wave, suppresses flying stones and dust through a combined protection measure of covering with cotton quilts and laying steel plates, while simplifying the construction process and reducing costs.

[0005] In order to solve the above technical problems, the present invention is solved through the following technical solutions: a steel plate protection static blasting construction method, comprising the following steps: step A: measurement and layout, the measurement team calibrates the front row resistance line and calibrates the original ground elevation, and determines the hole depth, angle and direction; step B: drilling, the drilling and blasting team performs drilling operations according to engineering requirements, and checks in time after each hole is drilled and protects the hole mouth with sandbags; step C: acceptance of blastholes, after the drilling is completed, the engineering and technical personnel should check whether the parameters such as the blasthole position, depth, angle, etc. meet the blasting design, and fill in the relevant records; step D: after receiving the instructions from the technical person in charge, the blaster performs the charging operation, and the charging should be carried out according to the blasting design charging amount and charging structure, and must be carefully checked before charging. Carefully check whether there is any blockage or sticking of the hole, and promptly adjust the charge of the blasthole if the geological weak surface and resistance line change; Step E: Use the rock chips generated by drilling to block the hole to prevent small stones from mixing in; Step F: After the blasthole is blocked, cover a layer of quilt directly above the blasthole, and then cover the blasting area with a layer of steel plate; Step G: The blaster sets the detonator delay time according to the blasting design requirements and then connects the detonation network; Step H: Before implementing the blasting, a safety alert plan must be formulated and safety alert work must be done well; Step I: Carry out blasting; Step J: 5 minutes after detonation, wait for the smoke and dust to dissipate, and the engineer and blaster will enter the blasting area to conduct a post-blast inspection. After confirming the safety of the blasting area, report to the blasting site commander, issue an alarm, and lift the alarm signal.

[0006] In the above technical solution, preferably, in step D, the depth of the charging part is frequently checked during the charging process to prevent overcharging of explosives causing flying rocks or inadequate charging causing upper and lower explosion isolation.

[0007] In the above technical solution, preferably, in step D, if overcharging occurs during the charging process, the excess explosives are removed from the hole with a wooden tool or flushed with high-pressure water.

[0008] In the above technical solution, preferably, in step H, the blasting warning can be carried out only after the detonator self-checks and confirms that there are no missing connections, short circuits, abnormal resistance and current, etc., and the detonation network is completely normal.

[0009] In the above technical solution, preferably, in step F, after the blast hole is blocked, a layer of quilt is covered directly above the blast hole, and then a layer of steel plate is covered above the quilt.

[0010] In the above technical solution, preferably, in step F, after the blast hole is blocked, a layer of quilt is covered on the explosion area, and then a layer of steel plate is covered on the quilt.

[0011] This application reduces the explosion shock wave at the static blasting construction site and reduces the impact of flying rocks on surrounding buildings by using the methods of covering with cotton-padded quilts and laying steel plates. The calculation of the maximum flying distance of blasting flying objects is Rmax = K*d, where 'd' is the diameter of the blast hole and 'K' is the safety factor (taking 15 - 16). If d = 90mm, then R = 135 - 144m. According to the requirements of the "Code for Blasting Safety" (GB6477 - 2014), the safety allowable distance of individual flying rocks from deep-hole bench blasting and trench blasting to personnel shall be in accordance with the design but not less than 200m. In this project, the warning range is set with a safety distance of not less than 200m. Because the flying rock speed v = √2gR, where R = 135 - 144m and g = 9.8N / kg, after calculation, when d = 90mm, the maximum flying rock speed v = 55m / s. The impact kinetic energy of the flying rock E = 1 / 2mv², and the mass of the flying rock is about 0.25kg, so the impact kinetic energy is about 380J. The impact toughness of 10mm thick Q235 steel plate at normal temperature is 27J / cm 2 , and the impact area of the flying rock is about 20cm 2 . The impact toughness of 10mm thick Q235 steel plate at normal temperature is about 540J, that is, by selecting the steel plate, the purpose of completely absorbing the impact kinetic energy of the flying rock can be achieved, thereby enhancing the safety of blasting construction. The blasting dust PM10 is about 120ug / m³, and the diffusion radius of the dust is 60m. Appropriate cotton-padded quilt thickness can be selected according to the dust monitoring data and the dust diffusion radius to achieve the purpose of controlling dust. When the thickness of the cotton-padded quilt is selected as 50cm, the monitoring standard of PM10 is not higher than 75ug / m³. That is, this application can reduce the safety warning range to less than 80m by using the methods of covering with cotton-padded quilts and laying steel plates.

[0012] This method is applicable to blasting projects at the "B" level according to the provisions of Articles 4.1 and 4.2 of the "Code for Blasting Safety" (GB6722 - 2014). For such blasting projects, the rock is hard rock, the rock hardness coefficient f is about 10, the rock is relatively hard, brittle, and the structural plane combination is relatively good. The basic quality grade of the rock is mainly grade Ⅳ geotechnical blasting. The total amount of explosive charged in a single blast of open-pit deep-hole bench blasting shall not be greater than 4500kg, and the total amount of explosive charged in a single blast of trench excavation blasting shall not be greater than 600kg. And there are important production area protection facilities within 500m and residential and village building groups within 200m.

[0013] Compared with the prior art, the method of this application is more convenient and simple to operate than the previous blasting methods. The dust, noise, and flying rocks are controlled, which can reduce the input of safety warning personnel and reduce the security cost. At the same time, the method of this application hardly generates vibration, impact, noise, dust, and flying rocks, and does not affect the surrounding environment, which avoids the indirect costs caused by environmental restoration and disturbing the people for appeasement. The method of this application increases the expenses for renting cotton-padded quilts, steel plates, and cranes, but reduces the input of safety protection personnel, environmental restoration input, and disturbing the people for appeasement input. Generally speaking, it can greatly reduce the expenses.

[0014] The social benefits of this application method are primarily reflected in improving construction efficiency, reducing safety hazards, and protecting the environment. By adopting advanced blasting technology, construction efficiency can be significantly improved, project cycles can be shortened, and time and cost savings can be achieved, which is of great significance for accelerating project progress and expediting production. By precisely controlling the blasting process, safety hazards during construction are reduced, ensuring the safety of construction workers and surrounding residents, and increasing residents' sense of social acceptance. The new method can reduce dust and noise pollution, minimize the impact on the surrounding environment, and contribute to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Flow chart of the method of the present invention.

[0016] Figure 2 This is the blasting construction layout diagram of the present invention. DETAILED DESCRIPTION

[0017] Example 1, as Figures 1 to 2 shown.

[0018] Surveying and staking out: Before drilling, the surveying team calibrates the front resistance line and determines the original ground elevation. This data is promptly provided to the blasting technical supervisor to determine the hole depth, angle, and direction. Blasting technicians and blasters then conduct on-site hole layout, specifying the depth and angle of the drill holes. This layout information is then submitted to the drilling and blasting team, and clearly communicated on-site.

[0019] Drilling: The drilling and blasting team will carry out drilling operations according to the project requirements. After each hole is drilled, they will check it in time and protect the hole opening with sandbags.

[0020] Acceptance of blastholes: After the drilling is completed, the engineering and technical personnel should check whether the parameters such as the blasthole position, depth, angle, etc. are in line with the blasting design, and fill in the relevant records. If not, they need to report to the engineer for confirmation before construction or modification.

[0021] Charging: Blasters can only begin charging after receiving instructions from the technical supervisor. Charging should be carried out according to the designed charge quantity and charge structure. Before charging, carefully inspect the hole for blockage or obstruction, and promptly adjust the charge if the geological weaknesses or resistance lines change. During charging, frequently check the depth of the charge area to prevent overcharging, which could cause flying rocks, or undercharging, which could cause upper and lower explosion isolation. If overcharging occurs, remove excess explosives from the hole with a wooden tool or flush with high-pressure water.

[0022] Blocking: Use rock debris from drilling to block the hole, preventing the intrusion of small stones. Pay attention to the quality of the blockage and the protection of the detonator leg wire. Block gently to prevent damage to the leg wire and cause detonation failure. Ensure the length and quality of the blockage. Excess pyrotechnic materials should be returned to the warehouse promptly.

[0023] Covering with quilts and laying steel plates: After the blasthole is blocked, a layer of quilt is placed directly above the blasthole. The steel plates prepared on-site are then hoisted to the area above the blasting site using a crane and lowered onto the quilt. This combination of quilts and steel plates reduces dust and flying rocks generated during the blasting process. Three methods of covering the quilt and steel plates include: covering the blasthole with the quilt, covering the quilt with the steel plate, covering the blasting area with the quilt, and finally covering the blasting area with the steel plate. The specific method is determined based on the site, and the thickness of the quilt and steel plate is determined according to the blasting requirements.

[0024] Networking: A technician or blaster sets the detonator delay time according to the blasting design requirements and then connects the blasting network. Blasting alerts can only be issued after the blasting network is fully functional after the blaster self-checks and confirms no missing connections, short circuits, or abnormal resistance or current.

[0025] Warning: Establish a blasting site command center, with the project technical leader serving as the overall commander. To ensure blasting safety, a safety warning plan must be developed and thorough safety precautions must be implemented before blasting. At least one day in advance, the detonation time, warning area, and warning signal must be notified to nearby residents and relevant departments, allowing them to make appropriate work and living arrangements and preparations.

[0026] Detonation: After the security process is completed and the chief commander of the blasting site confirms that all personnel and equipment in the security area have been evacuated, and the security personnel have arrived at their posts and completed safety precautions, he will sound a second alarm and issue a "detonate" command with a countdown of several seconds. The blaster will operate the firing gun (or detonator) to ignite and detonate.

[0027] Post-blast inspection: Five minutes after detonation, once smoke and dust have dissipated, engineers and blasters will enter the blasting area for a post-blast inspection. After confirming the area is safe, they will report to the on-site blasting commander, sound the third alarm, and clear the alarm. Any blind shots should be promptly addressed. After the blast, the excavation and transportation of the machinery should be observed, and a technical staff member will provide a blasting summary.

[0028] In the early stage of blasting construction, blasting seismic wave monitoring is carried out to obtain the true K and α values of the blasting area, which is convenient for accurate control of the blasting seismic wave velocity in the future.

[0029] Before each blasting, conduct an investigation on the surrounding buildings and structures to determine a reasonable blasting safety seismic wave velocity; measure the accurate distance from the blasting point to the building. Conduct a blasting seismic wave check before the implementation of blasting. Reasonably select the main blasting direction. The magnitude of the blasting seismic wave is related to the orientation of the protected area. When the protected area is in front of the blasting area, the seismic wave is the smallest, followed by the side, and the largest at the rear. Therefore, try to avoid the blasting direction facing away from the protected object. Reasonably determine the initiation method and adopt the precise millisecond delay blasting technology of electronic detonators to reduce vibration. Engineering experiments show that compared with simultaneous blasting, the average vibration reduction rate of precise millisecond delay blasting is about 50%; the more the number of segments, the better the vibration reduction effect. Control the charge amount of the largest single segment initiation. The general principle is: drill holes densely, charge less, and blast weakly; control the scale of each blasting and the charge amount of each blasting; strictly control the charge amount of the largest single segment in the same section. Control the blasting scale. To reduce the seismic effect while ensuring the blasting quality, while controlling the charge amount of the largest simultaneous segment initiation, controlling the total charge amount of each initiation can also effectively reduce the blasting vibration effect. Excavate and transport in a timely manner, and clean and regularize the blasting free face.

[0030] The "Blasting Safety Regulations" must be strictly followed during the collection, transportation, loading, and network detonation of explosives. Dedicated personnel must be assigned to designated posts and areas for security. Warning areas must be clearly marked and public notices must be issued. Before detonation, personnel must be cleared from hazardous areas, and clear audio and visual signals must be issued. Routine and regular maintenance of machinery and equipment must be strengthened to ensure trouble-free operation. Prominent safety signs must be posted at intersections and on steep slopes. The speed of loaded vehicles must be strictly controlled to ≤15 km / h and that of unloaded vehicles to ≤20 km / h. At night, construction areas and passageways must be adequately illuminated. Dedicated personnel must be on duty at intersections and turns to ensure transportation safety. Management of power sources, fire sources, and blasting equipment must be strengthened. Temporary structures such as construction site offices, equipment and material depots, processing areas, oil depots, and distribution rooms must be located on steps to avoid flooding and equipped with standard fire-fighting equipment. Management of electricity usage for construction and daily life must be strengthened. Electrical equipment and wiring must be regularly inspected and maintained by electricians, and equipment and equipment must be protected from rain. Appoint a dedicated person to receive and keep the materials, and carefully keep records. Unused blasting materials on site must be promptly returned to the warehouse and handover procedures must be strictly followed. When constructing in dangerous areas, adopt reasonable construction techniques, early support, frequent measurements, short advances, weak blasting, and avoid reckless advances. At the same time, strengthen safety education for construction personnel, and achieve early detection and early prevention of unsafe factors. Set up various necessary safety signs in conspicuous locations for each type of work at the construction site, and manage them by a full-time on-site safety officer. Strengthen the safety management of personnel and vehicles on site, adhere to civilized construction, and ensure the safety of personnel, machinery, and equipment. The construction site is located in a mountainous area with poor road conditions and slippery roads in the rainy season. Motor vehicles on the road must drive at the speed limit, do not encroach on the road, do not cut in, be civilized and courteous, honk the horn on curves, ensure driving safety, and strictly prevent traffic accidents. Strengthen the distribution, management, and use of labor protection supplies, and wear safety helmets correctly. Before construction begins, the on-site construction manager and dedicated safety officer should explain the construction details and safety precautions to the shift leader in writing. The shift leader should also explain the construction details and safety precautions to his or her team members in writing. Safety briefings should be signed by relevant personnel and recorded. A blasting command center should be established with the technical director as the commander-in-chief. This center will be responsible for coordinating daily blasting, safety precautions, and related matters, and will be composed of a construction team, detonation team, logistics team, safety monitoring team, and security team. Blasting technicians will be responsible for directing technical blasting tasks such as hole placement, explosive charging, blasting network, and blind shot handling. The blasting unit should issue a notice three days prior to the start of work and post it at the work site. The construction notice should include: the name of the blasting project, the commissioning unit, the design and construction unit, the safety assessment unit, the safety supervision unit, and the blasting time limit. A blasting notice should be issued and posted on site one day before charging, including: blasting location, time of each blast, safety warning range, warning signs, detonation signal, etc.

[0031] Measures for controlling blasting noise are as follows: Ensure the stemming length, do not use the bare charge blasting method, use detonating fuse network for blasting network connection, and use fewer detonators outside the holes. Do not use bare charge blasting and do not use detonating cord for blasting outside the holes. Control the amount of explosive for one-time blasting. Select a reasonable direction and value of the minimum burden, optimize blasting parameters, ensure the stemming length, and make full use of the explosion energy of each charge. Build a protective frame to block the air shock wave. Use blasting equipment with qualified quality and do not use expired or deteriorated explosives. Strengthen the waterproof and moisture-proof of explosives, ensure the stemming length and quality, and avoid incomplete reaction of explosives. Five minutes after blasting, construction personnel can enter the blasting site to prevent poisoning by blasting fumes.

Claims

1. A static blasting construction method for steel plate protection, characterized in that It includes the following steps: Step A: Survey and set out. The surveying team will calibrate the front resistance line and the original ground elevation, and determine the hole depth, angle and direction. Step B: Drilling. The drilling and blasting team will perform drilling operations according to the project requirements. After each hole is drilled, they will promptly check and protect the hole opening with sandbags. Step C: Check and accept the blastholes. After drilling is completed, the engineering and technical personnel should check whether the parameters such as the blasthole position, depth, angle, etc. meet the blasting design and fill in the relevant records; Step D: After receiving the instruction from the technical person in charge, the blaster shall carry out the charging operation. The charging shall be carried out according to the designed charging quantity and charging structure. Before charging, the blasthole shall be carefully checked for blockage or jamming. The charging quantity of the blasthole shall be adjusted in time if the geological weak surface and resistance line have changed. Step E: Use rock chips generated by drilling to block the hole to prevent small stones from mixing in; Step F: After the blast hole is blocked, cover the blast hole with a layer of quilt, and then cover the explosion area with a layer of steel plate; Step G: The blaster sets the detonator delay time according to the blasting design requirements and then connects the blasting network; Step H: Before blasting, a safety precaution plan must be developed and safety precautions must be carried out; Step I: blasting; Step J: 5 minutes after detonation, when the smoke and dust have dissipated, engineers and blasters will enter the blasting area to conduct a post-blast inspection. After confirming that the blasting area is safe, they will report to the blasting site commander and issue and clear alarm signals.

2. A steel plate protection static blasting construction method according to claim 1, characterized in that, in step D, the depth of the charging part is frequently checked during the charging process to prevent overcharging of explosives causing flying rocks or undercharging causing upper and lower explosion isolation.

3. A steel plate protection static blasting construction method according to claim 1, characterized in that, In step D, if overcharging occurs, use a wooden tool to dig out the excess explosives from the hole or flush it with high-pressure water.

4. The static blasting construction method for steel plate protection according to claim 1 is characterized in that, in In step H, the blasting alarm can be carried out only after the detonator self-checks and confirms that there are no missing connections, short circuits, abnormal resistance and current, etc. in the detonator network and it is completely normal.

5. A steel plate protection static blasting construction method according to claim 1, characterized in that, In step F, after the blasthole is blocked, a layer of quilt is covered directly above the blasthole, and then a layer of steel plate is covered on the quilt.

6. The construction method of static blasting for steel plate protection according to claim 1 is characterized in that, In step F, after the blast hole is blocked, a layer of quilt is covered on the blast area, and then a layer of steel plate is covered on the quilt.

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