Micro-vibration blasting construction method adjacent to high-speed rail business line

Abstract

The invention relates to the technical field of high-speed rail related construction, and discloses a micro-vibration blasting construction method adjacent to a high-speed rail business line, which comprises the steps of blasting design, surveying and setting out, drilling, drilling quality inspection, charging and filling, detonating network connection, detonating, ventilation and blasting effect inspection, and mainly solves the problem of insufficient vibration reduction timeliness in the prior art. By adopting the pre-splitting hole and mechanical reserved layer collaborative vibration reduction technology, potential safety hazards such as high-speed rail structure deformation and pier displacement possibly caused by vibration are avoided, the influence of blasting construction on high-speed rail operation is reduced to the minimum, and the safety of the high-speed rail structure is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of high-speed rail related construction, and in particular to a micro-vibration blasting construction method close to an operating high-speed rail line. Background Art

[0002] In recent years, my country's railway construction has achieved tremendous development results, with a large number of new or rebuilt railway lines gradually put into operation. As my country's railway operating mileage and network density continue to increase, due to the inherent long length of railway lines, as well as economic and geographical factors, the construction sites of some new or rebuilt railway projects are often located within a certain range on both sides of existing operating railway lines. They may directly parallel, cross, or even pass through existing lines. The construction process of these projects will have a certain impact on the transportation safety of existing operating lines.

[0003] Construction near operating lines poses potential risks that could impact railway transportation safety, and blasting construction near operating lines poses a significant threat. When conducting construction near existing operating lines, ensuring the safe operation of existing lines is paramount. Traditional blasting methods pose a serious threat to adjacent railway lines due to the difficulty in precisely controlling blasting vibration and spatter. Therefore, the digital micro-vibration blasting construction method has emerged. By introducing modern blasting control technologies such as digital electronic detonators, this method enables refined management and precise control of the blasting process. This not only addresses the problems of high vibration and difficulty in controlling spatter associated with traditional blasting methods, but also significantly reduces the range and intensity of blasting vibration, minimizing the impact on existing operating lines.

[0004] The prior art announcement number is CN116658178B, which discloses a step-by-step differentiated blasting vibration reduction and isolation construction method for ultra-small clearance tunnels, including S1: constructing a pilot tunnel and the primary support of the pilot tunnel; S2: burying vibration isolation pipes on the side walls of the pilot tunnel and constructing the secondary lining of the pilot tunnel; S3: drilling vibration reduction holes in the rear tunnel to form a vibration reduction hole group belt; dividing the rear tunnel into an excavation area and a blasting area along the vibration reduction hole group belt; S4: dividing the blasting area into an upper step blasting area and an upper step blasting area. Blasting area, middle bench blasting area, lower bench blasting area; the excavation area is divided into upper bench excavation area, middle bench excavation area, lower bench excavation area; S5: blasting the upper bench blasting area and excavating the upper bench excavation area; S6: blasting the middle bench blasting area and excavating the middle bench excavation area; S7: blasting the lower bench blasting area and excavating the lower bench excavation area; S9: pouring cement slurry into the slurry inlet pipe; reducing the vibration impact on the lining of the leading tunnel and the surrounding rock of the middle rock pillar during the blasting of the subsequent tunnel.

[0005] With respect to the above and existing related technologies, the inventors believe that the following defects often exist: The existing technology has the problem of insufficient timeliness of vibration reduction. The vibration isolation pipe needs to be buried and grouting cured before the second lining of the pilot tunnel. The process is cumbersome and time-consuming, and cannot meet the requirements of construction efficiency and response speed next to the high-speed railway operating line.

[0006] 2. Existing technologies lack monitoring and dynamic adjustment systems and focus on static physical vibration isolation measures, making them difficult to adapt to the prevention and control of sudden vibration risks in high-speed rail operations. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that the existing technology has the disadvantage of insufficient timeliness of vibration reduction. For this reason, we propose a micro-vibration blasting construction method close to the high-speed railway operating line.

[0008] To achieve the above objectives, the present application adopts the following technical solution: a micro-vibration blasting construction method close to an operating high-speed railway line, comprising the following steps: Step 1: Determine the parameters for pre-splitting blasting, shaft rock blasting, and tunnel rock blasting for the open-cut and tunnel sections. Conduct blasting tests to adjust the parameters before blasting the tunnel sections. Step 2: Position the working pit of the open-cut section as a whole, measure and lay out the pre-splitting hole positions and the blasthole positions in the main blasting area; set up the tunnel section network, and use the polar coordinate method of the total station to measure and lay out the excavation contour line and blasthole positions; Step 3: Drill pre-split holes in the open-cut section using a shallow-hole drill, and drill the main blast holes using a pneumatic rock drill; drill and repair the blast holes in the tunnel section; Step 4: The pre-crack holes in the open-cut section adopt an uncoupled charging structure, with continuous charging of tubular emulsion explosives, and the detonator located in the lower middle part of the blasthole. The cut holes, auxiliary holes, and floor holes in the tunnel section adopt a continuous charging structure, while the peripheral holes adopt an uncoupled air-spaced charging structure. Step 5: Electronic detonator initiation networks are used in both the cut-and-strip and tunnel sections. Delay times are set between blastholes, between rows, and within sections. Single-hole, single-shot technology is used. Delay times are adjusted in the cut-and-strip section based on on-site blasting vibration monitoring results. The initiation network is inspected before initiation in the tunnel section. Step 6: Use the blasting vibration monitoring system for real-time monitoring; the monitoring system collects data synchronously during detonation, and when the monitoring data reaches or exceeds the warning threshold, the emergency response procedure is initiated; Step 7: Repeat the above steps if there is intact rock mass that has not been blasted and cannot be excavated by machinery.

[0009] Preferably, the pre-splitting blasting hole is arranged 1 m inside the enclosure structure of the open-cut working shaft, and the hole depth can be drilled into 5-6 m depending on different working shafts.

[0010] Preferably, the single-hole single-shot technology means that each blasthole is equipped with an independent electronic detonator.

[0011] Preferably, the pre-splitting blasting holes are blasted before the vertical shaft stone blasting to form a pre-splitting vibration damping zone.

[0012] Preferably, the explosion delay time between blastholes in the open-cut section is 8-20ms, and the delay time between blasthole rows is 80-120ms.

[0013] Preferably, the tunnel section sets different intra-segment delays according to different blasthole types. The intra-segment delay time for the slot hole, auxiliary hole, and bottom plate hole is 5ms, and the intra-segment delay time for the peripheral hole is 2-4ms.

[0014] Preferably, the openings of the peripheral holes are arranged at a distance of 10 cm from the excavation edge, deviated 3°-5° outward, and the bottom of the holes falls 10 cm-15 cm outside the design contour line.

[0015] Preferably, the groove holes are wedge-shaped, each pair of groove holes gradually deepens, and the angle with the working surface gradually increases, and the intersection angle is 60°-80°; the groove holes are arranged at a distance of 0.8-1.0m from the bottom of the tunnel; the groove holes are 10-20cm deeper than the surrounding holes and auxiliary holes.

[0016] Preferably, the automated monitoring technology consists of monitoring sensors, data transmission modules and data analysis and processing terminals. Monitoring sensors are arranged around the blasting area and on high-speed rail-related structures. Data is transmitted to the data analysis and processing terminal in real time through the data transmission module. When the displacement of the monitoring target exceeds 3 mm or the vibration speed exceeds 1.7 cm / s, the emergency response procedure is activated.

[0017] Preferably, the open-cut section working shaft adopts a shallow hole step electron micro-vibration blasting method according to environmental conditions, and the layered excavation height is selected to be 1.0m-2.5m.

[0018] The technical effects and advantages of the present invention are as follows: In the present invention, by adopting the coordinated vibration reduction technology of pre-crack holes and mechanical reserved layers, safety hazards such as deformation of the high-speed railway track structure and displacement of bridge piers caused by vibration are avoided, the impact of blasting construction on high-speed railway operations is minimized, and the safety of the high-speed railway track structure is guaranteed.

[0019] In the present invention, by achieving single-hole single-shot, accurately controlling the detonation time of each blasthole, effectively dispersing the vibration peak, and coordinating with the three-step blasting process, the blasting effect is further optimized, the effective utilization rate of the explosive energy is improved, and at the same time the damage to the surrounding rock mass is reduced, which not only improves the construction efficiency but also reduces the construction time and cost.

[0020] In the present invention, by integrating an automated total station with a vibration monitoring system, when the displacement of the monitored target is too high or the vibration velocity exceeds a threshold, an emergency response program is initiated and blasting parameters are adjusted, which provides higher safety redundancy and can cope with the risk of sudden vibrations in high-speed rail operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The disclosure of the present invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the drawings, the same reference numerals are used to refer to the same components: Figure 1 It is a schematic flow chart of the construction method of the present invention; Figure 2 This is a schematic diagram of the planar structure of the square working pit construction plan of the present invention; Figure 3 This is a schematic diagram of the planar structure of the circular working pit construction plan of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the working well construction plan of the present invention; Figure 5 It is a schematic diagram of the blasthole arrangement structure of the present invention; Figure 6 This is a schematic diagram of the pre-splitting blasting charge structure of the present invention; Figure 7 It is a schematic diagram of the charge structure of the present invention; Figure 8 This is a schematic diagram of the charging structure of the slot hole of the present invention; Figure 9 This is a schematic diagram of the auxiliary hole charging structure of the present invention; Figure 10 This is a schematic diagram of the peripheral hole charging structure of the present invention; Figure 11 This is a schematic diagram of the step blasting initiation network structure of the present invention; Figure 12 This is a schematic diagram of the tunnel blasthole arrangement structure of the present invention; Figure 13 It is a schematic diagram of the three-level surrounding rock blasting network structure of the present invention. DETAILED DESCRIPTION

[0022] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the present invention.

[0023] Reference Figures 1-10 As shown, the present invention provides a technical solution: a micro-vibration blasting construction method close to a high-speed railway operating line, the method adopts the following specific steps: Step 1: Blasting Design. The project along the Xiamen-Shenzhen High-Speed ​​Railway operating line can be divided into an open-cut section and a tunnel section. The blasting parameters for the open-cut section can be divided into pre-splitting blasting parameters and vertical shaft rock blasting parameters.

[0024] In order to reduce the impact of shaft rock blasting on the retaining structure and the Xiamen-Shenzhen High-Speed ​​Railway, a pre-splitting blasting hole is drilled 1m away from the shaft retaining structure. The pre-splitting blasting hole precedes the shaft rock blasting to form a pre-splitting vibration damping zone, reducing the impact of subsequent shaft rock blasting on the retaining structure and the Xiamen-Shenzhen Railway. The pre-splitting blasting parameters include the deep hole pre-splitting blasting aperture, pre-splitting blasthole design parameters, hole depth, pre-splitting blasting line charge density, blocking length and delay time difference. The smaller the delay time difference, the better the effect. The initial value in this project is selected as 3ms. The pre-splitting blasting parameters are selected according to the rock properties. For intact hard rock, a large value is taken, and vice versa. The pre-splitting blasting uses a detonating cord to transmit the explosion in the hole. In order to ensure the crushing effect at the bottom of the blasthole, reinforced charges are used at the bottom of the hole. The amount of the reinforced charge section is determined according to the rock properties. The pre-splitting blasting parameters are shown in Table 1 below. Table 1.

[0025] The calculation formulas for the rock blasting parameters of the open-cut section shaft and the tunnel section are as follows: Minimum resistance line (W), unit is m, where d represents the diameter of the drill hole 50mm: W=25d Excessive drilling depth (h), unit: H=0.4W Blasthole depth (L), in m, where H represents the step height: L=H+h Blockage length (l`), unit: L`=(1.1~1.3)W Charge length (l) in m: L=Ll` Hole spacing (a), unit: m: a=1.2W Row spacing (b), unit: m: b=W Single hole dosage (Q), unit kg: Q=q·a·b·H Explosive consumption per unit (q), unit: kg / m³: q=0.35~0.45 The shallow hole controlled blasting parameters calculated are listed in Table 2 Table 2.

[0026] Before blasting the tunnel excavation, representative construction areas were selected based on the blasting design for blasting tests. Blasting parameters were adjusted based on the test results until the optimal blasting effect was achieved. The adjusted blasting parameters served as the basis for on-site excavation. Three monitoring sections were set up at the farthest point from the blasting face on the Xiamen-Shenzhen High-Speed ​​Railway, with horizontal spacing of 5 meters. The impact of blasting vibration on facilities at different locations in the tunnel was monitored. The test blasts were controlled according to different charge amounts and conducted in four stages: the first at 70% of the designed maximum charge, the second at 80%, the third at 90%, and the fourth at 100%. This test measured the impact of different charge amounts on the operating Xiamen-Shenzhen High-Speed ​​Railway line.

[0027] Step 2: Survey and set out. The minimum clearance between the open-cut blasting area and the Xiamen-Shenzhen High-Speed ​​Railway piers is: 31.87m for the Danzi first section working shaft; 29.5m for the Danzi second section working shaft; 17.4m for the West section working shaft; and 62.0m for the Lvzi working shaft. The blasting area is adjacent to the operating Xiamen-Shenzhen High-Speed ​​Railway line, so blasting vibrations must be strictly controlled during construction to ensure the safety of high-speed railway facilities.

[0028] For the overall positioning of the working well, the construction personnel used the total station to carry out the overall positioning measurement of the working well according to the coordinates provided in the design drawings. Taking the working well in the west area as an example, the center position and contour line of the working well were accurately measured on site by the total station. The measurement error was strictly controlled within 2 cm to ensure that the plane position of the working well met the design requirements.

[0029] Pre-splitting hole position measurement, refer to Figure 2 and Figure 3 , at 1.0m inside the working shaft enclosure structure, the hole positions are measured and laid out according to the designed pre-crack hole spacing. The surveying personnel use a total station with a steel ruler to first determine the starting hole position, and then measure and mark the positions of other pre-crack holes in sequence along the perimeter of the enclosure structure. After measuring and laying out 5-10 hole positions, they are reviewed with a total station to ensure that the error in the spacing between adjacent hole positions does not exceed 3cm, thereby ensuring the layout accuracy of the pre-crack holes and laying the foundation for the subsequent formation of an effective pre-crack vibration reduction belt.

[0030] The blast hole positioning in the main blasting area is as follows: Figure 4According to the blasthole layout plan of the main blasting area of ​​the blasting design, the blasthole depth and angle are determined in combination with the layer height. The plane position of each blasthole is measured using a total station, and the hole spacing error is controlled within 5cm, and the row spacing error is controlled within 3cm. For blastholes of different depths, such as when the layer height of the west area working well is 1.5m, the blasthole depth is designed to be 2.0m. The surveyors accurately mark the depth of the blasthole on site, and use the angle measuring instrument to assist in determining the inclination angle of the blasthole to ensure that the blasthole position and angle meet the design requirements and guarantee the blasting effect.

[0031] The minimum clearance distance between the tunnel section and the Xiamen-Shenzhen High-Speed ​​Railway is 55.73-65.1m. To ensure the safety of railway operation, harmful effects such as blasting vibration must be strictly controlled during construction. In the stable area of ​​the tunnel entrance, a total station and second-class leveling instruments are used to establish a plane and elevation control network to ensure the accuracy of the tunnel excavation direction and elevation. The third-level surrounding rock blasting parameter design of the tunnel section is based on a section of 222.1m. 2 For the standard design, other sections of the surrounding rock refer to this blasting design parameters and make corresponding adjustments. The three-level surrounding rock adopts three-step blasting construction, and the design control of each cycle footage is 1.2m. The excavation height of the upper step is 5.5m, the middle step is 5.8m, and the lower step is 6.64m. The surveying personnel use the total station and the polar coordinate method to accurately measure the excavation contours and blasthole positions of each step on the tunnel face according to the design drawings and control network. When measuring and laying out the upper step, first determine the center line of the tunnel, and then measure and mark the position of each blasthole according to the designed layout parameters of the slot holes, auxiliary holes and peripheral holes, and accurately measure the blasthole positions to ensure that the blastholes of each step are aligned up and down to form a blasting layer. After the measurement and layout are completed, different measurement methods are used for review to ensure that the measurement error is within the allowable range, the plane position error is controlled within 5cm, and the elevation error is controlled within 3cm. Measuring points that do not meet the requirements are re-measured until they meet the accuracy standards, providing accurate basis for subsequent drilling, charging and other processes, ensuring the safety of blasting construction from the source, and effectively controlling the impact of blasting vibration on nearby high-speed railways.

[0032] Step 3: Drilling. Figure 5 In the construction of pre-crack holes in the open-cut section, a down-the-hole drill is used to drill pre-crack holes 1.0m inside the retaining structure, with a hole spacing of 0.6m, a hole diameter of 76mm, and a hole depth of 5.0-6.0m. The holes are drilled vertically downward, and the verticality deviation is controlled within 1° to ensure the formation of continuous pre-cracks to block blasting vibrations; in the construction of the main blasting holes in the open-cut section, a pneumatic rock drill is used to determine the drilling depth according to the layer height. The drilling diameter is 50mm, and the blast holes are arranged in a plum blossom shape with a hole spacing of 1.1-1.2m and a row spacing of 1.0-1,1m to ensure uniform distribution of blasting energy.

[0033] refer to Figure 12The slot holes on the upper steps of the tunnel section adopt a wedge-shaped slot arrangement method. In order to prevent the detonation of adjacent blast holes or relative blast holes, the distance between the bottoms of the charged blast holes cannot be less than 20cm, the depth of the slot holes is 170cm, the distance between the hole mouths is 160cm, the hole spacing is 50cm, and the intersection angle between the slot holes and the working face is 60-65°; the auxiliary holes are evenly arranged between the slot holes and the peripheral holes and are perpendicular to the tunnel face, with a hole arrangement depth of 1.3-1.4m and a hole spacing of 70-95cm; the peripheral hole arrangement depth is 1.4m, the hole spacing is 50-55cm, the minimum resistance line is 70-85cm, the blast hole angle is 3° outward, and the bottom plate hole spacing is 90cm.

[0034] The front resistance line and row spacing of the middle step excavation holes are both 100cm, and the hole spacing is 100cm; the peripheral hole spacing is 50-55cm, and the minimum resistance line is 70-85cm; the bottom plate hole spacing is 90-100cm.

[0035] The front resistance line and row spacing of the lower step excavation holes are both 100cm, and the hole spacing is 100cm; the peripheral hole spacing is 50-55cm, the minimum resistance line is 70-85cm; the bottom plate hole spacing is 90-100cm. Specific parameters are shown in Table 3 below Table 3.

[0036] Step 4: Borehole Quality Inspection. After the holes are laid out, technicians use tools such as steel rulers and inclinometers to measure the depth, spacing, and verticality of each blasthole. The pre-crack hole depth must meet the designed value: 5.0m for the West District working well and 6.0m for the Danzi working well, with an error within 30cm. The hole spacing is 0.6m, with a deviation of no more than 3cm and a verticality deviation of less than 1°. The main blasthole depth is determined based on the layer height, with an over-depth of 0.5m. The hole spacing is 1.1-1.2m, and the row spacing is 1.0-1.1m, with an error within 5cm. Blastholes outside the error range are marked and immediately reworked. For blastholes with excessive depth, a "layered slag filling + compaction" process is used to repair them and ensure accurate and controllable charge height. After the drilling measurement work is completed, each hole is inspected and the presence of cavities or cracks is determined.

[0037] Step 5: Charge and pack. Figure 6Pre-crack blasting in the open-cut section and vertical shaft rock blasting utilize an uncoupled charging structure, with continuous charging of tubular emulsion explosives selected. During the specific operation, the explosives are loaded into the blasthole, and the detonating charge is placed in the lower middle portion of the blasthole. Electronic detonators, emulsion explosives, and detonating cords are arranged sequentially to form a hollow structure. The detonating cord ensures stable detonation of the explosives. Drill cuttings or building rubble are used as filling materials, which are tightly packed at the blasthole mouth. The detonator leg line extends beyond the plugging section. The filling length must be strictly controlled, generally not less than the design requirements, to prevent premature leakage of explosive gas and ensure that the blasting energy effectively acts on the rock mass, forming a continuous pre-crack vibration damping zone.

[0038] Reference Figures 8-10 The tunnel section's slot holes, auxiliary holes, and floor holes all utilize a continuous charging structure. Electronic detonators are connected to the explosives via a wire box. The length of the charging section is determined according to the design to ensure effective rock fragmentation during blasting, creating favorable conditions for subsequent blasting of auxiliary holes and peripheral holes. The auxiliary holes and floor holes are also charged according to the designed charge quantity and length, ensuring uniform rock fragmentation after blasting and facilitating subsequent excavation operations. The tunnel section's peripheral holes utilize an uncoupled air-spaced charging structure. Latex explosives are arranged at intervals on bamboo strips, forming air gaps in between. This utilizes the cushioning effect of air to minimize disturbances to the surrounding rock during blasting and ensure stability of the tunnel's surrounding rock. The detonators are fixed in place, and the individual charges are connected by detonating cords to ensure synchronous detonation. Filling the peripheral holes is crucial. The filling material and length must strictly meet design requirements to further minimize the impact of blasting energy on the surrounding rock and ensure safe tunnel construction.

[0039] Step 6: Connect the blasting network. The open-cut section utilizes an electronic detonator blasting network designed to optimize blast vibration reduction and fragmentation by precisely controlling the detonation time intervals. Based on theoretical research and engineering experience, the optimal delay between blastholes is set at 8-20ms, and the delay between rows of blastholes is 80-120ms. In this project, considering the surrounding environment, particularly the sensitivity of the adjacent Xiamen-Shenzhen High-Speed ​​Railway operating line, the delay between blastholes was initially set at 17ms, and the delay between rows was initially set at 111ms for the blasting network design. Single-hole, single-shot technology was employed, with each blasthole controlled by an independent electronic detonator. This avoids the potential for chaotic detonation sequencing and energy concentration associated with traditional blasting methods. The electronic detonators' high-precision delay function ensures that each blasthole detonates sequentially according to the scheduled time, evenly discharging blasting energy and effectively reducing the vibration stacking effect. In actual operation, technicians connected electronic detonators to blastholes in a one-to-one correspondence according to design requirements, accurately recording the detonator and blasthole numbers. Based on on-site blasting vibration monitoring results, they dynamically adjusted the detonation delay time. Vibration monitoring points were set up around the blasting area and at key locations, such as the high-speed rail pier, using high-precision vibration meters to collect vibration data in real time. If the monitoring data showed that the vibration peak approached or exceeded the warning value, professional software analysis was used to appropriately increase the delay time between blastholes or rows to further optimize the blasting vibration control effect.

[0040] refer to Figure 13 The tunnel section utilizes precise delayed detonation with electronic detonators, strictly controlling network delay to minimize blasting vibration. The inter-segment delay for tunnel blasting is set at 50ms, while the intra-segment delay for slot holes, auxiliary holes, and floor holes is 5ms. To achieve a smooth surface finish, the intra-segment delay for peripheral holes is controlled at 2-4ms. The tunnel section also utilizes single-hole, single-shot technology, with each blasthole equipped with its own electronic detonator. During the connection process, technicians carefully check the connection between the detonator and the explosive, ensuring the correct orientation of the detonator's energy-focusing hole for optimal initiation. Detonator delay parameters are precisely set for each blasthole type based on its function and location in the blasting process. Furthermore, to ensure the stability and reliability of the detonation network, a comprehensive inspection of the entire network is conducted before detonation. This inspection includes ensuring that the detonator connections are secure, the wiring is free of damage, and that the resistance value is within the normal range. Using detonation network testing equipment, simulated detonation tests are conducted on the network to identify and eliminate potential faults in advance.

[0041] Step 7: Detonation. During the blasting construction period, blasting vibration monitoring points must be set up on the existing Xiamen-Shenzhen Railway bridges within the railway area. Each blasting must be monitored in real time, and blasting parameters must be adjusted promptly based on the monitoring results. Before detonation, ensure that the blasting vibration automation monitoring system is in normal operation. The system mainly consists of monitoring sensors, data transmission modules, and data analysis and processing terminals. Monitoring sensors are precisely arranged in accordance with design requirements around the blasting area and on high-speed rail-related structures. Three vibrometers are arranged on the top of the high-speed rail pier cap closest to the blasting area to collect real-time vibration velocity data in three directions. At the same time, displacement monitoring prisms are installed on the sides of the piers to monitor pier displacement in conjunction with a total station.

[0042] Detonation operations were carried out according to the pre-defined detonation network design and safety procedures. At the moment of detonation, the monitoring system was simultaneously activated, and each monitoring sensor rapidly collected data. A vibrometer captured blasting vibration signals in real time at a sampling frequency of 1000 Hz and rapidly transmitted the data to a data analysis and processing terminal via a wireless data transmission module. A total station automatically measured the coordinates of the pier displacement prism at preset intervals, acquiring vertical, longitudinal, and transverse displacement data for the piers and transmitting this data in real time to the terminal. Upon receiving the monitoring data, the data analysis and processing terminal immediately performed real-time analysis. The system's built-in analysis software compared the data against pre-set warning thresholds—for this project, the vibration velocity warning threshold for the high-speed railway piers was 1.7 cm / s, and the displacement warning threshold was 3 mm for vertical and 2 mm for horizontal. When the monitoring data reached or exceeded the warning threshold, the system immediately issued an audible and visual alarm, and the abnormal data and corresponding monitoring location were highlighted on the terminal interface. Upon the issuance of the warning signal, on-site construction personnel and management personnel immediately initiated emergency response procedures. First, the current blasting operation was halted, along with subsequent charging, detonation, and other related operations. Technicians then quickly conduct an in-depth analysis of the alarm data to determine the extent of the blasting vibration's impact on the high-speed rail structure. If the impact is determined to be minor, subsequent blasting parameters can be adjusted to reduce the vibration. If the impact is significant, a comprehensive inspection and assessment of the high-speed rail structure is required. Based on the assessment results, appropriate reinforcement or repair measures will be formulated to ensure safe high-speed rail operations. Blasting operations can only proceed after confirming that the safety hazard has been eliminated and monitoring data has returned to normal.

[0043] Step 8: Ventilation. After each blast in the open-cut working shaft, mechanical and natural ventilation is used to dilute and expel toxic and hazardous gases. Only after safety requirements are met can the next construction process begin. Toxic gas levels are measured using specialized equipment before entering the shaft. A fog cannon or other device is installed near the blasting face of the working shaft. After blasting is complete, ventilation and sprinkler systems are activated to reduce dust. Only after the harmful gases in the shaft have been exhausted and the dust layer has settled can the working face be entered.

[0044] Mechanical ventilation is required in tunnel sections when the working face is more than 150m into the tunnel. The ventilation time is determined based on the concentration of blasting smoke and the ventilation effect. As the working face deepens, the ventilation time is increased, with the air in the tunnel meeting safety standards as the benchmark. Instrument monitoring can be used when necessary. This project plans to use a forced-in working fan. If the fan output pressure is insufficient, the wind tube diameter can be increased or a ventilator can be connected in series to increase the pressure. If the forced-in fan cannot meet the air volume and pressure requirements, axial flow fans can be added in sequence, using 150cm diameter nylon air ducts as the air inlet and outlet channels. At the same time, the forced-in ventilator must be installed in the fresh air flow.

[0045] Step 9: Check the blasting effect. Post-blasting inspections should be conducted by blasting engineers or experienced blasters. This includes confirming the presence of blind shots, the stability of the blast pile, and the presence of dangerous slopes and rocks. If unblasted rock mass is found and mechanical excavation is impractical, repeat steps 1 through 8.

[0046] The technical scope of the present invention is not limited to the contents of the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A micro-vibration blasting construction method close to a high-speed railway operating line, characterized in that: The steps include: Step 1: Determine the parameters for pre-splitting blasting, shaft rock blasting, and tunnel rock blasting for the open-cut and tunnel sections. Conduct blasting tests to adjust the parameters before blasting the tunnel sections. Step 2: Position the working pit of the open-cut section as a whole, measure and lay out the pre-splitting hole positions and the blasthole positions in the main blasting area; set up the tunnel section network, and use the polar coordinate method of the total station to measure and lay out the excavation contour line and blasthole positions; Step 3: Drill pre-split holes in the open-cut section using a shallow-hole drill, and drill the main blast holes using a pneumatic rock drill; drill and repair the blast holes in the tunnel section; Step 4: The pre-crack holes in the open-cut section adopt an uncoupled charging structure, with continuous charging of tubular emulsion explosives, and the detonator located in the lower middle part of the blasthole. The cut holes, auxiliary holes, and floor holes in the tunnel section adopt a continuous charging structure, while the peripheral holes adopt an uncoupled air-spaced charging structure. Step 5: Electronic detonator initiation networks are used in both the cut-and-strip and tunnel sections. Delay times are set between blastholes, between rows, and within sections. Single-hole, single-shot technology is used. Delay times are adjusted in the cut-and-strip section based on on-site blasting vibration monitoring results. The initiation network is inspected before initiation in the tunnel section. Step 6: Use the blasting vibration monitoring system for real-time monitoring; the monitoring system collects data synchronously during detonation, and when the monitoring data reaches or exceeds the warning threshold, the emergency response procedure is initiated; Step 7: Repeat the above steps if there is intact rock mass that has not been blasted and cannot be excavated by machinery.

2. The micro-vibration blasting construction method close to a high-speed railway operating line according to claim 1 is characterized in that: The pre-splitting blasting hole is arranged at 1m inside the enclosure structure of the open-cut section working shaft, and the hole depth can be drilled into 5-6m depending on different working shafts.

3. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1 is characterized in that: The single-hole single-shot technology means that each blast hole is equipped with an independent electronic detonator.

4. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1, characterized in that: The pre-splitting blasting holes are blasted before the vertical shaft stonework to form a pre-splitting vibration damping zone.

5. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1 is characterized in that: The delayed explosion time between blastholes in the open-cut section is 8-20ms, and the delayed explosion time between blasthole rows is 80-120ms.

6. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1, characterized in that: The tunnel section sets different intra-segment delays according to different blasthole types. The intra-segment delay time for slot holes, auxiliary holes, and bottom plate holes is 5ms, and the intra-segment delay time for peripheral holes is 2-4ms.

7. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1 is characterized in that: The openings of the peripheral holes are arranged at a distance of 10 cm from the excavation edge, deviated 3°-5° outward, and the bottom of the holes falls 10 cm-15 cm outside the design contour line.

8. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1, characterized in that: The slot holes are wedge-shaped, and each pair of slot holes gradually deepens, and the angle with the working surface gradually increases, and the intersection angle is 60°-80°; the slot holes are arranged 0.8-1.0m away from the bottom of the tunnel; the slot holes are 10-20cm deeper than the surrounding holes and auxiliary holes.

9. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1, characterized in that: The automated monitoring technology consists of monitoring sensors, data transmission modules, and data analysis and processing terminals. Monitoring sensors are deployed around the blasting area and on high-speed rail-related structures. Data is transmitted to the data analysis and processing terminal in real time through the data transmission module. When the displacement of the monitored target exceeds 3 mm or the vibration speed exceeds 1.7 cm / s, the emergency response procedure is initiated.

10. The micro-vibration blasting construction method adjacent to a high-speed railway operating line according to claim 1, characterized in that: The open-cut section working shaft adopts the shallow hole step electronic micro-vibration blasting method according to the environmental conditions, and the layered excavation height is selected from 1.0m to 2.5m.

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