A boulder static blasting intelligent cracking method and system based on reaction state feedback and a one-time multi-port synchronous water fracturing device

Abstract

The application discloses a kind of intelligent fracturing method and system of boulder static blasting based on reaction state feedback and disposable multi-port synchronous water fracturing device, it is related to rock breaking technical field in underground engineering and tunnel construction, method includes the digital signal of shield tunneling and / or drilling process is collected, filtering standardization and fusion score are carried out and mapping is obtained Boulder occurrence probability, output graded early warning information;Drill and pack static blasting agent, install disposable multi-port synchronous water fracturing device;Water injection channel and sensor initialization are realized, and synchronous water injection starts hydration expansion reaction;Real-time data acquisition constructs reaction state index;According to the deviation of reaction state index and expected reaction trajectory, adjust water injection parameters in closed loop, and can implement differentiated control guide crack directional extension;Reaction is completed to generate construction decision, solves the problem that boulder disposal detection relies on experience, reaction process black box, water injection is not synchronized, construction period is uncertain and cleavage direction is not controllable.

Description

Technical Field

[0001] This invention relates to the field of rock fracturing and underground engineering construction technology, and more specifically, to an intelligent fracturing method and system for static blasting of isolated boulders based on reaction state feedback, and a one-time multi-port synchronous water injection fracturing device. Background Technology

[0002] Static blasting technology (also known as static fracturing technology) relies on the reaction of an expanding agent with water to generate continuous expansion pressure, causing the rock to slowly fracture under vibration-free and low-noise conditions. It has become an important method for rock treatment in sensitive urban areas and complex geological environments. In tunnel excavation, especially shield tunneling, high-strength boulders exposed at the tunnel face often become key obstacles restricting project progress and safety. Static blasting, due to its safety, has become one of the preferred methods for dealing with such boulders.

[0003] However, traditional static blasting still faces a series of unresolved technical bottlenecks in practical applications: Traditional construction methods often involve drilling, filling the borehole with explosives, and then injecting water once or relying on natural seepage. However, the hydration reaction state within the borehole cannot be monitored in real time. Due to factors such as uneven agent compaction, differences in borehole fracture distribution, groundwater interference, and the self-accelerating effect of hydration heat release, the reaction processes in different boreholes, and even within the same borehole along the depth direction, are often severely asynchronous. This frequently results in the upper part of the reaction completing before the lower part has even started, or localized overheating leading to "burnt-out" failure. This asynchrony prevents the expansion pressure from effectively superimposing in time and space, severely impacting the fracturing effect and block size control. Traditional methods rely on construction experience to estimate cracking time, but the actual reaction time fluctuates greatly (from several hours to tens of hours), making precise scheduling difficult. Lacking means to perceive the internal reaction state, operators can only passively observe surface phenomena and cannot actively intervene or optimize. The expansion force generated by traditional static blasting is released radially and uniformly, and the direction of crack propagation is highly random. In situations requiring avoidance of nearby important structures or directional fracturing, the lack of effective guidance and control methods leads to construction risks and uncertainties in the results.

[0004] To improve reaction uniformity, the industry has attempted "segmented water injection" methods such as layered charging and pre-embedding multiple permeable pipes. These methods are essentially open-loop control, meaning that water injection is performed according to a preset time or sequence. However, because the actual reaction status of each segment cannot be perceived in real time, when a segment experiences abnormal reactions due to geological or environmental factors, the preset program cannot adaptively adjust, making it difficult to achieve synchronous reaction throughout the borehole, and the construction process remains in a "black box" state.

[0005] Therefore, there is an urgent need in this field for a new static blasting technology that can achieve closed-loop control of perception, decision-making, and regulation. By monitoring the reaction status in real time and dynamically adjusting the water injection parameters, it can overcome the core problems of asynchronous reaction, uncontrollable process, and random pyrolysis direction, thereby improving the reliability, efficiency, and engineering adaptability of static blasting in the treatment of isolated boulders. Summary of the Invention

[0006] This invention aims to overcome at least one of the defects of the prior art and provides a method and system for intelligent fracturing of isolated boulders based on reaction state feedback, as well as a one-time multi-port synchronous water injection fracturing device, to solve the problems of asynchronous reaction, uncontrollable process, random fracturing direction, and uncertain construction period in the prior art.

[0007] The technical solution adopted in this invention is a smart fracturing method for static blasting of isolated boulders based on reaction state feedback, which mainly includes the following steps: S0: Isolated rock identification and early warning; S101: Installation of drilling and simultaneous multi-port water injection fracturing device at the working face; S102: Channel activation and sensor initialization; S103: Simultaneous water injection initiates the hydration and expansion reaction; S104: Real-time monitoring of multi-parameter reaction status and construction of reaction status indicators; S105: Closed-loop synchronous control based on reaction state indicators; S106: Differentiated regulation of directional fracture control; S107: Reaction completion determination, effect evaluation, and construction decision-making.

[0008] In step S0, the data acquisition and intelligent control unit acquires digital signals of thrust, torque, drive current, penetration depth, vibration, and / or acoustic emission during the shield tunneling and / or drilling process. For the digital signal Perform sliding filtering to obtain Based on baseline mean with standard deviation Standardization is performed to obtain the standardized dimensionless signal. ; through dimensionless signals Calculate its rate of change The absolute value of a dimensionless signal With the absolute value of the rate of change By weighting factor , The fusion anomaly score S(t) is obtained through fusion; and the probability of isolated rock occurrence is obtained through a logistic mapping function:

[0009] In the formula: P(t) is the probability of a boulder occurring (0~1); exp(·) is the exponential function; k is the probability mapping scale coefficient; and b is the probability mapping bias term. When the probability of an isolated rock occurring, P(t), exceeds the threshold and continues to meet the preset time window, a graded early warning message W(t) is output, and the subsequent static blasting fracturing treatment process is triggered.

[0010] In step S101, after the working face exposes the isolated rock, multiple water injection fracturing holes / blasting holes are drilled on the surface of the isolated rock according to the expected fracturing direction and static blasting agent is filled into the holes; a disposable multi-hole synchronous water injection fracturing device is inserted into the hole for positioning or attached to the hole opening area and aligned with the hole opening. The water inlet end of the device is connected to the water supply execution unit through a quick-connect connector to ensure that multiple holes / multi-zones can supply water at the same time.

[0011] In step S102, low-pressure water is injected into the main water circuit of the device to pre-flush the internal pipeline and to destroy or dissolve the destructible sealing membrane / isolation layer at the water inlet to open the water injection channel; at the same time, the zero-point calibration and baseline data acquisition of the temperature, pressure, acoustic emission and / or conductivity sensors are completed to provide a reference for subsequent reaction identification and judgment.

[0012] In step S103, water is supplied to the main water circuit of the device through a single water inlet, so that multiple branch water inlets can simultaneously output water and inject water into the explosive agent at multiple points, quickly and evenly wetting the explosive agent and initiating the hydration expansion reaction; wherein, each branch channel can adopt equivalent hydraulic impedance, pressure equalization chamber and / or flow limiting device design to achieve flow balance under parallel water supply.

[0013] In step S104, temperature, pressure, acoustic emission signal and / or conductivity data of each hole / water injection zone are collected in real time, and a reaction state index (reaction intensity index) is constructed based on the data to characterize the degree of hydration reaction advancement, abnormal temperature / pressure and crack activity characteristics.

[0014] In step S105, the reaction status indicators of each hole / section are compared with the preset expected reaction trajectory. Based on the deviation, the water injection pressure, flow rate, pulse water injection duty cycle and / or water injection sequence are dynamically adjusted to synchronize the hydration reaction process of multiple holes / sections. In case of overheating, abnormal pressure or reaction lag, safety control such as water replenishment, pressure reduction or start-up and shutdown is achieved.

[0015] In step S106, based on the expected crack propagation direction, different desired reaction trajectories are configured for holes with different spatial orientations or different water injection zones to form a reaction rate difference or peak difference, thereby guiding the cracks to preferentially propagate in the predetermined direction and achieving controllable pyrolysis.

[0016] In step S107, when all reaction state indicators exceed their peak values ​​and enter the decay stage, or when characteristics such as pressure release and acoustic emission event decay that characterize cracking appear, the reaction is determined to be complete and a completion signal is output; and the pyrolysis effect is evaluated based on the full-process monitoring data to guide the cessation of water injection, slag removal and subsequent shield / excavation construction.

[0017] The method introduces boulder identification and early warning before the fracturing process, and implements multi-parameter monitoring and closed-loop control of the static blasting reaction process. It integrates borehole water injection fracturing, multi-sensor real-time monitoring, closed-loop feedback control and directional crack guidance technology to realize the perception, controllability and intelligence of the static blasting process. It is especially suitable for the refined and controllable fracturing construction of boulders at the working face in underground engineering such as tunnels and roadways.

[0018] Furthermore, the one-time multi-port synchronous water injection fracturing device includes a main water pipe and its main water path, branch water injection channels and branch water injection ports, and achieves flow balance of each branch water injection port under parallel water supply through equivalent hydraulic impedance, pressure equalization chamber and / or flow limiting device.

[0019] In actual fracturing operations, different branch injection ports may have varying flow resistances due to factors such as location and pipe length. Without flow equalization, some injection ports will have high flow rates while others will have low flow rates. This will result in uneven fracturing effects, affecting the overall quality and efficiency of the fracturing operation. By using equivalent hydraulic impedance, pressure equalization chambers, and / or flow restrictors, the flow rates of each branch injection port are ensured to remain balanced when multiple ports are injected simultaneously.

[0020] Furthermore, the outer shell of the one-time multi-port synchronous water injection fracturing device is provided with a crack induction weak zone. The material of the outer shell is a destructible material, so that when the expansion pressure of the static blasting agent reaches the threshold, the outer shell cracks and transmits the pressure to the borehole wall rock mass.

[0021] The design of the crack-inducing weak zone guides the shell to crack under specific conditions. When the pressure generated by the expansion of the static explosive reaches a threshold, the shell will crack in the weak zone. This allows for precise control of the pressure release direction and method, effectively transmitting pressure to the borehole wall rock mass, thereby achieving fracturing of the isolated rock. The shell and pipelines of the disposable multi-port synchronous water injection fracturing device, which are in direct contact with water / explosive, are disposable consumables, while the water supply pump valve and data acquisition and control unit are reusable.

[0022] Furthermore, the reaction state index is obtained by normalizing and weighting at least one or more of the following: the rate of temperature rise, the rate of pressure rise, the acoustic emission event rate, and / or the change in conductivity.

[0023] The normalization and weighted fusion approach can unify different indicators into a reasonable range and weight them according to their importance, making the reaction state indicators more scientific and accurate. This enables closed-loop control of the fracturing process and comprehensively and accurately reflects the reaction state of the static explosive.

[0024] Optionally, the reaction status monitoring includes at least one of temperature monitoring and pressure monitoring, and may further include acoustic emission monitoring and / or conductivity monitoring, with monitoring points located at the orifice of the fracture hole, the device casing, or the water injection pipeline. The closed-loop regulation employs one or more combinations of PID control, fuzzy control, and model predictive control. The reaction completion determination satisfies one or a combination of the following conditions: the reaction status index reaches a peak and then continuously decays; pressure release is detected and the pressure change rate is below a threshold within a preset time window; the acoustic emission event rate decays to below a threshold.

[0025] Another objective of this invention is to provide a smart fracturing system for static blasting of isolated rocks based on reaction state feedback for implementing the aforementioned method. The system includes a single-stage multi-port synchronous water injection fracturing device, a water supply execution unit, and a data acquisition and intelligent control unit. The water supply execution unit includes a water supply pump, a distribution manifold, and a valve assembly, used to supply water to the single-stage multi-port synchronous water injection fracturing device and regulate the injection pressure and flow rate. The data acquisition and intelligent control unit is electrically connected to temperature, pressure, acoustic emission, and / or conductivity sensors, used to construct reaction state indicators and output closed-loop control commands to regulate the water supply execution unit.

[0026] Furthermore, the data acquisition and intelligent control unit includes a processor, a memory, a control algorithm module, and a boulder identification and early warning module. The boulder identification and early warning module is used to perform fusion calculations on the thrust, torque, drive current, penetration depth, vibration, and / or acoustic emission digital signals during shield tunneling and / or drilling, and output graded early warning information to trigger the boulder disposal process. The control algorithm module is used to generate the desired reaction trajectory and implement differentiated control for different fracture holes or different water injection zones.

[0027] The system's data acquisition and intelligent control unit includes a boulder identification and early warning module and a reaction status monitoring and feedback control module. It can transform static blasting from experience-based construction into an intelligent fracturing process that is perceptible, predictable, identifiable, and controllable, thereby improving the efficiency, safety, and controllability of boulder handling.

[0028] Another objective of this invention is to provide a one-time multi-port synchronous water injection fracturing device, comprising a shell, a blasting agent containment chamber, a main water pipe and its main water passage, and multiple branch water injection channels and branch water injection ports connected to the main water passage; the branch water injection ports are used to inject water into the blasting agent containment chamber or fracturing borehole at multiple points; the shell is provided with a crack induction weak zone, and the shell is made of a destructible material, so that when the pressure generated by the hydration expansion of the blasting agent reaches a threshold, the shell cracks and transmits the pressure to the rock mass.

[0029] Furthermore, the main water channel and / or the branch water injection channels are provided with pressure equalization chambers, flow limiting devices, or equivalent hydraulic impedance structures to improve the consistency of synchronous water injection across multiple branches. Optionally, a destructible sealing membrane or isolation layer is provided at the branch water injection port to be broken during pre-flushing or water injection startup to open the water injection channel.

[0030] Furthermore, the outer surface of the outer shell is provided with a sealing serrated structure, which is distributed at intervals along the axial or circumferential direction of the device, and is used to form a mechanical engagement with the sealing material during the sealing process of the cracked hole.

[0031] By setting a sealing anchor tooth structure on the surface of the fracturing device shell and sealing the fracturing hole with fast-hardening cement, the mechanical interlocking between the sealing material and the device shell can be enhanced, effectively limiting the release of the blasting agent expansion pressure along the hole axis, so that the expansion pressure mainly acts radially towards the hole wall, thereby improving the static blasting energy utilization efficiency and enhancing the initiation and propagation effect of isolated rock cracks.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects: To address the challenges of static blasting of isolated boulders at the tunnel face in shield tunneling, such as one-time consumption of equipment, slow water injection startup, uneven water absorption of the blasting agent leading to asynchronous reactions, and the invisibility and difficulty in determining the completion time of the reaction process, this project transforms static blasting from an experience-based approach into a monitorable, assessable, and controllable fracturing process. By employing multi-port synchronous water injection and flow balancing design, the project accelerates blasting agent water absorption and reaction startup, improving the consistency of the reaction within the borehole. Multi-parameter monitoring and reaction status indicators enable visualization of the reaction process and determineable completion, reducing project timeline uncertainty. Closed-loop control and differentiated trajectory control achieve reaction synchronization and controllable fracturing direction, improving the efficiency, safety, and controllability of isolated boulder treatment. Attached Figure Description

[0033] Figure 1 This is a flowchart of the steps in Embodiment 1 of the present invention.

[0034] Figure 2 This is a schematic diagram of the application of Embodiment 2 of the present invention to a solitary rock.

[0035] Figure 3 This is a schematic diagram of the transverse arrangement of blasting holes for isolated boulders at the working face in Embodiment 2 of the present invention.

[0036] Figure 4 This is a three-dimensional exploded view of Embodiment 3 of the present invention.

[0037] Figure 5 This is a schematic diagram of the axial cross-sectional structure of Embodiment 3 of the present invention.

[0038] Figure 6 This is a schematic diagram of the hydration expansion reaction and cracking principle in Embodiment 3 of the present invention. Detailed Implementation

[0039] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1 like Figure 1 As shown, this embodiment is a smart fracturing method for static blasting of isolated boulders based on reaction state feedback, including the following steps: Step S101: Identification of Isolated Bodies and Construction Preparation. During the tunnel boring machine (TBM) advance, isolated boulders at the tunnel face are identified based on construction parameters, geological forecasts, or on-site monitoring; after confirmation, a borehole layout and construction parameter plan are formulated.

[0042] Step S102: Drilling and device installation. Drill water-injection fracturing holes on the surface of the boulder and fill the holes with static explosive; insert and position the pre-filled explosive multi-port synchronous water-injection fracturing device in the holes, and connect the water inlet end of the device to the water supply unit.

[0043] Step S103: Initialization and Channel Activation. Inject low-pressure water into the main water circuit of the device to pre-flush the internal pipelines and dissolve or break the destructible isolation layer on the outside of the device, and open the water injection channel; perform zero-point calibration and baseline data acquisition for the sensors in each hole.

[0044] Step S104: Synchronous water injection to initiate the reaction. Start-up water is simultaneously injected into each orifice via the water supply unit, causing multiple branch water inlets to discharge water synchronously, promoting rapid and uniform water absorption by the explosive agent and initiating the hydration and expansion reaction.

[0045] Step S105: Real-time monitoring of multi-parameter reaction status. During the reaction process, reaction status data are collected in real time using temperature, pressure, acoustic emission, and / or conductivity sensors arranged in each orifice.

[0046] Step S106: Status Indicator Construction and Feedback Adjustment. Calculate reaction status indicators based on monitoring data; when overheating, abnormal pressure, or asynchronous reactions occur, issue adjustment commands such as water injection start / stop, water replenishment, or pressure reduction to the water supply unit to optimize the reaction process.

[0047] Step S107: Reaction Completion Determination and Construction Decision. When the reaction status indicators reach their peak and enter the decay stage, or when cracking characteristics such as pressure release and acoustic emission event decay occur, the reaction is determined to be complete and a completion signal is output; subsequently, slag removal is organized, and the tunnel boring machine continues excavation.

[0048] Before step S101, there is also a boulder identification and early warning step: Collect digital signals of thrust, torque, drive current, penetration depth, vibration, and / or acoustic emission during shield tunneling and / or drilling. For the digital signal Perform sliding filtering to obtain : (1-1) (1-2) Baseline mean based on normal surrounding rock conditions with standard deviation Standardize: (1-3) And calculate the rate of change: (1-4) Constructing a fusion anomaly score: (1-5) Map S(t) to the probability of an isolated rock occurring: (1-6) When P(t)≥ It will continuously output a level 1 warning for M time windows, when P(t)≥ It will continuously output a level-two warning for M time windows. > The warning level is recorded as: W(t)=Level(P(t))(1-7) In the formula: t is the time variable; Δt is the sampling time interval; i is the signal channel number, i=1,2,…,m; m is the total number of digital signal channels acquired; Let be the sampled value of the i-th original digital signal at time t; or The value is the smoothed value of the i-th signal after sliding filtering; N is the length of the sliding filter window; j is the sampling point index within the window, j=0,1,…,N 1; The filter weight coefficients are and satisfy the following conditions: ; The filter weight coefficients are and satisfy the following conditions: ; Let be the baseline mean value of the i-th signal under normal operating conditions; Let be the baseline standard deviation of the i-th signal under normal operating conditions; This is the standardized dimensionless signal; S(t) represents the rate of change of the standardized signal; S(t) represents the fusion anomaly score / comprehensive anomaly index. For the amplitude anomaly weighting coefficient, is the anomaly weighting coefficient for the rate of change; |·| is the absolute value operation; ∑ is the summation operation; P(t) is the probability of the occurrence of a boulder (0~1); exp(·) is the exponential function; k is the probability mapping scaling coefficient, and b is the probability mapping bias term; The threshold for Level 1 warning is... The threshold for Level II warning and > M is the number of continuous windows; W(t) is the warning output information / warning level result; Level(·) is the warning level mapping function, used to map P(t) to the preset warning level and corresponding text / control instructions.

[0049] This method is applicable to safe and efficient crushing operations when encountering large, high-strength boulders at the working face during the construction of tunnels, underground caverns, and similar underground projects. These boulders are typically embedded in the surrounding rock, are irregular in size, have hard rock properties, and are located in confined spaces, making conventional mechanical crushing or traditional blasting methods unsuitable.

[0050] During the tunnel boring machine's excavation process, isolated boulders or suspected isolated boulders can be identified through monitoring construction parameters such as cutterhead torque, penetration depth, and propulsion resistance, as well as through advanced geological forecasting and / or tunnel face inspection. Once an isolated boulder is confirmed to be exposed at the tunnel face, a drilling layout and equipment installation plan are formulated according to the size of the boulder and the requirements for breaking it.

[0051] Example 2 like Figure 2 and 3As shown, this embodiment is an intelligent fracturing system for static blasting of isolated boulders based on reaction state feedback. It mainly consists of three parts: a one-time multi-hole synchronous water injection fracturing device, a water supply execution unit, and a data acquisition and intelligent control unit. The one-time multi-hole synchronous water injection fracturing device is installed inside the boulder borehole to complete synchronous water injection, hydration and expansion of the blasting agent, and pressure transmission fracturing within the borehole. The water supply execution unit is located in a safe area behind the working face to provide unified or branched water supply conditions to each borehole device and to perform actions such as water injection start / stop / replenishment / pressure reduction. The data acquisition and intelligent control unit is electrically connected to temperature, pressure, acoustic emission, and / or conductivity sensors to construct reaction state indicators and output closed-loop control commands to adjust the water supply execution unit. It monitors and processes reaction state data, identifies reaction initiation, fracturing characteristics, and completion status, and outputs construction prompts and completion signals.

[0052] The data acquisition and intelligent control unit includes a processor, a memory, a control algorithm module, and a boulder identification and early warning module. The boulder identification and early warning module takes multi-source digital signals as input and converts "parameter mutations / anomalies" into quantifiable boulder occurrence probabilities and graded early warning information. One implementation includes: performing sliding filtering, standardization, rate of change extraction, and fusion scoring on each signal, and mapping the fusion score to a boulder probability; when the boulder probability meets the threshold and continuous window conditions, an early warning level is output, and the subsequent drilling and static blasting fracturing treatment process is triggered simultaneously.

[0053] During construction, once boulders are exposed at the working face, the working surface is first cleaned and the fracturing range and block size requirements are determined. Subsequently, based on the size of the boulders, lithology, and the dimensions of the device, several water-injection fracturing holes are drilled on the surface of the boulders. The borehole diameter and depth are selected to match the external dimensions of the device, ensuring that the outer shell of the device is in close contact with the borehole wall after insertion and can maintain stable positioning within the borehole.

[0054] After drilling is completed, the pre-loaded static explosive agent multi-hole synchronous water injection fracturing device is inserted and positioned hole by hole. The water inlet of the device is connected to the water supply execution unit via a quick-connect connector, and the sensor / data cable (or wireless monitoring node) is connected to the data monitoring and status determination unit. Then, the water supply to multiple holes is turned on at the same time, so that multiple branch water injection ports of the main water circuit of each device can output water simultaneously, and quickly start the hydration and expansion reaction of the explosive agent.

[0055] As the reaction progresses, the hydration expansion pressure generated by the static blasting agent is transmitted to the borehole wall rock mass through the fracturing shell, inducing rock mass cracking. The data monitoring and status determination unit identifies the reaction stage, cracking characteristics, and completion status based on multi-parameter monitoring results. After the completion criteria are met, a completion signal is output, prompting the cessation of water injection, the clearing of broken blocks, and the organization of the tunnel boring machine to continue excavation. After the reaction is completed, the simultaneous multi-hole water injection fracturing device can be left inside the borehole or cleared and transported off-site along with the broken blocks, depending on site requirements.

[0056] Before the hydration reaction is officially started, the system first enters the initialization phase. The water supply unit delivers low-pressure water to the main water circuit of the intelligent water injection fracturing device to pre-flushing the internal pipelines of the device, while simultaneously causing the destructible isolation layer on the outside of the device to dissolve or rupture, so that the water injection nozzles can fully contact the rupture agent.

[0057] Simultaneously, the multi-parameter sensing modules within each well begin operating, and the data monitoring and status determination unit performs zero-point calibration and baseline data monitoring on each sensor, establishing an initial state database before the reaction. This baseline data serves as a crucial reference for subsequent judgments regarding reaction initiation, cracking event identification, and completion status determination.

[0058] After initialization, the water supply unit simultaneously injects the preset starting water volume into each orifice device, and the static explosive agent begins to undergo a hydration and expansion reaction after absorbing water. As the reaction proceeds, the internal temperature of the explosive agent gradually increases, the expansion pressure continuously accumulates, and microcracks are generated and propagated, acoustic emission events gradually increase, and the electrical conductivity also changes with the degree of reaction.

[0059] The multi-parameter sensing module continuously monitors the aforementioned reaction state data at a set sampling frequency and transmits it to the data monitoring and status determination unit in real time. Through comprehensive analysis of multi-source data, the system can dynamically reflect the actual progress of the hydration reaction in each pore.

[0060] The data monitoring and status determination unit calculates reaction status indicators based on the monitored temperature, pressure, acoustic emission and / or conductivity data, and judges the reaction stage in combination with threshold and trend characteristics. When overheating, abnormal pressure or individual orifice reaction lag occurs, it can send feedback adjustment commands such as water injection start / stop, water replenishment or pressure reduction to the water supply execution unit to ensure construction safety and reduce invalid waiting time.

[0061] By synchronously monitoring the reaction status of multiple pores, the consistency of the multi-pore reaction can be evaluated. When the monitoring shows that the indicators of each pore enter the same stage and show similar peak values ​​and decay trends, it can be considered that the static blasting reaction is relatively synchronous, which is conducive to the effective superposition of expansion energy in the boulder and the formation of a stable crushing effect.

[0062] During the reaction process, a rapid increase in pressure accompanied by a sudden increase in the density of acoustic emission events usually corresponds to crack initiation and propagation; when a significant release of pressure is detected (sudden drop or change from rising to stabilizing) and the acoustic emission events gradually decay, it can be used as a characteristic signal that the boulder is cracking and entering the later reaction stage.

[0063] Example 3 like Figure 4 and 5 As shown, this embodiment is a disposable multi-port synchronous water injection fracturing device, preferably an in-hole installed disposable fracturing cylinder / plug structure, which is inserted entirely into a pre-drilled water injection fracturing hole to complete the entire process of water injection-hydration expansion-pressure transmission-fracturing within the hole. This device does not rely on a hole-mouth sealing structure, but mainly relies on the contact between the device shell and the hole wall to transmit the expansion pressure to the rock mass.

[0064] The device includes a fracturing outer shell, a blasting agent containment chamber located inside the fracturing outer shell, a static blasting agent filled in the containment chamber, a main water pipe disposed within the containment chamber, and multiple branch water injection channels connected to the main water pipe. The main water pipe is arranged along the axial direction of the device, and the branch water injection channels are distributed axially and / or radially to form multiple branch water injection ports; each branch water injection port is arranged facing the blasting agent space to achieve simultaneous water output from multiple points and rapid and uniform wetting of the blasting agent during water injection.

[0065] To ensure that multiple branch injection points can simultaneously discharge water and provide approximately balanced water supply from a single inlet, the branch injection channels can employ an equivalent hydraulic impedance design. This can be achieved by ensuring that the length and cross-section of each branch channel are consistent with the throttling structure, or by installing microporous throttling devices / flow-limiting orifice plates / pressure equalization chambers at each branch injection point. This avoids the problems of localized early reaction and delayed reaction in other areas caused by traditional single-point injection, thereby significantly accelerating the reaction start-up rate and improving the consistency of the reaction within the orifice.

[0066] Considering that the expansion pressure of the static explosive agent needs to effectively act on the borehole wall rock mass, the crackable shell should not be made of materials with excessively high stiffness or strength; preferably, a shell material with medium strength, relatively low elastic modulus, and controllable cracking should be used, and axial or circumferential crack-inducing weak zones (such as thinning grooves, notches, or weak interfaces of interlayers) should be set on the outer periphery of the shell. When the explosive agent absorbs water and expands, generating pressure that reaches a set threshold, the shell cracks along the weak zone and releases the pressure to the borehole wall, thereby promoting the formation and propagation of cracks in the rock mass; the device is retained as a disposable consumable or removed and discarded after the reaction is completed.

[0067] To further improve the effective utilization rate of the blasting agent's expansion pressure on the rock mass, a circumferentially or spirally distributed sealing serrated structure is provided on the outer surface of the fracturing shell. This serrated structure is spaced apart along the axial direction of the device and is used to form a mechanical interlocking action with the sealing material after the device is inserted into the fracturing hole.

[0068] After the device is installed, the borehole is sealed by filling the orifice area with quick-setting cement or other high-strength sealing materials. During the solidification process, the sealing material fills the spaces between the serrated structures, thereby significantly improving the bonding strength and anti-slip capability between the sealing material and the device casing.

[0069] The above structural design effectively limits the pressure release along the axial direction of the fracture pore during the hydration and expansion of the explosive agent, allowing the expansion pressure to be mainly transmitted radially to the pore wall. This improves the initiation efficiency and propagation capability of cracks inside boulders, and enhances the directionality and energy utilization efficiency of static blasting fracture.

[0070] like Figure 6 As shown, the water supply enters the main water pipe from the inlet of the device and is distributed to multiple branch water inlets, supplying water to the blasting agent simultaneously at multiple points, causing the blasting agent to quickly absorb water and undergo a hydrothermal expansion reaction; the expansion pressure accumulates in the crackable shell and causes the shell to crack along the weak area of ​​the shell, and the pressure is transmitted to the rock mass of the borehole wall through the crack interface, thereby inducing the isolated rock to generate cracks and expand and break.

[0071] As the hydration reaction continues, the reaction status indicators of each pore gradually reach their peak and enter the decay stage. The data monitoring and status determination unit combines the temperature drop trend, pressure release, and acoustic emission event density changes to determine the completion status of the reaction and outputs a "complete / cleanable" signal.

[0072] After the reaction is completed, the system can generate construction parameters and reaction history records based on the full process monitoring records, providing a reference for setting the hole layout and water injection parameters under similar working conditions in the future; after the slag is cleared, the tunnel boring machine continues to excavate through the isolated rock section.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A smart fracturing method for static blasting of isolated boulders based on reaction state feedback, characterized in that, Includes the following steps: S101: Drill at least one fracturing hole on the exposed boulder at the tunnel face in the expected fracturing direction, fill the fracturing hole with static explosive, and install an attached, disposable, multi-port synchronous water injection fracturing device in the fracturing hole. The disposable, multi-port synchronous water injection fracturing device is connected to the water supply execution unit. S102: Pre-flushing and activating the main water circuit of the one-time multi-port synchronous water injection fracturing device, and simultaneously initializing and collecting baseline data of temperature, pressure, acoustic emission and / or conductivity sensors; S103: Supply water to the main water channel so that multiple branch water inlets simultaneously inject water into the fracturing hole to initiate the hydration and expansion reaction of the static explosive agent. S104: Real-time acquisition of temperature, pressure, acoustic emission and / or electrical conductivity data during the reaction process, and construction of reaction state indicators characterizing the degree of reaction advancement and crack activity; S105: Based on the deviation between the reaction state index and the preset expected reaction trajectory, the water injection pressure, water injection flow rate, pulse water injection duty cycle and / or water injection sequence are adjusted in a closed loop to keep the reaction process of multiple rupture holes or multiple water injection zones synchronized, and water replenishment, pressure reduction or water stoppage is performed in case of abnormality. S106: Based on the expected crack propagation direction, set differentiated expected response trajectories for crack-inducing pores in different spatial orientations or different water injection zones and implement differentiated control to guide the directional propagation of cracks. S107: When the reaction status index exceeds the peak and enters the decay stage, and / or cracking characteristics of pressure release and acoustic emission event decay appear, the reaction is determined to be completed and a control command is output to evaluate the cracking effect and generate a construction decision.

2. The intelligent fracturing method for static blasting of isolated boulders based on reaction state feedback according to claim 1, characterized in that, Before step S101, there is also a boulder identification and early warning step: Collect digital signals of thrust, torque, drive current, penetration depth, vibration, and / or acoustic emission during shield tunneling and / or drilling. For the digital signal Perform sliding filtering to obtain Based on baseline mean with standard deviation Standardization is performed to obtain the standardized dimensionless signal. ; through dimensionless signals Calculate its rate of change The absolute value of a dimensionless signal With the absolute value of the rate of change By weighting factor , The fusion anomaly score S(t) is obtained through fusion; and the probability of isolated rock occurrence is obtained through a logistic mapping function: In the formula: P(t) is the probability of a boulder occurring (0~1); exp(·) is the exponential function; k is the probability mapping scale coefficient; and b is the probability mapping bias term. When the probability of an isolated rock occurring, P(t), exceeds the threshold and continues to meet the preset time window, a graded early warning message W(t) is output, and the subsequent static blasting fracturing treatment process is triggered.

3. The intelligent fracturing method for static blasting of isolated boulders based on reaction state feedback according to claim 1, characterized in that, The one-time multi-port synchronous water injection fracturing device includes a main water pipe and its main water path, branch water injection channels and branch water injection ports, and achieves flow balance of each branch water injection port under parallel water supply through equivalent hydraulic impedance, pressure equalization chamber and / or flow limiting device.

4. The intelligent fracturing method for static blasting of isolated boulders based on reaction state feedback according to claim 1, characterized in that, The outer shell of the one-time multi-port synchronous water injection fracturing device is provided with a crack induction weak zone. The material of the outer shell is a destructible material, so that when the expansion pressure of the static explosive reaches the threshold, the outer shell cracks and transmits the pressure to the rock mass of the borehole wall.

5. The intelligent fracturing method for static blasting of isolated boulders based on reaction state feedback according to claim 1, characterized in that, The reaction state index is obtained by normalizing and weighting at least one or more of the following: rate of temperature rise, rate of pressure rise, acoustic emission event rate, and / or change in conductivity.

6. A smart fracturing system for static blasting of isolated boulders based on reaction state feedback, used to implement the method described in any one of claims 1-5, characterized in that, The device includes a single-use multi-port synchronous water injection fracturing device, a water supply execution unit, and a data acquisition and intelligent control unit. The water supply execution unit includes a water supply pump, a distribution manifold, and a valve group, used to supply water to the single-use multi-port synchronous water injection fracturing device and regulate the water injection pressure and flow rate. The data acquisition and intelligent control unit is electrically connected to temperature, pressure, acoustic emission, and / or conductivity sensors, used to construct reaction status indicators and output closed-loop control commands to regulate the water supply execution unit.

7. The intelligent fracturing system for static blasting of isolated boulders based on reaction state feedback according to claim 6, characterized in that, The data acquisition and intelligent control unit includes a processor, a memory, a control algorithm module, and a boulder identification and early warning module. The boulder identification and early warning module is used to fuse and calculate the thrust, torque, drive current, penetration depth, vibration, and / or acoustic emission digital signals during shield tunneling and / or drilling, and output graded early warning information to trigger the boulder disposal process. The control algorithm module is used to generate the desired reaction trajectory and implement differentiated control for different fracture holes or different water injection zones.

8. A one-time multi-port synchronous water injection fracturing device, characterized in that, It includes an outer shell, a blasting agent containment chamber, a main water pipe and its main water passage, as well as multiple branch water injection channels and branch water injection ports connected to the main water passage; the branch water injection ports are used to inject water into the blasting agent containment chamber or the fracture-inducing pore at multiple points; the outer shell is provided with a crack-inducing weak zone, and the outer shell is made of a destructible material, so that when the pressure generated by the hydration expansion of the blasting agent reaches a threshold, the outer shell cracks and transmits the pressure to the rock mass.

9. The single-use multi-port synchronous water injection fracturing device according to claim 8, characterized in that, The main waterway and / or the branch water injection channels are equipped with pressure equalization chambers, flow limiting devices, or equivalent hydraulic impedance structures to improve the consistency of synchronous water injection in multiple branches.

10. The single-use multi-port synchronous water injection fracturing device according to claim 8, characterized in that: The outer surface of the outer shell is provided with a sealing serrated structure, which is distributed at intervals along the axial or circumferential direction of the device, and is used to form a mechanical engagement with the sealing material during the sealing process of the cracked hole.

Images