A small interval cavern group blasting vibration intelligent early warning and collaborative excavation control method

Abstract

The application belongs to the technical field of geotechnical engineering blasting construction and underground cavern group excavation control, and provides a small interval cavern group blasting vibration intelligent early warning and collaborative excavation control method. The method simultaneously determines the blasting construction parameters and the cavern group excavation timing parameters under the unified collaborative control framework, utilizes the blasting vibration numerical analysis model and the multi-objective optimization algorithm, comprehensively weighs the cavern group structure stability, the blasting vibration control effect and the engineering construction efficiency, obtains the collaborative optimization design scheme, and combines the real-time monitoring data of the blasting vibration and the cavern surrounding rock deformation in the construction process to perform feedback correction. The method introduces the construction whole process monitoring data, constructs the blasting vibration early warning model based on the intelligent algorithm, dynamically adjusts the blasting parameters and the excavation timing according to the actual working conditions, and significantly improves the safety and the construction efficiency of the small interval cavern group excavation.

Description

Technical Field

[0001] This application belongs to the field of geotechnical engineering blasting construction and underground cavern excavation control technology, specifically, it relates to a method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing cavern groups. Background Technology

[0002] Small-spacing cavern complexes are a type of dense underground structure widely used in engineering fields such as water conservancy and hydropower, transportation tunnels, and underground mines. Due to their small net distance between adjacent caverns and compact spatial arrangement, the surrounding rock exhibits a significant spatial coupling effect, making construction safety management far more challenging than in conventional single-cave projects. Blasting, as the core excavation method in such projects, generates vibration waves that propagate and amplify between adjacent caverns, easily causing the expansion of rock fissures and deformation and damage to the support structure. In severe cases, this can lead to cavern instability and collapse. Furthermore, it may cause vibration hazards to existing underground structures and surface buildings. Therefore, precise control of blasting vibrations and ensuring the stability of the surrounding rock structure of the cavern complex are the core management points for the construction of small-spacing cavern complexes.

[0003] In current blasting excavation construction of small-spacing cavern groups, blasting parameter design is mostly geared towards optimizing the effect of single-hole blasting, focusing on adjusting local parameters such as single-hole charge amount and detonation network. It generally fails to adequately consider the cumulative effect of blasting vibrations between cavern groups. Vibration control precision is difficult to adapt to the safety requirements of small-spacing conditions, easily leading to cumulative damage to the surrounding rock of adjacent caverns, cracking of the support structure, and a decrease in the overall stability of the cavern group. Furthermore, the formulation of cavern excavation sequence and support schemes relies heavily on engineering experience, which is disconnected from the dynamic characteristics of blasting construction and lacks a coordinated mechanism. This easily leads to problems such as improper connection between blasting and excavation procedures and untimely support follow-up, failing to effectively ensure the stability of the surrounding rock structure and easily resulting in low construction efficiency and construction safety issues. Summary of the Invention

[0004] To address the aforementioned technical challenges, achieve precise coordination between blasting vibration control and tunnel excavation, balance surrounding rock stability and construction efficiency, and enhance the scientific nature, safety, and overall benefits of the project, this application provides a method for intelligent early warning and coordinated excavation control of blasting vibration in small-spacing tunnel groups.

[0005] In one approach, a method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups includes the following steps: S1. Obtain basic geological and engineering condition data of the target small-spacing cavern group through on-site geological survey, indoor rock and soil dynamics test, three-dimensional seismic exploration and numerical simulation inversion.

[0006] S2. Set the blasting vibration control target and the cavern group structural stability target, and define the collaborative design variables that characterize the timing of blasting construction and cavern group excavation.

[0007] S3. With the goal of quantifying the superposition effect of vibration in small-spacing cavern groups, a closed-loop numerical analysis model of blasting vibration is constructed through theory, simulation, and inversion. Cooperative design variables and stress parameters of soil and original rock are input into the numerical analysis model of blasting vibration. The correlation index between the blasting vibration response of the cavern group and the stability of the surrounding rock under the calculated working conditions is then used to perform multi-objective optimization solution.

[0008] S4. Based on the advantageous strategy obtained from the solution, and on the basis of the blasting control measures and excavation support measures, formulate a collaborative construction plan that covers the zoning of the cavern group, the layering and segmentation of blasting, the connection of excavation sequence, and the follow-up of support.

[0009] S5. Deploy an intelligent monitoring and sensing network in the blasting excavation area to collect monitoring data on blasting vibration velocity, surrounding rock displacement, stress and strain, and blasting shock wave of the target small-spaced cavern group during excavation construction, and evaluate the impact of blasting vibration of the cavern group and the stability of the surrounding rock structure in real time.

[0010] S6. When any indicator of the monitoring data deviates from the target value or reaches the warning threshold, under the basic configuration constraints of blasting control measures and excavation support measures, the blasting vibration numerical analysis model adjusts the collaborative design variables and generates corresponding control strategies through parameter inversion, guiding operators to dynamically adjust the collaborative control of blasting and excavation.

[0011] Furthermore, in step S1, the basic geological and engineering condition data include the geometric parameters of the cavern group, the physical and mechanical parameters of the rock and soil, the hydrogeological conditions, and the distribution characteristics of the original rock stress field.

[0012] Furthermore, in step S2, the blasting vibration control targets include ensuring that the peak velocity of blasting vibration and the blasting shock wave pressure of the surrounding rock of the cavern and adjacent caverns meet the design requirements; the structural stability targets of the cavern group include ensuring that the convergence deformation of the surrounding rock of the cavern, the range of the plastic zone, and the stress of the support structure meet the design requirements.

[0013] Furthermore, in step S2, the collaborative design variables include blasting construction parameters and excavation timing parameters.

[0014] Among them, the blasting construction parameters include at least the spacing between blast holes, the resistance line, the amount of explosive charge, the detonation time difference, and the diameter of the blast holes; the excavation sequence parameters include at least the excavation spacing between caverns, the thickness of each excavation layer, the interval between excavations of adjacent caverns, and the support follow-up distance.

[0015] Furthermore, in step S3, the construction logic of the numerical analysis model for blasting vibration is as follows: A theoretical model was established based on the extended Sadovsky formula. A three-dimensional numerical model was constructed using LS-DYNA to simulate blasting loads and wave propagation. The parameters were corrected by inverting measured data through particle swarm optimization algorithm. Then, the blasting vibration control target, the surrounding rock stability target, and the construction efficiency target were integrated into the NSGA-Ⅲ optimization framework and solved by a non-dominated sorting multi-objective optimization algorithm to achieve collaborative decision-making between blasting parameters and safety thresholds.

[0016] Furthermore, during the multi-objective optimization algorithm solution process, the following constraints are imposed on candidate solutions: The peak velocity of blasting vibration in the surrounding rock of the cavern complex shall not exceed the preset vibration limit; the convergence deformation of the surrounding rock shall not exceed the preset deformation limit; the range of the plastic zone of the surrounding rock shall not exceed the preset control range; and the interval between excavations of adjacent caverns shall not be less than the preset safe time threshold.

[0017] Furthermore, in step S5, the deployment of the intelligent monitoring and sensing network includes: Blasting vibration sensors were installed at the working face, perimeter walls, and free surfaces of adjacent caverns in the small-spacing cavern complex; rock displacement monitoring points were installed at the cavern arch, sidewalls, and floor slab, with each displacement point monitored using a combination of a total station and a joint gauge; stress-strain sensors were installed at the interface between the initial support anchor bolts and the shotcrete to monitor stress changes in the support structure.

[0018] Furthermore, in step S6, the control measures for adjusting the collaborative design variables and generating corresponding blasting parameter adjustments, excavation sequence optimization, and support reinforcement in the numerical analysis model of blasting vibration include: Based on the monitored peak velocity of blasting vibration, the amount of surrounding rock convergence deformation, the range of the plastic zone, and the construction period data, determine whether they exceed or fall below the corresponding thresholds in the preset vibration limit, deformation limit, plastic zone control range, and construction period target value, respectively.

[0019] When any indicator triggers the threshold condition, the collaborative design variables are re-solved to generate adjustment measures including borehole charge, detonation time difference, excavation interval, and local support reinforcement method. The adjustment measures are then fed back to relevant personnel in a tiered early warning system to guide on-site construction implementation.

[0020] The beneficial effects of this application are: This application constructs a unified collaborative control framework, incorporating blasting construction parameters and tunnel excavation sequence parameters into the same multi-objective optimization system. By combining blasting vibration numerical analysis and multi-objective optimization algorithms for comprehensive solution, an optimal balance can be achieved between tunnel group structural stability, blasting vibration control, and construction efficiency, thereby improving the scientific and rational nature of the scheme design. At the same time, real-time monitoring data of blasting vibration and surrounding rock deformation throughout the construction process are introduced, and blasting parameters, excavation sequence, and support measures are dynamically adjusted according to the actual on-site conditions. This effectively reduces the superimposed vibration effects between tunnel groups, fully ensures the safety of the surrounding rock structure, optimizes process connections, and improves overall construction efficiency. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic flowchart of a method for intelligent early warning and collaborative excavation control of blasting vibration in a small-spacing cavern group according to an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0025] In one embodiment, please refer to Figure 1 A method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups includes the following steps: Step S1: Obtain basic geological and engineering condition data of the target small-spacing cavern group through on-site geological survey, indoor rock and soil dynamics test, three-dimensional seismic exploration and numerical simulation inversion.

[0026] In this step, the basic geological and engineering condition data include geometric parameters of the cavern group such as cavern span, height, net distance between caverns, and burial depth; physical and mechanical parameters of the soil and rock such as cohesion, internal friction angle, elastic modulus, wave velocity, and dynamic Poisson's ratio; hydrogeological conditions such as groundwater level and rock permeability coefficient; and the distribution characteristics of the original rock stress field such as the magnitude and direction of the maximum and minimum stresses.

[0027] Step S2: Set the blasting vibration control target and the cavern group structural stability target, and define the collaborative design variables that characterize the timing of blasting construction and cavern group excavation.

[0028] In this step, the blasting vibration control targets include ensuring that the peak velocity of blasting vibration and the blasting shock wave pressure in the surrounding rock of the cavern and adjacent caverns meet design requirements; the structural stability targets of the cavern group include ensuring that the convergence deformation of the surrounding rock, the range of the plastic zone, and the stress of the support structure meet design requirements. Based on the basic geological and engineering condition data and the above targets, a comprehensive evaluation index system for small-interval cavern groups can be established to classify different blasting vibration risk levels and surrounding rock stability control difficulty levels.

[0029] Furthermore, based on the blasting vibration risk level, the difficulty level of surrounding rock stability control, and basic geological and engineering conditions, the basic configuration of blasting control measures and excavation support measures can be selected. Blasting types include smooth blasting, pre-splitting blasting, and millisecond delay blasting; excavation support types include bench excavation, CD method excavation, advanced anchor bolt support, shotcrete-mesh initial support, and secondary lining. Simultaneously, the material and parameter requirements of core components in each scheme are clearly defined: high-velocity, low-brittle emulsion explosives are preferred for blasting materials, and high-precision digital detonators are used for initiation devices; high-strength threaded steel anchor bolts and high-toughness shotcrete are used for support structures to ensure the vibration resistance and load-bearing capacity of the support structure.

[0030] As a preferred implementation method, for cavern groups with high blasting vibration risk and high difficulty in controlling surrounding rock stability, a combination scheme of "millisecond delay pre-splitting blasting + CD method excavation + advanced support anchor bolts + shotcrete and anchor mesh initial support" can be adopted. Millisecond delay pre-splitting blasting reduces the superposition effect of blasting vibration, advanced support anchor bolts reinforce the surrounding rock in advance, and shotcrete and anchor mesh initial support timely restrains the deformation of the surrounding rock, ensuring the overall stability of the small-spaced cavern group.

[0031] As a preferred implementation method, for cavern groups with moderate blasting vibration risk and moderate difficulty in controlling surrounding rock stability, a combination of "smooth blasting + bench excavation + shotcrete and anchor mesh initial support" can be adopted. Smooth blasting reduces the damage of blasting to the surrounding rock, bench excavation achieves orderly connection between blasting and excavation, and shotcrete and anchor mesh initial support balances the stress of the surrounding rock.

[0032] As a preferred implementation method, for cavern groups with low blasting vibration risk and low difficulty in controlling surrounding rock stability, a combination of "conventional millisecond delay blasting + full-section excavation + simple shotcrete support" can be adopted. Conventional millisecond delay blasting takes into account both construction efficiency and vibration control, full-section excavation improves construction progress, and simple shotcrete support meets the stability requirements of the foundation surrounding rock.

[0033] In this step, the collaborative design variables include blasting construction parameters and excavation timing parameters. Blasting construction parameters include at least one or more of the following: borehole spacing, resistance line, charge amount, detonation time difference, and borehole diameter; excavation timing parameters include at least one or more of the following: tunnel excavation spacing, excavation layer thickness, interval between excavations of adjacent tunnels, and support follow-up distance.

[0034] Specifically, blasting construction design variables ,in, For the spacing between blast holes, For the resistance line, For single-hole charge amount, For the detonation time difference, The borehole diameter is given; the feasible value range for each parameter is as follows: , , , , .

[0035] Excavation timing design variables ,in, Spacing between adjacent caverns For excavation layer thickness, The interval between excavations of adjacent chambers The support follow-up distance; the constraint condition is... , , , Furthermore, the overall design variable vector .

[0036] Step S3: With the goal of quantifying the superposition effect of vibration in small-spacing cavern groups, a closed-loop numerical analysis model of blasting vibration is constructed through theory, simulation, and inversion. Cooperative design variables and stress parameters of soil and original rock are input into the numerical analysis model of blasting vibration. The correlation index between the blasting vibration response of the cavern group and the stability of the surrounding rock under the working conditions is calculated, and multi-objective optimization is performed.

[0037] In this step, the construction logic of the numerical analysis model for blasting vibration is as follows: a theoretical model is established based on the extended Sadovsky formula; a three-dimensional numerical model is constructed using LS-DYNA to simulate blasting load and wave propagation; and the parameters are corrected by inverting measured data through particle swarm optimization algorithm. Then, the blasting vibration control target, the surrounding rock stability target, and the construction efficiency target are integrated into the NSGA-Ⅲ optimization framework and solved by a non-dominated sorting multi-objective optimization algorithm to achieve collaborative decision-making between blasting parameters and safety thresholds.

[0038] Furthermore, during the multi-objective optimization algorithm solution process, constraints are imposed on candidate solutions: the peak velocity of the blasting vibration of the surrounding rock of the cavern group is not higher than the preset vibration limit; the convergence deformation of the surrounding rock of the cavern does not exceed the preset deformation limit; the range of the plastic zone of the surrounding rock does not exceed the preset control range; and the excavation interval between adjacent caverns is not lower than the preset safety time threshold.

[0039] Specifically, based on wave theory, a superposition model for the propagation of vibration waves from blasting in small-spaced cavern groups is established, and the improved Sadovsky formula is used as the benchmark for vibration velocity prediction. in, The damping coefficient for blasting vibration in rock and soil mass. For the distance between the centers, It is the superposition coefficient of the group effect of the cavern group, which is determined according to the net distance between the caverns and the blasting direction, and the value ranges from 1.2 to 2.0.

[0040] A three-dimensional blasting vibration model of the cavern group was established using the numerical analysis software LS-DYNA to simulate the reflection, refraction and superposition of vibration waves in the surrounding rock under different blasting parameters, and to obtain the peak velocities of blasting vibration at various parts of the surrounding rock.

[0041] A mechanical model of the surrounding rock of the cavern complex was established using the finite element software MIDAS / GTS. A Mohr-Coulomb constitutive model was adopted for the rock mass, and the reduction in rock mass strength due to cumulative damage from blasting vibrations was considered. The convergence deformation, plastic zone range, and stress of the support structure of the surrounding rock were calculated. The overall stability coefficient of the surrounding rock was obtained using the strength reduction method. in, For the shear strength of the rock mass, This represents the actual shear stress of the rock mass. A surrounding rock coefficient FS ≥ 1 indicates stability, while a smaller value indicates higher risk.

[0042] Furthermore, during the construction and operation phases, the differences between the measured blasting vibration velocity and surrounding rock displacement at monitoring points and the numerical simulation results are used to invert and correct the dynamic and mechanical parameters of the soil and rock mass, resulting in the inverted parameter vector. ,in, Let be the rock mass cohesion and internal friction angle. The inversion objective function is: in, For the selected monitoring time, For the number of monitoring points, Weights for each monitoring point , The measured or numerically simulated vibration velocity value at the i-th monitoring time and the j-th monitoring point. , Let be the measured or simulated rock mass displacement value at the i-th monitoring time and the j-th monitoring point. That is, by minimizing the errors in vibration velocity and rock mass displacement between the measured and simulated values, the parameter vector of the soil and rock is inverted and corrected.

[0043] Furthermore, the target of blasting vibration control Target of surrounding rock stability Construction efficiency target .

[0044] in, The plastic zone is the area within the surrounding rock that enters a plastic state due to stress exceeding the rock mass strength. The unit is meters (m). The larger the plastic zone, the more severe the damage to the surrounding rock. The total construction cost includes the cost of blasting materials, excavation costs, and support engineering costs. The construction period is calculated based on excavation efficiency and process coordination. The constraints applied to the candidate solutions are: ; ; ; ; .

[0045] Furthermore, based on , , The multi-objective constraints were solved using the NSGA-III algorithm to obtain the Pareto optimal solution set. Based on the comprehensive evaluation, the recommended scheme was selected with weighted blasting vibration control (0.4), surrounding rock stability (0.4), and construction efficiency cost (0.2).

[0046] Step S4: Referring to the advantageous strategy scheme obtained from the solution, based on the basic configuration of blasting control measures and excavation support measures, formulate a collaborative construction plan that covers the zoning of the cavern group, the layering and segmentation of blasting, the connection of excavation sequence, and the follow-up of support.

[0047] Specifically, as a preferred implementation method, the first 10 days are used as the preliminary preparation stage. Ground-penetrating radar is used to conduct advanced detection of the surrounding rock of the cavern group to identify the distribution of adverse geological bodies; high-precision digital detonators and emulsion explosives are processed and customized, and the borehole layout parameters are determined according to the optimization results; precast shotcrete mixture is prepared, steel mesh and anchor bolts are processed, and the construction trestle and ventilation and drainage system inside the cave are built.

[0048] The period from day 11 to day 20 is designated as the advanced support and blasting drilling stage. Rock drills are used to construct advanced support anchors with a drilling depth of 4.2m and a grouting pressure of 1.0-1.2MPa to ensure tight bonding between the anchors and the surrounding rock. Drilling is carried out according to optimized blast hole parameters, with the main blast holes and surrounding blast holes arranged alternately. After drilling is completed, the hole depth and hole spacing are checked to ensure that the drilling deviation is ≤5cm.

[0049] The blasting excavation and initial support stage is from day 21 to day 150. Digital detonators are used for blasting, and millisecond delay blasting is strictly implemented according to the blasting time difference. Ventilation and smoke removal are carried out in a timely manner after blasting, and dangerous rocks are removed from the tunnel face. Excavators and loaders are used to remove slag. The left and right tunnels are excavated in layers according to the CD method, with a layer thickness of 3m. After excavation, shotcrete and anchor mesh initial support is applied in a timely manner, with a support follow-up distance of 1.5m. Wet spraying process is used for shotcrete to ensure uniform spray thickness.

[0050] The 151st to 170th day is designated as the secondary lining and finishing stage. After the excavation of the tunnel is completed and the deformation of the surrounding rock tends to stabilize, the secondary lining is constructed. C30 concrete is poured using a formwork trolley. During the pouring process, tamping is carried out to prevent voids. After the construction is completed, the tunnel group is inspected as a whole, including blasting vibration damage detection, surrounding rock deformation detection, and support structure strength detection.

[0051] Step S5: Deploy an intelligent monitoring and sensing network in the blasting excavation area to collect monitoring data on blasting vibration velocity, surrounding rock displacement, stress and strain, and blasting shock wave of the target small-spaced cavern group during excavation construction, and evaluate the impact of blasting vibration on the cavern group and the stability of the surrounding rock structure in real time.

[0052] The intelligent monitoring and sensing network deployment project includes installing several blasting vibration sensors at the working face, cavern walls, and adjacent cavern free faces of the small-spacing cavern complex. The preferred deployment point is at least 20 sensors, using high-precision vibration meters for real-time monitoring during blasting operations. Several surrounding rock displacement monitoring points are also installed at the cavern arch, sidewalls, and floor slab. The preferred monitoring point is at least 15 points, with each displacement point monitored using a combination of a total station and a joint gauge, every 12 hours during construction. Several stress-strain sensors are also installed at the interface between the initial support anchor bolts and shotcrete, with the preferred monitoring point at least 10 points, to monitor stress changes in the support structure. Monitoring data is wirelessly transmitted and uploaded to a cloud platform in real-time for simultaneous analysis and evaluation by the blasting vibration numerical analysis model.

[0053] Step S6: When any indicator of the monitoring data deviates from the target value or reaches the warning threshold, under the basic configuration constraints of blasting control measures and excavation support measures, the blasting vibration numerical analysis model adjusts the collaborative design variables and generates corresponding control strategies through parameter inversion, guiding operators to dynamically adjust the collaborative control of blasting and excavation.

[0054] In this step, the numerical analysis model for blasting vibration adjusts the collaborative design variables and generates corresponding control measures for blasting parameter adjustment, excavation sequence optimization, and support reinforcement, including: Based on the monitored peak velocity of blasting vibration, the amount of surrounding rock convergence deformation, the range of the plastic zone, and the construction period data, it is determined whether these values ​​exceed or fall below the corresponding thresholds in the preset vibration limits, deformation limits, plastic zone control ranges, and construction period target values, respectively. When any indicator triggers a threshold condition, the collaborative design variables are re-solved to generate adjustment measures, including borehole charge amount, detonation time difference, excavation interval, and local support reinforcement methods. These adjustment measures are then simultaneously fed back to relevant personnel in a tiered early warning system to guide on-site construction implementation.

[0055] In cases where monitoring results indicate an increased risk of rock stability in the cavern complex or excessive blasting vibration, a dynamic weight adjustment mechanism is employed for the post-processing of the multi-objective optimization results: the weights of the blasting vibration control objective and the rock stability objective are increased in the comprehensive evaluation, while the weight of the engineering construction efficiency and cost objective is decreased. A comprehensive evaluation function is then calculated for each candidate solution in the Pareto optimal solution set. The comprehensive evaluation function is as follows: in, , , The weights are respectively assigned to the objectives of blasting vibration control, surrounding rock stability, and construction efficiency and cost. The solution with the smallest value is selected as the adjusted recommended parameter combination to correspond to the normalized result of the objective function value.

[0056] Specifically, when any indicator triggers a threshold condition, monitoring data from the most recent period is used, according to... , , Parameter inversion is performed under multi-objective constraints to obtain optimized soil and rock mass parameters. Update the numerical analysis model for blasting vibration and automatically adjust the target weights based on the current risk level.

[0057] As a preferred implementation method, the following is adopted under normal circumstances: The weighting is automatically adjusted when excessive blasting vibration or increased risk of surrounding rock stability is detected. And perform a normalized evaluation on each solution x in the Pareto solution set: By selecting the solution with the smallest value as the new recommended adjustment scheme, the new single-hole charge amount, the new detonation time difference, and the updated excavation interval between adjacent chambers can be automatically calculated. In addition, based on the risk level, reinforcement suggestions such as increasing the density of anchor bolts and thickening the shotcrete in local areas can be proposed.

[0058] In this step, the tiered early warning system can be implemented using a three-tiered warning threshold. The first-tier warning condition is when the peak velocity of blasting vibration reaches 70% to 80% of the limit, or the deformation rate of the surrounding rock slightly increases. In this case, a warning message can be sent to the on-site construction management personnel to remind them to strengthen monitoring. The second-tier warning condition is when the peak velocity of blasting vibration reaches 80% to 90% of the limit, or the deformation rate of the surrounding rock continues to rise. In this case, a warning message can be sent to the on-site construction management and technical personnel to suspend blasting operations and check blasting parameters. The third-tier warning condition is when the peak velocity of blasting vibration exceeds the limit, or the deformation of the surrounding rock accelerates, or cracks and spalling occur. In this case, a warning message can be sent to all on-site personnel to immediately stop construction and take emergency support measures.

[0059] In particular, the numerical analysis model of blasting vibration can also incorporate the influence of the group effect of small-spaced caverns on the propagation of blasting vibration waves. Based on wave theory, a calculation model for the reflection, refraction, and superposition of blasting vibration waves in the surrounding rock of the cavern group is established. Combined with the explosive energy release law corresponding to different blasting parameters, the propagation attenuation characteristics of blasting vibration waves in the surrounding rock of adjacent caverns are determined. The propagation attenuation characteristics are incorporated into the calculation process of the peak velocity of blasting vibration, thereby improving the calculation accuracy of the numerical analysis model for the blasting vibration response of small-spaced cavern groups.

[0060] In summary, this application constructs a unified collaborative control framework, incorporating blasting construction parameters and tunnel excavation sequence parameters into a single multi-objective optimization system. By combining numerical analysis of blasting vibration with multi-objective optimization algorithms for comprehensive solutions, it achieves an optimal balance between tunnel structure stability, blasting vibration control, and construction efficiency. This transforms excavation scheme design from traditional experience-based decision-making to quantitative and systematic optimization, enhancing the scientific rigor and rationality of the design. Simultaneously, it introduces real-time monitoring data of blasting vibration and surrounding rock deformation throughout the construction process, constructing a graded early warning model for blasting vibration based on intelligent algorithms. This allows for dynamic adjustment of blasting parameters, excavation sequence, and support measures according to actual site conditions, forming a closed-loop control mechanism of design-construction-monitoring-early warning-re-optimization. This effectively reduces the cumulative impact of vibrations between tunnels, fully ensuring the safety of the surrounding rock structure, while also optimizing process connections and improving overall construction efficiency. Furthermore, while meeting safety control objectives, this application also incorporates construction efficiency and project cost into the multi-objective optimization dimension, balancing safety redundancy and construction economy. This facilitates refined cost control throughout the entire lifecycle of small-spacing tunnel projects.

[0061] The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups, characterized in that, The method includes the following steps: S1. Obtain basic geological and engineering condition data of the target small-spacing cavern group through on-site geological survey, indoor rock and soil dynamics test, three-dimensional seismic exploration and numerical simulation inversion; S2. Set the blasting vibration control target and the cavern group structural stability target, and define the collaborative design variables that characterize the blasting construction and cavern group excavation sequence; S3. With the goal of quantifying the superposition effect of vibration of small-spacing cavern groups, a closed-loop numerical analysis model of blasting vibration is constructed through theory, simulation and inversion. The collaborative design variables and the stress parameters of soil and original rock are input into the numerical analysis model of blasting vibration. The relevant indices of blasting vibration response of cavern groups and surrounding rock stability under the working conditions are calculated, and multi-objective optimization solution is performed. S4. Based on the advantageous strategy obtained from the solution, and on the basis of the blasting control measures and excavation support measures, formulate a collaborative construction plan that covers the zoning of the cavern group, the layering and segmentation of blasting, the connection of excavation sequence and the follow-up of support. S5. Deploy an intelligent monitoring and sensing network in the blasting excavation area to collect monitoring data on blasting vibration velocity, surrounding rock displacement, stress and strain, and blasting shock wave of the target small-spaced cavern group during excavation construction, and evaluate the impact of blasting vibration of the cavern group and the stability of the surrounding rock structure in real time. S6. When any indicator of the monitoring data deviates from the target value or reaches the warning threshold, under the basic configuration constraints of blasting control measures and excavation support measures, the blasting vibration numerical analysis model adjusts the collaborative design variables and generates corresponding control strategies through parameter inversion, guiding operators to dynamically adjust the collaborative control of blasting and excavation.

2. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to claim 1, characterized in that, In step S1, the basic geological and engineering condition data include the geometric parameters of the cavern group, the physical and mechanical parameters of the rock and soil, the hydrogeological conditions, and the distribution characteristics of the original rock stress field.

3. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to claim 1, characterized in that, In step S2, the blasting vibration control targets include ensuring that the peak velocity of blasting vibration and the blasting shock wave pressure of the surrounding rock of the cavern and adjacent caverns meet the design requirements; the structural stability targets of the cavern group include ensuring that the convergence deformation of the surrounding rock of the cavern, the range of the plastic zone, and the stress of the support structure meet the design requirements.

4. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to claim 3, characterized in that, In step S2, the collaborative design variables include blasting construction parameters and excavation timing parameters; The blasting construction parameters include at least the borehole spacing, resistance line, charge amount, detonation time difference, and borehole diameter; the excavation sequence parameters include at least the tunnel excavation spacing, excavation layer thickness, excavation interval between adjacent tunnels, and support follow-up distance.

5. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to claim 4, characterized in that, In step S3, the construction logic of the numerical analysis model for blasting vibration is as follows: A theoretical model was established based on the extended Sadovsky formula. A three-dimensional numerical model was constructed using LS-DYNA to simulate blasting loads and wave propagation. The parameters were corrected by inverting measured data through particle swarm optimization algorithm. Then, the blasting vibration control target, the surrounding rock stability target, and the construction efficiency target were integrated into the NSGA-Ⅲ optimization framework and solved by a non-dominated sorting multi-objective optimization algorithm to achieve collaborative decision-making between blasting parameters and safety thresholds.

6. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to claim 5, characterized in that, In the process of solving multi-objective optimization algorithms, the following constraints are imposed on candidate solutions: The peak velocity of blasting vibration in the surrounding rock of the cavern complex shall not exceed the preset vibration limit; the convergence deformation of the surrounding rock shall not exceed the preset deformation limit; the range of the plastic zone of the surrounding rock shall not exceed the preset control range; and the interval between excavations of adjacent caverns shall not be less than the preset safe time threshold.

7. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to claim 1, characterized in that, In step S5, the deployment of the intelligent monitoring and sensing network includes: Blasting vibration sensors were installed at the working face, perimeter walls, and free surfaces of adjacent caverns in the small-spacing cavern complex; rock displacement monitoring points were installed at the cavern arch, sidewalls, and floor slab, with each displacement point monitored using a combination of a total station and a joint gauge; stress-strain sensors were installed at the interface between the initial support anchor bolts and the shotcrete to monitor stress changes in the support structure.

8. The method for intelligent early warning and collaborative excavation control of blasting vibration in small-spacing tunnel groups according to any one of claims 1 to 7, characterized in that, In step S6, the control measures for adjusting collaborative design variables and generating corresponding blasting parameter adjustments, excavation sequence optimization, and support reinforcement in the numerical analysis model of blasting vibration include: Based on the monitored peak velocity of blasting vibration, the amount of surrounding rock convergence deformation, the range of the plastic zone, and the construction period data, determine whether they exceed or fall below the corresponding thresholds in the preset vibration limit, deformation limit, plastic zone control range, and construction period target value, respectively. When any indicator triggers a threshold condition, the collaborative design variables are re-solved to generate adjustment measures including borehole charge amount, detonation time difference, excavation interval time, and local support reinforcement method. The adjustment measures are then synchronously fed back to relevant personnel in the form of graded early warning to guide on-site construction implementation.

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