BIM (Building Information Modeling)-based open-air goaf charging safety risk early warning method and system

Abstract

The invention relates to the field of safety risk early warning, in particular to a BIM (Building Information Modeling)-based open-air goaf charging safety risk early warning method and a BIM-based open-air goaf charging safety risk early warning system. A three-dimensional BIM geologic model containing rock mass hardness data, joint density and fracture distribution data is constructed through unmanned aerial vehicle scanning and rock core sampling; determining a minimum effective explosive loading amount meeting a preset crushing lumpiness mean value in the three-dimensional BIM geological model, performing dynamic simulation through the three-dimensional BIM geological model to obtain a simulation result, and outputting a final explosive loading amount when the simulation result meets a preset safety constraint condition; and generating charge parameters according to the final charge amount, binding the charge parameters with space coordinates of the three-dimensional BIM geologic model, and outputting an early warning area through a visual interface. By determining the optimal explosive loading amount and optimizing the blast hole layout and the detonating sequence, the explosive loading safety risk is effectively reduced while the blasting effect is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of safety risk early warning, and specifically to a method and system for early warning of the safety risk of charging in open-pit mined-out areas based on BIM. Background Art

[0002] Open-pit mined-out area blasting operation is a key link in mine exploitation, aiming to break rock mass through the energy generated by explosive explosion to meet the exploitation requirements. With the expansion of mine exploitation scale and the increase of exploitation depth, the safety and efficiency problems of blasting operation become increasingly prominent. In particular, the reasonable control of the charge amount is directly related to the blasting effect, cost investment and the life safety of operating personnel.

[0003] In traditional open-pit mined-out area blasting operations, the determination of the charge amount often relies on empirical formulas or simple on-site tests. This method is difficult to comprehensively consider the comprehensive influence of multiple factors such as geological conditions, rock mass characteristics and blasting environment, resulting in great blindness in setting the charge amount. On the one hand, insufficient charge amount may lead to poor blasting effect and failure to achieve the expected rock fragmentation, thus affecting the efficiency of subsequent exploitation operations. On the other hand, excessive charge amount not only causes waste of explosive resources, but more importantly, may trigger safety hazards such as blasting flyrock and vibration propagation, posing a serious threat to surrounding facilities, personnel and the environment.

[0004] Although there have been some attempts in the prior art to optimize the charge amount design through means such as numerical simulation and physical model tests, it is difficult to accurately reflect the complex geological structure and rock mass characteristics of open-pit mined-out areas, resulting in great limitations in practical applications. Especially when dealing with open-pit mined-out areas with complex fracture networks, high-hardness rock masses or special terrain conditions, the prior art often has difficulty in effectively reducing the amount of explosive used while ensuring the blasting effect, thus unable to fundamentally solve the problem of safety risk control.

[0005] Therefore, there is an urgent need for an early warning method that can comprehensively consider multiple factors such as geological conditions, rock mass characteristics and blasting environment of open-pit mined-out areas, determine the optimal charge amount through scientific methods, and reduce safety risks on the premise of ensuring the blasting effect. Summary of the Invention

[0006] (1) Technical Problems to be Solved The purpose of the present invention is to provide a method and system for early warning of the safety risk of charging in open-pit mined-out areas based on BIM, so as to solve the problem of accurately balancing the blasting effect and safety on the premise of minimizing the amount of explosive used.

[0007] (2) Technical Solutions To achieve the above purpose, on the one hand, the present invention provides a method for early warning of the safety risk of charging in open-pit mined-out areas based on BIM. The method includes: S1. Obtain the geological data, borehole parameter data, and historical blasting data of the open-pit goaf, and construct a three-dimensional BIM geological model containing rock mass hardness data, joint density, and fracture distribution data through UAV scanning and core sampling.

[0008] S2. Conduct rock mass blastability zoning for the open-pit goaf according to the three-dimensional BIM geological model. Calculate the effective coverage radius of the single-hole blasting stress wave based on the rock mass hardness and fracture distribution data in the rock mass blastability zoning, and determine the energy attenuation coefficient of the stress wave superposition effect according to the fracture connectivity between adjacent holes. Establish an optimization model for blast hole spacing based on the energy attenuation coefficient and effective coverage radius, and generate the initial blasting point coordinates according to the blast hole spacing optimization model. Input the initial blasting point coordinates into the three-dimensional BIM geological model, and use the discrete element algorithm to simulate the rock mass fragmentation distribution under the gradient change of the single-hole charge amount, and screen out the critical charge amount that meets the preset average fragmentation size as the minimum effective charge amount. Dynamically simulate the minimum effective charge amount through the three-dimensional BIM geological model to obtain the simulation results. When the simulation results meet the preset safety constraint conditions, output the final charge amount; the simulation results include the blasting flyrock trajectory and the vibration propagation range.

[0009] S3. Generate charge parameters according to the final charge amount and bind them to the spatial coordinates of the three-dimensional BIM geological model, and output the warning area through the visualization interface; the charge parameters include the single-hole charge amount, initiation sequence, and millisecond delay time.

[0010] Further, the method of dynamically simulating the minimum effective charge amount through the three-dimensional BIM geological model and outputting the final charge amount when the simulation results meet the preset safety constraint conditions includes: Calculate the energy coupling efficiency of the blasting stress wave between adjacent holes under different initiation sequences according to the spatial distribution of the blasting point coordinates and the relationship between the millisecond delay time and the stress wave propagation rate, and select the initiation sequence with the energy coupling efficiency greater than the preset coupling efficiency threshold as the optimal time coordination scheme.

[0011] When the blasting flyrock trajectory or vibration propagation range of the simulation results exceeds the preset safety threshold, recalculate the minimum effective charge amount and the energy coupling efficiency until the simulation results meet the preset safety constraint conditions.

[0012] Further, the method of establishing an optimization model for blast hole spacing based on the energy attenuation coefficient and effective coverage radius and generating the initial blasting point coordinates according to the blast hole spacing optimization model includes: Construct a multi-objective optimization function aiming at minimizing the total charge amount and maximizing the area of the superposition region of the blasting stress wave between adjacent holes according to the energy attenuation coefficient and effective coverage radius.

[0013] Iteratively generate a candidate solution set for the blasting hole spacing from the multi-objective optimization function; extract the Pareto front solutions from the candidate solution set, screen the optimal blasting hole spacing from the Pareto front solutions according to the preset charge priority weights, and map the optimal blasting hole spacing through the coordinate system of the 3D BIM geological model to obtain the initial blasting point coordinates.

[0014] Verify whether the crack connectivity between adjacent holes in the 3D BIM geological model leads to the energy attenuation coefficient of the stress wave superposition effect exceeding the preset energy attenuation threshold for the initial blasting point coordinates. If it exceeds the preset energy attenuation threshold, adjust the blasting hole spacing until the energy attenuation coefficient constraint is satisfied.

[0015] Further, the method for verifying whether the crack connectivity between adjacent holes leads to the energy attenuation coefficient of the blasting stress wave superposition effect exceeding the preset energy attenuation threshold includes: Extract the crack trend and crack connectivity length between adjacent blasting holes according to the crack distribution data in the 3D BIM geological model, and calculate the crack connectivity index, where the crack connectivity index is the ratio of the crack connectivity length to the adjacent hole spacing; simulate the propagation path of the blasting stress wave in the cracked rock mass through the finite element analysis method with the crack connectivity index and the rock mass hardness data, and calculate the actual energy attenuation coefficient.

[0016] If the actual energy attenuation coefficient is greater than the preset energy attenuation threshold, adjust the blasting hole spacing according to the angle between the crack trend and the connection line of adjacent holes, and recalculate the crack connectivity index and the actual energy attenuation coefficient of the adjusted area. If the actual energy attenuation coefficient is still greater than the preset energy attenuation threshold after a preset number of adjustments, mark the adjusted area as a high energy loss area in the 3D BIM geological model and trigger a charge compensation instruction.

[0017] Further, the method for adjusting the blasting hole spacing according to the angle between the crack trend and the connection line of adjacent holes and recalculating the crack connectivity index and the actual energy attenuation coefficient of the adjusted area includes: Calculate the cosine value of the angle according to the three-dimensional spatial geometric relationship between the crack trend and the connection line of adjacent holes in the 3D BIM geological model. If the cosine value of the angle is greater than the preset angle cosine value threshold, adjust the blasting hole spacing along the direction perpendicular to the crack trend; if the cosine value of the angle is less than or equal to the preset angle cosine value threshold, adjust the blasting hole spacing along the direction parallel to the crack trend.

[0018] After each adjustment, recalculate the crack connectivity index between adjacent holes according to the updated blasting hole coordinates; if the adjusted actual energy attenuation coefficient is greater than the preset energy attenuation threshold, increase the blasting hole spacing according to the preset step size.

[0019] Further, the method for calculating the energy coupling efficiency of the blasting stress waves between adjacent holes in different initiation sequences based on the spatial distribution of the blasting point coordinates and the millisecond delay time and the stress wave propagation rate, and selecting the initiation sequence with an energy coupling efficiency greater than the preset coupling efficiency threshold as the optimal time coordination scheme includes: Based on the spatial distribution of the blasting point coordinates generated by the blasting hole spacing optimization model, calculate the three-dimensional spatial distance vector between adjacent holes, and determine the theoretical time reference for the stress wave propagation between adjacent holes according to the stress wave propagation rate corresponding to the rock mass blastability grade in each rock mass blastability partition in the three-dimensional BIM geological model.

[0020] Based on the theoretical time reference, establish a dynamic candidate interval for the millisecond delay time to obtain a set of candidate schemes for the initiation sequence permutations; for each initiation sequence permutation in the set of candidate schemes, calculate the matching degree between the initiation time difference between adjacent holes and the stress wave propagation time according to the three-dimensional spatial distance vector and the stress wave propagation rate, and quantify the ratio of the superimposed stress wave peak energy to the single-hole stress wave peak energy as the energy coupling efficiency through numerical simulation methods.

[0021] If there are multiple initiation sequence permutations with an energy coupling efficiency greater than the preset coupling efficiency threshold, select the optimal time coordination scheme according to the principle of the minimum total millisecond delay time.

[0022] Further, the method for establishing a dynamic candidate interval for the millisecond delay time based on the theoretical time reference to obtain a set of candidate schemes for the initiation sequence permutations includes: Generate a set of candidate initiation time points for each blasting hole according to the millisecond delay time range within the dynamic candidate interval, and the set of candidate initiation time points is evenly distributed according to the preset interval based on the theoretical time reference for the stress wave propagation.

[0023] Establish an adjacency constraint rule for the initiation sequence according to the topological relationship of the spatial distribution of the blasting point coordinates, traverse all initiation sequence permutations through the backtracking algorithm with the adjacency constraint rule and the set of candidate initiation time points to obtain a set of candidate schemes, and perform conflict detection on the initiation sequence permutations in the set of candidate schemes.

[0024] Further, the method for performing conflict detection on the initiation sequence permutations in the set of candidate schemes includes: Construct a spatio-temporal influence relationship matrix between the blasting holes according to the spatial distribution of the blasting points and the stress wave propagation rate data in the three-dimensional BIM geological model, and each element in the spatio-temporal influence relationship matrix represents whether the initiation time difference between adjacent holes is less than the theoretical time required for the stress wave to propagate to the adjacent hole.

[0025] Traverse each permutation and combination of initiation sequences. When the detected initiation time difference between adjacent holes is less than the theoretical time benchmark and the energy abnormally increases in the stress wave superposition area by more than the preset energy abnormal increase threshold, it is determined as a time overlap conflict; calculate the spatial intersection area of the stress wave propagation paths of adjacent holes under different initiation sequences according to the spatial coordinates of the blast holes in the 3D BIM geological model. If the average value of the broken rock block size in the intersection area exceeds the preset average broken rock block size, it is determined as a path intersection interference conflict; mark and remove the permutation and combination of initiation sequences with time overlap conflicts or path intersection interference conflicts.

[0026] Further, the method for generating charge parameters based on the final charge amount and binding them to the spatial coordinates of the 3D BIM geological model includes: Extract the coordinate data of each blast hole and the corresponding rock mass explosibility partition from the 3D BIM geological model, and generate the single-hole charge amount parameter in combination with the final charge amount. The single-hole charge amount parameter is dynamically corrected according to the initial charge density threshold of the rock mass explosibility partition to which the blast hole belongs and the blast hole spacing.

[0027] Bind the single-hole charge amount parameter to the corresponding blast hole coordinates, form a structured charge parameter set, and store it in the blast parameter database of the 3D BIM geological model.

[0028] On the other hand, based on the same inventive concept, the present invention also provides a BIM-based open-pit goaf charging safety risk warning system, which includes: a 3D BIM geological model construction module, a final charge amount analysis module, and a safety warning management module, and the modules are communicatively connected in sequence.

[0029] The 3D BIM geological model construction module is used to obtain the geological data, drilling parameter data, and historical blasting data of the open-pit goaf, and construct a 3D BIM geological model containing rock mass hardness data, joint density, and fracture distribution data through unmanned aerial vehicle scanning and core sampling.

[0030] The final charge amount analysis module is used to conduct rock mass explosibility zoning for the open-pit goaf based on the 3D BIM geological model, calculate the effective coverage radius of the single-hole blasting stress wave according to the rock hardness and fracture distribution data of the rock mass explosibility zoning, and determine the energy attenuation coefficient of the stress wave superposition effect according to the fracture connectivity between adjacent holes; establish an optimization model for the blasting hole spacing based on the energy attenuation coefficient and the effective coverage radius, and generate the initial blasting point coordinates according to the blasting hole spacing optimization model; input the initial blasting point coordinates into the 3D BIM geological model, simulate the rock fragmentation distribution under the gradient change of the single-hole charge amount by using the discrete element algorithm, and screen out the critical charge amount that meets the preset average fragmentation size as the minimum effective charge amount; obtain the simulation results through the dynamic simulation of the minimum effective charge amount by the 3D BIM geological model, and output the final charge amount when the simulation results meet the preset safety constraint conditions; the simulation results include the blasting flyrock trajectory and the vibration propagation range.

[0031] The safety warning management module is used to generate charge parameters according to the final charge amount and bind them to the spatial coordinates of the 3D BIM geological model, and output the warning area through the visualization interface; the charge parameters include the single-hole charge amount, the initiation sequence, and the millisecond delay time.

[0032] (3)Beneficial effects Compared with the prior art, the beneficial effects of the present invention are: 1. By constructing a 3D BIM geological model including rock hardness, joint density, and fracture distribution, conducting rock mass explosibility zoning, calculating relevant parameters of the blasting stress wave, determining the minimum effective charge amount, etc., and combining the dynamic simulation results to output the final charge amount that meets the safety constraint conditions, and at the same time generating charge parameters bound to the spatial coordinates, it can accurately adapt to the complex geological conditions of the open-pit goaf, effectively reduce safety risks such as flyrock and vibration during blasting, and ensure the safety of personnel and equipment.

[0033] 2. Establish an optimization model for the blasting hole spacing by using the energy attenuation coefficient and the effective coverage radius, generate the initial blasting point coordinates through the multi-objective optimization function and the non-dominated sorting genetic algorithm, verify the influence of the fracture connectivity between adjacent holes on the energy attenuation coefficient, and make local adjustments until the constraints are met; at the same time, calculate the energy coupling efficiency of the blasting stress wave between adjacent holes under different initiation sequences according to the spatial distribution of the blasting point coordinates and the stress wave propagation rate, and select the optimal time coordination scheme, so as to optimize the layout and initiation sequence of the blasting holes, improve the blasting effect, and reduce unnecessary charge amounts.

[0034] 3. Bind the charging parameters generated by the final charge amount to the spatial coordinates of the 3D BIM geological model to form a structured set of charging parameters and store it in the blasting parameter database; output the warning area through the visualization interface, enabling an intuitive understanding of the safety range and potential risk points of the blasting operation, and improving the safety management level and decision-making efficiency of the blasting operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flowchart of the method for warning safety risks of charging in an open-pit goaf based on BIM according to Embodiment 1 of the present invention.

[0036] Figure 2 It is a schematic diagram of the module composition of the system for warning safety risks of charging in an open-pit goaf based on BIM according to Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] Before giving examples, it is necessary to elaborate on the application scenarios of the inventive concept of the present invention. The present invention is a method and system for warning safety risks of charging in an open-pit goaf based on BIM, which is applied to accurately adapt to complex geological conditions, considering multiple factors such as the geological conditions of the open-pit goaf, rock mass characteristics, and blasting environment. By determining the optimal charge amount and optimizing the layout and initiation sequence of blasting holes, while ensuring the blasting effect, the safety risks are effectively reduced, providing scientific decision-making support for open-pit mine blasting operations.

[0039] Embodiment 1: As Figure 1 shown, this embodiment provides a method for warning safety risks of charging in an open-pit goaf based on BIM, and the method includes: S1. Obtain the geological data, drilling parameter data, and historical blasting data of the open-pit goaf, and construct a three-dimensional BIM geological model containing rock mass hardness data, joint density, and fracture distribution data through drone scanning and core sampling; the geological data includes information such as stratum distribution, rock type, and geological structure; the drilling parameter data includes hole diameter, hole depth, hole position coordinates, etc.; the historical blasting data includes charge amount, blasting effect, and safety accident statistics in past blasting projects. The drone scanning uses high-precision LiDAR equipment to collect three-dimensional point cloud data of the open-pit goaf, with a resolution of up to centimeter level, and the coverage area includes the entire open-pit mining area and the surrounding safety impact area. The core sampling is carried out in a grid-point layout manner in the predetermined blasting area, and the sampling depth is matched with the planned blasting depth. The core samples are tested in the laboratory to obtain physical parameters such as rock mass hardness and joint density. Through the integration of these data, a three-dimensional BIM geological model containing rock mass hardness data, joint density, and fracture distribution can be constructed, which can truly reflect the geological conditions of the open-pit goaf.

[0040] S2. Zone the rock mass' explosibility in the open-pit goaf according to the 3D BIM geological model. Calculate the effective coverage radius of the single-hole blasting stress wave based on the rock mass hardness and fracture distribution data in the zoned rock mass' explosibility, and determine the energy attenuation coefficient of the stress wave superposition effect according to the fracture connectivity between adjacent holes. Establish an optimization model for the blasting hole spacing based on the energy attenuation coefficient and the effective coverage radius, and generate the initial blasting point coordinates according to the optimization model for the blasting hole spacing. Input the initial blasting point coordinates into the 3D BIM geological model, and use the discrete element algorithm to simulate the rock mass fragmentation distribution under the gradient change of the single-hole charge amount, and screen out the critical charge amount that meets the preset average fragmentation size as the minimum effective charge amount. Obtain the simulation result by dynamically simulating the minimum effective charge amount through the 3D BIM geological model. When the simulation result meets the preset safety constraint conditions, output the final charge amount. The simulation results include the blasting flyrock trajectory and the vibration propagation range. Zone the goaf into a high-explosibility zone (such as a soft rock zone with well-developed joints), a medium-explosibility zone (such as a medium-hard rock zone with moderately developed joints), and a low-explosibility zone (such as a hard rock zone with underdeveloped joints) according to the rock mass hardness, joint density, and fracture distribution. For each zoned rock mass' explosibility, calculate the effective coverage radius of the single-hole blasting stress wave based on the rock mass hardness and fracture distribution data. For example, for the medium-hard rock zone with a hardness of 60 - 70 MPa, the effective coverage radius of the single-hole stress wave is about 2.5 - 3.5 meters; for the hard rock zone with a hardness exceeding 80 MPa, the coverage radius will be reduced to 1.8 - 2.3 meters. At the same time, considering the fracture connectivity between adjacent holes, determine the energy attenuation coefficient of the stress wave superposition effect, which is usually between 0.6 - 0.9. The better the fracture connectivity, the smaller the energy attenuation coefficient. The discrete element algorithm can simulate the fracture, scattering, and accumulation processes of the rock medium, and the calculation accuracy can reach the centimeter level. By analyzing the fragmentation effects under 5 - 8 different charge amount gradients (such as 15 kg, 20 kg, 25 kg, etc. per meter of hole depth), screen out the critical charge amount that meets the preset average fragmentation size (such as the proportion of ≤500 mm is not less than 80%), and determine it as the minimum effective charge amount.

[0041] S3. Generate charging parameters based on the final charge amount and bind them to the spatial coordinates of the 3D BIM geological model, and output the warning area through the visualization interface; the charging parameters include the charge amount per hole, the initiation sequence, and the millisecond delay time. The charge amount per hole is optimized according to the rock hardness and fracture distribution. The charge amount per hole in areas with higher rock hardness can reach 50 - 80 kg, while in areas with dense fractures, it is reduced to 30 - 50 kg; the initiation sequence follows the principle of "advancing from the free face backward" and is optimized for specific terrain conditions; the millisecond delay time is accurately calculated based on the stress wave propagation rate and the blast hole spacing. The warning area is visually presented through the visualization interface, including the dangerous area of blasting flyrock, the vibration influence area, etc., and is marked with different colors to represent the risk level, enabling on-site operators to clearly understand the safety distance and evacuation area, and effectively reducing the safety risks of blasting operations.

[0042] The method for obtaining the simulation result by dynamically simulating the minimum effective charge amount through the 3D BIM geological model and outputting the final charge amount when the simulation result meets the preset safety constraint conditions includes: Calculate the energy coupling efficiency of the blasting stress waves between adjacent holes under different initiation sequences according to the spatial distribution of the blast point coordinates and the millisecond delay time and the stress wave propagation rate, and select the initiation sequence with an energy coupling efficiency greater than the preset coupling efficiency threshold as the optimal time coordination scheme; When the blasting flyrock trajectory or the vibration propagation range of the simulation result exceeds the preset safety threshold, recalculate the minimum effective charge amount and the energy coupling efficiency until the simulation result meets the preset safety constraint conditions. For example, if the throwing distance of the flyrock exceeds the safety distance of 300 meters, the charge amount will be reduced and the initiation sequence will be adjusted; if the peak particle velocity at some monitoring points within the vibration propagation range exceeds 2.0 cm / s, the millisecond delay time will be optimized to reduce the stress wave superposition effect.

[0043] The method for establishing an optimization model for the blast hole spacing according to the energy attenuation coefficient and the effective coverage radius and generating the initial blast point coordinates according to the optimization model of the blast hole spacing includes: Construct a multi-objective optimization function aiming at minimizing the total charge amount and maximizing the area of the superposition region of the blasting stress waves between adjacent holes according to the energy attenuation coefficient and the effective coverage radius; among them, the total charge amount objective function is defined as the sum of the products of the charge amount per hole of each blast hole and the number of blast holes, and the objective function of the area of the superposition region of the blasting stress waves between adjacent holes is defined as the sum of the superposition region areas under the geometric relationship between the effective coverage radius of the stress waves of each adjacent hole pair and the hole spacing.

[0044] Generate a candidate solution set of blast hole spacing by iteratively generating the multi-objective optimization function through a genetic algorithm; extract the Pareto front solutions from the candidate solution set, screen the optimal blast hole spacing from the Pareto front solutions according to the preset charge priority weight, and map the optimal blast hole spacing through the coordinate system of the 3D BIM geological model to obtain the initial blast point coordinates; optimize and solve the two conflicting objective functions of minimizing the total charge and maximizing the superposition area through the non-dominated sorting genetic algorithm (NSGA-II). When initializing the population, generate a set of randomly distributed blast hole spacing schemes according to the preset proportional range of the effective coverage radius, and each scheme, as an individual, contains the spacing parameters of all blast holes; evaluate the fitness of the individuals in the population, calculate the total charge value and the superposition area value of each individual respectively, and classify the individuals according to the non-dominated sorting algorithm. At the same time, calculate the crowding distance of the individuals to measure the diversity of the solution set; perform crossover operation and mutation operation on the parent population to generate the offspring population, where the crossover operation randomly selects two parent individuals to exchange part of the hole spacing parameters, and the mutation operation randomly adjusts the hole spacing parameters of a single individual; after merging the parent population and the offspring population, screen the new generation population according to the non-dominated sorting level and the crowding distance, and retain the individuals with high non-dominated level and large crowding distance until the preset iteration termination condition is reached; extract the Pareto front solution set from the final population, and each solution in the Pareto front solution set represents a trade-off scheme in which the total charge and the superposition area cannot be optimized simultaneously. For example, the non-dominated sorting genetic algorithm sets the population size to 50 - 100 individuals, the crossover probability to 0.8 - 0.9, the mutation probability to 0.1 - 0.2, and the number of iterations to 100 - 200 generations. In this way, a candidate solution set of blast hole spacing is generated. Extract the Pareto front solutions from the candidate solution set, that is, those solutions that cannot be dominated by other solutions in terms of both the total charge and the superposition area. According to the preset charge priority weight (usually 0.6 - 0.7, which reflects the importance of reducing the total charge relative to improving the blasting efficiency), screen out the optimal blast hole spacing from the Pareto front solutions. For example, in the medium-hard rock area, the optimal hole spacing is determined to be 3.5 meters, while in the hard rock area it is 2.8 meters. Map the optimal blast hole spacing through the coordinate system of the 3D BIM geological model to obtain the initial blast point coordinates, taking into account factors such as terrain undulation and rock mass hardness distribution, and forming a regular or irregular arrangement of blast point distribution in 3D space.

[0045] Verify whether the energy attenuation coefficient of the stress wave superposition effect caused by the fracture connectivity between adjacent holes exceeds the preset energy attenuation threshold through the 3D BIM geological model with the initial blast point coordinates. If it exceeds the preset energy attenuation threshold, adjust the blast hole spacing until the energy attenuation coefficient constraint is satisfied. The verification and adjustment process ensure the effective utilization of blasting energy and reduce unnecessary waste of charge.

[0046] The method for verifying whether the energy attenuation coefficient of the superposition effect of blasting stress waves caused by the fracture connectivity between adjacent holes exceeds a preset energy attenuation threshold includes: Extract the fracture trend and fracture connectivity length between adjacent blasting holes according to the fracture distribution data in the 3D BIM geological model, and calculate the fracture connectivity index, where the fracture connectivity index is the ratio of the fracture connectivity length to the adjacent hole spacing; simulate the propagation path of blasting stress waves in fractured rock masses through the finite element analysis method with the fracture connectivity index and rock mass hardness data, and calculate the actual energy attenuation coefficient; the fracture connectivity index is defined as the ratio of the fracture connectivity length to the adjacent hole spacing. For example, when the fracture connectivity length is 2 meters and the adjacent hole spacing is 3.5 meters, the fracture connectivity index is 0.57. Input the fracture connectivity index and rock mass hardness data into the finite element analysis model to simulate the propagation path of blasting stress waves in fractured rock masses. The simulation uses finite element software such as ANSYS or LS-DYNA. By setting the rock mass material parameters (such as density, elastic modulus, Poisson's ratio) and fracture interface parameters (such as normal stiffness, tangential stiffness, friction coefficient), calculate the actual energy attenuation coefficient, which reflects the degree of energy loss after the stress wave passes through the fracture.

[0047] If the actual energy attenuation coefficient is greater than the preset energy attenuation threshold, adjust the blasting hole spacing according to the angle between the fracture trend and the connection line of adjacent holes, and recalculate the fracture connectivity index and actual energy attenuation coefficient in the adjusted area. If the actual energy attenuation coefficient is still greater than the preset energy attenuation threshold after a preset number of adjustments, mark the adjusted area as a high energy loss area in the 3D BIM geological model and trigger a charge compensation instruction. For example, in a blasting project, it is detected that the angle between the fracture trend and the connection line between two adjacent blasting holes is 75 degrees, and the energy attenuation coefficient reaches 0.35, exceeding the preset threshold of 0.3. At this time, the position of the blasting hole will be adjusted in a specific direction to reduce the impact of energy attenuation. If the actual energy attenuation coefficient is still greater than the preset energy attenuation threshold after a preset number of times (usually 3 - 5 times) of adjustment, mark this area as a high energy loss area in the 3D BIM geological model and trigger a charge compensation instruction to ensure that an appropriate amount of charge is increased in the area with serious energy loss to maintain the consistency of the blasting effect.

[0048] The method for adjusting the blasting hole spacing according to the angle between the fracture trend and the connection line of adjacent holes and recalculating the fracture connectivity index and actual energy attenuation coefficient in the adjusted area includes: Calculate the cosine value of the included angle according to the three-dimensional spatial geometric relationship between the fracture strike and the connection line of adjacent holes in the three-dimensional BIM geological model. If the cosine value of the included angle is greater than the preset angle cosine value threshold, adjust the blasting hole spacing along the direction perpendicular to the fracture strike; if the cosine value of the included angle is less than or equal to the preset angle cosine value threshold, adjust the blasting hole spacing along the direction parallel to the fracture strike; consider the three-dimensional spatial strike of the fracture and the direction vector of the blasting hole connection line, and calculate the cosine value of the included angle through vector dot product. When the cosine value of the included angle is greater than the preset angle cosine value threshold, it indicates that the fracture strike is relatively parallel to the hole connection line, and the blasting hole spacing will be adjusted along the direction perpendicular to the fracture strike. For example, when the fracture strike is east-west and the hole connection line is nearly north-south, the blasting hole position will be adjusted along the east-west direction, and the natural extensibility of the fracture network can be utilized to optimize the transmission effect of the blasting energy by the fracture network.

[0049] After each adjustment, recalculate the fracture connectivity index between adjacent holes according to the updated blasting hole coordinates; if the actual energy attenuation coefficient after adjustment is greater than the preset energy attenuation threshold, increase the blasting hole spacing according to the preset step size. If the actual energy attenuation coefficient after adjustment is still greater than the preset energy attenuation threshold, the blasting hole spacing will be increased according to the preset step size (usually 5%-10% of the initial hole spacing). This progressive adjustment method ensures that the optimal blasting hole layout plan can be found under the premise of meeting the safety constraint conditions.

[0050] The method for calculating the energy coupling efficiency of the blasting stress waves between adjacent holes under different initiation sequences according to the spatial distribution of the blasting point coordinates and the millisecond delay time and the stress wave propagation rate, and selecting the initiation sequence with the energy coupling efficiency greater than the preset coupling efficiency threshold as the optimal time coordination scheme includes: According to the spatial distribution of the blasting point coordinates generated by the blasting hole spacing optimization model, calculate the three-dimensional spatial distance vector between adjacent holes according to the spatial distribution of the blasting point coordinates, and determine the theoretical time reference for the stress wave propagation between adjacent holes according to the stress wave propagation rate corresponding to the rock blasting grade in each rock mass blastability zone in the three-dimensional BIM geological model; the three-dimensional spatial distance vector contains the horizontal distance and vertical elevation difference information between the blasting holes, and accurately reflects the relative position relationship of the blasting holes in the three-dimensional space. Combine the rock mass blastability grades in each rock mass blastability zone in the three-dimensional BIM geological model to determine the corresponding stress wave propagation rate. For example, in high-hardness (>80 MPa) low-joint-density rock masses, the stress wave propagation rate can reach 4500-5500 m / s; while in medium-hardness (50-80 MPa) medium-joint-density rock masses, the propagation rate drops to 3500-4500 m / s; in low-hardness (<50 MPa) high-joint-density rock masses, the propagation rate further drops to 2500-3500 m / s. Determine the theoretical time reference for the stress wave propagation between adjacent holes according to these data.

[0051] Based on the theoretical time reference, a dynamic candidate interval for the millisecond delay time is established to obtain a set of candidate solutions for the initiation sequence permutations and combinations; for each initiation sequence permutation and combination in the set of candidate solutions, the matching degree between the initiation time difference of adjacent holes and the stress wave propagation time is calculated according to the three-dimensional space distance vector and the stress wave propagation rate, and the ratio of the peak energy of the superimposed stress wave to the peak energy of the single-hole stress wave is quantified as the energy coupling efficiency by numerical simulation methods. For example, for a medium-scale blasting project with 20 blasting holes, 4-5 different main initiation sequence schemes are considered, such as "free face advancing type", "V-shaped", "fan-shaped", etc. Under each main scheme, 3-4 millisecond delay time variables are set to form 60-100 different candidate solution combinations. For example, when the initiation time difference between two adjacent blasting holes is exactly equal to the time required for stress wave propagation, the energy coupling efficiency can reach 0.85-0.95; while when the time difference deviates from the theoretical value by more than 10%, the energy coupling efficiency will drop below 0.7.

[0052] If there are multiple initiation sequence permutations and combinations with energy coupling efficiency greater than the preset coupling efficiency threshold, the optimal time coordination scheme is selected according to the principle of the minimum sum of millisecond delay times. According to the practical experience of blasting engineering, the shorter the total blasting time, the smaller the uncertainty of the blasting process, and the higher the safety and controllability. For example, in a blasting project, from three schemes with energy coupling efficiency exceeding 0.85, the scheme with the sum of millisecond delay times of 240 ms is selected instead of the schemes with sums of 280 ms and 320 ms as the final optimal time coordination scheme.

[0053] The method of establishing a set of candidate solutions for the initiation sequence permutations and combinations by establishing a dynamic candidate interval for the millisecond delay time based on the theoretical time reference includes: According to the millisecond delay time range within the dynamic candidate interval, a set of candidate initiation time points is generated for each blasting hole, and the set of candidate initiation time points is evenly distributed at a preset interval according to the theoretical time reference of stress wave propagation; for example, for two blasting holes 4 meters apart, if the stress wave propagation rate in the rock mass is 4000 m / s, the theoretical propagation time is 1 ms. Candidate initiation time points are set at intervals of 3 ms within the range of floating 20%-30% above and below the theoretical time reference to form a candidate set of {0.7 ms, 1.0 ms, 1.3 ms}. For all blasting holes in the blasting area, a complete matrix of candidate initiation time points is constructed in a similar manner.

[0054] Based on the topological relationship of the spatial distribution of the blasting point coordinates, establish the adjacency constraint rules for the initiation sequence. Traverse all the permutations and combinations of the initiation sequences through the backtracking algorithm with the adjacency constraint rules and the set of candidate initiation time points to obtain a set of candidate solutions, and perform conflict detection on the permutations and combinations of the initiation sequences in the set of candidate solutions. The adjacency constraint rules consider the basic principles in blasting engineering, such as "advancing from the free face to the interior" and "initiating from the lower position to the higher position", etc., to ensure that the blasting sequence meets the requirements of engineering practice. For example, in a stepped open-pit stope, an adjacency constraint of "the blast holes in the front row must initiate before the blast holes in the back row" will be set to ensure a reasonable blasting sequence. The backtracking algorithm can efficiently search for feasible solutions under complex constraint conditions. For medium-scale blasting projects, such as 20 - 30 blast holes, the calculation can usually be completed within 1 - 3 minutes.

[0055] The method for performing conflict detection on the permutations and combinations of the initiation sequences in the set of candidate solutions includes: Construct a spatio-temporal influence relationship matrix between blast holes based on the spatial distribution of the blasting points and the stress wave propagation rate data in the 3D BIM geological model. Each element in the spatio-temporal influence relationship matrix represents whether the initiation time difference between adjacent holes is less than the theoretical time required for the stress wave to propagate to the adjacent hole; Traverse each permutation and combination of the initiation sequences. When it is detected that the initiation time difference between adjacent holes is less than the theoretical time reference, resulting in an abnormal increase in the energy value in the stress wave superposition area greater than the preset energy abnormal increase threshold, it is determined as a time overlap conflict; calculate the spatial intersection area of the stress wave propagation paths of adjacent holes under different initiation sequences according to the spatial coordinates of the blast holes in the 3D BIM geological model. If the average value of the broken rock block sizes in the intersection area exceeds the preset average broken rock block size, it is determined as a path intersection interference conflict; mark and eliminate the permutations and combinations of the initiation sequences with time overlap conflicts or path intersection interference conflicts. For example, in a blasting design, the distance between two adjacent blast holes is 3.5 meters, and the stress wave propagation rate of the rock mass is 4000 m / s, and the theoretical propagation time is about 0.88 ms. If the initiation sequence arrangement makes the initiation time difference between these two holes 0.5 ms, less than the theoretical time reference, it will cause abnormal superposition of the blasting energy of the two holes in the middle area, and the energy increase value reaches 35%, exceeding the preset threshold of 25%, and it is determined that this scheme has a time overlap conflict. If the average value of the broken rock block sizes in the intersection area exceeds the preset average broken rock block size (such as 500 mm), it is determined as a path intersection interference conflict. The path intersection interference conflict may lead to over-breaking or under-blasting phenomena in local areas, affecting the uniformity of the blasting effect. The conflict detection process ensures that the finally selected blasting scheme has good spatio-temporal coordination, can reduce safety risks while ensuring the blasting effect.

[0056] The method for generating the charging parameters according to the final charge amount and binding them to the spatial coordinates of the 3D BIM geological model includes: Extract the coordinate data of each blast hole and the corresponding rock mass explosibility zoning from the 3D BIM geological model, and generate the single-hole charge amount parameter in combination with the final charge amount. The single-hole charge amount parameter is dynamically corrected according to the initial charge density threshold of the rock mass explosibility zoning to which the blast hole belongs and the blast hole spacing. For example, for a high-hardness area with a hardness of 85 MPa, the initial charge density threshold may be set to 1.2 - 1.4 kg / m³; while for a medium-hardness area with a hardness of 60 MPa, the initial charge density threshold may be reduced to 0.9 - 1.1 kg / m³. Adjust the charge density by ±10% according to the ratio of the actual value to the theoretical optimal value of the blast hole spacing to ensure the precise matching of the charge amount and the blasting conditions.

[0057] Bind the single-hole charge amount parameter with the corresponding blast hole coordinates to form a structured charge parameter set and store it in the blast parameter database of the 3D BIM geological model. The structured charge parameter set includes information such as blast hole ID, 3D coordinates, the rock mass explosibility zoning to which it belongs, single-hole charge amount, initiation sequence number, millisecond delay time, etc., which is convenient for on-site construction personnel to precisely execute blasting operations and provides data support for subsequent blasting effect evaluation and parameter optimization.

[0058] Example 2: Based on the same inventive concept, as Figure 2 shown, this example also provides a BIM-based open-pit goaf charging safety risk warning system, which includes: a 3D BIM geological model construction module, a final charge amount analysis module, and a safety warning management module, and the modules are sequentially communicatively connected.

[0059] The 3D BIM geological model construction module is used to obtain the geological data, drilling parameter data, and historical blasting data of the open-pit goaf, and construct a 3D BIM geological model including rock mass hardness data, joint density, and fracture distribution data through drone scanning and core sampling.

[0060] The final charge amount analysis module is used to conduct rock mass explosibility zoning for the open-pit goaf according to the 3D BIM geological model, calculate the effective coverage radius of the single-hole blasting stress wave based on the rock mass hardness and fracture distribution data of the rock mass explosibility zoning, and determine the energy attenuation coefficient of the stress wave superposition effect according to the fracture connectivity between adjacent holes; establish an optimized model for the blasting hole spacing based on the energy attenuation coefficient and the effective coverage radius, and generate the initial blasting point coordinates according to the optimized model for the blasting hole spacing; input the initial blasting point coordinates into the 3D BIM geological model, simulate the distribution of rock fragmentation under the gradient change of the single-hole charge amount using the discrete element algorithm, and screen out the critical charge amount that meets the preset average fragmentation size as the minimum effective charge amount; obtain the simulation results through dynamic simulation of the minimum effective charge amount using the 3D BIM geological model, and output the final charge amount when the simulation results meet the preset safety constraint conditions; the simulation results include the trajectory of blasting flyrock and the vibration propagation range.

[0061] The safety warning management module is used to generate charging parameters according to the final charge amount and bind them to the spatial coordinates of the 3D BIM geological model, and output the warning area through the visualization interface; the charging parameters include the single-hole charge amount, the initiation sequence, and the millisecond delay time.

[0062] It should be noted that regarding the system in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0063] Finally, it should be noted that although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for early warning of charging safety risks in open-pit mined-out areas based on BIM, characterized in that, The method includes: Obtaining geological data, borehole parameter data, and historical blasting data of the open goaf, and constructing a three-dimensional BIM geological model containing rock mass hardness data, joint density, and fracture distribution data through drone scanning and core sampling; Conducting rock mass explosibility zoning for the open goaf according to the three-dimensional BIM geological model, calculating the effective coverage radius of the single-hole blasting stress wave based on the rock mass hardness and fracture distribution data in the rock mass explosibility zoning, and determining the energy attenuation coefficient of the stress wave superposition effect according to the fracture connectivity between adjacent holes; establishing a blasting hole spacing optimization model based on the energy attenuation coefficient and the effective coverage radius, and generating initial blasting point coordinates according to the blasting hole spacing optimization model; inputting the initial blasting point coordinates into the three-dimensional BIM geological model, simulating the rock mass fragmentation distribution under the gradient change of the single-hole charge amount by using the discrete element algorithm, and screening out the critical charge amount that meets the preset average fragmentation size as the minimum effective charge amount; obtaining the simulation result by dynamically simulating the minimum effective charge amount through the three-dimensional BIM geological model, and outputting the final charge amount when the simulation result meets the preset safety constraint conditions; the simulation results include blasting flyrock trajectory and vibration propagation range; Generating charge parameters according to the final charge amount and binding them to the spatial coordinates of the three-dimensional BIM geological model, and outputting the warning area through the visualization interface; the charge parameters include single-hole charge amount, initiation sequence, and millisecond delay time.

2. The method for warning safety risks of charging in open goafs based on BIM according to claim 1, characterized in that The method of obtaining the simulation result by dynamically simulating the minimum effective charge amount through the three-dimensional BIM geological model and outputting the final charge amount when the simulation result meets the preset safety constraint conditions includes: Calculating the energy coupling efficiency of the blasting stress wave between adjacent holes under different initiation sequences according to the spatial distribution of the blasting point coordinates and the millisecond delay time and the stress wave propagation rate, and selecting the initiation sequence with the energy coupling efficiency greater than the preset coupling efficiency threshold as the optimal time coordination scheme; When the blasting flyrock trajectory or vibration propagation range of the simulation result exceeds the preset safety threshold, recalculate the minimum effective charge amount and the energy coupling efficiency until the simulation result meets the preset safety constraint conditions.

3. The method for early warning of charging safety risks in open goafs based on BIM according to claim 1, characterized in that, The method of establishing a blasting hole spacing optimization model based on the energy attenuation coefficient and the effective coverage radius and generating initial blasting point coordinates according to the blasting hole spacing optimization model includes: Constructing a multi-objective optimization function with the minimization of the total charge amount and the maximization of the area of the superposition region of the blasting stress wave between adjacent holes based on the energy attenuation coefficient and the effective coverage radius; Iteratively generating a candidate solution set of the blasting hole spacing by using the genetic algorithm for the multi-objective optimization function; extracting the Pareto front solutions from the candidate solution set, screening the optimal blasting hole spacing from the Pareto front solutions according to the preset charge amount priority weight, and mapping the optimal blasting hole spacing through the coordinate system of the three-dimensional BIM geological model to obtain the initial blasting point coordinates; Verify whether the fracture connectivity between adjacent holes leads to an energy attenuation coefficient of the stress wave superposition effect exceeding a preset energy attenuation threshold through the three-dimensional BIM geological model using the initial blasting point coordinates. If it exceeds the preset energy attenuation threshold, adjust the blasting hole spacing to meet the energy attenuation coefficient constraint.

4. The method for warning the safety risk of charging in open goafs based on BIM according to claim 3, wherein The method for verifying whether the fracture connectivity between adjacent holes leads to an energy attenuation coefficient of the blasting stress wave superposition effect exceeding a preset energy attenuation threshold includes: Extract the fracture trend and fracture connectivity length between adjacent blasting holes according to the fracture distribution data in the three-dimensional BIM geological model, and calculate the fracture connectivity index, which is the ratio of the fracture connectivity length to the adjacent hole spacing; simulate the propagation path of the blasting stress wave in the fractured rock mass through the finite element analysis method using the fracture connectivity index and rock mass hardness data, and calculate the actual energy attenuation coefficient. If the actual energy attenuation coefficient is greater than the preset energy attenuation threshold, adjust the blasting hole spacing according to the angle between the fracture trend and the connection line of adjacent holes, and recalculate the fracture connectivity index and the actual energy attenuation coefficient of the adjusted area. If the actual energy attenuation coefficient is still greater than the preset energy attenuation threshold after a preset number of adjustments, mark the adjusted area as a high energy loss area in the three-dimensional BIM geological model and trigger a charge compensation instruction.

5. The method for warning of the safety risk of charging in an open goaf based on BIM according to claim 4, wherein, The method for adjusting the blasting hole spacing according to the angle between the fracture trend and the connection line of adjacent holes and recalculating the fracture connectivity index and the actual energy attenuation coefficient of the adjusted area includes: Calculate the cosine value of the angle according to the three-dimensional spatial geometric relationship between the fracture trend and the connection line of adjacent holes in the three-dimensional BIM geological model. If the cosine value of the angle is greater than the preset angle cosine value threshold, adjust the blasting hole spacing along the direction perpendicular to the fracture trend; if the cosine value of the angle is less than or equal to the preset angle cosine value threshold, adjust the blasting hole spacing along the direction parallel to the fracture trend. After each adjustment, recalculate the fracture connectivity index between adjacent holes according to the updated blasting hole coordinates; if the adjusted actual energy attenuation coefficient is greater than the preset energy attenuation threshold, increase the blasting hole spacing by a preset step size.

6. The method for warning of charging safety risks in open goafs based on BIM according to claim 2, characterized in that, The method for calculating the energy coupling efficiency of the blasting stress wave between adjacent holes under different initiation sequences according to the spatial distribution of the blasting point coordinates and the millisecond delay time and the stress wave propagation rate, and selecting the initiation sequence with an energy coupling efficiency greater than the preset coupling efficiency threshold as the optimal time coordination scheme includes: According to the spatial distribution of the blasting point coordinates generated by the blasting hole spacing optimization model, calculate the three-dimensional space distance vector between adjacent holes, and determine the theoretical time reference for the stress wave propagation between adjacent holes according to the stress wave propagation rate corresponding to the rock mass explosibility grade of each rock mass explosibility partition in the three-dimensional BIM geological model. Based on the theoretical time reference, a dynamic candidate interval for the millisecond delay time is established to obtain a set of candidate solutions for the initiation sequence permutations; for each initiation sequence permutation in the set of candidate solutions, the matching degree between the initiation time difference of adjacent holes and the stress wave propagation time is calculated according to the three-dimensional space distance vector and the stress wave propagation rate, and the ratio of the peak energy of the superimposed stress wave to the peak energy of the single-hole stress wave is quantified by numerical simulation as the energy coupling efficiency. If there are multiple initiation sequence permutations with an energy coupling efficiency greater than the preset coupling efficiency threshold, the optimal time coordination solution is selected according to the principle of the minimum total millisecond delay time.

7. The method for warning of charging safety risks in open-pit mined-out areas based on BIM according to claim 6, characterized in that, The method of establishing a set of candidate solutions for the initiation sequence permutations by establishing a dynamic candidate interval for the millisecond delay time based on the theoretical time reference includes: According to the millisecond delay time range within the dynamic candidate interval, a set of candidate initiation time points is generated for each blast hole, and the set of candidate initiation time points is evenly distributed according to the preset interval based on the theoretical time reference of stress wave propagation. Based on the topological relationship of the spatial distribution of the blast point coordinates, an adjacency constraint rule for the initiation sequence is established. By traversing all initiation sequence permutations using the backtracking algorithm with the adjacency constraint rule and the set of candidate initiation time points, a set of candidate solutions is obtained, and conflict detection is performed on the initiation sequence permutations in the set of candidate solutions.

8. The method for early warning of charging safety risks in open goafs based on BIM according to claim 7, wherein, The method of performing conflict detection on the initiation sequence permutations in the set of candidate solutions includes: Based on the spatial distribution of the blast points and the stress wave propagation rate data in the three-dimensional BIM geological model, a spatio-temporal influence relationship matrix between blast holes is constructed. Each element in the spatio-temporal influence relationship matrix represents whether the initiation time difference between adjacent holes is less than the theoretical time required for the stress wave to propagate to the adjacent hole. Traverse each initiation sequence permutation. When it is detected that the initiation time difference between adjacent holes is less than the theoretical time reference and the abnormal increase value of the energy in the stress wave superposition area is greater than the preset energy abnormal increase threshold, it is determined as a time overlap conflict; according to the spatial coordinates of the blast holes in the three-dimensional BIM geological model, the spatial intersection area of the stress wave propagation paths of adjacent holes under different initiation sequences is calculated. If the average value of the broken rock block sizes in the intersection area exceeds the preset average broken rock block size, it is determined as a path intersection interference conflict; the initiation sequence permutations with time overlap conflicts or path intersection interference conflicts are marked and removed.

9. The method for warning of charging safety risks in open goafs based on BIM according to claim 1, characterized in that, The method of generating charge parameters based on the final charge amount and binding them to the spatial coordinates of the three-dimensional BIM geological model includes: Extract the coordinate data of each blast hole and the corresponding rock mass explosibility partition from the three-dimensional BIM geological model, and generate the single-hole charge amount parameters in combination with the final charge amount. The single-hole charge amount parameters are dynamically corrected according to the initial charge density threshold of the rock mass explosibility partition to which the blast hole belongs and the blast hole spacing. Bind the single-hole charge amount parameters to the corresponding blast hole coordinates to form a structured set of charge parameters and store them in the blast parameter database of the three-dimensional BIM geological model.

10. The BIM-based safety risk early warning system for charging in open goafs is characterized in that, The system includes: a three-dimensional BIM geological model construction module, a final charge amount analysis module, and a safety warning management module, and the modules are sequentially communicatively connected; 3D BIM geological model construction module, which is used to obtain geological data, borehole parameter data and historical blasting data of the open-pit goaf, and construct a 3D BIM geological model containing rock mass hardness data, joint density and fracture distribution data through UAV scanning and core sampling; Final charge amount analysis module, which is used to conduct rock mass explosibility zoning on the open-pit goaf according to the 3D BIM geological model, calculate the effective coverage radius of the single-hole blasting stress wave according to the rock mass hardness and fracture distribution data of the rock mass explosibility zoning, and determine the energy attenuation coefficient of the stress wave superposition effect according to the fracture connectivity between adjacent holes; establish a blasting hole spacing optimization model according to the energy attenuation coefficient and the effective coverage radius, and generate the initial blasting point coordinates according to the blasting hole spacing optimization model; input the initial blasting point coordinates into the 3D BIM geological model, and use the discrete element algorithm to simulate the rock mass fragmentation distribution under the gradient change of the single-hole charge amount, and screen out the critical charge amount that meets the preset average fragmentation size as the minimum effective charge amount; obtain the simulation result by dynamically simulating the minimum effective charge amount through the 3D BIM geological model, and output the final charge amount when the simulation result meets the preset safety constraint conditions; the simulation results include blasting flyrock trajectory and vibration propagation range; Safety early warning management module, which is used to generate charging parameters according to the final charge amount and bind them to the spatial coordinates of the 3D BIM geological model, and output the early warning area through the visualization interface; the charging parameters include single-hole charge amount, initiation sequence and millisecond delay time.

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