A method and system for optimizing the blasting parameters of smooth blasting for tunnel surrounding rock

Abstract

The present invention relates to the technical field of blasting construction, and particularly to a method and system for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock. The method comprises the following steps: determining the blasting parameters for smooth blasting of tunnel surrounding rock; establishing a first mathematical model among the hole spacing, the smooth blasting layer thickness and the decoupling coefficient, and a second mathematical model between the hole spacing and the maximum allowable delay time; constructing a parameter optimization design model to obtain the optimal parameter values of the hole spacing, the smooth blasting layer thickness, the hole diameter and the hole depth; substituting the optimal parameter values of the hole spacing and the smooth blasting layer thickness into the first mathematical model to calculate the optimal decoupling coefficient; and obtaining the optimal maximum allowable delay time according to the optimal parameter values, the optimal decoupling coefficient and the second mathematical model. The present invention can improve the efficiency and accuracy of the design of blasting parameters for smooth blasting, and is beneficial to improving the efficiency of optimizing blasting parameters, and ensuring the effect and safety of smooth blasting of tunnel surrounding rock.

Description

Technical Field

[0001] The present invention relates to the technical field of blasting construction, and in particular to a method and system for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock. Background Technique

[0002] Tunnel engineering is an important part of traffic construction. As an important construction technique for tunnel excavation, smooth blasting has many advantages such as reducing the disturbance to the surrounding rock, maximizing the self-bearing capacity of the surrounding rock, facilitating the construction safety of subsequent processes, effectively controlling overbreak and underbreak, and saving the construction cost of the primary support. However, in practical applications, the effect of smooth blasting is affected by various factors, including the hole form and blasting parameters, charge structure, initiation network, and intelligent control technology. Among them, the selection of blasting parameters has a direct impact on the blasting effect.

[0003] In current tunnel smooth blasting, the design method of blasting parameters is mainly based on empirical formulas and engineering analogy methods, lacking theoretical support and quantitative calculation. This results in that in practical applications, the blasting effect often fails to meet the expectations, and even overbreak or underbreak may occur, increasing the construction cost and construction period. To address the above problems, some methods such as numerical simulation and machine learning algorithms have been used to optimize the pre-set smooth blasting parameters, thereby improving the blasting effect. However, the pre-set numerical values of smooth blasting parameters often differ greatly from the optimal numerical values of smooth blasting parameters. Moreover, when using numerical simulation or machine learning algorithms to optimize the smooth blasting parameters, a blasting test needs to be carried out for each newly generated set of blasting parameters to verify the blasting effect under this set of blasting parameters, which greatly increases the computational amount, time consumption, and cost of optimizing the smooth blasting parameters. However, if the accuracy of the initially designed blasting parameters is relatively high, this problem can be effectively alleviated.

[0004] Therefore, a more efficient and accurate design scheme for smooth blasting parameters is needed to improve the accuracy of blasting parameter design, thereby improving the optimization efficiency of blasting parameters and ensuring the effect and safety of smooth blasting of tunnel surrounding rock. Summary of the Invention

[0005] Aiming at the defects in the prior art, the present invention provides a method and system for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock.

[0006] To achieve the above object, in a first aspect, the present invention provides a method for optimizing the blasting parameters of smooth blasting of tunnel surrounding rock. The method comprises the following steps: determining the blasting parameters of smooth blasting of tunnel surrounding rock, where the blasting parameters include hole spacing, smooth blasting layer thickness, hole diameter, hole depth, decoupling coefficient, and delay time; establishing a first mathematical model among the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and simultaneously establishing a second mathematical model between the hole spacing and the maximum allowable delay time; constructing a parameter optimization design model, and using the parameter optimization design model to obtain the optimal parameter values of the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth; substituting the optimal parameter values of the hole spacing and the smooth blasting layer thickness into the first mathematical model, and then calculating the optimal decoupling coefficient; and obtaining the optimal delay time according to the optimal parameter values, the optimal decoupling coefficient, and the second mathematical model. The present invention can improve the efficiency and accuracy of the design of blasting parameters for smooth blasting, and is conducive to improving the efficiency of optimizing blasting parameters, and ensuring the effect and safety of smooth blasting of tunnel surrounding rock.

[0007] Optionally, the step of establishing a first mathematical model among the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and simultaneously establishing a second mathematical model between the hole spacing and the maximum allowable delay time comprises the following steps:

[0008] Using numerical simulation software to construct a first numerical model of the test blasting object;

[0009] Adjusting the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and performing blasting numerical simulation on the test blasting object, and then constructing a first data set;

[0010] Adjusting the hole spacing and the maximum allowable delay time, and performing blasting numerical simulation on the test blasting object, and then constructing a second data set;

[0011] Obtaining the first mathematical model according to the first data set, and simultaneously obtaining the second mathematical model according to the second data set.

[0012] Optionally, the step of adjusting the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and performing blasting numerical simulation on the test blasting object, and then constructing a first data set comprises the following steps:

[0013] Adjusting the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and performing blasting numerical simulation on the test blasting object;

[0014] Setting a plurality of stress observation points in the middle of two adjacent holes on the test blasting object, and calculating the first average stress of all the stress observation points;

[0015] If the first average stress is greater than the dynamic tensile strength of the test blasting object, record the corresponding hole spacing, smooth blasting layer thickness, and decoupling coefficient as a set of first available data;

[0016] Construct the first data set using multiple sets of the first available data.

[0017] Optionally, the steps of adjusting the hole spacing and the maximum allowable delay time, performing blasting numerical simulation on the test blasting object, and then constructing the second data set include the following:

[0018] Adjust the hole spacing and the maximum allowable delay time, perform blasting numerical simulation on the test blasting object, and calculate the second average stress of the stress observation point;

[0019] If the second average stress is greater than the dynamic tensile strength of the test blasting object, record the corresponding hole spacing and maximum allowable delay time as a set of second available data;

[0020] Construct the second data set using multiple sets of the second available data.

[0021] Optionally, the first mathematical model satisfies the following relationship:

[0022]

[0023] Where is the hole spacing, , , , and are the first set of fitting coefficients, is the smooth blasting layer thickness, is the decoupling coefficient.

[0024] Optionally, the second mathematical model satisfies the following relationship:

[0025]

[0026] Where is the hole spacing, A, B, and C are the second set of fitting coefficients, T is the maximum allowable delay time, and n is the number of holes.

[0027] Optionally, the steps of constructing the parameter optimization design model and using the parameter optimization design model to obtain the optimal parameter values of the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth include the following:

[0028] Collect the geological condition data, blasting operation parameter data, the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth of successful blasting cases in history, and then construct a model training and validation set;

[0029] Using the geological condition data and the blasting operation parameter data as inputs, construct a parameter optimization design model using the model training and validation set and a BP neural network;

[0030] Input the geological condition data and the blasting operation parameter data of the blasting target into the parameter optimization design model to obtain the optimal parameter values of the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth.

[0031] Optionally, the obtaining the optimal delay time according to the optimal parameter values, the optimal decoupling coefficient, and the second mathematical model includes the following steps:

[0032] According to the optimal parameter values and the optimal decoupling coefficient, determine the first preset optimal value of blasting delay using a blasting delay setting scheme;

[0033] Substitute the optimal parameter value of the hole spacing into the second mathematical model, calculate the maximum allowable delay time and use it as the second preset optimal value of blasting delay;

[0034] If the first preset optimal value of blasting delay is not less than the second preset optimal value of blasting delay, then use the second preset optimal value of blasting delay as the optimal delay time;

[0035] If the first preset optimal value of blasting delay is less than the second preset optimal value of blasting delay, then use the average value of the two as the optimal delay time.

[0036] Optionally, the determining the first preset optimal value of blasting delay according to the optimal parameter values and the optimal decoupling coefficient using a blasting delay setting scheme includes the following steps:

[0037] Use numerical simulation software to construct a second numerical model of the blasting target, and the second numerical model contains a plurality of holes set according to the optimal parameter values and a vibration monitoring point;

[0038] Conduct a single-hole blasting numerical simulation test on any one hole of the second numerical model, and monitor the vibration waveform of the test at the vibration monitoring point;

[0039] Fit the vibration waveform to obtain a fitting function, and use wavelet transform to intercept the single-hole blasting vibration waveform on the fitting function, and then determine the blasting action duration;

[0040] Set multiple blasting delay times within the blasting action duration. For any one of the blasting delay times, obtain a multi-hole vibration superposition waveform within the blasting action duration according to the single-hole blasting vibration waveform;

[0041] Determine the maximum vibration velocity corresponding to the corresponding blasting delay time according to the multi-hole vibration superposition waveform, and take the blasting delay time corresponding to the maximum vibration velocity with the smallest value as the preset optimal value of the first blasting delay.

[0042] In a second aspect, the present invention also provides a blasting parameter optimization design system for smooth blasting of tunnel surrounding rock. The blasting parameter optimization design system for smooth blasting of tunnel surrounding rock includes: a data acquisition device, a data output device, a processor, and a storage. The storage includes a computer-readable storage medium, and a computer program is stored in the computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the processor, the processor implements the blasting parameter optimization design method for smooth blasting of tunnel surrounding rock provided by the present invention.

[0043] In summary, the present invention has at least the following beneficial effects:

[0044] 1. First, this method designs the hole spacing, smooth blasting layer thickness, hole diameter, and hole depth by constructing a parameter optimization design model. Then, based on the numerical simulation results, a first mathematical model and a second mathematical model are constructed. Furthermore, the decoupling coefficient and delay time are optimized and designed in combination with the design results of the parameter optimization design model, enabling the various blasting parameters to be mutually adapted, reducing the calculation, time consumption, and cost of designing the blasting parameters, and improving the accuracy and efficiency of designing the blasting parameters.

[0045] 2. Since the blasting parameters optimized and designed by this method have high accuracy, it provides a good start for further optimizing the blasting parameters. Using the blasting parameters optimized and designed by the present invention as the initial blasting parameters is beneficial for reducing the number of blasting tests required for further optimizing the blasting parameters, thereby improving the efficiency of optimizing the blasting parameters and ensuring the effect and safety of smooth blasting of tunnel surrounding rock.

[0046] 3. The system provided by the present invention not only has the advantages of the method provided by the present invention, but also can improve the design efficiency of the blasting parameters and the practicability of this method. Description of the Drawings

[0047] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0048] Figure 1 It is a schematic flow chart of a method for optimizing the blasting parameters of smooth blasting of tunnel surrounding rock according to an embodiment of the present invention;

[0049] Figure 2 It is a schematic framework diagram of a system for optimizing the blasting parameters of smooth blasting of tunnel surrounding rock according to an embodiment of the present invention. Detailed implementation manners

[0050] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described here are only for illustrative purposes and do not limit the present invention. In the following description, in order to provide a thorough understanding of the present invention, a large number of specific details are elaborated. However, it is obvious to those of ordinary skill in the art that the present invention does not have to adopt these specific details. In other instances, well-known circuits, software, or methods are not specifically described to avoid obscuring the present invention.

[0051] Throughout the specification, the reference to "one embodiment", "an embodiment", "an example" or "an example" means that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment", "in an embodiment", "an example" or "an example" appearing throughout the specification do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, or characteristics can be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. In addition, those of ordinary skill in the art should understand that the drawings provided here are for illustrative purposes and the drawings are not necessarily drawn to scale.

[0052] It should be noted in advance that in an optional embodiment, except for making independent explanations, the same symbols or letters appearing in all formulas represent the same meanings and values.

[0053] In an optional embodiment, please refer to Figure 1 , the present invention provides a method for optimizing the blasting parameters of smooth blasting of tunnel surrounding rock, and the method includes the following steps:

[0054] S1. Determine the blasting parameters for smooth blasting of tunnel surrounding rock. The blasting parameters include hole spacing, smooth blasting layer thickness, hole diameter, hole depth, decoupling coefficient, and delay time.

[0055] Specifically, in this embodiment, the decoupling coefficient refers to the ratio of the hole diameter to the cartridge diameter, and the delay time refers to the blasting time interval between two adjacent holes in the same row of holes.

[0056] S2. Establish a first mathematical model among the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and at the same time establish a second mathematical model between the hole spacing and the maximum allowable delay time.

[0057] Among them, step S2 specifically includes the following steps:

[0058] S21. Use numerical simulation software to construct a first numerical model of the test blasting object.

[0059] Specifically, in this embodiment, the test blasting object is the blasting surface for blasting tests. When using numerical simulation software to construct the first numerical model, its various parameters can be set with reference to the blasting target or other blasting surfaces.

[0060] More specifically, the numerical simulation software described in this embodiment is specifically ANSYS / LS-DYNA. There is a row of holes on the first numerical model, with a total of 4 holes. In addition, the blasting target refers to the surrounding rock to be blasted in the tunnel.

[0061] S22. Adjust the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and conduct blasting numerical simulation on the test blasting object, and then construct a first data set.

[0062] Among them, step S22 specifically includes the following steps:

[0063] S221. Adjust the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient, and conduct blasting numerical simulation on the test blasting object.

[0064] Specifically, in this embodiment, keeping other conditions unchanged, randomly adjust any one of the hole spacing, the smooth blasting layer thickness, and the decoupling coefficient. After each adjustment, use the first numerical model to conduct a blasting numerical simulation once, and record a corresponding set of hole spacing, smooth blasting layer thickness, and decoupling coefficient. In addition, in this step, in order to obtain a more accurate and reliable first mathematical model, sufficient blasting numerical simulations should be carried out.

[0065] S222. Set multiple stress observation points in the middle of two adjacent holes on the test blasting object, and calculate the first average stress of all the stress observation points.

[0066] Specifically, in this embodiment, the distances between the stress observation points and the two adjacent blast holes on both sides are the same, and the sum of the distances between the stress observation points and the two adjacent blast holes on both sides is equal to the distance between these two blast holes, and three stress observation points are set in the middle of two adjacent blast holes.

[0067] More specifically, since there are a total of 4 blast holes arranged in a row on the first numerical model, 9 stress observation points need to be set, and the stress changes at these nine stress observation points can also be obtained in real time during numerical simulation. The first average stress is the average value of the maximum stress values at each of these stress observation points.

[0068] S223. If the first average stress is greater than the dynamic tensile strength of the test blasting object, then record the corresponding blast hole spacing, smooth blasting layer thickness, and decoupling coefficient as a set of first available data.

[0069] Specifically, in this embodiment, if a certain first average stress is greater than the dynamic tensile strength of the test blasting object, it is considered that effective blasting of the test blasting object can be achieved under the corresponding blast hole spacing, smooth blasting layer thickness, and decoupling coefficient, then record this set of blast hole spacing, smooth blasting layer thickness, and decoupling coefficient as a set of first available data.

[0070] S224. Use multiple sets of the first available data to construct the first data set.

[0071] S23. Adjust the blast hole spacing and the maximum allowable delay time, and conduct blasting numerical simulation on the test blasting object, and then construct the second data set.

[0072] Among them, step S23 specifically includes the following steps:

[0073] S231. Adjust the blast hole spacing and the maximum allowable delay time, conduct blasting numerical simulation on the test blasting object, and calculate the second average stress of the stress observation points.

[0074] Specifically, in this embodiment, the maximum allowable delay time refers to the maximum delay time that can meet the blasting requirements. If the delay time exceeds the maximum allowable delay time, it is considered that a good blasting effect cannot be achieved. The specific implementation plan of this step can refer to step S221 and step S222, and will not be elaborated here.

[0075] S232. If the second average stress is greater than the dynamic tensile strength of the test blasting object, then record the corresponding blast hole spacing and maximum allowable delay time as a set of second available data.

[0076] Specifically, in this embodiment, if a certain second average stress is greater than the dynamic tensile strength of the test blasting object, it is considered that effective blasting of the test blasting object can be achieved at the corresponding hole spacing and maximum allowable delay time. Then, this set of hole spacing and maximum allowable delay time is recorded as a set of second available data.

[0077] S233. Use multiple sets of the second available data to construct the second data set.

[0078] S24. Obtain the first mathematical model according to the first data set, and at the same time obtain the second mathematical model according to the second data set.

[0079] Specifically, in this embodiment, the hole spacing, smooth blasting layer thickness, and decoupling coefficient are respectively used as the x-axis coordinate, y-axis coordinate, and z-axis coordinate in the space rectangular coordinate system. Then, the data in the first data set are marked in the space rectangular coordinate system, and the first mathematical model can be obtained by fitting with Origin software. Similarly, with the hole spacing as the abscissa and the maximum allowable delay time as the ordinate, the data in the second data set are marked in the plane rectangular coordinate system, and the second mathematical model can be obtained through fitting.

[0080] More specifically, the first mathematical model and the second mathematical model respectively satisfy the following relationships:

[0081]

[0082]

[0083] Among them, is the hole spacing, 、 、 、 and are the first set of fitting coefficients, is the smooth blasting layer thickness, is the decoupling coefficient, A, B, and C are the second set of fitting coefficients, T is the maximum allowable delay time, and n is the number of holes. 、 、 、 and take the values of -807.43, 5.19, 185.22, and 0.003 in sequence, and the values of A, B, and C take the values of 1788.69, 966.24, and 155.65 in sequence.

[0084] In this embodiment, by constructing the first mathematical model and the second mathematical model, the efficiency of the optimal design of blasting parameters can be improved. Moreover, the first mathematical model and the second mathematical model are obtained based on numerical simulation, and one of the advantages of numerical simulation is its high accuracy. Therefore, using the first mathematical model and the second mathematical model for the optimal design of blasting parameters also has high accuracy.

[0085] S3. Construct a parameter optimal design model, and use the parameter optimal design model to obtain the optimal parameter values of the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth.

[0086] The hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth are the basic parameters in smooth blasting. Compared with the decoupling coefficient and the delay time, they directly affect the blasting effect and cost, and there is a certain dependence and independence among these parameters, which can be effectively predicted by machine learning algorithms. The decoupling coefficient and the delay time more depend on these basic parameters and the specific blasting conditions and requirements. Therefore, in order to reduce the model complexity and improve the design efficiency on the basis of ensuring the accuracy of the blasting parameter design in this embodiment, only the parameter optimal design model is used to design the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth. Step S3 specifically includes the following steps:

[0087] S31. Collect the geological condition data, the blasting operation parameter data, the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth of historical successful blasting cases, and then construct a model training and validation set.

[0088] Specifically, in this embodiment, query and collect the geological condition data, the blasting operation parameter data, the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth of historical successful blasting cases on the Internet, magazines, and periodicals to construct a model training and validation set.

[0089] More specifically, the geological condition data specifically includes the rock compressive strength, the rock tensile strength, and the blasting surface area, and the blasting operation parameter data specifically includes the explosive type, the explosive dosage, and the charging structure. In other alternative embodiments, the geological condition data and the blasting operation parameter data may also include other types of data, but the types should not be too many to avoid the curse of dimensionality when constructing the parameter optimal design model, and it is also beneficial to reduce feature redundancy and model complexity.

[0090] S32. Use the geological condition data and the blasting operation parameter data as inputs, and construct a parameter optimal design model using the model training and validation set and the BP neural network.

[0091] Specifically, in this embodiment, first, using the geological condition data and the blasting operation parameter data as inputs and the hole spacing, smooth blasting layer thickness, hole diameter, and hole depth as outputs, a parameter optimization initial model is constructed using a BP neural network. Then, the model training verification set is divided into a training set and a verification set according to a ratio of 8:2 to complete the training and verification of the parameter optimization initial model respectively, and finally a parameter optimization design model is obtained.

[0092] S33. Input the geological condition data and the blasting operation parameter data of the blasting target into the parameter optimization design model to obtain the optimal parameter values of the hole spacing, the smooth blasting layer thickness, the hole diameter, and the hole depth.

[0093] S4. Substitute the optimal parameter values of the hole spacing and the smooth blasting layer thickness into the first mathematical model to calculate the optimal decoupling coefficient.

[0094] Specifically, in this embodiment, according to the optimal parameter values of the hole spacing and the smooth blasting layer thickness, the optimal decoupling coefficient is calculated using the first mathematical model, so that the various blasting parameters are adapted to each other, reducing the calculation, time consumption, and cost of designing the blasting parameters, and improving the accuracy and efficiency of designing the blasting parameters.

[0095] S5. Obtain the optimal delay time according to the optimal parameter values, the optimal decoupling coefficient, and the second mathematical model.

[0096] In this embodiment, first, the hole spacing, the smooth blasting layer thickness, the hole diameter, the hole depth, and the decoupling coefficient are designed, and then the optimal delay time is obtained in combination with the second mathematical model, so that the various blasting parameters are adapted to each other, reducing the calculation, time consumption, and cost of designing the blasting parameters, and improving the accuracy and efficiency of designing the blasting parameters. Step S5 specifically includes the following steps:

[0097] S51. According to the optimal parameter values and the optimal decoupling coefficient, determine the first preset optimal value of blasting delay using a blasting delay setting scheme.

[0098] Among them, step S51 specifically further includes the following steps:

[0099] S511. Use numerical simulation software to construct a second numerical model of the blasting target, and the second numerical model includes a plurality of holes set according to the optimal parameter values and a vibration monitoring point.

[0100] Specifically, in this embodiment, according to the parameters obtained in step S33, namely the blasthole spacing, the smooth blasting layer thickness, the blasthole diameter, and the blasthole depth, multiple rows of blastholes are set on the second numerical model, and a vibration monitoring point is set on the ground at the location where the blasting target is located. When setting the blastholes, the number of blastholes can be set according to the blasthole spacing and the blasting surface area.

[0101] More specifically, the blastholes set are numbered from left to right in sequence. When numbering, for two adjacent blastholes, the last blasthole in the previous row and the first blasthole in the next row are regarded as adjacent blastholes. Suppose there are two rows of blastholes, with three blastholes in each row. Then the blasthole numbers in the first row are 1, 2, and 3 in sequence, and the blasthole numbers in the second row are 4, 5, and 6 in sequence.

[0102] S512. Conduct a single-hole blasting numerical simulation test on any one of the blastholes on the second numerical model, and monitor the vibration waveform of the test at the vibration monitoring point.

[0103] S513. Fit the vibration waveform to obtain a fitting function, and use wavelet transform to intercept the single-hole blasting vibration waveform on the fitting function, thereby determining the blasting action duration.

[0104] Specifically, in this embodiment, the vibration waveform obtained in step S512 is fitted based on the Fourier series, and the obtained fitting function satisfies the following relationship:

[0105]

[0106] Among them, is the fitting function, n is the series number, is the fundamental frequency, t is the time, and are the fitting coefficients of the i-th series, and D is also a fitting coefficient.

[0107] More specifically, when conducting the blasting numerical simulation, the vibration waveform at the vibration monitoring point often includes some waveforms caused by non-blasting factors, such as numerical model initialization and boundary condition setting. Therefore, the vibration waveform obtained in step S512 cannot be directly used as the effective vibration waveform. In order to obtain the vibration waveform truly and completely generated by blasting, this embodiment uses wavelet transform to obtain the time-frequency characteristic curve of, and determines the start time and end time of the blasting vibration according to the rising edge and falling edge of the time-frequency characteristic curve, thereby determining the blasting action duration. The wavelet used in this embodiment is specifically the Symlet wavelet. In other alternative embodiments, other wavelets can also be used.

[0108] S514. Set multiple blasting delay times within the blasting action duration. For any one of the blasting delay times, obtain the multi-hole vibration superposition waveform within the blasting action duration according to the single-hole blasting vibration waveform.

[0109] Specifically, in this embodiment, set the blasting delay time sequence , where , , , , is the j-th blasting delay time in the blasting delay time sequence, is the (j + 1)-th blasting delay time in the blasting delay time sequence, and M is the number of blasting delay times set in the blasting delay time sequence.

[0110] Further, for any one of the blasting delay times in the blasting delay time sequence, superpose multiple single-hole blasting vibration waveforms within a blasting action duration, and the obtained multi-hole vibration superposition waveform satisfies the following relationship:

[0111]

[0112]

[0113] where, is the vibration velocity; K is the number of single-hole blasting vibration waveforms participating in the superposition within a blasting action duration. Considering the blasting delay time, the participation of K single-hole blasting vibration waveforms in the superposition means that the 1st to the K-th blast holes participate in the blasting; is an algebraic expression; is the distance between the blast hole corresponding to the k-th multi-hole vibration superposition waveform and the vibration monitoring point, is the distance between the blast hole corresponding to the 1st multi-hole vibration superposition waveform and the vibration monitoring point, is the propagation velocity of the vibration wave in the surrounding rock.

[0114] S515. Determine the maximum vibration velocity at the corresponding blasting delay time according to the multi-hole vibration superposition waveform, and take the blasting delay time corresponding to the minimum maximum vibration velocity as the first preset optimal value of the blasting delay.

[0115] Specifically, in this embodiment, one blasting delay time corresponds to one multi-hole vibration superposition waveform, and there is a maximum vibration velocity in each multi-hole vibration superposition waveform, that is, one blasting delay time corresponds to one maximum vibration velocity. In this embodiment, the blasting delay time corresponding to the minimum maximum vibration velocity is taken as the first preset optimal value of the blasting delay.

[0116] S52. Substitute the optimal parameter value of the blasthole spacing into the second mathematical model, calculate the maximum allowable delay time, and use it as the preset optimal value of the second blasting delay.

[0117] S53. If the preset optimal value of the first blasting delay is not less than the preset optimal value of the second blasting delay, then use the preset optimal value of the second blasting delay as the optimal delay time.

[0118] Specifically, in this embodiment, too large a delay time will lead to a decrease in the rock fragmentation effect, thereby increasing the risks of overbreak and underbreak. Too small a delay time will result in insufficient rock fragmentation and an increase in vibration and noise. Therefore, if the preset optimal value of the first blasting delay is not less than the preset optimal value of the second blasting delay, it is considered that the blasting requirements cannot be met at the preset optimal value of the first blasting delay, and then the preset optimal value of the second blasting delay is directly used as the optimal delay time.

[0119] S54. If the preset optimal value of the first blasting delay is less than the preset optimal value of the second blasting delay, then use the average value of the two as the optimal delay time.

[0120] Specifically, in this embodiment, if the preset optimal value of the first blasting delay is less than the preset optimal value of the second blasting delay, it is considered that the blasting requirements can be met at the preset optimal value of the first blasting delay. However, to avoid insufficient rock fragmentation and an increase in vibration and noise caused by too small a delay time, the average value of the preset optimal value of the first blasting delay and the preset optimal value of the second blasting delay is used as the optimal delay time in this embodiment.

[0121] It should be noted that in some cases, the actions recorded in the specification can be executed in a different order and still achieve the desired results. In this embodiment, the given step order is only for making the embodiment look clearer and more convenient for explanation, rather than a limitation.

[0122] In an alternative embodiment, please refer to Figure 2 , to improve the design efficiency of blasting parameters and the practicability of the method provided in this embodiment, the present invention also provides a blasting parameter optimization design system for smooth blasting of tunnel surrounding rock. The blasting parameter optimization design system for smooth blasting of tunnel surrounding rock includes: a data acquisition device 1, a data output device 2, a processor 3, and a storage 4. The storage 4 includes a computer-readable storage medium, and a computer program is stored in the computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the processor 3, the processor 3 is caused to implement the content described in steps S1 to S5.

[0123] Specifically, in this embodiment, the data acquisition device 1 can be used to input the data in the model training verification set, as well as the geological condition data and blasting operation parameter data of the blasting target. The data output device 2 is used to output the optimal parameter values of the hole spacing, smooth blasting layer thickness, hole diameter, and hole depth, as well as the optimal decoupling coefficient and optimal delay time.

[0124] In summary, this method first designs the hole spacing, smooth blasting layer thickness, hole diameter, and the hole depth by constructing a parameter optimization design model. Then, based on the numerical simulation results, the first mathematical model and the second mathematical model are constructed. Furthermore, in combination with the design results of the parameter optimization design model, the decoupling coefficient and the delay time are optimized and designed, enabling the mutual adaptation of each blasting parameter, reducing the calculation, time consumption, and cost of designing the blasting parameters, and improving the accuracy and efficiency of designing the blasting parameters. Since the blasting parameters optimized and designed by this method have high accuracy, it provides a good start for the further optimization of the blasting parameters. Using the blasting parameters optimized and designed by the present invention as the initial blasting parameters is conducive to reducing the number of blasting tests required for further optimizing the blasting parameters, thereby improving the efficiency of optimizing the blasting parameters and ensuring the effect and safety of smooth blasting of the tunnel surrounding rock. In addition, the system provided by the present invention not only has the advantages of the method provided by the present invention, but also can improve the design efficiency of the blasting parameters and the practicality of this method.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the specification of the present invention.

Claims

1. A method for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock, characterized in that: The steps include: Determine blasting parameters for smooth blasting of tunnel surrounding rock, wherein the blasting parameters include blast hole spacing, smooth blast layer thickness, blast hole diameter, blast hole depth, uncoupling coefficient and delay time; Establishing a first mathematical model between the blasthole spacing, the light explosion layer thickness and the uncoupling coefficient, and establishing a second mathematical model between the blasthole spacing and the maximum allowable delay time; Collect geological condition data, blasting operation parameter data, the blasthole spacing, the smooth blasting layer thickness, the blasthole diameter and the blasthole depth of historical successful blasting cases, and then construct a model training and verification set; Taking the geological condition data and the blasting operation parameter data as input, using the model training verification set and BP neural network to construct a parameter optimization design model; Inputting the geological condition data of the blasting target and the blasting operation parameter data into the parameter optimization design model to obtain the optimal parameter values ​​of the blasthole spacing, the smooth blasting layer thickness, the blasthole diameter and the blasthole depth; Bringing the optimal parameter values ​​of the blasthole spacing and the thickness of the light explosion layer into the first mathematical model, and then calculating the optimal uncoupling coefficient; According to the optimal parameter value and the optimal uncoupling coefficient, a blasting delay setting scheme is adopted to determine a first blasting delay preset optimal value; Bringing the optimal parameter value of the blasthole spacing into the second mathematical model, calculating the maximum allowable delay time and using it as the second blasting delay preset optimal value; If the first blasting delay preset optimal value is not less than the second blasting delay preset optimal value, the second blasting delay preset optimal value is used as the optimal delay time; If the first blasting delay preset optimal value is smaller than the second blasting delay preset optimal value, the average value of the two is taken as the optimal delay time.

2. The method for optimizing the design of blasting parameters for smooth blasting of surrounding rock in a tunnel according to claim 1, characterized in that: The step of establishing a first mathematical model between the blasthole spacing, the light explosion layer thickness and the uncoupling coefficient, and simultaneously establishing a second mathematical model between the blasthole spacing and the maximum allowable delay time comprises the following steps: constructing a first numerical model of the test blasting object using numerical simulation software; Adjusting the blasthole spacing, the light explosion layer thickness and the uncoupling coefficient, and performing blasting numerical simulation on the test blasting object, thereby constructing a first data set; adjusting the blasthole spacing and the maximum allowable delay time, and performing blasting numerical simulation on the test blasting object, thereby constructing a second data set; The first mathematical model is obtained according to the first data set, and the second mathematical model is obtained according to the second data set.

3. The method for optimizing the design of blasting parameters for smooth blasting of surrounding rock in a tunnel according to claim 2, characterized in that: The adjusting the blasthole spacing, the smooth explosion layer thickness and the uncoupling coefficient, and performing blasting numerical simulation on the test blasting object, and then constructing a first data set comprises the following steps: adjusting the blasthole spacing, the light explosion layer thickness and the uncoupling coefficient, and performing blasting numerical simulation on the test blasting object; Setting a plurality of stress observation points between two adjacent blast holes on the test blasting object, and calculating a first average stress of all the stress observation points; If the first average stress is greater than the dynamic tensile strength of the test blasting object, the corresponding blasthole spacing, smooth blasting layer thickness and uncoupling coefficient are recorded as a set of first available data; The first data set is constructed using a plurality of sets of the first available data.

4. The method for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock according to claim 3, characterized in that: The adjusting the blasthole spacing and the maximum allowable delay time, and performing blasting numerical simulation on the test blasting object, and then constructing a second data set comprises the following steps: adjusting the blasthole spacing and the maximum allowable delay time, performing blasting numerical simulation on the test blasting object, and calculating the second average stress of the stress observation point; If the second average stress is greater than the dynamic tensile strength of the test blasting object, the corresponding blasthole spacing and maximum allowable delay time are recorded as a set of second available data; The second data set is constructed using a plurality of sets of the second available data.

5. The method for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock according to claim 2, characterized in that: The first mathematical model satisfies the following relationship: in, is the blasthole spacing, , , , and is the first set of fitting coefficients, is the thickness of the light explosion layer, is the decoupling coefficient.

6. The method for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock according to claim 2, characterized in that: The second mathematical model satisfies the following relationship: in, is the blasthole spacing, A, B and C are the second set of fitting coefficients, T is the maximum allowable delay time, and n is the number of blastholes.

7. The method for optimizing the design of blasting parameters for smooth blasting of tunnel surrounding rock according to claim 1, characterized in that: The method of determining the first blasting delay preset optimal value according to the optimal parameter value and the optimal uncoupling coefficient by using the blasting delay setting scheme comprises the following steps: Using numerical simulation software to construct a second numerical model of the blasting target, the second numerical model includes a plurality of blast holes and a vibration monitoring point set according to the optimal parameter values; Performing a single-hole blasting numerical simulation test on any blasthole on the second numerical model, and monitoring the vibration waveform of the test at the vibration monitoring point; Fitting the vibration waveform to obtain a fitting function, and using wavelet transform to intercept the single-hole blasting vibration waveform on the fitting function, thereby determining the blasting action duration; A plurality of blasting delay times are set within the blasting action duration, and for any of the blasting delay times, a multi-hole vibration superposition waveform within the blasting action duration is obtained according to the single-hole blasting vibration waveform; The maximum vibration speed under the corresponding blasting delay time is determined according to the multi-hole vibration superposition waveform, and the blasting delay time corresponding to the maximum vibration speed with the smallest value is used as the first blasting delay preset optimal value.

8. A blasting parameter optimization design system for smooth blasting of tunnel surrounding rock, characterized in that: The blasting parameter optimization design system for smooth blasting of tunnel surrounding rock comprises: a data acquisition device, a data output device, a processor and a storage device, wherein the storage device comprises a computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and wherein the computer program comprises program instructions, and when the program instructions are executed by the processor, the processor implements the blasting parameter optimization design method for smooth blasting of tunnel surrounding rock as described in any one of claims 1 to 7.

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