Intelligent evaluation and prediction method for blasting quality of drilling and blasting tunnel

Abstract

The invention belongs to the technical field of tunnel engineering construction, and provides an intelligent evaluation and prediction method for the blasting quality of a drilling and blasting tunnel, which comprises the following steps: obtaining the outline of the tunnel after blasting, comparing the outline with the design outline of the tunnel for shape difference evaluation, and obtaining the under-excavation rate Pq and the over-excavation rate Pc of the tunnel after blasting; the actual rock burst volume after blasting is calculated, evaluation is conducted on the actual rock burst volume and the theoretical value of the surrounding rock volume under single circulation footage, and the rock burst volume difference rate Pb after tunnel blasting is obtained; simulating a tunnel blasting effect, obtaining a surrounding rock simulation stress value based on the simulated tunnel blasting effect, comparing the surrounding rock simulation stress value with the surrounding rock initial stress value for surrounding rock stability evaluation, and calculating a stress difference rate Pf after blasting; and carrying out coupling calculation on the under-excavation rate Pq, the over-excavation rate Pc, the rock burst volume difference rate Pb and the stress difference rate Pf to obtain a blasting quality evaluation value Pz of the drilling and blasting tunnel. The method considers the tunnel shape and the surrounding rock stability at the same time, and can comprehensively and accurately evaluate the blasting quality of the drilling and blasting tunnel.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering construction, and particularly relates to an intelligent evaluation and prediction method for the blasting quality of drill-and-blast tunnels. Background Art

[0002] For tunnel construction, the drill-and-blast method is widely used in traffic tunnels, hydraulic tunnels, mine roadways, and municipal tunnel projects due to a series of advantages such as strong applicability, great flexibility, high reliability, and good economy. It is also the most commonly used construction method for railway tunnel construction in China. How to evaluate the blasting quality of drill-and-blast tunnels and thus provide a basis for the subsequent blasting scheme design is of great significance.

[0003] The existing technical research mainly focuses on establishing an evaluation index system using the analytic hierarchy process, combining the index weights for blasting quality evaluation, or optimizing the blasting parameters. However, neither the deformation and stress characteristics of the surrounding rock after tunnel blasting nor the use of intelligent algorithms to predict the blasting quality has been considered. Summary of the Invention

[0004] The purpose of the invention is to provide an intelligent evaluation and prediction method for the blasting quality of drill-and-blast tunnels to solve the above problems.

[0005] To achieve the above purpose, the invention provides the following solution: An intelligent evaluation and prediction method for the blasting quality of drill-and-blast tunnels, the steps are as follows:

[0006] Obtain the contour of the tunnel after blasting, compare it with the designed contour of the tunnel for shape difference evaluation, and based on the shape difference evaluation, obtain the under-excavation rate P q and over-excavation rate P c ;

[0007] Calculate the actual blasted rock volume after blasting, conduct a blasted rock volume evaluation by comparing it with the theoretical value of the surrounding rock volume under a single-cycle advance, and obtain the blasted rock volume difference rate P b ;

[0008] Simulate the tunnel blasting effect, obtain the simulated stress value of the surrounding rock based on the simulated tunnel blasting effect, compare the simulated stress value of the surrounding rock with the initial stress value of the surrounding rock for surrounding rock stability evaluation, and calculate the stress difference rate P f ;

[0009] Couple and calculate the under-excavation rate P q , over-excavation rate P c , blasted rock volume difference rate P b and stress difference rate P f to obtain the blasting quality evaluation value P z of the drill-and-blast tunnel. According to P zThe value optimizes the drilling layout and explosive charge filling of the current blasting section.

[0010] Preferably, obtaining the contour after tunnel blasting, comparing it with the designed contour of the tunnel for shape difference evaluation, and based on the shape difference evaluation, obtaining the under-excavation rate P of the tunnel after blasting q and the over-excavation rate P c The steps include:

[0011] Based on the designed shape contour of the tunnel, calculate the designed net area S of the tunnel;

[0012] Scan the point cloud data of the contour after tunnel blasting to obtain the actual shape contour of the tunnel;

[0013] Overlay and display the designed shape contour and the actual shape contour of the tunnel to obtain the over-under-excavation area of the tunnel. Based on the over-under-excavation area, obtain the sum of the under-excavation areas as S q and the sum of the over-excavation areas as S c Through the net area S, the sum of the under-excavation areas S q and the sum of the over-excavation areas S c Calculate the under-excavation rate P q and the over-excavation rate P c .

[0014] Preferably, the calculation formula for the under-excavation rate P q is: P q =S q / S, and the calculation formula for the over-excavation rate P c is: P c =S c / S.

[0015] Preferably, calculating the actual volume of the blasted rock after blasting, comparing it with the theoretical value of the surrounding rock volume under a single-cycle advance for blasted rock volume evaluation, and obtaining the blasted rock volume difference rate P b The steps include:

[0016] Calculate the theoretical value V of the surrounding rock volume under a single-cycle advance of the tunnel l ;

[0017] After tunnel blasting, calculate the blasted rock volume difference rate P according to the actual volume V of the blasted rock s . b

[0018] Preferably, the calculation formula for the blasted rock volume difference rate P b is: P b =(V l -V s ) / V l .

[0019] Preferably, based on the simulated tunnel blasting effect, the surrounding rock simulated stress value is obtained, and the surrounding rock stability is evaluated by comparing the surrounding rock simulated stress value with the initial stress value of the surrounding rock, and the stress difference rate P after blasting is calculated. f The steps include:

[0020] A numerical model is constructed using 3D simulation software, and corresponding boundary constraints are applied to the model.

[0021] Combined with the actual on-site blasting plan, a corresponding blast hole layout diagram is constructed, and then the on-site blasting effect is simulated, and the surrounding rock simulated stress value F is obtained according to the simulation results. s ;

[0022] The initial in-situ stress F of the surrounding rock is obtained. o , according to the actual stress F of the surrounding rock s and the initial in-situ stress F o , the stress difference rate P after the surrounding rock blasting is calculated. f .

[0023] Preferably, the stress difference rate P after the surrounding rock blasting f The calculation formula is:

[0024] P f = (F s - F o ) / F o .

[0025] Preferably, the steps of coupling the under-excavation rate P q , the over-excavation rate P c , the blasted rock volume difference rate P b and the stress difference rate P f to obtain the blasting quality evaluation value P of the drill-and-blast tunnel z include:

[0026] Couple the under-excavation rate P of the tunnel q and the over-excavation rate P of the tunnel c to obtain the shape difference evaluation value P1 of the tunnel;

[0027] Couple the blasted rock volume difference rate P b and the shape difference evaluation value P1 of the tunnel to obtain the body evaluation value P of the tunnel x ;

[0028] Couple the stress difference rate P after blasting f and the body evaluation value P x to finally obtain the blasting quality evaluation value P of the drill-and-blast tunnel z .

[0029] Preferably, the blasting quality evaluation value P of the drill-and-blast tunnelz When the value is greater than or equal to 0.9 and less than 1, the tunnel blasting quality is regarded as excellent.

[0030] Compared with the prior art, the present invention has the following advantages and technical effects: The evaluation and prediction method of the present invention synchronously considers the dual factors of the tunnel shape and the surrounding rock stability, can realize the comprehensive and accurate evaluation of the blasting quality of the drill-blast tunnel, and can also intelligently predict the subsequent drill-blast quality. According to the prediction results and combined with the evaluation criteria, the quality of the blasting is judged. When the blasting quality is low, the blasting scheme or the blast hole layout drawing can be optimized in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0032] Figure 1 It is a schematic diagram of the superposition of the tunnel shape contours of the present invention;

[0033] Figure 2 It is a schematic diagram of the radial and circumferential directions of the tunnel of the present invention;

[0034] Figure 3 It is the blast hole layout drawing of the present invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the 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 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 belong to the scope of protection of the present invention.

[0036] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0037] Embodiment 1:

[0038] Referring to Figures 1 - 3 , the present invention provides an intelligent evaluation and prediction method for the blasting quality of a drill-blast tunnel, and the steps are as follows:

[0039] Obtain the contour of the tunnel after blasting, compare it with the designed contour of the tunnel for shape difference evaluation, and based on the shape difference evaluation, obtain the under-excavation rate P q and the over-excavation rate P c ;

[0040] Calculate the actual volume of blasted rock after blasting, and evaluate the volume of blasted rock by comparing it with the theoretical value of the surrounding rock volume under a single-cycle advance, so as to obtain the difference rate P of the volume of blasted rock after tunneling b ;

[0041] Simulate the tunneling blasting effect, obtain the simulated stress value of the surrounding rock based on the simulated tunneling blasting effect, compare the simulated stress value of the surrounding rock with the initial stress value of the surrounding rock to evaluate the stability of the surrounding rock, and calculate the stress difference rate P after blasting f ;

[0042] The under-excavation rate P q , over-excavation rate P c , difference rate P of the volume of blasted rock b and stress difference rate P f are coupled and calculated to obtain the blasting quality evaluation value P of the drill-and-blast tunnel z , and optimize the drilling layout and explosive charge filling of the current blasting section according to the P z value.

[0043] For further optimization of the plan, the following preparatory work needs to be carried out before the evaluation and prediction:

[0044] ① Combine the geological exploration report, design documents, and on-site investigation, etc., to sort out and collect the geometric information and geological data of the tunnel. Among them, the geometric information mainly refers to the tunnel cross-section dimensions, such as the tunnel height and width, etc.; the geological data mainly refers to the topography, geological structure, surrounding rock type, hydrogeology, and adverse geology, etc., such as the tunnel depth, groundwater depth, etc.

[0045] ② Combine the tunnel geometric dimensions and surrounding rock types to search for similar projects at home and abroad and accumulate the basic data for intelligent evaluation and prediction.

[0046] The steps to further optimize the plan, obtain the contour after tunneling blasting, compare it with the tunnel design contour for shape difference evaluation, and obtain the under-excavation rate P q and over-excavation rate P c after blasting include:

[0047] Based on the tunnel design shape contour, calculate the designed net area S of the tunnel;

[0048] Scan the point cloud data of the contour after tunneling blasting to obtain the actual shape contour of the tunnel;

[0049] Overlay and display the tunnel design shape contour and the actual shape contour to obtain the over-under-excavation area of the tunnel. Based on the over-under-excavation area, the sum of the under-excavation areas is S q , and the sum of the over-excavation areas is S c , through the net area S, the sum of the under-excavation areas Sq Sum of over-excavated areas S c Calculate the under-excavation rate P q and the over-excavation rate P c .

[0050] For the further optimized solution, the calculation formula for the under-excavation rate P q is: P q = S q / S, and the calculation formula for the over-excavation rate P c is: P c = S c / S.

[0051] In this embodiment, specifically, the evaluation process of the shape difference is as follows:

[0052] ① Based on the tunnel design document, determine the designed shape contour of the tunnel and calculate the designed net area S of the tunnel.

[0053] ② Use laser scanning or image acquisition technology to obtain the point cloud data of the actual shape after tunnel blasting and perform digital simulation display, and then obtain the actual shape contour of the tunnel.

[0054] ③ Overlay and display the designed shape of the tunnel and the actual shape contour (as Figure 1 shown), and the over-excavated and under-excavated areas of the tunnel can be obtained, so as to evaluate the blasting quality of the tunnel from the aspect of tunnel shape difference.

[0055] ④ The area within the designed shape contour of the tunnel represents the under-excavated part of the tunnel, and the sum of the over-excavated areas is represented by S q ; the area outside the designed shape contour of the tunnel represents the over-excavated part of the tunnel. The sum of the over-excavated areas is represented by S c .

[0056] ⑤ Calculate the under-excavation rate P q and the over-excavation rate P c of the tunnel respectively. The smaller the over-excavation and under-excavation rate, the better the blasting quality of the tunnel, and vice versa.

[0057] For the further optimized solution, the steps to calculate the actual volume of blasted rock after blasting and evaluate the volume difference of blasted rock with the theoretical value of the surrounding rock volume under a single-cycle advance include: b

[0058] Calculate the theoretical value V l of the surrounding rock volume under a single-cycle advance of the tunnel;

[0059] After tunnel blasting, calculate the blasted rock volume difference rate P s based on the actual volume V b of the blasted rock.

[0060] ​Further optimization plan, the difference rate P of the blasted rock volume b The calculation formula is as follows:

[0061] P b = (V l - V s ) / V l ,

[0062] In this embodiment, specifically, the evaluation process of the blasted rock volume is as follows:

[0063] ① Combine the tunnel section size and the excavation footage to calculate the theoretical value V of the surrounding rock volume under the single-cycle excavation footage of the tunnel. Among them, the calculation formula of V l is the cross-sectional area × the single-cycle excavation footage length L. l ② After the tunnel blasting, calculate the actual value V of the blasted rock volume according to the muck trucks. Among them, V

[0064] = the number of muck trucks N × the transportation volume V of a single muck truck s . s = the number of muck trucks N × the transportation volume V of a single muck truck c .

[0065] ③ Calculate the difference rate P of the blasted rock volume b = (V l - V s ) / V l .

[0066] ④ When the difference rate P of the blasted rock volume b is greater than 0, it means that the tunnel is under-excavated, and vice versa for over-excavation. The smaller the absolute value of P b , the smaller the over- and under-excavation phenomenon, and the better the tunnel blasting quality in terms of the blasted rock volume, and vice versa.

[0067] Further optimization plan, simulate the tunnel blasting effect, obtain the simulated stress value of the surrounding rock based on the simulated tunnel blasting effect, compare the simulated stress value of the surrounding rock with the initial stress value of the surrounding rock for the evaluation of the surrounding rock stability, and calculate the stress difference rate P f after blasting. The steps include:

[0068] ① Use three-dimensional simulation software to build a numerical model and apply corresponding boundary constraints to the model;

[0069] ② Combine the actual on-site blasting plan to build a corresponding blast hole layout diagram, then simulate the on-site blasting effect, and obtain the simulated stress value F of the surrounding rock according to the simulation results s ;

[0070] ③ Obtain the initial in-situ stress F of the surrounding rock o , and calculate the stress difference rate P of the surrounding rock after blasting according to the actual stress F s of the surrounding rock and the initial in-situ stress F o of the surrounding rock f。

[0071] For the further optimization plan, the stress difference rate P of the surrounding rock after blasting f has the following calculation formula:

[0072] P f = (F s - F o ) / F o ,

[0073] In this embodiment, specifically, the process of evaluating the stability of the surrounding rock is as follows:

[0074] ① Use three-dimensional simulation software to construct a numerical model and apply corresponding constraint conditions to the model boundaries.

[0075] ② Combine the geological exploration report, laboratory results, and supplementary tests to determine the basic physical and mechanical parameters of the model, such as the density of the surrounding rock, shear modulus, cohesion, etc. Select the corresponding constitutive model and determine the corresponding constitutive model parameters, such as strain rate, damage coefficient, failure strain, etc.

[0076] ③ Combine the actual on-site blasting plan to arrange the corresponding blast hole layout diagram, and then simulate the on-site explosive blasting effect.

[0077] ④ Numerical analysis: When the actual number of calculation steps in the numerical simulation exceeds the set number of steps, the model calculation stops.

[0078] ⑤ According to the model calculation results, obtain the stress and deformation data of the surrounding rock.

[0079] ⑥ According to the geological exploration report of the surrounding rock, determine the initial in-situ stress F o ; According to the numerical simulation results, determine the actual stress value F s of the surrounding rock after blasting, and calculate the stress difference rate P f = (F s - F o ) / F o . When the stress difference rate is greater than 0, it indicates over-excavation of the tunnel, and vice versa for under-excavation. The smaller the absolute value of the P f value, the smaller the difference between the stress value of the surrounding rock and the initial in-situ stress after the tunnel blasting, the lower the degree of disturbance of the surrounding rock, and the better the blasting quality of the tunnel is reflected. Vice versa, it is worse.

[0080] For the further optimization plan, through the radial direction of the surrounding rock (such as Figure 2Based on the deformation and evolution law (as shown), the range of blasting disturbance can be determined. The surrounding rock deformation gradually decreases along the tunnel radial direction and tends to zero. When the surrounding rock stress or deformation area is zero, the corresponding position is the boundary between the blasted and unblasted areas. The area within the boundary is the blasting influence range of the tunnel, and the area outside the boundary is the unblasted range of the tunnel. The smaller the disturbance range, the better the blasting quality, and vice versa.

[0081] For the further optimized scheme, in step S5, the formula for coupled calculation is as follows:

[0082] (1)

[0083] Where M is the analysis result after coupling of factor A and factor B, and α and β represent the weight coefficients of factor A and factor B respectively. α and β are determined by the expert investigation method or the Delphi method.

[0084] Specifically, the method for determining the values of α and β can choose the qualitative value-taking method, that is, the expert gives specific numbers for α and β according to personal experience, and it is only necessary to ensure that the sum of the two values is 1;

[0085] The quantitative value-taking method can also be adopted, which is to determine specific data using the game theory idea.

[0086] For the further optimized scheme, in step S5, the process of coupled calculation is as follows:

[0087] Use formula (1) to perform coupled calculation on the tunnel under-excavation rate P q and the tunnel over-excavation rate P c to obtain the shape difference evaluation value P1 of the tunnel. Among them, one of the tunnel under-excavation rate P q or the tunnel over-excavation rate P c is substituted into A, and the other is substituted into B;

[0088] Use formula (1) to perform coupled calculation on the blasted rock volume difference rate P b and the shape difference evaluation value P1 of the tunnel to obtain the body evaluation value P x of the tunnel. Among them, one of the body evaluation value P x or the shape difference evaluation value P1 is substituted into A, and the other is substituted into B;

[0089] Use formula (1) to perform coupled calculation on the stress difference rate P f after blasting and the body evaluation value P x to finally obtain the blasting quality evaluation value P z of the drill-and-blast tunnel. Among them, one of the stress difference rate P f or the body evaluation value P x is substituted into A, and the other is substituted into B.

[0090] Further optimization plan, blasting quality evaluation value P of drill and blast tunnel z If the value of P is within the range of [0.9, 1.0), the blasting quality of the tunnel is considered excellent.

[0091] Further optimization plan, the intelligent evaluation and prediction process of blasting quality is as follows:

[0092] ①Construct a basic database, including tunnel cross-section size, tunnel burial depth, surrounding rock type, explosive type, explosive quantity, blasting quality evaluation value P of drill and blast tunnel z and so on.

[0093] ②Use 80% of the data in the basic database to train the intelligent model. The intelligent model includes artificial neural network, particle swarm optimization algorithm, grey wolf algorithm, etc.

[0094] ③Use the remaining 20% of the data in the basic database to verify the accuracy of the trained intelligent model. When the relative deviation between the prediction result and the actual result is less than 10%, the training result of the intelligent model can be considered to meet the requirements.

[0095] ④Use the trained intelligent model to evaluate the blasting quality of subsequent drill and blast tunnels. The input basic data includes tunnel cross-section size, tunnel burial depth, surrounding rock type, explosive type, explosive quantity, etc. The output result is the blasting quality evaluation value P of drill and blast tunnel z .

[0096] Specifically, according to the value of P z The rating criteria are as follows in the table:

[0097]

[0098] Example 2:

[0099] This example is the specific application of Example 1:

[0100] 4.1 Evaluation preparation

[0101] The example tunnel is a one-way two-lane highway tunnel, with a tunnel burial depth of 250.0 m and an excavation cross-section of 200.0 m 2 , and the surrounding rock type is shale intercalated with mudstone. The two-bench construction method is adopted in the blasting test section, and the cross-section is quickly expanded back by the sectional blasting cycle method. The single-shot blasting cycle footage is 2.0 m. The air-deck charging method is proposed for the perimeter holes and auxiliary holes, and the bottom continuous charging is proposed for other blast holes. All blast holes are blasted in the reverse direction, and the explosive is emulsion explosive.

[0102] 4.2 Tunnel shape evaluation

[0103] (1)Shape difference evaluation

[0104] ①Based on the tunnel design document, determine the designed shape contour of the tunnel, and calculate the designed net area of the tunnel S = 200.0 m 2 .

[0105] ②Adopt laser scanning or image acquisition technology to obtain the point cloud data of the actual shape after tunnel blasting, and perform digital simulation display, and then obtain the actual shape contour of the tunnel.

[0106] ③Overlap and display the designed shape of the tunnel with the actual shape contour, and the over-excavation and under-excavation areas of the tunnel can be obtained, so as to evaluate the blasting quality of the tunnel from the aspect of the shape difference of the tunnel.

[0107] ④The area within the designed shape contour of the tunnel represents the under-excavated part of the tunnel, and the sum of the over-excavation areas S q = 15.0 m 2 . The area outside the designed shape contour of the tunnel represents the over-excavated part of the tunnel. The sum of the over-excavation areas S c = 20.0 m 2 .

[0108] ⑤Calculate the under-excavation rate P q = S q / S = 15 / 200 = 0.075 and the over-excavation rate P c = S c / S = 20 / 200 = 0.10.

[0109] ⑥Use formula (1) to perform coupled calculation on the under-excavation rate and over-excavation rate of the tunnel. The weight coefficients α and β are taken as 0.4 and 0.6 respectively,

[0110] and then obtain the shape difference evaluation value of the tunnel P1 = 0.4 × 0.075 + 0.6 × 0.1 = 0.09.

[0111] (2) Evaluation of blasted rock volume

[0112] ①Combined with the tunnel section size and excavation footage, calculate the theoretical value V of the surrounding rock volume under the single-cycle footage of the tunnel l = cross-sectional area × single-cycle footage length L = 200 × 2.0 = 400 m 3 .

[0113] ②After tunnel blasting, calculate the actual value V of the blasted rock volume according to the muck trucks s = number of muck trucks N × transportation volume V of a single muck truck c = 18 × 20 = 360 m 3 .

[0114] ③Calculate the difference rate P of the blasted rock volume b = (V l - V s ) / Vl =(400 - 360) / 400 = 0.1。

[0115] ④ Use formula (1) to perform coupled calculations on the shape difference evaluation value P1 and the blasted rock volume difference rate P b The weight coefficients α and β are respectively taken as 0.6 and 0.4, and then the shape evaluation value P of the tunnel is obtained x = 0.6 × 0.09 + 0.4 × 0.1 = 0.094。

[0116] 4.3 Surrounding Rock Stability Evaluation

[0117] (1) Use a three-dimensional simulation software to construct a numerical model, apply strict displacement constraints to the boundaries, that is, constrain the X-direction displacement of the left and right boundaries, the Y-direction displacement of the upper and lower boundaries, and the Z-direction displacement of the front and back boundaries, and use non-reflective boundary conditions to eliminate the influence of boundary reflected waves.

[0118] (2) Combine the actual on-site blasting scheme, arrange the corresponding blasthole layout diagram, and then simulate the on-site explosive blasting effect. The blasthole layout is as Figure 3 shown.

[0119] (3) According to the surrounding rock geological exploration report, determine the initial in-situ stress F of the surrounding rock o = 25.0 MPa,

[0120] (4) According to the numerical simulation results, determine the actual stress value F of the surrounding rock after blasting s = 23.0 Mpa, calculate the stress difference rate of the surrounding rock after blasting

[0121] P f =(F s - F o ) / F o =(23 - 25) / 25 = -0.08。

[0122] (5) Determine the range of blasting disturbance through the deformation evolution law of the surrounding rock in the radial direction. When the radial distance of the surrounding rock exceeds 2.5 m from the tunnel contour, the deformation of the surrounding rock decreases to 0, indicating that the range of blasting disturbance of the surrounding rock is 2.0 m outside the tunnel contour line.

[0123] (6) Use formula (1) to perform coupled calculations on the tunnel shape evaluation value P x and the surrounding rock stability evaluation value P f The weight coefficients α and β are respectively taken as 0.5 and 0.5, and finally the blasting quality evaluation value P of the drill-and-blast tunnel is obtained z = 0.5 × 0.094 + 0.5 × 0.08 = 0.087。

[0124] 4.4 Intelligent Evaluation and Prediction of Blasting Quality

[0125] (1) Build a basic database, which includes a total of 100 pairs of data materials.

[0126] (2) Use 80% of the data in the basic database to train the artificial neural network model.

[0127] (3) Use the remaining 20% of the data in the basic database to verify the accuracy of the trained artificial neural network. When the relative deviation rate between the predicted result and the actual result is 5.0%, which is less than 10%, it can be considered that the training result of the intelligent model meets the requirements.

[0128] (4) Use the trained artificial neural network model to evaluate the blasting quality of subsequent drill-and-blast tunnels.

[0129] (5) The cross-sectional dimension of the tunnel is 200.0 m 2 , the tunnel burial depth is 250 m, the surrounding rock type is shale intercalated with mudstone, and the explosive type is emulsion explosive. The intelligent prediction result P of the blasting quality evaluation value of the drill-and-blast tunnel z = 0.085.

[0130] (6) According to Table 1, the blasting quality of the drill-and-blast tunnel is good.

[0131] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0132] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. An intelligent evaluation and prediction method for the blasting quality of drill-and-blast tunnels, characterized in that The steps are as follows: The tunnel contour after blasting is obtained, and compared with the tunnel design contour to evaluate the shape difference. Based on the shape difference evaluation, the under-excavation rate P of the tunnel after blasting is obtained. q and over-excavation rate P c ; Calculate the actual volume of blasted rock after blasting, evaluate the volume of blasted rock by comparing it with the theoretical value of the surrounding rock volume under a single-cycle footage, and obtain the difference rate P of the volume of blasted rock after tunneling by blasting b ; Simulate the tunnel blasting effect, obtain the simulated stress value of the surrounding rock based on the simulated tunnel blasting effect, compare the simulated stress value of the surrounding rock with the initial stress value of the surrounding rock to evaluate the stability of the surrounding rock, and calculate the stress difference rate P after blasting f ; The under-excavation rate P q , the over-excavation rate P c , the volume difference rate of blasted rock P b and the stress difference rate P f are subjected to coupled calculation to obtain the blasting quality evaluation value P z of the drill-and-blast tunnel. Based on the value of P z , the drilling layout and explosive charge filling of the current blasting section are optimized.

2. The intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 1, wherein: Obtaining the contour after tunnel blasting, comparing it with the designed contour of the tunnel to evaluate the shape difference, and obtaining the under-excavation rate P of the tunnel after blasting based on the shape difference evaluation q and the over-excavation rate P c The steps are as follows: Based on the designed shape contour of the tunnel, calculate the designed net area S of the tunnel; Scan the point cloud data of the contour after tunnel blasting to obtain the actual shape contour of the tunnel; Overlap and display the designed tunnel shape profile and the actual shape profile to obtain the over-excavation and under-excavation areas of the tunnel, and based on the over-excavation and under-excavation areas, obtain the sum of the under-excavation areas as S q , and the sum of the over-excavation areas as S c . Calculate the under-excavation rate P q through the net area S, the sum of the under-excavation areas S c , and the sum of the over-excavation areas S q and the over-excavation rate P c .

3. The intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 2, characterized in that: Under-excavation rate P q The calculation formula is: P q = S q / S, over-excavation rate P c The calculation formula is: P c = S c / S.

4. An intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 1, characterized in that: The actual volume of blasted rock after calculation is evaluated with the theoretical value of the surrounding rock volume under a single-cycle footage to obtain the difference rate P of the blasted rock volume after tunneling by blasting. b The steps include: Calculate the theoretical value V of the surrounding rock volume under the single-cycle advance of the tunnel l ; After tunnel blasting, the volume difference rate P of the blasted rock is calculated according to the actual volume Vs of the blasted rock b .

5. The intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 4, characterized in that: Volume difference rate P of rock fragmentation b The calculation formula is: P b = (V l - V s ) / V l .

6. The intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 1, characterized in that: Simulating the tunnel blasting effect, obtaining the simulated stress value of the surrounding rock based on the simulated tunnel blasting effect, comparing the simulated stress value of the surrounding rock with the initial stress value of the surrounding rock to evaluate the stability of the surrounding rock, and calculating the stress difference rate P after blasting f The steps include: Use 3D simulation software to construct a numerical model and apply corresponding constraint conditions to the model boundary; Combined with the actual on-site blasting plan, construct the corresponding blast hole layout diagram, then simulate the on-site blasting effect, and obtain the simulated stress value F of the surrounding rock according to the simulation results s ; Obtain the initial in-situ stress F of the surrounding rock o , according to the actual stress F of the surrounding rock s and the initial in-situ stress F o , calculate the stress difference rate P after blasting of the surrounding rock f .

7. An intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 6, characterized in that: The stress difference rate P of the surrounding rock after blasting f The calculation formula is as follows: P f = (F s - F o ) / F o .

8. An intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 1, characterized in that: The step of coupling and calculating the under-excavation rate P q , the over-excavation rate P c , the volume difference rate P of blasted rock b and the stress difference rate P f to obtain the blasting quality evaluation value P z of the drill-blast tunnel includes: For the under-excavation rate P of the tunnel q and the over-excavation rate P of the tunnel c perform coupled calculations to obtain the shape difference evaluation value P1 of the tunnel; For the blasting rock volume difference rate P b and the shape difference evaluation value P1 of the tunnel are coupled and calculated to obtain the shape evaluation value P of the tunnel x ; For the stress difference rate P after blasting f and the body evaluation value P x perform coupled calculations to finally obtain the blasting quality evaluation value P of the drill-and-blast tunnel z .

9. The intelligent evaluation and prediction method for the blasting quality of a drill-and-blast tunnel according to claim 8, wherein: The blasting quality evaluation value P of the drill and blast tunnel z When the value is greater than or equal to 0.9 and less than 1, the tunnel blasting quality is regarded as excellent.

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