Explosive-rock matching parameter optimization method based on residual blasting crater inversion

Abstract

The application discloses a kind of explosive-rock matching parameter optimization design methods based on residual blasting crater inversion, including the steps of residual blasting crater cleaning and profile scanning, residual blasting crater profile discrete point cloud fitting, residual blasting crater profile numerical calculation inversion, residual blasting crater profile numerical inversion result and actual result comparison, residual blasting crater difference judgment, complete blasthole blasting damage partition profile numerical calculation inversion and effect evaluation.The beneficial effects of the present application are that the three-dimensional laser scanning technology and three-dimensional numerical simulation technology are integrated, the asymmetry of the actual blasting crater and the non-uniformity of the rock mass in the actual project are considered, the geometric and physical information of the blasting crater can be accurately described, the blasting production is not affected, the test cost is saved, and the explosive parameter design method is more scientific, reasonable and efficient.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of blasting parameter design, and particularly relates to a blasting-rock matching parameter optimization design method based on residual blasting crater inversion for open pit and underground site mixed explosive blasting. BACKGROUND

[0002] Blasting crater test is an important test in rock mass blasting parameter design. How much energy and how fast the speed is transmitted to the rock mass by the explosive depends on the rock mass properties, explosive performance, charge mass, explosive embedding depth and initiation mode and other factors. When the explosive charge is embedded in the rock mass near the free surface, the explosive explosion will produce a crushing zone, a crack zone and a vibration zone in the surrounding rock mass, and the damage of the rock mass in the free surface direction will be strengthened. Depending on the distance from the explosive charge to the free surface, the rock mass will also cause rock mass rupture, bulging and throwing at the free surface, and a crater-shaped blast pit, called blasting crater, will be formed in the rock mass.

[0003] The traditional blasting crater test has the following defects:

[0004] (1) The traditional blasting crater test is based on semi-infinite rock mass, while the blasting in actual engineering is often group-hole blasting with multiple blast holes according to a certain delay time interval. Before the current blast hole is initiated, the previous blast hole will inevitably create a blast free surface for it, that is, the blast hole blasting in actual engineering is generally not semi-infinite rock mass, so the blasting crater is not rotationally symmetric, and the true blasting crater has different shapes on different interfaces.

[0005] (2) The traditional blasting crater test is usually based on small-diameter, shallow-hole, packaged explosive equivalent spherical charge concentrated charging, while the open pit or underground site mixed explosive blasting in actual engineering is relatively large-diameter, deep-hole, extended charging, and cannot be equivalent to spherical charge concentrated charging.

[0006] (3) The traditional special blasting crater test has high cost, affects normal production and construction, is difficult to carry out on a large scale, the shallow borehole data cannot reflect the characteristics of the middle and deep rock mass, and only relying on the volume, angle and depth of the blasting crater cannot comprehensively and accurately describe the geometric and physical information of the blasting crater, and the data obtained based on the shallow crater test in deep-hole blasting engineering may mislead the blasting parameter design.

[0007] In order to optimize the existing middle and deep hole drilling blasting parameters, a reasonable explosive specific energy, minimum burden and maximum hole bottom distance parameter range are provided for blasting design through a series of blasting crater tests, so as to improve the blasting effect and reduce the blasting cost. It is urgent to propose a blasting-rock matching parameter optimization design method based on residual blasting crater inversion for site mixed explosive blasting, which is scientific and reasonable, saves test cost, and does not affect normal production and construction. Summary of the Invention

[0008] The existing blasting funnel test is based on semi-infinite rock mass and small-diameter shallow hole conditions and requires special testing, which has the hidden dangers of long test cycles and unreliable test results. The present invention proposes an explosive-rock matching parameter optimization design method based on residual blasting funnel inversion. This method utilizes the residual blasting funnel formed at the bottom of the blasthole on the bottom plane after excavation and loading, and calculates the geometric parameters of each typical residual blasting funnel by cleaning the residual blasting funnel and performing three-dimensional laser scanning of the contour. The bottom residual blasting funnel and the complete blasthole damage zone range are numerically calculated and inverted. Finally, the rationality of the explosive-rock matching parameters is evaluated based on the three indicators of fine ore rate, large block rate and root rate, and then the performance parameters such as explosive density, detonation velocity and detonation heat are adjusted.

[0009] To achieve the aforementioned objectives, the present invention adopts the following technical solutions.

[0010] A method for optimizing explosive-rock matching parameters based on residual blasting funnel inversion includes the following steps:

[0011] S1, residual blasting funnel cleaning and contour scanning: blasting operations and excavation are carried out according to the initial explosive-rock matching parameters, typical blast holes are selected, and residual blasting funnels are cleaned out; a 3D laser scanner is used to obtain a 3D laser point cloud data model of a typical residual blasting funnel;

[0012] S2, residual blasting funnel contour discrete point cloud fitting: Fit the residual blasting funnel 3D laser discrete point cloud data of each typical blast hole, and calculate the residual blasting funnel volume V1, depth H1, cross-sectional radius r of each typical blast hole H1 , longitudinal radius r L1 ;

[0013] S3, numerical calculation and inversion of residual blasting funnel contour: Combined with the on-site blasting design, a three-dimensional numerical model of group hole blasting is established, and the blasting rock breaking effect is calculated using a three-dimensional dynamic finite element or discrete element model. The theoretical volume V2, depth H2, and cross-sectional radius r of the residual blasting funnel of a typical blast hole are obtained by inversion. H2 , longitudinal radius r L2 ;

[0014] S4. Comparison between the numerical inversion results and actual results of the residual blasting funnel contour: the volume V2, depth H2, and cross-sectional radius r H2 , longitudinal radius r L2 The volume V1, depth H1, and cross-sectional radius r of the actual residual blasting funnel H1 , longitudinal radius r L1 Compare and calculate the volume difference η respectively V , depth difference ηH ; Cross-sectional radius difference η rH and the longitudinal radius difference η rL ;

[0015] S5. Judgment of residual blasting funnel differences: η V ,η rH ,η rL and η H Compare with the corresponding error tolerance values ​​η1, η2, η3 and η4, if the following cannot be satisfied at the same time: V ≤η1, η H ≤η2, then return to step S3, and adjust the numerical calculation model parameters and continue to perform the calculation inversion; if it satisfies: η V ≤η1, η H ≤η2, then proceed to the next step; where η1, η2, η3, and η4 are the allowable error ranges;

[0016] S6, Numerical calculation inversion of complete blast hole blasting damage zone contour: Invert the complete blast hole blasting damage zone contour on the cluster hole blasting numerical calculation model, and calculate the fine ore rate P on this basis fine , blasting large block rate P oversize and base rate P toe ;

[0017] S7. Effect evaluation: Based on the evaluation criteria, the powder ore rate P fine , blasting large block rate P oversize and base rate P toe Perform evaluation. If all items are qualified, the process ends. If any item is unqualified, optimize the explosive-rock matching parameters and return to S1.

[0018] Among them, in step S1, cleaning out the residual blasting funnel means cleaning out the loose soil at the bottom of the blast hole, and retaining the pit formed by the blasting as the residual blasting funnel; in addition, the method for selecting typical blast holes is: selecting at least one blast hole in each row of the first row, the middle row and the last row of blast holes.

[0019] In step S4, the volume difference η V , depth difference η H ; Cross-sectional radius difference η rH and the longitudinal radius difference η rL The following formulas are used for calculation:

[0020]

[0021] In step S7, the fine ore rate P fine , blasting large block rate P oversize and base rate P toeThe evaluation criteria are: if the powder ore rate P fine ≤[P fine ], large block rate P oversize ≤[P oversize ], basic rate P toe ≤[P toe ], it means that the existing explosive-rock matching parameters are reasonable; otherwise, it means that the previously selected explosive-rock matching parameters are unreasonable, and it is necessary to adjust and optimize the explosive performance parameters to enter the next cycle; Among them, [P fine ] is the control index of fine ore rate, [P oversize ] is the large block rate control index, [P toe ]Base rate control index; explosive performance parameters include adjustment of explosive density, detonation velocity, and detonation heat parameter indicators.

[0022] The beneficial effect of the present invention is that it integrates three-dimensional laser scanning technology and three-dimensional numerical simulation technology, takes into account the asymmetry of the real blasting funnel and the heterogeneity of the rock mass in actual engineering, can comprehensively and accurately describe the geometric physical information of the blasting funnel pit, does not affect the blasting production, saves test costs, and makes the explosive parameter design method more scientific, reasonable and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Flowchart of the explosive-rock matching parameter optimization method based on residual blasting funnel inversion;

[0024] Figure 2 Schematic diagram of the residual blasting funnel;

[0025] Figure 3 Cross-section of residual blasting funnel;

[0026] Figure 4 Three-dimensional blasting numerical simulation model;

[0027] Figure 5 Numerical simulation inversion profile of the funnel profile.

[0028] In the figure, 1 is the upper step surface of the rock mass; 2 is the blast hole; 3 is the front line of the step; 4, 5, 6 are selected typical blasting residual funnel pits; 7 is the lower step surface; 8 is the over-depth blast hole; 9 is the contour line of the bottom plate damage range; 10 is the profile of the residual funnel pit; 11 is the free surface; 12 is the toe line; 13 is the excavated rock mass; 14 is the rock block in the residual blasting funnel; 15 is the contour of the residual blasting funnel; 16 is the contour line of the inverted complete blasting funnel; 17 is the contour of the funnel inverted by numerical simulation; 18 is the blast hole in the numerical calculation model. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the scope of the embodiments described.

[0030] Referring to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , a method for optimizing explosive-rock matching parameters based on residual blasting crater inversion, comprising the following steps:

[0031] S1, residual blasting crater cleaning and contour scanning: performing blasting operation, digging and loading according to initial explosive-rock matching parameters, selecting typical blast holes, and cleaning out residual blasting craters; using a three-dimensional laser scanner to obtain a three-dimensional laser point cloud data model of a typical residual blasting crater;

[0032] S2, contour discrete point cloud fitting of residual blasting crater: fitting the three-dimensional laser discrete point cloud data of the residual blasting crater of each typical blast hole, and calculating the residual blasting crater volume V1, depth H1, cross-sectional radius r H1 , and longitudinal cross-sectional radius r L1 of each typical blast hole;

[0033] S3, numerical calculation and inversion of residual blasting crater contour: combining with on-site blasting design, establishing a three-dimensional numerical modeling of group hole blasting, using a three-dimensional dynamic finite element or discrete element model to calculate the blasting rock breaking effect, and inversely obtaining the theoretical volume V2, depth H2, cross-sectional radius r H2 , and longitudinal cross-sectional radius r L2 of the typical blast hole residual blasting crater;

[0034] S4, comparison of numerical inversion results and actual results of residual blasting crater contour: comparing the volume V2, depth H2, cross-sectional radius r H2 , and longitudinal cross-sectional radius r L2 inverted from the residual blasting crater with the volume V1, depth H1, cross-sectional radius r H1 , and longitudinal cross-sectional radius r L1 of the actual residual blasting crater, and respectively calculating the volume difference η V , the depth difference η H , the cross-sectional radius difference η rH , and the longitudinal cross-sectional radius difference η rL ;

[0035] S5, difference judgment of residual blasting crater: comparing η V , η rH , η rL , and η H with the corresponding error tolerance values η1, η2, η3, and η4, if η V ≤η1, η H≤η2, then return to step S3, and adjust the numerical calculation model parameters and continue to perform the calculation inversion; if it satisfies: η V ≤η1, η H ≤η2, then proceed to the next step; where η1, η2, η3, and η4 are the allowable error ranges;

[0036] S6, Numerical calculation inversion of complete blast hole blasting damage zone contour: Invert the complete blast hole blasting damage zone contour on the cluster hole blasting numerical calculation model, and calculate the fine ore rate P on this basis fine , blasting large block rate P oversize and base rate P toe ;

[0037] S7. Effect evaluation: Based on the evaluation criteria, the powder ore rate P fine , blasting large block rate P oversize and base rate P toe Perform evaluation. If all items are qualified, the process ends. If any item is unqualified, optimize the explosive-rock matching parameters and return to S1.

[0038] Among them, in step S1, cleaning out the residual blasting funnel means cleaning out the loose soil at the bottom of the blast hole, and retaining the pit formed by the blasting as the residual blasting funnel; in addition, the method for selecting typical blast holes is: selecting at least one blast hole in each row of the first row, the middle row and the last row of blast holes.

[0039] In step S4, the volume difference η V , depth difference η H ; Cross-sectional radius difference η rH and the longitudinal radius difference η rL The following formulas are used for calculation:

[0040]

[0041] In step S7, the fine ore rate P fine , blasting large block rate P oversize and base rate P toe The evaluation criteria are: if the powder ore rate P fine ≤[P fine ], large block rate P oversize ≤[P oversize ], basic rate P toe ≤[P toe ], it means that the existing explosive-rock matching parameters are reasonable; otherwise, it means that the previously selected explosive-rock matching parameters are unreasonable, and it is necessary to adjust and optimize the explosive performance parameters to enter the next cycle; Among them, [P fine ] is the control index of fine ore rate, [P oversize] is the large block rate control index, [P toe ]Base rate control index; explosive performance parameters include adjustment of explosive density, detonation velocity, and detonation heat parameter indicators.

[0042] Taking the blasting mining of a large open-pit limestone mine as an example, the explosive type used for blasting is mixed emulsion explosive, the step height is 15m, it belongs to deep hole step blasting, and the blasthole diameter is 152mm. Figure 1 , an explosive-rock matching parameter optimization method based on residual blasting funnel inversion, including:

[0043] First, the initial density of the mixed emulsion explosive used to crush the limestone mine is 1150kg / m 3 , the detonation velocity is 4500m / s, and the rock density is 2625kg / m 3 The blasting hole spacing is 6×4m, there are 3 blasting rows, and the total number of holes is 34, including 12 in the first row, 11 in the middle row, and 11 in the back row.

[0044] The first step is to clean the residual blasting funnel and scan the contour: blasting operations are carried out according to the initial blasting parameters and the blast pile is excavated and slag removed; the third hole in the first row is selected as a typical blast hole (in order to clearly express the method of the present invention, only one blast hole is selected here as the calculation process for the middle and last rows of typical blast holes to illustrate the calculation process), the residual blasting funnel after the typical blast hole is excavated and loaded is cleaned to obtain the actual residual blasting funnel prototype (see Figure 2 and Figure 3 );

[0045] The second step is to fit the outline of the residual blasting funnel with discrete point cloud: a 3D laser scanner is used to obtain a 3D laser point cloud data model of a typical residual blasting funnel; the 3D laser discrete point cloud data of each typical residual blasting funnel is fitted, and the volume V1, depth H1, and cross-sectional radius r of the typical blast hole residual funnel are calculated using 3D software. H1 , longitudinal radius r L1 , the calculation results are as follows: Among them, the typical blastholes in the first row: volume V 11 =14.39m 3 , depth H 11 =2.2m, cross-sectional radius r H11 =2.5m, longitudinal radius r L11 =2.3m; the calculation steps for other typical blastholes are the same and will not be repeated here.

[0046] The third step is the numerical calculation and inversion of the residual blasting funnel contour: Combined with the on-site blasting design, a three-dimensional numerical model of the group hole blasting is established (see Figure 4 ), using three-dimensional dynamic finite element or discrete element model to calculate the blasting rock breaking effect (see Figure 5), statistical residual funnel inversion volume V2, depth H2, cross-sectional radius r H2 , longitudinal radius r L2 , the calculation results are as follows: Among them, the typical blastholes in the first row: volume V 21 =14.78m 3 , depth H 21 =2.3m, cross-sectional radius r H21 =2.6m, longitudinal radius r L21 =2.4m; the inversion process of other typical blastholes is the same, and the results will not be repeated here.

[0047] The fourth step is to compare the numerical inversion results of the residual blasting funnel contour with the actual results: the volume V2, depth H2, and cross-sectional radius r obtained by the inversion of the residual blasting funnel are respectively H2 , longitudinal radius r L2 The volume V1, depth H1, and cross-sectional radius r of the actual residual blasting funnel H1 , longitudinal radius r L1 Compare and calculate the volume difference η respectively V , depth difference η H ; Cross-sectional radius difference η rH and the longitudinal radius difference η rL The calculation formula is:

[0048]

[0049] The calculation results for a typical blasthole in the first row are as follows:

[0050] η V =2.64%, η H =4.35%; other typical blasthole inversion results are omitted.

[0051] Step 5: Determine the difference between the residual blasting funnels: V ,η rH ,η rL and η H Compare with the corresponding error tolerance values ​​η1, η2, η3 and η4 to determine whether they are within the set tolerance range. The general error tolerance range is 5%, so here η1, η2, η3, η4 are all set with 5% as the tolerance value. It can be seen that η V , η H The error between the calculated result and the actual result is small, indicating that the calculation model of the first row of typical blastholes meets the requirements; the difference judgment process of other typical blastholes is the same and will not be repeated here. V ≤η1, η HIf ≤η2, return to step 3, adjust the numerical calculation model parameters, and continue to perform the calculation inversion.

[0052] The sixth step is the numerical calculation and inversion of the complete blast hole blasting damage zone contour: the effective model is used to perform the numerical calculation and inversion of the complete blast hole blasting damage zone contour and parameter optimization, and the powder ore rate P is extracted according to the results of the numerical model calculation. fine =16.4%, blasting large block rate P oversize =5.2% and the base rate P toe =1.2%, respectively with the fine ore rate control index P fine , large block rate control index P oversize , basic rate control index P toe Compare and determine whether explosive parameters need to be adjusted. The control indexes of fine ore rate, large lump rate, and root rate in limestone mines are usually set at 15%, 5%, and 2%. According to the extraction results, the fine ore rate and large lump rate do not meet the standards, and the explosive performance parameters need to be optimized.

[0053] Step 7: Effect evaluation: Optimize the explosive performance parameters and repeat the above steps until the fine ore rate control index, large block rate control index, and root rate control index meet the requirements.

[0054] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for optimizing explosive-rock matching parameters based on residual blasting funnel inversion, characterized in that: The following steps are involved: S1, residual blasting funnel cleaning and contour scanning: Blasting operations and excavation are carried out according to the initial explosive-rock matching parameters. Typical blastholes are selected and the residual blasting funnels are cleaned out. A 3D laser scanner is used to obtain a 3D laser point cloud data model of the typical residual blasting funnel. Cleaning out the residual blasting funnel means removing the loose soil at the bottom of the blasthole, retaining the pit formed by the blasting as the residual blasting funnel. The typical blasthole selection method is to select at least one blasthole from each of the first, middle, and last rows of blastholes. S2, residual blasting funnel contour discrete point cloud fitting: Fit the residual blasting funnel 3D laser discrete point cloud data of each typical blast hole, and calculate the residual blasting funnel volume V1, depth H1, cross-sectional radius r of each typical blast hole H1 , longitudinal radius r L1 ; S3, numerical calculation and inversion of residual blasting funnel contour: Combined with the on-site blasting design, a three-dimensional numerical model of group hole blasting is established, and the blasting rock breaking effect is calculated using a three-dimensional dynamic finite element or discrete element model. The theoretical volume V2, depth H2, and cross-sectional radius r of the residual blasting funnel of a typical blast hole are obtained by inversion. H2 , longitudinal radius r L2 ; S4. Comparison between the numerical inversion results and actual results of the residual blasting funnel contour: the volume V2, depth H2, and cross-sectional radius r H2 , longitudinal radius r L2 The volume V1, depth H1, and cross-sectional radius r of the actual residual blasting funnel H1 , longitudinal radius r L1 Compare and calculate the volume difference η respectively V , depth difference η H ; Cross-sectional radius difference η rH and the longitudinal radius difference η rL ; S5. Judgment of residual blasting funnel differences: η V ,η rH ,η rL and η H Compare with the corresponding error tolerance values ​​η1, η2, η3 and η4, if the following cannot be satisfied at the same time: V ≤η1, η H ≤η2, then return to step S3, and adjust the numerical calculation model parameters and continue to perform the calculation inversion; if it satisfies the following conditions at the same time: η V ≤η1, η H ≤η2, then proceed to the next step; where η1, η2, η3, and η4 are the allowable error ranges; S6, Numerical calculation inversion of complete blast hole blasting damage zone contour: Invert the complete blast hole blasting damage zone contour on the cluster hole blasting numerical calculation model, and calculate the fine ore rate P on this basis fine , blasting large block rate P oversize and base rate P toe ; S7. Effect evaluation: Based on the evaluation criteria, the powder ore rate P fine , blasting large block rate P oversize and base rate P toe Perform evaluation. If all items are qualified, the process ends. If any item is unqualified, optimize the explosive-rock matching parameters and return to S1.

2. The method according to claim 1, characterized in that In step S4, the volume difference η V , depth difference η H ; Cross-sectional radius difference η rH and the longitudinal radius difference η rL The following formulas are used for calculation:

3. The method according to claim 1, characterized in that In step S7, the fine ore rate P fine , blasting large block rate P oversize and base rate P toe The evaluation criteria are: if the powder ore rate P fine ≤[P fine ], large block rate P oversize ≤[P oversize ], basic rate P toe ≤[P toe ], it means that the existing explosive-rock matching parameters are reasonable; otherwise, it means that the previously selected explosive-rock matching parameters are unreasonable, and it is necessary to adjust and optimize the explosive performance parameters to enter the next cycle; Among them, [P fine ] is the control index of fine ore rate, [P oversize ] is the large block rate control index, [P toe ]Base rate control index; explosive performance parameters include adjustment of explosive density, detonation velocity, and detonation heat parameter indicators.

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