Blasting method

• US 20050010385A1
• Filed: 08/03/2004
• Published: 01/13/2005
• Est. Priority Date: 09/08/1999
• Status: Active Grant

• Current Assignee: Optimuck, LLC
• Original Assignee: Live Oak Ministries
• Inventors: Heck, Jay Howard Sr.
• Granted Patent: US 7,418,373 B2
• Time in Patent Office: Days
• US Class Current: 703/10
• CPC Class Codes: E21C 37/16 by fire-setting or by similar methods based on a heat effect drilling by use of heat E21B7/14
• CPC Class Codes: F42D 1/00 Blasting methods or apparatus, e.g. loading or tamping
• CPC Class Codes: G01V 9/00 Prospecting or detecting by methods not provided for in groups G01V1/00 - G01V8/00

Abstract

Methods for evaluating drill pattern parameters such as burden, spacing, borehole diameter, etc., at a blast site are disclosed. One method involves accumulating the burden contributed by successive layers of rock and matching the accumulated rock burden to a target value for a borehole having a length related to the average height of the layers. Another method relates to varying drill pattern parameters and characteristics to match blast design constraints, including the substitution of one explosive material for another by the proper balance of materials and/or output energies to the associated rock burden. Analysis of deviations from target rock burdens and corrective measures are disclosed, as well as cost optimization methods. The various methods can be practiced using an appropriately programmed general purpose computer.

Claims

1. A method for choosing at least one explosive material for use in a segment of a borehole, the method comprising determining a target specific volume energy required for an explosive material in the borehole, and identifying at least one explosive material that provides at least the target specific volume energy.

2. The method of claim 1 comprising comparing specific energies of candidate explosive materials to the target specific volume energy.

3. The method of claim 2 wherein comparing specific energies comprises referring to stored data that indicate specific volume energies of a plurality of explosive materials.

4. The method of claim 3 wherein the stored data indicate the densities and specific mass energies of the various candidate explosive materials, and wherein identifying an explosive material comprises calculating the specific volume energy of a candidate explosive material and comparing the candidate specific volume energy to the target specific volume energy.

5. The method of claim 1, claim 2, claim 3 or claim 4, comprising partitioning the borehole into segments and determining rock burden and target specific volume energy for various segments of the borehole and separately identifying an explosive material for each segment.

6. The method of claim 1 comprising determining the rock burden for the borehole and using a predetermined Energy Factor and the size of the borehole to determine the corresponding specific volume energy.

7. A method for evaluating the suitability of a candidate explosive material of known specific energy for use in at least a segment of a borehole having a predetermined diameter and having a rock burden associated therewith, comprising:

identifying a reference Material Factor (MF_R) for the associated rock burden with reference to a reference explosive material of known specific energy;

calculating an adjusted Material Factor (MF_A) corresponding to the use of the candidate explosive material in the borehole for the associated rock burden; and

indicating whether the adjusted Material Factor (MF_A) compares favorably to the reference Material Factor (MF_R).

8. The method of claim 7 wherein calculating the adjusted Material Factor (MF_A) comprises multiplying the reference Material Factor (MF_R) by (M_Ref)(E_Ref)/(M_EXP)(E_EXP);

wherein M_Ref=the mass of reference explosive in the section of the borehole;

M_EXP=the mass of candidate explosive in the section of the borehole;

E_Ref=the specific mass energy of the reference explosive; and

E_EXP=the specific mass energy of the candidate explosive, so that MF_A=MF_R((M_Ref)(E_Ref)/(M_EXP)(E_EXP)).

9. A method for selecting the diameter of a borehole, the method comprising:

(a) determining the rock burden associated with at least a segment of the borehole;

(b) determining a target Energy Factor EF_T for the rock burden EF_T;

(c) selecting an explosive material of known specific volume energy; and

(d) calculating the diameter of the borehole needed to accommodate a volume of the explosive material sufficient to attain at least the target Energy Factor EF_T.

10. A computer-readable medium having computer-readable code therein for choosing at least one explosive material for use in at least a segment of a borehole having a rock burden associated therewith, the method comprising:

code for determining a target specific energy required for an explosive material relative to the associated rock burden; and

code for identifying at least one explosive material that provides at least the target specific energy.

11. The medium of claim 10 comprising code for referring to stored data indicating the specific energies of candidate explosive materials and comparing the data to the target specific energy.

12. The medium of claim 11 comprising data indicating the specific energies of a plurality of blends of two or more materials.

13. The medium of claim 10 comprising data indicating the densities and specific mass energies of the various candidate explosive materials, and comprising code for calculating the specific volume energy of a candidate explosive material, code for calculating the target specific volume energy and code for comparing the candidate specific volume energy to the target specific volume energy.

14. The medium of claim 10 comprising code for determining the rock burden for the borehole and using a predetermined Energy Factor and the size of the borehole to determine the required specific volume energy.

15. The medium of claim 10, comprising code for partitioning the borehole into segments and determining rock burden and target specific volume energy for various segments of the borehole and separately identifying an explosive material for each segment.

43. An apparatus for choosing at least one explosive material for use in at least one segment of a borehole having a rock burden associated therewith, the apparatus comprising:

a computer processor;

at least one storage medium accessible to the processor, for storing data and executable code;

input means for delivering data to at least one storage medium; and

output means for conveying data identifying an explosive material for use in a borehole;

wherein the at least one storage medium comprises a storage medium as defined in claim 10.

16. A computer-readable medium having computer-readable code therein for evaluating the suitability of a candidate explosive material of known specific energy for use in at least a segment of a borehole having a predetermined diameter and having a rock burden associated therewith, the code comprising:

code responsive to data indicating the specific energy of reference explosive material and a target rock burden to determine a reference Material Factor (MF_R) for the rock burden associated with the borehole;

code responsive to data for a candidate explosive material for calculating an adjusted Material Factor (MF_A) corresponding to the use of the candidate explosive material in the borehole; and

code for comparing the adjusted Material Factor (MF_A) to the reference Material Factor (MF_R) and for indicating the result.

17. The medium of claim 16 comprising code for calculating the adjusted Material Factor (MF_A) by multiplying the reference Material Factor (MF_R) by (M_Ref)(E_Ref)/(M_EXP)(E_EXP);

wherein M_Ref=the mass of reference explosive in the section of the borehole;

M_EXP=the mass of candidate explosive in the section of the borehole;

E_Ref=the specific mass energy of the reference explosive; and

E_EXP=the specific mass energy of the candidate explosive material.

44. An apparatus for evaluating the suitability of a candidate explosive material of known specific energy for use in at least a segment of a borehole having a predetermined diameter and having a rock burden associated therewith, the apparatus comprising:

a computer processor;

at least one storage medium accessible to the processor, for storing data and executable code;

input means for delivering data to at least one storage medium; and

output means for conveying at least data indicating the result of the evaluation;

wherein the storage media comprise a storage medium as set forth in claim 16.

18. A computer-readable medium having a computer-executable code therein for selecting the diameter of a borehole, the medium comprising:

(a) code for accepting rock burden data associated with at least a segment of the borehole;

(b) code for accepting a target Energy Factor for the rock burden EF_T;

(c) code for accessing data pertaining to the specific energy of an explosive material; and

(d) code for calculating the diameter of the borehole needed to accommodate a volume of the explosive material sufficient to attain the target Energy Factor EF_T.

19. The medium of claim 18 comprising code for accessing data pertaining to the specific volume energy of the explosive material.

45. An apparatus for selecting the diameter for a borehole, the apparatus comprising:

a computer processor;

at least one storage medium accessible to the processor, for storing data and executable code;

input means for delivering data to at least one storage medium; and

output means for conveying data representing the diameter of a borehole;

wherein the storage media comprise a storage medium as set forth in claim 18.

20. A method for using a computer to assign positions for boreholes at a bench blasting site having a rock face, comprising:

inputting data indicating bench characteristics indicating at least bench height, bank angle, rock face configuration and rock density;

inputting blast design constraints pertaining to spacing, hole-to-rock face burden, explosive material properties, desired borehole angle, and at least one of Material Factor and Energy Factor;

inputting a proposed drill line, start point and end point; and

receiving a report containing proposed drill pattern characteristics.

21. The method of claim 20 wherein the report identifies boreholes having excess toe burdens and further comprising inputting data indicating the placement of boreholes in the toe and receiving a report indicating positions for boreholes on the drill line.

22. The method of claim 20 or claim 21 wherein the report identifies boreholes having rock face swells and comprising inputting data indicating the elimination of at least one borehole position and the addition of at least one borehole on a swell between the drill line and the rock face.

23. The method of claim 21 wherein inputting data comprises retrieving data from a memory medium.

24. The method of claim 20 wherein inputting data comprises transferring data from an electronic surveying device.

25. The method of claim 20 wherein inputting data comprises entering data via a user input device.

26. A method for determining a priority-directed loading configuration for a borehole subject to blast design criteria, the method comprising:

(a) selecting a segment of the explosive column portion of the borehole to be filled with explosive material;

(b) determining the rock burden associated with the identified segment;

(c) evaluating candidate explosive materials for use in the identified segment in order of priority until one is found that meets the blast design criteria (referred to herein as a compliant material), and assigning the first compliant material to the selected segment, assigning stemming to the segment when all the candidate explosive materials fail to meet the minimum energy factor criterion and indicating whether all the candidate explosive materials exceed the maximum energy factor criterion; and

(d) repeating steps (a), (b) and (c) for each segment of the explosive column.

27. The method of claim 26 wherein explosive materials are evaluated in order of cost to generate a cost-directed loading configuration.

28. The method of claim 27 wherein explosive materials are evaluated in order of specific energy.

29. The method of claim 26 further comprising assigning stemming to the segment when each evaluated explosive material provides less than a minimum energy factor criterion for the rock burden.

30. The method of claim 26 or claim 29 further comprising assigning an “

unknown”

to a segment for which all candidate explosive materials exceed the maximum energy criterion and continuing the method until each segment of the borehole is evaluated.

31. A method for assigning a cost-directed spacing to a borehole of predetermined diameter on a drill line along a bench of rock having a known density and a rock face, each location and borehole being subject to blast design criteria including a minimum spacing criterion, a maximum spacing criterion, and a minimum energy factor criterion, the method comprising:

(i) proposing a compliant spacing for a borehole on the drill line with reference to at least one associated burden boundary;

(ii) associating with the borehole a rock burden determined in part relative to the at least one burden boundary;

(iii) determining a cost-based loading configuration for the borehole according to the method of claim 59, and recording the resulting compliant configuration (if any) and determining its associated cost;

(iv) proposing a different compliant spacing with a corresponding borehole-boundary distance;

(v) repeating step (ii), (iii) and (iv) for each different compliant spacing; and

(vi) identifying the compliant spacing with the lowest cost (on a dollar per ton basis) compliant loading configuration (referred to as the cost-directed spacing).

32. The method of claim 31 wherein step (vi) comprises identifying the location of the borehole and of the first and second boundaries of the rock burden associated with the cost-directed spacing.

33. The method of claim 31 or claim 32 comprising using a boundary associated with the cost-directed spacing as a fixed boundary for the rock burden of a subsequent borehole on the drill line and repeating the method to assign a cost-directed spacing to the subsequent borehole.

34. The method of claim 31 comprising stopping the repeat of code (iv) and (v) when an energy factor constraint is not met.

35. The method of claim 31 comprising first proposing in step (i) a spacing that corresponds to the minimum spacing criterion and proposing in step (iv) an incrementally larger spacing than was used in the previous steps (ii) and (iii).

36. The method of claim 31 comprising proposing in step (ii) a spacing that corresponds to the maximum spacing criterion and proposing in step (iv) an incrementally smaller spacing than was used in the previous steps (ii) and (iii).

50. The method of claim 31 further comprising broadening at least one blast design constraint by an acceptable degree and repeating the steps of claim 63.

37. A computer-readable medium having computer-executable code therein, the medium comprising:

(a) code for selecting a segment of the explosive column portion of a borehole to be filled with explosive material;

(b) code for determining the rock burden associated with the selected segment and for accessing data pertaining to blast design criteria comprising minimum and maximum energy factors and for accessing data pertaining to candidate explosive materials;

(c) code for evaluating candidate explosive materials for use in the selected segment in order of priority until one is found that meets the blast design criteria (referred to herein as a compliant material), and for assigning the first compliant material to the selected segment, for assigning stemming to the segment when all candidate explosive materials fail to meet the minimum energy factor criterion, and for indicating whether all candidate explosive materials exceed the maximum energy factor criterion; and

(d) code that causes code (a), (b) and (c) to repeat for each segment of the explosive column.

38. The medium of claim 37 comprising code for evaluating explosive materials in order of cost to generate a cost-directed loading configuration.

39. The medium of claim 38 comprising code for evaluating explosive materials in order of specific energy.

40. A computer-readable medium having computer-executable code therein for assigning a cost-directed spacing to a borehole of predetermined diameter on a drill line along a bench of rock having a known density and a rock face, each spacing and borehole being subject to blast design criteria including minimum spacing, maximum spacing, and minimum and maximum energy factors, the medium comprising:

(i) code for accessing data relating to the configuration of a bench and to blast design criteria comprising minimum and maximum energy factors and data comprising energy and cost characteristics of candidate explosive materials;

(ii) code responsive to user input defining on the bench a drill line having a drill line start point and a drill line end point;

(iii) code for proposing a compliant spacing for a borehole on the drill line with reference to at least one burden boundary;

(iv) code for associating with the borehole a rock burden determined in part relative to the at least one burden boundary;

(v) code for determining a cost-based loading configuration for the borehole as described in claim 38, and for indicating the resulting compliant configuration (if any) and determining its associated cost;

(vi) code for proposing a different compliant spacing with a corresponding borehole-boundary distance and for causing code (iv) and (v) to repeat for each different compliant spacing; and

(vii) code for indicating the compliant spacing with the lowest cost (on a dollar per ton basis) compliant loading configuration (referred to as the cost-directed spacing).

41. The medium of claim 40 comprising code for indicating the location of the borehole and of the first and second boundaries of the rock burden associated with the cost-directed spacing.

42. The medium of claim 40 or claim 41 comprising code for using a boundary associated with the cost-directed spacing as a boundary for the rock burden of a subsequent borehole on the drill line and executing the code of parts (iii)-(vii) to assign a cost-directed spacing to the subsequent borehole.

46. An apparatus for assigning positions for boreholes of predetermined diameter for use with a specified explosive material along a primary drill line along a bench of rock having a known density and a rock face, the apparatus comprising:

a computer processor;

at least one storage medium accessible to the processor, for storing data and executable code;

input means for delivering data to at least one storage medium; and

output means for conveying data representing locations of boreholes;

wherein the storage media comprise a storage medium as set forth in claim 37.

47. The medium of claim 38 comprising code for permitting code (vi) to repeat code (iv) and (v) until an energy factor criterion is not met.

48. The medium of claim 40 wherein code (iii) proposes a borehole and associated boundary spacing that corresponds to the minimum spacing criterion;

and

wherein code (iv) comprises code for proposing an incrementally larger spacing than was used previously in code (iii), (iv) and (v).

49. The medium of claim 40 wherein code (iii) proposes a borehole and associated boundary spacing that corresponds to the maximum spacing criterion;

and

wherein code (iii) comprises code for proposing incrementally smaller spacing than was used previously in code (iii), (iv) and (v).