Blasting method

• US 7,418,373 B2
• Filed: 08/03/2004
• Issued: 08/26/2008
• Est. Priority Date: 09/08/1999
• Status: Expired due to Fees

• Current Assignee: Optimuck, LLC
• Original Assignee: Live Oak Ministries
• Inventors: Heck, Jay Howard Sr.
• Primary Examiner(s): Shah; Kamini
• Assistant Examiner(s): Silver; David
• Application Number:
  US10/911,792
• Publication Number:
  US 20050010385A1
• Time in Patent Office: 1,484 Days
• Field of Search: 703/10, 703/6, 703/7, 102/301.313, 175/24
• 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 of assigning positions for boreholes at a bench blasting site, wherein the rock face has one or more rock face irregularities, the method comprising:

inputting one or more bench characteristics of the bench blasting site, one or more blast design constraints, and a proposed drill line having a start point and an end point into a computer; and

using the computer to automatically determine a drill position for each borehole and one or more drill pattern characteristics of each borehole based on the blast design constraints, the one or more bench characteristics, and the one or more rock face irregularities, wherein said computer determines a drill position for each borehole by;

(1) determining a target rock burden for an initial borehole having a predetermined diameter and depth at the start point;

(2) defining along the proposed drill line a progression of successive layers of rock each defining an incremental burden, determining a cumulative burden of successive defined layers;

(3) comparing each cumulative burden with the target burden;

(4) revising the drill position for the borehole on the drill line in the layer most distant from the start point;

(5) defining additional successive layers of rock until the blast constraints of the borehole at a drill position causes the target burden to remove the rock burden associated with the borehole;

(6) setting a location for a distant boundary of the rock burden for the borehole; and

(7) using the distant boundary as the drill position for an additional borehole and repeating (1), (2), (3), (4), (5) and (6) for each additional borehole until a layer coincides with the end point to calculate the drill position for each borehole; and

outputting a report containing the drill position of each borehole.

2. The method of claim 1, wherein the one or more rock face irregularities comprise a trough, and wherein the report identifies boreholes located in the trough and further comprising inputting data indicating the placement of boreholes in the trough and receiving a report indicating positions for boreholes on the drill line.

3. The method of claim 1 or claim 2, wherein the one or more rock face irregularities comprise rock face swells, and 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.

4. The method of claim 2 wherein inputting the one or more bench characteristics of the bench blasting site, the one or more blast design constraints, and the proposed drill line having a start point and an end point into the computer comprises retrieving the one or more bench characteristics of the bench blasting site, the one or more blast design constraints, and the proposed drill line having a start point and an end point from a memory medium.

5. The method of claim 1 wherein inputting the one or more bench characteristics of the bench blasting site into the computer comprises transferring data from an electronic surveying device.

6. The method of claim 1 wherein inputting the one or more bench characteristics of the bench blasting site, the one or more blast design constraints, and the proposed drill line having a start point and an end point into the computer comprises entering the one or more bench characteristics of the bench blasting site, the one or more blast design constraints, and the proposed drill line having a start point and an end point via a user input device.

13. The method of claim 1 wherein inputting one or more bench characteristics of the bench blasting site into a computer comprises inputting one or more bench characteristics selected from the group consisting of bench height, bank angle, rock face configuration, density, and combinations thereof, into the computer so as to allow the computer determine a drill position for each borehole.

14. The method of claim 1 wherein inputting one or more blast design constraints into the computer comprises inputting one or more blast design constraints selected from the group consisting of a minimum spacing constraint, a maximum spacing constraint, a hole-to-rock face burden constraint, explosive material property constraints, or a Material Factor constraint, an Energy Factor constraint, desired borehole angle constraint, and combinations thereof into the computer so as to allow the computer to determine a drill position for each borehole.

18. The method of claim 1 wherein the one or more rock face irregularities comprises a swell, a trough, or combinations thereof.

7. A method of using a processor to assign positions for boreholes at a bench blasting site to blast a bench of rock with explosives housed in the boreholes, the bench of rock having bench characteristics selected from the group of bench height, bank angle, borehole-to-rock face distance, and rock density, and having a rock face with one or more rock face irregularities selected from the group of a swell, a hollow, and combinations thereof, the method comprising:

a) inputting into a processor one or more bench characteristics of the bench of rock, one or more blast design constraints, and a proposed drill line having a start point and an end point;

b) calculating an optimum drill pattern of boreholes using one or more of the bench characteristics, wherein the processor automatically;

i) determines an initial drill pattern with location of the boreholes between the start point and the end point based on the bench characteristics;

ii) determines one or more blast characteristics for each borehole based on the location of the borehole due to the initial drill pattern;

iii) identifies boreholes located in one or more rock face irregularities based on the rock burden for each borehole;

iv) modifies the initial drill pattern of the boreholes to compensate for one or more rock face irregularities;

v) compares one or more drill pattern characteristics of the boreholes with the one or more blast constraints;

vi) repeats steps iv-v until the one or more blast constraints are met; and

c) outputting a report containing an optimum drill pattern of boreholes.

9. The method of claim 7 wherein inputting into a processor one or more bench characteristics of the bench of rock comprises inputting one or more bench characteristics selected from the group consisting of bench height, bank angle, rock face configuration, rock density, and combinations thereof into the processor so as to allow the processor to calculate an optimum drill pattern of boreholes.

10. The method of claim 7 wherein the processor in (b)(v) compares one or more drill pattern characteristics selected from the group consisting of spacing, hole-to-rock face burden, explosive material properties, a Material Factor, an Energy Factor, borehole angle, and combinations thereof so as to allow the processor to calculate an optimum drill pattern of boreholes.

11. The method of claim 7 wherein inputting into a processor one or more blast design constraints comprises inputting one or more blast constraints selected from the group consisting a minimum spacing constraint, a maximum spacing constraint, a hole-to-rock face burden constraint, explosive material property constraints, or a material factor constraint, an energy factor constraint, desired borehole angle constraint, into the processor so as to allow the processor to calculate an optimum drill pattern of boreholes.

12. The method of claim 7 wherein the processor in (b)(iv) add boreholes, subtracts boreholes, or changes borehole diameters to compensate for the one or more rock face irregularities.

8. A method of using a processor to assign positions for boreholes at a bench blasting site to blast a bench of rock with explosives housed in the boreholes, the bench of rock having bench characteristics selected from the group consisting of bench height, bank angle, a borehole-to-rock face distance, and rock density, and having a rock face, the rock face having one or more rock face irregularities selected from the group consisting of a swell, a hollow, and combinations thereof, the method comprising:

a) inputting into a processor one or more bench characteristics of the bench of rock, one or more blast design constraints, and a proposed drill line having a start point and an end point;

b) calculating an optimum drill pattern of boreholes using the one or more bench characteristics, wherein the processor automatically;

i) determines an initial drill pattern of the boreholes between the start point and end point based on the bench characteristics, wherein the processor determines the initial drill pattern by;

(1) determining a target rock burden B_T for a hypothetical borehole having a predetermined diameter at the start point;

(2) defining along the drill line a progression of successive layers of rock each defining an incremental burden, determining a cumulative burden B_cum of the defined layers and revising B_T with each successive layer until B_cum accounts for one-half B_T;

(3) setting and indicating a position for the borehole on the drill line in the layer most distant from the start point;

(4) defining additional successive layers of rock until the total of the incremental burdens of the layers defined in steps (c) and (e) accounts for B_T;

(5) setting and indicating a location for a distant boundary of the rock burden for the borehole; and

(6) using the distant boundary as the start point for an additional borehole and repeating (1), (2), (3), (4) and (5) for each additional borehole until a layer coincides with the end point to calculate the initial drill pattern;

ii) determines one or more drill pattern characteristics for each borehole based on borehole location in the bench of rock;

iii) compares one or more drill pattern characteristics of the boreholes with the one or more blast constraints;

iv) identifies boreholes situated in the one or more rock face irregularities based on the rock burden for each borehole;

v) modifies the initial drill pattern of the boreholes to compensate for the one or more rock face irregularities;

vi) repeats steps iv-v until the one or more blast constraints are met; and

c) outputting a report containing an optimum drill pattern of boreholes.

15. The method of claim 8 wherein the drill pattern characteristics include an initial hole-to-rock face burden and an initial hole spacing, wherein the blast design constraints include a hole-to-rock face burden constraint and a hole spacing constraint, and wherein (b)(iii) comprises:

1) comparing the initial hole-to-rock face burden for each borehole to the hole-to-rock face burden constraint to determine one or more deviations from the blast design constraints;

2) moving the drill line and repeating (b)(ii) and (1) to eliminate the one or more deviations;

3) if the one or more deviations cannot be eliminated by moving the drill line, then comparing the initial hole spacing for each borehole to the hole spacing constraints; and

4) if the initial hole spacing for a series of boreholes is different from the hole spacing constraints, then the series of boreholes is situated in a rock face irregularity.

16. The method of claim 8 wherein (b)(iii) comprises:

1) comparing the initial hole-to-rock face burden for each borehole to the hole-to-rock face burden constraint to determine one or more deviations from the blast design constraints;

2) moving the drill line and repeating (b)(ii) and (1) to eliminate the one or more deviations;

3) if the one or more deviations cannot be eliminated by moving the drill line, then comparing the initial hole spacing for each borehole to the hole spacing constraints; and

4) if the initial hole spacing for a series of boreholes is different from the hole spacing constraints, then the series of boreholes is situated in a rock face irregularity.

17. The method of claim 16 wherein (b)(iii) further comprises:

5) determining whether the initial hole spacing for the series of boreholes is greater or less than the hole spacing constraints;

6) if the initial hole spacing is less than the blast design hole spacing, the series of boreholes is situated in a swell; and

7) if the initial hole spacing is greater than the hole spacing constraints, the series of boreholes is situated in a hollow.

19. A method of designing blast hole constraints for a bench blasting site to blast a bench of rock, the bench of rock having a rock with irregularities, the blast hole constraints including at least one borehole with explosives to blast a bench rock portion associated with the at least one borehole, the bench of rock having bench characteristics including a bench height, a bank angle, a borehole-to-rock face distance, and rock density, the method comprising:

a) inputting into a processor a start point and an end point for a proposed drill line of boreholes;

b) inputting into the processor one or more blast design constraints for the at least one borehole;

c) calculating a target burden of the at least one borehole based on the one or more blast design constraints;

d) inputting into the processor the bench characteristics of the bench rock portion and calculating an incremental rock burden of a layer of the bench rock portion defined by a first cross-section of the bench rock portion extending from a plane through the at least one borehole to the to the rock face using the bench angle and bench height and by a second cross-section area an incremental distance from the first cross-section area;

e) comparing the incremental burden of the layer with the target burden of the at least one borehole, and, if the incremental burden is less than one-half the target burden, repeating steps a) through d) adding the incremental rock burdens of successive layers until an aggregate of the incremental burdens to a last plane defined by a last layer is greater than one-half the target burden;

f) determining a new position of the at least one borehole based upon the start point and last plane;

g) inputting into the processor an initial set of blast design constraints for a successive borehole and initially locating the successive borehole at the last plane; and

h) repeating the steps c) through f) until the positions of all successive boreholes are determined along the drill line to the end point.

20. The method of claim 19, wherein the blast hole constraints are revised and the target burden recalculated after each incremental burden for a layer is determined.

21. The method of claim 20, wherein the dimensions of the borehole and/or the amount or type of explosives are modified to substantially match the target burden of the blast constraints to the bench rock portion associated with the blast constraints of the borehole.

22. The method of claim 19 wherein each borehole is subject to blast design criteria including minimum and maximum spacing and/or a minimum energy factor of the explosives and the blast constraints for a borehole are revised to meet the blast design criteria and the rock burden of the bench rock portion associated with the borehole.

23. The method of claim 22 further including identifying an explosive that meets the requirements of the blast design constraints.

24. The method of claim 22 further including using different explosives in different segments of the borehole to meet the requirements of the blast design constraints.