A construction method for rock roadway cut blasting tunneling

Abstract

An embodiment of the present invention discloses a construction method for rock roadway cut blasting tunneling, which relates to the technical field of rock roadway tunneling by drilling and blasting method, and is beneficial to reducing the clamping effect on the blasting of the surrounding rock of the rock roadway, thereby improving the blasting tunneling efficiency. The method includes: arranging a central cut area, a first cut area and a second cut area on the working face, below the intersection of the roadway springing line and the center line, detonating the central cut area first to form a first blasting free face, creating favorable conditions for the detonation of the first cut area and the second cut area, and after the detonation of the first cut area and the second cut area is completed, forming a horizontal wedge-shaped cut cavity approximately below the springing line, creating a larger free face for the blasting of the remaining blast holes arranged at positions such as the arch part of the working face in the future. The present invention is beneficial to reducing the clamping effect on the blasting of the surrounding rock of the rock roadway, thereby improving the blasting tunneling efficiency; it is applicable to blasting tunneling projects such as rock roadways, tunnels and chambers.

Description

Technical Field

[0001] The present invention relates to the technical field of tunneling in rock roadway by drilling and blasting method, and particularly relates to a construction method for tunneling and blasting in rock roadway with cut. Background Art

[0002] The development of tunneling construction technology in rock roadway is crucial for improving the tunneling level of rock roadway and alleviating the contradiction between mining and excavation. At present, 90% of rock roadways are constructed by drilling and blasting method, while the tunneling level of rock roadway by drilling and blasting method has been hovering at about 70m / month for a long time, resulting in unbalanced mining and excavation, and seriously restricting the continuous production of coal mines. As the most important part of tunneling in rock roadway by drilling and blasting method, with the continuous increase of the depth of blast holes, the clamping effect on the cut blasting of surrounding rock in rock roadway under hard rock conditions is significantly strengthened, resulting in low blasting efficiency and the utilization rate of blast holes not meeting the design requirements.

[0003] Cutting techniques can generally be divided into two categories: inclined hole cutting and parallel hole cutting, and can be further divided into the following types: wedge cutting, cone cutting, wedge and parallel composite cutting, diamond cutting, triangular prism cutting, quadrangular prism cutting, five-star cutting, hexagonal prism cutting, spiral cutting, etc.

[0004] The characteristic of inclined hole cutting is that the cut holes intersect obliquely with the free face. The commonly used one is wedge cutting. The main characteristic of this kind of cutting is that the working face is used as the free face and the cut holes detonate simultaneously. After the explosive detonates, under the combined action of stress wave and explosion-generated gas, the rock in the wedge-shaped area is broken. Under good stemming conditions, due to the high-pressure state maintained by the detonation gas products in the blast holes for a long time, the broken rock in the wedge is thrown out to form a cut cavity to achieve the purpose of cutting.

[0005] The characteristic of parallel hole cutting is the blasting with empty holes as the main free face, and its minimum resistance line is the distance from the charged hole to the empty hole. Since the cut holes are parallel to each other, the minimum resistance line from the hole mouth to the bottom of the hole is the same, and the shape of the cut cavity formed is regular.

[0006] In traditional blasting technology, after the cut holes are blasted, continuous blasting is generally carried out in circles, as Figure 1 shown. When blasting, a circle of rock mass can be simplified as an arch. According to the mechanical principle, the size of the load borne by the arch mainly depends on the reaction force provided at the arch feet. Moreover, in traditional blasting tunneling, cut holes are only arranged in the tunneling direction, and there are not many free faces in the direction of the working face, which is not conducive to weakening the clamping effect on the cut blasting of surrounding rock in rock roadway, resulting in low blasting tunneling efficiency and affecting the construction progress of rock roadway tunneling. Summary of the Invention

[0007] In view of this, the embodiment of the present invention provides a construction method for tunneling and blasting in rock roadway with cut, which is beneficial to weakening the clamping effect on the cut blasting of surrounding rock in rock roadway, thereby improving the blasting tunneling efficiency.

[0008] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0009] A construction method for cutting and blasting tunneling in rock headings, comprising the steps of:

[0010] Roughly arrange a central cut area on the working face, below the intersection of the arch line and the center line of the roadway; the central cut area is a vertical cut area, including: a plurality of central holes arranged on the center line, auxiliary cut holes, and a plurality of wedge-shaped cut holes symmetrically arranged on both sides of the central hole, the auxiliary cut holes are located at the upper and lower vertex positions of the central cut area, and the plurality of central holes, auxiliary cut holes and the plurality of wedge-shaped cut holes enclose a central cut area with a hexagonal contour;

[0011] Arrange a first cut area on the first side of the central cut area, and arrange a second cut area on the second side of the central cut area; both the first cut area and the second cut area are horizontal cut areas, respectively including: multiple rows of horizontal cut holes, and the first cut area and the second cut area are arranged back to back;

[0012] After the central cut area, the first cut area and the second cut area are arranged, first detonate the auxiliary cut holes and the plurality of wedge-shaped cut holes located on the hexagonal contour in the central cut area;

[0013] After a first predetermined time, detonate the central holes between the upper and lower vertices on the center line;

[0014] After the blasting of the central cut area is completed, a first blasting free face is formed;

[0015] Detonate the first row of cut holes on both sides of the plurality of wedge-shaped cut holes adjacent to the first cut area in the first cut area and the second cut area, and based on the first blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the first row of cut holes, forming a second blasting free face;

[0016] After a second predetermined time, detonate the second row of cut holes adjacent to the first row of cut holes in the first cut area and the second cut area, and based on the second blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the second row of cut holes, forming a third blasting free face;

[0017] After a third predetermined time, detonate the third row of cut holes adjacent to the second row of cut holes in the first cut area and the second cut area, and based on the third blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the third row of cut holes, forming a fourth blasting free face;

[0018] After the fourth predetermined time, initiate the (n + 3)-rd row of cut holes in the first cut area and the second cut area that are adjacent to the third row of cut holes, and based on the fourth blasting free face, guide the surrounding rock to collapse towards the first cut area after the initiation of the (n + 3)-rd row of cut holes, thereby forming the (n + 4)-th blasting free face; where n ≥ 1 and n is a positive integer;

[0019] Repeat the above step of initiating the (n + 3)-rd row of cut holes in the first cut area and the second cut area, and initiate them outward in sequence until all rows of cut holes in the first cut area and the second cut area are initiated;

[0020] After the initiation of the first cut area and the second cut area is completed, a horizontal wedge-shaped cut cavity is formed approximately below the springing line.

[0021] Optionally, 3 central holes are arranged at intervals from top to bottom in the central cut area, 1 auxiliary cut hole is arranged at each of the upper end and the lower end of the central holes, and 4 wedge-shaped cut holes are arranged on each of the left and right sides;

[0022] The first cut area and the second cut area are each provided with 4 rows of cut holes. Among them, the spacing between the upper and lower cut holes in each row from the vertical wedge-shaped cut hole side to the outside decreases in a geometric progression. The first cut area and the second cut area have a trapezoidal profile, and the fourth row of cut holes is located on the straight wall section of the rock roadway.

[0023] Optionally, the first row of cut holes is provided with 4, the second row and the third row of cut holes are provided with 3, and the fourth row of cut holes is provided with 2.

[0024] Optionally, the vertical depth of the wedge-shaped cut holes, the central holes, and the auxiliary cut holes in the central cut area is 2.9 m. Among them, the wedge-shaped cut holes are obliquely arranged with the working face, and the included angle is 70 - 85°. The central holes and the auxiliary cut holes are vertically arranged with the working face, and the included angle is 90°. The hole spacing between two adjacent wedge-shaped cut holes is 450 mm;

[0025] The charging depth of the wedge-shaped cut holes is 0.8 times the length of the blast hole. The charging length of the central hole located between the upper and lower vertices of the center line is 0.15 times the length of the blast hole. The charging length of the auxiliary cut holes is 0.75 times the length of the blast hole;

[0026] The depth of the cut blast holes in the horizontal cut area is 2.8 m. The adjacent hole spacing of the first row of cut holes in the first cut area and the second cut area is 360 mm, the adjacent hole spacing of the second row of cut holes is 422 mm, the adjacent hole spacing of the third row of cut holes is 300 mm, and the adjacent hole spacing of the fourth row of cut holes is 300 mm;

[0027] The charging length of the cut holes in the first row is 0.75 times the hole length of the blast hole, the charging length of the cut holes in the second row is 0.6 times the hole length of the blast hole, the charging length of the cut holes in the third row is 0.5 times the hole length of the blast hole, and the charging length of the cut holes in the fourth row is 0.4 times the hole length of the blast hole;

[0028] The first predetermined time, the second predetermined time, the third predetermined time, and the fourth predetermined time respectively correspond to the delay durations of different segments of detonators.

[0029] Optionally, the horizontal wedge-shaped cut cavity truncates the arch part and the straight wall part of the rock roadway to be driven.

[0030] Optionally, after the blasting in the central cut area, the first cut area, and the second cut area is completed, the method further includes: detonating the remaining blast holes arranged on the working face, and the remaining blast holes are arranged on the working face in circles;

[0031] Specifically, it includes the steps of: first blasting the first circle of auxiliary holes located above the arch line, and the charging length of the first circle of auxiliary holes is 0.7 times the hole length of the blast hole;

[0032] After the first predetermined delay duration, detonating the second circle of auxiliary holes located above the arch line; the charging length of the second circle of auxiliary holes is 0.6 times the hole length of the blast hole;

[0033] After the second predetermined delay duration, detonating the third circle of auxiliary holes located above the arch line and the auxiliary holes located below the first cut area and the second cut area and on the contour line and the center line of the current detonation of the first circle of auxiliary holes, the second circle of auxiliary holes, and the third circle of auxiliary holes; the charging length of the third circle of auxiliary holes is 0.5 times the hole length of the blast hole;

[0034] After the third predetermined delay duration, detonating the fourth circle of auxiliary holes located above the arch line and the auxiliary holes located below the first cut area and the second cut area and on the contour line of the current detonation of the third circle of auxiliary holes and the fourth circle of auxiliary holes; the charging length of the fourth circle of auxiliary holes is 0.4 times the hole length of the blast hole;

[0035] After the fourth predetermined delay duration, detonating the perimeter holes located outside the fourth circle of auxiliary holes and the auxiliary holes located below the first cut area and the second cut area and on the contour line of the current detonation of the perimeter holes, and the bottom holes located at the bottom of the rock roadway; the charging length of the perimeter holes is 0.3 times the hole length of the blast hole, and the charging length of the bottom holes at the bottom of the rock roadway is 0.5 times the hole length of the blast hole.

[0036] Optionally, the remaining blast holes arranged on the working face are arranged on the working face in circles;

[0037] The method further includes: after a first predetermined time, while detonating the central hole between the upper and lower vertices on the center line and the first row of cut holes in the horizontal cut area, detonating the first circle of auxiliary holes above the arch line to make full use of the wedge cut voids to form a cavity with a second blasting free surface;

[0038] After a second predetermined time, while detonating the second row of cut holes, detonating the second circle of auxiliary holes above the arch line and the auxiliary holes below the first cut area and the second cut area and on the contour line of the current detonation of the first, second, and third circles of auxiliary holes and on the center line;

[0039] After a third predetermined time, while detonating the third row of cut holes, detonating the third circle of auxiliary holes above the arch line and the auxiliary holes below the first cut area and the second cut area and on the contour line of the current detonation of the first, second, third, and fourth circles of auxiliary holes;

[0040] After a fourth predetermined time, while detonating the (n + 3)-rd row of cut holes adjacent to the third row of cut holes in the first cut area and the second cut area, detonating the fourth circle of auxiliary holes above the arch line and the auxiliary holes below the first cut area and the second cut area and on the contour line of the current detonation of the fourth circle of auxiliary holes and the peripheral holes;

[0041] After a fifth predetermined time, detonating the peripheral holes above the arch line and the bottom holes at the bottom of the rock roadway.

[0042] Optionally, the remaining blast holes arranged on the working face are arranged in circles on the working face;

[0043] The method further includes: after a first predetermined time, while detonating the central hole between the upper and lower vertices on the center line and the first row of cut holes in the horizontal cut area, detonating the first circle of auxiliary holes above the arch line to make full use of the wedge cut voids to form a cavity with a second blasting free surface;

[0044] After a second predetermined time, while detonating the second row of cut holes, detonating the second circle of auxiliary holes above the arch line;

[0045] After a third predetermined time, while detonating the third row of cut holes, detonating the third circle of auxiliary holes above the arch line;

[0046] After a fourth predetermined time, while detonating the (n + 3)-rd row of cut holes adjacent to the third row of cut holes in the first cut area and the second cut area, detonating the fourth circle of auxiliary holes above the arch line;

[0047] After the sixth predetermined time, initiate the auxiliary holes located below the first cut area and the second cut area and on the contour line of the current initiation of the first ring of auxiliary holes, the second ring of auxiliary holes, the third ring of auxiliary holes, the fourth ring of auxiliary holes, and the perimeter holes;

[0048] After the seventh predetermined time, initiate the auxiliary holes located below the first cut area and the second cut area and on the contour line of the current initiation of the third ring of auxiliary holes, the fourth ring of auxiliary holes, and the perimeter holes;

[0049] After the eighth predetermined time, initiate the bottom holes at the bottom of the rock roadway.

[0050] Optionally, the charging length of the first ring of auxiliary holes is 0.7 times the length of the blast hole, the charging length of the second ring of auxiliary holes is 0.6 times the length of the blast hole, the charging length of the third ring of auxiliary holes is 0.5 times the length of the blast hole, the charging length of the fourth ring of auxiliary holes is 0.4 times the length of the blast hole, the charging length of the perimeter holes is 0.3 times the length of the blast hole, and the charging length of the bottom holes at the bottom of the rock roadway is 0.5 times the length of the blast hole.

[0051] Optionally, the included angle between the extension lines of the two waists of the trapezoidal contour of the first cut area and the second cut area is 10 - 45°.

[0052] The rock roadway cut blasting tunneling construction method provided by the embodiments of the present invention, by arranging the central cut area, the first cut area and the second cut area, first initiate the central cut area to form a vertical cut area and a new first blasting free face, and then sequentially initiate the first cut area and the second cut area with step-by-step time delay to gradually expand the first blasting free face and form second, third, etc. blasting free faces, which is beneficial to reducing the clamping effect suffered by each rock roadway surrounding rock cut blasting. Finally, a horizontal cut area is formed, creating a larger free face for the blasting of the remaining blast holes arranged at positions such as the arch of the working face next, which is beneficial to reducing the clamping effect suffered by the rock roadway surrounding rock cut blasting, making it easier for the rock at the arch to be blasted down, saving the unit consumption of explosives, and thus being able to improve the blasting tunneling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] 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 for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0054] Figure 1 It is a schematic diagram of sequential blasting in circles for traditional rock roadway blasting tunneling technology;

[0055] Figure 2 It is a schematic layout diagram of the cut area of the rock roadway working face in the rock roadway cut blasting tunneling construction method of the present invention;

[0056] Figure 3 It is a schematic diagram after blasting in the cut area of the rock roadway working face in the rock roadway cut blasting tunneling construction method of the present invention;

[0057] Figure 4 It is a schematic layout diagram of the cut holes in the rock roadway working face to be tunneled in the first embodiment of the present invention;

[0058] Figures 5 to 9 It is a schematic diagram of the delay initiation process in the cut area of the rock roadway working face to be tunneled in the first embodiment;

[0059] Figures 10 to 14 It is a schematic diagram of the blasting process of the remaining blast holes in the rock roadway working face to be tunneled in the first embodiment;

[0060] Figures 15 to 20 It is a schematic diagram of the blasting process of the rock roadway cut blasting tunneling construction method provided in the second embodiment;

[0061] Figures 21 to 28 It is a schematic diagram of the blasting process of the rock roadway cut blasting tunneling construction method provided in the third embodiment. Detailed implementation manners

[0062] The following describes in detail the rock roadway cut blasting tunneling construction method provided by the embodiments of the present invention with reference to the accompanying drawings.

[0063] It should be clear that the described embodiments are only a part of the embodiments of the present invention, rather than all 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.

[0064] Refer to Figures 2 to 28 As shown, the rock roadway cut blasting tunneling construction method provided by the embodiments of the present invention is mainly applicable to blasting tunneling engineering operations such as rock drilling operations, tunnels, roadway operations, and mines; hard rock roadways, specifically referring to rock roadways with a rock solidity coefficient (Prandtl coefficient) f greater than or equal to 7, and also including headings, tunnels, and chambers belonging to hard rock determined by any other surrounding rock classification method.

[0065] As Figure 2 shown, the method includes the steps:

[0066] A central cut area is arranged approximately on the working face and below the intersection point of the arch line and the center line of the roadway; the central cut area is a vertical cut area, including: a plurality of central holes, auxiliary cut holes arranged on the center line, and a plurality of wedge-shaped cut holes symmetrically arranged on both sides of the central holes. Located at the upper and lower vertex positions of the central cut area, the plurality of central holes, auxiliary cut holes and the plurality of wedge-shaped cut holes enclose a central cut area with a hexagonal contour.

[0067] The blast holes in the central cut area are arranged perpendicular to the working face. In some embodiments, 3 central holes are arranged at intervals from top to bottom in the central cut area, 1 auxiliary cut hole is arranged at each of the upper and lower ends of the central holes, a total of 2; 4 vertical wedge-shaped cut holes are arranged on each of the left and right sides; the central holes 1-3 and auxiliary cut holes 12-13 in the central cut area, and the vertical wedge-shaped cut holes 4-11 holes. The wedge-shaped cut holes are obliquely intersecting with the working face, and the angle is generally between 70-85°, and the central holes 1-3 and 12-13 are perpendicular to the working face, which is 90°.

[0068] A first cut area is arranged on the first side of the central cut area, and a second cut area is arranged on the second side of the central cut area; both the first cut area and the second cut area are horizontal cut areas, respectively including: multiple rows of horizontal cut holes, and the first cut area and the second cut area are arranged back to back.

[0069] As Figure 2 shown, 4 rows of cut holes are respectively arranged in the first cut area and the second cut area. Among them, the spacing between the upper and lower cut holes in each row from the side of the vertical wedge-shaped cut holes decreases in a series. The first cut area and the second cut area have a trapezoidal contour, and the fourth row of cut holes is located on the straight wall section of the rock roadway. Specifically, the included angle between the extension lines of the two waists of the trapezoidal contour of the first cut area and the second cut area is 10-45°.

[0070] Continue to refer to Figure 2 shown, exemplarily, 4 cut holes are arranged in the first row of cut holes in the first cut area and the second cut area, which are respectively: cut holes 14-21, 3 cut holes are arranged in the second and third rows of cut holes, including: cut holes 22-27 and the third row of cut holes 28-33, and 2 cut holes are respectively arranged in the fourth row of cut holes, including: cut holes 34-37.

[0071] After the central cut area, the first cut area and the second cut area are arranged, first detonate the auxiliary cuts and a plurality of wedge-shaped cut holes located on the hexagonal contour in the central cut area; among them, the wedge-shaped cut holes 4-11 and the auxiliary cut holes 12-13 are detonated simultaneously first, and 1-section detonators are used for detonation. Or detonate the 4-11 holes first, using 1 section; then detonate the 1-3 and 12-13 holes, using 2 sections.

[0072] After the first predetermined time, initiate the center hole located between the upper and lower vertices on the center line; in some embodiments, the center holes 1-3 are initiated by two-stage detonators with a delay of 10 milliseconds, that is, the first predetermined time is 10 milliseconds.

[0073] After the blasting in the center cut area is completed, a first blasting free face is formed, providing more free faces for the subsequent blasting of the first cut area and the second cut area, which is beneficial to reducing the clamping effect of the surrounding rock.

[0074] Initiate the first row of cut holes 14-21 on both sides of the multiple wedge-shaped cut holes adjacent to the first cut area in the first cut area and the second cut area. Based on the first blasting free face, guide the surrounding rock to collapse towards the first cut area after the initiation of the first row of cut holes, forming a second blasting free face; in some embodiments, the first row of cut holes 14-21 is initiated by three-stage detonators, with a 10-millisecond delay compared to two-stage detonators.

[0075] After the second predetermined time, initiate the second row of cut holes 22-27 in the first cut area and the second cut area adjacent to the first row of cut holes. Based on the second blasting free face, guide the surrounding rock to collapse towards the first cut area after the initiation of the second row of cut holes, forming a third blasting free face; in some embodiments, the second row of cut holes 22-27 is initiated by four-stage detonators, with a 10-millisecond delay compared to three-stage detonators.

[0076] After the third predetermined time, initiate the third row of cut holes 28-33 in the first cut area and the second cut area adjacent to the second row of cut holes. Based on the third blasting free face, guide the surrounding rock to collapse towards the first cut area after the initiation of the third row of cut holes, forming a fourth blasting free face; in some embodiments, the second row of cut holes 28-33 is initiated by five-stage detonators, with a 10-millisecond delay compared to four-stage detonators.

[0077] After the fourth predetermined time, initiate the (n + 3)-th row of cut holes in the first cut area and the second cut area adjacent to the third row of cut holes, for example, the fourth row of cut holes 34-37. Based on the fourth blasting free face, guide the surrounding rock to collapse towards the first cut area after the initiation of the (n + 3)-th row of cut holes, forming the (n + 4)-th blasting free face; where n≥1 and n is a positive integer; in some embodiments, the fourth row of cut holes 34-37 is initiated by six-stage detonators, with a 10-millisecond delay compared to five-stage detonators.

[0078] Repeat the above steps of initiating the (n + 3)-th row of cut holes in the first cut area and the second cut area, and initiate them sequentially outward until all the rows of cut holes in the first cut area and the second cut area are initiated;

[0079] It can be understood that when specifically arranging the cut holes in the first cut area and the second cut area, the number of columns is determined according to the size of the specific working face to be driven. Based on the technical concept of the present invention, no matter how many columns of cut holes are arranged, the above steps of detonating the cut holes in the (n + 3)-rd column in the first cut area and the second cut area can be repeated, and detonated successively from the inside to the outside until all the cut holes in the first cut area and the second cut area are detonated.

[0080] After the first cut area and the second cut area are detonated, a horizontal wedge-shaped cut cavity is formed approximately below the spring line, as Figure 3 shown.

[0081] Continue to refer to Figure 3 shown. After successive detonations, a horizontal wedge-shaped cut cavity is formed approximately below the spring line, and the horizontal wedge-shaped cut cavity cuts off the arch part and the straight wall section of the rock roadway to be driven.

[0082] In some embodiments, the vertical depth of the wedge-shaped cut holes, the center hole, and the auxiliary cut holes in the central cut area is 2.9 m. Among them, the wedge-shaped cut holes are arranged obliquely to the working face, with an included angle of 70 - 85°, and the center hole and the auxiliary cut holes are arranged perpendicular to the working face, with an included angle of 90°; the hole spacing between two adjacent wedge-shaped cut holes is 450 mm;

[0083] The charging depth of the wedge-shaped cut holes is 0.8 times the length of the blast hole, the charging length of the center hole located between the upper and lower vertices of the center line is 0.15 times the length of the blast hole, and the charging length of the auxiliary cut holes is 0.75 times the length of the blast hole;

[0084] The adjacent hole spacing of the first column of cut holes in the first cut area and the second cut area is 360 mm, the adjacent hole spacing of the first column of cut holes in the first cut area and the second cut area is 360 mm, the adjacent hole spacing of the second column of cut holes is 422 mm, the adjacent hole spacing of the third column of cut holes is 300 mm, and the adjacent hole spacing of the fourth column of cut holes is 300 mm;

[0085] The charging length of the first column of cut holes is 0.75 times the length of the blast hole, the charging length of the second column of cut holes is 0.6 times the length of the blast hole, the charging length of the third column of cut holes is 0.5 times the length of the blast hole, and the charging length of the fourth column of cut holes is 0.4 times the length of the blast hole;

[0086] The first predetermined time, the second predetermined time, the third predetermined time, and the fourth predetermined time respectively correspond to the delay durations of different sections of detonators.

[0087] It can be understood that according to the mechanical principle, the magnitude of the load borne by the arch part of the rock roadway mainly depends on the reaction force provided at the arch feet, which is not conducive to the blasting of the arch part of the rock roadway.

[0088] In this embodiment, by flexibly configuring the number of segments of the detonators, a vertical cut cavity can be formed first, and then a horizontal wedge-shaped cut cavity can be formed. By means of the horizontal wedge-shaped cut cavity, the mechanical effect of the rock arch is weakened, the bearing capacity of the rock foot is reduced, the blasting free surface of the arch part is increased, the clamping effect is reduced, making it easier for the rocks in the arch part to be blasted down and saving the unit consumption of explosives. Thus, a high hole utilization rate can be achieved.

[0089] The rock roadway cut blasting tunneling construction method provided by the embodiment of the present invention, by arranging a central cut area, a first cut area and a second cut area, first detonates the central cut area to form a vertical cut area and create a new first blasting free surface, and then sequentially detonates the first cut area and the second cut area with a step-by-step time delay to gradually expand the first blasting free surface and form second, third, etc. blasting free surfaces, which is beneficial to reducing the clamping effect suffered by each cut blasting of the surrounding rock of the rock roadway. Finally, a horizontal cut area is formed, creating a larger free surface for the blasting of the remaining blast holes arranged at positions such as the arch of the working face next, which is beneficial to reducing the clamping effect suffered by the cut blasting of the surrounding rock of the rock roadway, making it easier for the rocks in the arch part to be blasted down, saving the unit consumption of explosives, and thus being able to improve the blasting tunneling efficiency.

[0090] To more clearly illustrate the technical solution provided by the embodiment of the present invention, the following is a detailed description by taking a 5.0m * 4.4m straight-wall semi-circular arch roadway in blasting tunneling as an example:

[0091] Embodiment 1

[0092] Refer to Figures 4 to 14 As shown, the rock roadway cut blasting tunneling construction method provided by this embodiment arranges a central cut area, a first cut area and a second cut area according to the Figure 4 rock roadway working face cut area layout method shown. Refer to Figures 5 to 9 As shown, according to the foregoing method steps, the central cut area, the first cut area and the second cut area are first blasted to form a horizontal wedge-shaped cut cavity. By means of the horizontal wedge-shaped cut cavity, the mechanical effect of the rock arch is weakened, the bearing capacity of the rock foot is reduced, the blasting free surface of the arch part is increased, the clamping effect is reduced, which is beneficial to the subsequent collapse after the blasting of the remaining blast holes in the arch part.

[0093] Among them, cut holes are arranged in the middle and lower parts of the working face of the roadway to be tunnelled. The central cut area is composed of 3 central holes 1 to 3, two auxiliary cut holes 12 and 13, and 4 pairs of wedge-shaped cut holes 4 to 11 to form the first cut area and the second cut area on both sides, as shown respectively by Figure 4 the areas enclosed by the dotted lines.

[0094] The vertical depth of each cut hole (including the auxiliary cut holes) and the center hole in the central cut area (vertical cut area) is 2.9 m. The angle between the cut holes and the working face is 75°, and the angle between the center hole and the working face is 90°. The hole spacing between two adjacent wedge cut holes 4-11 is 450 mm. The adjacent hole spacing of the first row of cut holes 14-21 in the first cut area and the second cut area is 360 mm, the adjacent hole spacing of the second row of cut holes 22-27 is 422 mm, the adjacent hole spacing of the third row of cut holes 28-33 is 300 mm, and the adjacent hole spacing of the fourth row of cut holes 34-37 is 300 mm.

[0095] The charging depth of the wedge cut holes 4-11 is 0.8 times the hole length, and is detonated by 1-section electronic detonators; the charging length of the center holes 1 to 3 is 0.15 times the hole length, and is detonated by 2-section electronic detonators. The charging length of the auxiliary cut holes 12 and 13 is 0.75 times the hole length, and is detonated by 2-section electronic detonators. The charging length of the first row of cut holes 14-21 is 0.75 times the hole length, and is detonated by 2-section electronic detonators. The charging length of the second row of cut holes 22-27 is 0.6 times the hole length, and is detonated by 3-section electronic detonators. The charging length of the third row of cut holes is 0.5 times the hole length, and is detonated by 4-section electronic detonators. The charging length of the fourth row of cut holes 34-37 is 0.4 times the hole length, and is detonated by 5-section detonators; the total delay time in the cut area is 50 ms.

[0096] After the blasting in the central cut area, the first cut area and the second cut area is completed, the method further includes: detonating the remaining blast holes arranged on the working face, and the remaining blast holes are arranged on the working face in circles;

[0097] Specifically, it includes the steps of: first blasting the first circle of auxiliary holes 38-40 located above the arch line, as Figure 10 shown. The charging length of the first circle of auxiliary holes 38-40 is 0.7 times the hole length, and is detonated by 6-section detonators, with a delay time of 15 ms.

[0098] After the first predetermined delay duration, detonating the second circle of auxiliary holes 41-45 located above the arch line, as Figure 11 shown; the charging length of the second circle of auxiliary holes 41-45 is 0.6 times the hole length, and is detonated by 7-section detonators. Compared with the 6-section detonators, the delay time is 15 milliseconds;

[0099] As Figure 12As shown, after the second predetermined delay duration, initiate the third circle of auxiliary holes 46-55 above the arch line and the auxiliary holes 56-62 below the first cut area and the second cut area and on the current initiation contour line and the center line of the first circle of auxiliary holes 38-40, the second circle of auxiliary holes 41-45, and the third circle of auxiliary holes 46-55; the charge length of the third circle of auxiliary holes 46-55 and the auxiliary holes 56-62 is 0.5 times the hole length; the current initiation uses an 8-segment detonator, with a delay time of 15 milliseconds compared to a 7-segment detonator.

[0100] As Figure 13 shown, after the third predetermined delay duration, initiate the fourth circle of auxiliary holes 66-80 above the arch line and the auxiliary holes 63-65 and 81-83 below the first cut area and the second cut area and on the current initiation contour line of the third circle of auxiliary holes 46-55 and the fourth circle of auxiliary holes; the charge length of the fourth circle of auxiliary holes 66-80 and the auxiliary holes 63-65 and 81-83 is 0.4 times the hole length; initiate with a 9-segment detonator, with a delay time of 15 milliseconds compared to an 8-segment detonator.

[0101] As Figure 14 shown, after the fourth predetermined delay duration, initiate the perimeter holes 84-107 outside the fourth circle of auxiliary holes 66-80 and the auxiliary holes 107, 108, 121, and 122 below the first cut area and the second cut area and on the current initiation contour line of the perimeter holes, as well as the bottom holes 110-120 at the bottom of the rock roadway; the charge length of the perimeter holes 84-107 and the auxiliary holes 107, 108, 121, and 122 is 0.3 times the hole length, and the charge length of the bottom holes 110-120 at the bottom of the rock roadway is 0.5 times the hole length.

[0102] The blasting tunneling construction method provided by the embodiment of the present invention first forms a horizontal wedge-shaped cut cavity, uses the horizontal cut area to weaken the mechanical effect of the rock arch, reduce the bearing capacity of the rock foot, increase the blasting free surface of the arch part, reduce the clamping effect, make the rock in the arch part easier to blast down, and save the explosive specific consumption. Thus, high hole utilization rate is achieved.

[0103] Embodiment Two

[0104] Refer to Figures 15 to 20 shown, the rock roadway cut blasting tunneling construction method provided by the embodiment of the present invention is basically similar in basic concept to Embodiment One, the difference lies in the blasting step process of the remaining blast holes.

[0105] The method includes the steps: the remaining blast holes arranged on the working face are arranged on the working face in circles; as Figure 15As shown, after the layout of the central cut area, the first cut area and the second cut area is completed, first detonate the auxiliary cut holes 12 and 13 located on the hexagonal contour and the multiple wedge-shaped cut holes 4-11 in the central cut area to form a new cavity, as Figure 15 shown. After that, the method further includes:

[0106] As Figure 16 shown, after the first predetermined time, detonate the central hole between the upper and lower vertices on the center line and the first column of cut holes in the horizontal cut area, and at the same time, detonate the first circle of auxiliary holes 38-40 above the arch line to make full use of the wedge-shaped cut space to form a cavity with a second blasting free surface;

[0107] As Figure 17 shown, after the second predetermined time, detonate the second column of cut holes, and at the same time, detonate the second circle of auxiliary holes 41-45 above the arch line and the auxiliary holes 46-52 below the first cut area and the second cut area and on the current detonation contour line of the first circle of auxiliary holes, the second circle of auxiliary holes, the third circle of auxiliary holes and the center line;

[0108] As Figure 18 shown, after the third predetermined time, detonate the third column of cut holes, and at the same time, detonate the third circle of auxiliary holes 53-62 above the arch line and the auxiliary holes 63-71 below the first cut area and the second cut area and on the current detonation contour line of the first circle of auxiliary holes, the second circle of auxiliary holes, the third circle of auxiliary holes and the fourth circle of auxiliary holes;

[0109] As Figure 19 shown, after the fourth predetermined time, detonate the (n+3)th column of cut holes adjacent to the third column of cut holes in the first cut area and the second cut area, and at the same time, detonate the fourth circle of auxiliary holes 72-86 above the arch line and the auxiliary holes 87-92 below the first cut area and the second cut area and on the current detonation contour line of the fourth circle of auxiliary holes and the peripheral holes;

[0110] As Figure 20 shown, after the fifth predetermined time, detonate the peripheral holes 93-115 above the arch line and the bottom holes 116-126 at the bottom of the rock roadway.

[0111] In the blasting tunneling construction method provided in this embodiment, the blast holes located in the horizontal cut area are detonated in section 1 before the other blast holes in the "circle" where this column of blast holes is located, which can create a new free surface, weaken the arch foot effect, reduce the clamping effect, make the rock in the arch part easier to be blasted down, save the explosive consumption per unit, and thus achieve a high blast hole utilization rate.

[0112] Embodiment 3

[0113] SeeFigures 21 to 28 As shown, the rock roadway cut blasting tunneling construction method provided by the embodiment of the present invention is similar to the basic concept of Embodiment 2, except for the blasting step flow of the remaining blast holes.

[0114] As Figure 21 shown, after the central cut area, the first cut area, and the second cut area are arranged, first detonate the auxiliary cut holes 12 and 13 and a plurality of wedge cut holes 4-11 located on the hexagonal contour in the central cut area to form a new cut cavity. After that, the method further includes:

[0115] The remaining cut holes arranged on the working face are arranged in circles on the working face;

[0116] As Figure 22 shown, the method further includes: after the first predetermined time, while detonating the central hole between the upper and lower vertices on the center line and the first row of cut holes in the horizontal cut area, detonate the first circle of auxiliary holes above the arch line to make full use of the wedge cut space to form a cut cavity with a second blasting free surface;

[0117] As Figure 23 shown, after the second predetermined time, while detonating the second row of cut holes, detonate the second circle of auxiliary holes above the arch line;

[0118] As Figure 24 shown, after the third predetermined time, while detonating the third row of cut holes, detonate the third circle of auxiliary holes above the arch line;

[0119] As Figure 25 shown, after the fourth predetermined time, while detonating the (n + 3)th row of cut holes adjacent to the third row of cut holes in the first cut area and the second cut area, detonate the fourth circle of auxiliary holes above the arch line;

[0120] As Figure 26 shown, after the sixth predetermined time, detonate the auxiliary holes located below the first cut area and the second cut area and on the current detonation contour line of the first circle of auxiliary holes, the second circle of auxiliary holes, the third circle of auxiliary holes, the fourth circle of auxiliary holes, and the perimeter holes;

[0121] As Figure 27 shown, after the seventh predetermined time, detonate the auxiliary holes located below the first cut area and the second cut area and on the current detonation contour line of the third circle of auxiliary holes, the fourth circle of auxiliary holes, and the perimeter holes;

[0122] As Figure 28 shown, after the eighth predetermined time, detonate the bottom holes at the bottom of the rock roadway.

[0123] As described above, the rock roadway cut blasting tunneling construction method provided by the embodiments of the present invention is conducive to reducing the clamping effect on the cut blasting of the surrounding rock of the rock roadway, making it easier to blast the rock in the arch part, saving the unit consumption of explosives, and thus improving the blasting tunneling efficiency.

[0124] It should be noted that the emphases described in the various embodiments of the present invention are different, but they are related to each other and can be referred to each other. In addition, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0125] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A construction method for tunneling blasting in rock headings, characterized in that, The method includes the steps of: A central cut area is arranged on the working face, below the intersection point of the arch springing line and the center line of the roadway; the central cut area is a vertical cut area, including: a plurality of central holes arranged on the center line, auxiliary cut holes, and a plurality of wedge-shaped cut holes symmetrically arranged on both sides of the central holes. The auxiliary cut holes are located at the upper and lower vertex positions of the central cut area. The plurality of central holes, auxiliary cut holes, and the plurality of wedge-shaped cut holes enclose a central cut area with a hexagonal contour; A first cut area is arranged on the first side of the central cut area, and a second cut area is arranged on the second side of the central cut area; both the first cut area and the second cut area are horizontal cut areas, respectively including: multiple rows of horizontal cut holes, and the first cut area and the second cut area are arranged back to back; After the central cut area, the first cut area, and the second cut area are arranged, first detonate the auxiliary cut holes and the plurality of wedge-shaped cut holes located on the hexagonal contour in the central cut area; After a first predetermined time, detonate the central holes located between the upper and lower vertices on the center line; After the blasting of the central cut area is completed, a first blasting free face is formed; Detonate the first row of cut holes on both sides of the plurality of wedge-shaped cut holes adjacent to the first cut area in the first cut area and the second cut area. Based on the first blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the first row of cut holes, forming a second blasting free face; After a second predetermined time, detonate the second row of cut holes adjacent to the first row of cut holes in the first cut area and the second cut area. Based on the second blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the second row of cut holes, forming a third blasting free face; After a third predetermined time, detonate the third row of cut holes adjacent to the second row of cut holes in the first cut area and the second cut area. Based on the third blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the third row of cut holes, forming a fourth blasting free face; After a fourth predetermined time, detonate the (n + 3)-th row of cut holes adjacent to the third row of cut holes in the first cut area and the second cut area. Based on the fourth blasting free face, guide the surrounding rock to collapse towards the first cut area after the detonation of the (n + 3)-th row of cut holes, forming the (n + 4)-th blasting free face; where n ≥ 1 and n is a positive integer; Repeat the above step of detonating the (n + 3)-th row of cut holes in the first cut area and the second cut area, and detonate outward in sequence until all rows of cut holes in the first cut area and the second cut area are detonated; After the detonation of the first cut area and the second cut area is completed, a horizontal wedge-shaped cut cavity is formed below the arch springing line; Three central holes are arranged at intervals from top to bottom in the central cut area, one auxiliary cut hole is arranged at the upper end and the lower end of the central holes respectively, and four wedge-shaped cut holes are arranged on each of the left and right sides; The first cut area and the second cut area are respectively provided with 4 rows of cut holes. Among them, the spacing between the upper and lower cut holes in each row decreases in a geometric progression from the vertical wedge-shaped cut hole side outwards. The first cut area and the second cut area are in a trapezoidal contour, and the fourth row of cut holes is located on the straight wall section of the rock roadway; The vertical depth of the wedge cut holes, the center hole and the auxiliary cut holes in the central cut area is 2.9 m. Among them, the wedge cut holes are arranged obliquely to the working face, with an included angle of 70-85°, and the center hole and the auxiliary cut holes are arranged perpendicular to the working face, with an included angle of 90°; the hole spacing between two adjacent wedge cut holes is 450 mm; The charging depth of the wedge cut holes is 0.8 times the hole length of the blast hole, the charging length of the center hole located between the upper and lower vertices of the center line is 0.15 times the hole length of the blast hole, and the charging length of the auxiliary cut holes is 0.75 times the hole length of the blast hole; The depth of the cut blast holes in the horizontal cut area is 2.8 m. The adjacent hole spacing of the first row of cut holes in the first cut area and the second cut area is 360 mm, the adjacent hole spacing of the second row of cut holes is 422 mm, the adjacent hole spacing of the third row of cut holes is 300 mm, and the adjacent hole spacing of the fourth row of cut holes is 300 mm; The charging length of the first row of cut holes is 0.75 times the hole length of the blast hole, the charging length of the second row of cut holes is 0.6 times the hole length of the blast hole, the charging length of the third row of cut holes is 0.5 times the hole length of the blast hole, and the charging length of the fourth row of cut holes is 0.4 times the hole length of the blast hole; The first predetermined time, the second predetermined time, the third predetermined time, and the fourth predetermined time respectively correspond to the delay durations of different sections of detonators.

2. The method according to claim 1, wherein There are 4 cut holes in the first row, 3 cut holes in the second row and the third row, and 2 cut holes in the fourth row; or, According to the roadway width, 4, 3, 2, and 1 cut holes are sequentially arranged in the first row, the second row, the third row, and the fourth row of cut holes.

3. The method according to claim 1, wherein The horizontal wedge cut cavity cuts off the arch part and the straight wall section of the rock roadway to be driven.

4. The method according to claim 1, wherein After the blasting in the central cut area, the first cut area and the second cut area is completed, the method further includes: detonating the remaining blast holes arranged on the working face, and the remaining blast holes are arranged in circles on the working face; Specifically, it includes the steps of: first blasting the first circle of auxiliary holes located above the spring line; the charging length of the first circle of auxiliary holes is 0.7 times the hole length of the blast hole; After the first predetermined delay duration, detonating the second circle of auxiliary holes located above the spring line; the charging length of the second circle of auxiliary holes is 0.6 times the hole length of the blast hole; After the second predetermined delay duration, detonating the third circle of auxiliary holes located above the spring line and the auxiliary holes located below the first cut area and the second cut area and on the current detonation contour line and the center line of the first circle of auxiliary holes, the second circle of auxiliary holes, and the third circle of auxiliary holes; the charging length of the third circle of auxiliary holes is 0.5 times the hole length of the blast hole; After the third predetermined delay duration, detonating the fourth circle of auxiliary holes located above the spring line and the auxiliary holes located below the first cut area and the second cut area and on the current detonation contour line of the third circle of auxiliary holes and the fourth circle of auxiliary holes; the charging length of the fourth circle of auxiliary holes is 0.4 times the hole length of the blast hole; After the fourth predetermined delay duration, initiate the perimeter holes located outside the fourth circle of auxiliary holes, the auxiliary holes located below the first cut area and the second cut area and on the current initiation contour line of the perimeter holes, and the bottom holes located at the bottom of the rock roadway; the charging length of the perimeter holes is 0.3 times the hole length, and the charging length of the bottom holes at the bottom of the rock roadway is 0.5 times the hole length.

5. The method according to claim 1, characterized in that, The remaining blast holes arranged on the working face are arranged in circles on the working face; The method further includes: after the first predetermined time, while initiating the center hole between the upper and lower vertices on the center line and the first row of cut holes in the horizontal cut area, initiate the first circle of auxiliary holes above the arch line to make full use of the wedge-shaped cut holes to form a cavity with a second free face of blasting; After the second predetermined time, while initiating the second row of cut holes in the horizontal cut area, initiate the second circle of auxiliary holes above the arch line and the auxiliary holes located below the first cut area and the second cut area and on the current initiation contour lines of the first circle of auxiliary holes, the second circle of auxiliary holes, and the third circle of auxiliary holes and on the center line; After the third predetermined time, while initiating the third row of cut holes in the horizontal cut area, initiate the third circle of auxiliary holes above the arch line and the auxiliary holes located below the first cut area and the second cut area and on the current initiation contour lines of the first circle of auxiliary holes, the second circle of auxiliary holes, the third circle of auxiliary holes, and the fourth circle of auxiliary holes; After the fourth predetermined time, while initiating the (n + 3)rd row of cut holes adjacent to the third row of cut holes in the first cut area and the second cut area, initiate the fourth circle of auxiliary holes above the arch line and the auxiliary holes located below the first cut area and the second cut area and on the current initiation contour lines of the fourth circle of auxiliary holes and the perimeter holes; After the fifth predetermined time, initiate the perimeter holes above the arch line and the bottom holes at the bottom of the rock roadway.

6. The method according to claim 1, wherein The remaining blast holes arranged on the working face are arranged in circles on the working face; The method further includes: after the first predetermined time, while initiating the center hole between the upper and lower vertices on the center line and the first row of cut holes in the horizontal cut area, initiate the first circle of auxiliary holes above the arch line to make full use of the wedge-shaped cut holes to form a cavity with a second free face of blasting; After the second predetermined time, while initiating the second row of cut holes in the horizontal cut area, initiate the second circle of auxiliary holes above the arch line; After the third predetermined time, while initiating the third row of cut holes in the horizontal cut area, initiate the third circle of auxiliary holes above the arch line; After the fourth predetermined time, while initiating the (n + 3)rd row of cut holes adjacent to the third row of cut holes in the first cut area and the second cut area, initiate the fourth circle of auxiliary holes above the arch line; After the sixth predetermined time, initiate the auxiliary holes located below the first cut area and the second cut area and on the current initiation contour lines of the first circle of auxiliary holes, the second circle of auxiliary holes, the third circle of auxiliary holes, the fourth circle of auxiliary holes, and the perimeter holes; After the seventh predetermined time, initiate the auxiliary holes located below the first cut area and the second cut area and on the current initiation contour lines of the third circle of auxiliary holes, the fourth circle of auxiliary holes, and the perimeter holes; After the eighth predetermined time, the bottom holes located at the bottom of the rock roadway are detonated.

7. The method according to claim 5 or 6, characterized in that, The charging length of the first circle of auxiliary holes is 0.7 times the length of the blast holes, the charging length of the second circle of auxiliary holes is 0.6 times the length of the blast holes, the charging length of the third circle of auxiliary holes is 0.5 times the length of the blast holes, the charging length of the fourth circle of auxiliary holes is 0.4 times the length of the blast holes, the charging length of the peripheral holes is 0.3 times the length of the blast holes, and the charging length of the bottom holes at the bottom of the rock roadway is 0.5 times the length of the blast holes.

8. The method according to claim 1, wherein The included angle between the extension lines of the two waists of the trapezoidal profiles of the first cut area and the second cut area is 10-45°.

Images