Coal mine rock drift ultra-deep hole blasting-mechanical combined tunneling method

Abstract

The invention discloses an ultra-deep hole blasting-mechanical combined tunneling method for a coal mine rock roadway. The method comprises the following steps: step 1, analyzing basic mechanical properties and ground stress conditions of rocks of the excavated rock roadway; 2, the number of ultra-deep blast holes needing to be drilled in the rock drift tunneling section is determined; 3, a drilling machine is used for drilling all ultra-deep blast holes in the rock roadway tunneling section; 4, explosive is loaded into all the ultra-deep blast holes, and blocking is carried out; 5, the detonation sequence is determined, the explosives in all the ultra-deep blast holes are detonated in sequence, and blasting weakening is conducted on the rock within the tunneling path range; and step 6, tunneling by adopting a tunneling machine. According to the method, the rock in the tunneling path range is pre-split through ultra-deep blast hole blasting, the integrality of the rock in the tunneling path range is reduced, then tunneling is conducted through the tunneling machine, the working efficiency of the tunneling machine is improved, the stability of surrounding rock is improved, the blasting weakening distance is long, and the tunneling continuity is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine rock tunnel excavation, and in particular relates to a coal mine rock tunnel ultra-deep hole blasting-mechanical combined excavation method. Background Art

[0002] The tunnel is the main vein of the mine production system and plays an extremely important role in mine production. The tunnel excavation speed affects the normal succession of the working face and is a key factor restricting the efficient production of the mine. According to statistics, the annual tunnel excavation engineering volume of state-owned key coal mines alone is more than 2,000 kilometers. The amount of rock tunnel engineering in mine construction and production accounts for 15% to 25% of the total engineering volume, and the construction period accounts for 25% to 35% of the total mine construction period. In the past two decades, my country's coal mining technology and equipment have developed rapidly, but the rock tunnel construction technology and equipment are not satisfactory.

[0003] At present, the traditional blasting excavation method and tunnel boring machine excavation method are commonly used in coal mine rock tunnel excavation in my country.

[0004] The main advantages of blasting excavation method are: quick operation preparation, strong adaptability to various types of rocks, flexible movement, easy handling of technical failures and geological faults, high efficiency and low cost. Its disadvantages are: small underground tunnel space, improper operation during blasting, easy to cause rock fragments to splash, causing harm to personnel and equipment safety; low average excavation speed; over-blasting and under-excavation often occur during blasting, poor peripheral shaping, and low utilization rate of blastholes.

[0005] Tunneling machine excavation can be divided into full-section tunneling machine excavation and comprehensive tunneling machine excavation.

[0006] The advantages of full-face tunnel boring machine: the tunneling speed is higher than the drilling and blasting method, the longer the tunneling time, the better the economic benefits, when the tunneling speed is high, the operating cost of tunneling is similar to that of drilling and blasting; the stability of the tunnel is better. Its disadvantages are: the tunneling operation must be kept uninterrupted, and it is more economical only to dig a longer tunnel and maintain a higher tunneling speed. Most full-face tunnel boring machines can only dig circular cross-section tunnels, and the lower part needs to be backfilled; they cannot excavate branch tunnels and bends, etc.; the investment in the whole set of equipment is very high, and the installation and transportation costs are also very high; it is difficult to pass through faults and has poor adaptability to engineering geological conditions.

[0007] The advantages of tunneling with a multi-purpose machine: it can increase the tunneling speed of rock tunnels and improve economic benefits; the integrity of the rock layer is not damaged; it can be tunneled according to the designed section, thereby improving support conditions and reducing maintenance costs; the accident rate is low, etc. Its disadvantages are: when encountering hard rock, the picks are very easy to wear and need to be replaced frequently, resulting in a decrease in tunneling speed and economic benefits. Rocks are difficult to break, and the tunneling efficiency is low; the collision between the picks and rocks produces sparks, which poses a safety hazard.

[0008] Based on the above problems, the present application proposes a coal mine rock tunnel ultra-deep hole blasting-mechanical combined excavation method, which combines the advantages of blasting excavation and tunneling machine excavation, overcomes their respective shortcomings, firstly pre-cracks the rock within the excavation path range by ultra-deep blasting, reduces the integrity of the rock within the excavation path range, and then uses the tunneling machine for excavation, the overall investment cost is low, the excavation can be carried out according to the design, the excavation operation can be interrupted, and the average excavation speed is high; ultra-deep hole blasting is used to reduce the integrity of the rock within the excavation path range, avoids the splashing of broken rocks, over-blasting and under-excavation in the existing blasting excavation method, and at the same time, the rock pre-cracking effect brought by the ultra-deep hole blasting increases the excavation advance of the rock tunnel, improves the adaptability of the tunneling machine to engineering geological conditions, effectively reduces the wear of the tunneling machine's pick, the amount of dust, and the probability of sparks generated by the collision of the pick and rock, improves the working efficiency of the tunneling machine, improves the stability of the surrounding rock, and the blasting weakening distance is long, which effectively improves the continuity of excavation. Summary of the invention

[0009] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a coal mine rock tunnel ultra-deep hole blasting-mechanical combined excavation method.

[0010] To achieve the above object, the present invention adopts the following technical solution:

[0011] A coal mine rock tunnel ultra-deep hole blasting-mechanical combined excavation method, comprising the following steps:

[0012] Step 1: Collect and analyze the engineering, hydrogeological data and rock tunnel design data of the excavated rock tunnel, and test and analyze the basic mechanical properties and ground stress conditions of the rock of the excavated rock tunnel;

[0013] Step 2, determining the number of ultra-deep blastholes to be drilled on the rock tunnel excavation section;

[0014] Step 3, using a drilling machine to drill each ultra-deep blasthole on the rock tunnel excavation section in a direction perpendicular to the excavation section;

[0015] Step 4, loading explosives into each ultra-deep blast hole and plugging it;

[0016] Step 5, determine the detonation sequence, detonate the explosives in each ultra-deep blasthole in turn, and blast and weaken the rocks within the excavation path;

[0017] Step 6: Use a tunnel boring machine to carry out excavation.

[0018] Preferably, step 2 comprises the following sub-steps:

[0019] Step 21, determining the diameter D and depth of the ultra-deep blasthole;

[0020] Step 22, determine the weakened area S1 of a single ultra-deep blasthole, S1 = 350D2 ~650D 2 ;

[0021] Step 23, calculate the number N of ultra-deep blastholes that need to be drilled on the rock tunnel excavation section, N = [S / S1] + 1, S is the cross-sectional area of ​​the rock tunnel excavation section, and [S / S1] represents the maximum integer not exceeding S / S1.

[0022] Preferably, in step 21, the diameter D of the ultra-deep blasthole is not greater than 110 mm.

[0023] Preferably, in step 21, the depth of the ultra-deep blasthole is not less than 30m.

[0024] Preferably, an inscribed circle of the contour line of the rock tunnel excavation section is drawn with the center point of the ultra-deep blasthole on the rock tunnel excavation section as the center, and the radius of the inscribed circle is not less than 13D;

[0025] The line connecting the center points of any two super-deep blastholes on the rock tunnel excavation section is not parallel to the bottom edge of the rock tunnel and the vertical wall of the rock tunnel side;

[0026] The hole spacing between any super-deep blasthole and other super-deep blastholes on the rock tunnel excavation section ranges from 15D to 35D.

[0027] Preferably, the vertical distance between the center points of any two ultra-deep blastholes on the rock tunnel excavation section along the extension direction of the straight wall of the rock tunnel side and the horizontal distance along the extension direction of the bottom edge of the rock tunnel are not less than 150 mm.

[0028] Preferably, in step 4, the blasting uncoupling coefficient is not greater than 1.5.

[0029] Preferably, in step 4, the plugging length of the ultra-deep blasthole is L, L≥L0, L0 is the larger value of 90D and L1, D is the diameter of the ultra-deep blasthole, and L1 is one third of the depth of the ultra-deep blasthole;

[0030] The plugging material for ultra-deep blastholes is expansive quick-setting cement.

[0031] Preferably, in step 5, the method for determining the detonation sequence is:

[0032] Determine the surrounding rock parts of the rock tunnel that need to be protected, and determine the distance values ​​of each ultra-deep blasthole from the surrounding rock parts of the rock tunnel that need to be protected. The order of distance values ​​from low to high is the detonation order of the ultra-deep blastholes.

[0033] Preferably, in step 6, the cutting path of the tunnel boring machine is perpendicular to the expansion direction of the blasting cracks during tunneling.

[0034] The beneficial effects of the present invention are:

[0035] The present invention first pre-cracks the rock within the excavation path range through ultra-deep blasting, reduces the integrity of the rock within the excavation path range, and then uses a tunneling machine to excavate. The overall investment cost is low, the excavation can be carried out according to the design, the excavation operation can be interrupted, and the average excavation speed is high; ultra-deep hole blasting is used to reduce the integrity of the rock within the excavation path range, avoiding the splashing of broken rocks, over-blasting and under-excavation in the existing blasting excavation method. At the same time, the rock pre-crack effect brought by the ultra-deep hole blasting increases the excavation footage of the rock tunnel, improves the adaptability of the tunneling machine to engineering geological conditions, effectively reduces the wear of the tunneling machine's pick, the amount of dust, and the probability of sparks generated by the collision of the pick and rock, improves the working efficiency of the tunneling machine, improves the stability of the surrounding rock, and the blasting weakening distance is long, which effectively improves the continuity of excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0037] Figure 1 It is a schematic flow chart of the ultra-deep hole blasting-mechanical combined excavation method for coal mine rock tunnel of the present invention;

[0038] Figure 2 It is the plane shape diagram of the explosion crack expansion;

[0039] Figure 3 Schematic diagram of the cross section of the auxiliary transport tunnel in the embodiment of the present invention;

[0040] Figure 4 is a blasthole location diagram of five ultra-deep blastholes in an embodiment of the present invention;

[0041] Figure 5 Schematic diagram of the blockage of the ultra-deep blasthole in an embodiment of the present invention;

[0042] in:

[0043] 1-explosive, 2-sealing bag, 3-grouting pipe, 4-return grouting pipe, 5-grouting pump, 6-expanding quick-setting cement supply tank, 7-detonator, 8-detonator foot line. DETAILED DESCRIPTION

[0044] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] In the present invention, the directions or positional relationships indicated by terms such as "upper", "lower", "bottom", "top", etc. are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention.

[0047] In the present invention, terms such as "connected" and "connection" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0048] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0049] like Figure 1 As shown, a coal mine rock tunnel ultra-deep hole blasting-mechanical combined excavation method includes the following steps:

[0050] Step 1, collecting and analyzing the engineering, hydrogeological data and rock tunnel design data of the excavated rock tunnel, testing and analyzing the basic mechanical properties and ground stress conditions of the rock of the excavated rock tunnel; the specific implementation method of this step is the existing technology and will not be repeated here;

[0051] Step 2, determining the number of ultra-deep blastholes to be drilled on the rock tunnel excavation section;

[0052] Specifically, step 2 includes the following sub-steps:

[0053] Step 21, determining the diameter D and depth of the ultra-deep blasthole;

[0054] Step 22, determine the weakened area S1 of a single ultra-deep blasthole, S1 = 350D 2 ~650D 2 , under ground stress conditions, the plane shape of the blast crack extension is elliptical, such as Figure 2 As shown, the major axis is parallel to the maximum principal stress σ1, and the minor axis is parallel to the minimum principal stress σ3;

[0055] Step 23, calculate the number N of ultra-deep blastholes that need to be drilled on the rock tunnel excavation section, N = [S / S1] + 1, S is the cross-sectional area of ​​the rock tunnel excavation section, and [S / S1] represents the maximum integer not exceeding S / S1.

[0056] Specifically, in step 21, the diameter D of the ultra-deep blasthole is not greater than 110 mm.

[0057] Specifically, in step 21, the depth of the ultra-deep blasthole is not less than 30m.

[0058] Step 3, using a drilling machine to drill each ultra-deep blasthole on the rock tunnel excavation section in a direction perpendicular to the excavation section;

[0059] Specifically, an inscribed circle of the rock tunnel excavation section contour line is drawn with the center point of the super-deep blasthole on the rock tunnel excavation section as the center, and the radius of the inscribed circle is not less than 13D;

[0060] The line connecting the center points of any two super-deep blastholes on the rock tunnel excavation section is not parallel to the bottom edge of the rock tunnel and the straight wall on the side of the rock tunnel, that is, all super-deep blastholes are staggered in the horizontal and vertical directions to achieve uniform weakening of the rock tunnel excavation section by super-deep blastholes;

[0061] The hole spacing between any super-deep blasthole and other super-deep blastholes on the rock tunnel excavation section ranges from 15D to 35D.

[0062] Specifically, the vertical distance between the center points of any two ultra-deep blastholes on the rock tunnel excavation section along the extension direction of the straight wall of the rock tunnel side and the horizontal distance along the extension direction of the bottom edge of the rock tunnel shall not be less than 150 mm.

[0063] Step 4, loading explosives into each ultra-deep blast hole and plugging it;

[0064] Specifically, in step 4, the explosion uncoupling coefficient is not greater than 1.5.

[0065] Specifically, in step 4, the plugging length of the ultra-deep blasthole is L, L≥L0, L0 is the larger value of 90D and L1, D is the diameter of the ultra-deep blasthole, and L1 is one third of the depth of the ultra-deep blasthole;

[0066] The plugging material for ultra-deep blastholes is expansive quick-setting cement.

[0067] Step 5, determine the detonation sequence, detonate the explosives in each ultra-deep blasthole in turn, and blast and weaken the rocks within the excavation path;

[0068] Specifically, in step 5, the method for determining the detonation sequence is:

[0069] Determine the surrounding rock parts of the rock tunnel that need to be protected, and determine the distance values ​​of each ultra-deep blasthole from the surrounding rock parts of the rock tunnel that need to be protected. The order of distance values ​​from low to high is the detonation order of the ultra-deep blastholes.

[0070] Step 6: Use a tunnel boring machine to dig.

[0071] Specifically, in step 6, the cutting path of the tunnel boring machine is perpendicular to the expansion direction of the blasting cracks during tunneling.

[0072] Example:

[0073] This embodiment takes a coal mine auxiliary transport tunnel as an example. The auxiliary transport tunnel is entirely arranged in sandstone. The rock strength is relatively high and the traditional excavation method is inefficient. Therefore, the ultra-deep hole blasting-mechanical combined excavation method of the coal mine rock tunnel of this application is adopted.

[0074] The cross section of the auxiliary transport tunnel is a semicircular arch. Figure 3 As shown, the tunnel is 5700mm wide and 4650mm high, of which the side straight wall is 1800mm high and the semicircular arch is 2850mm high.

[0075] The ultra-deep hole blasting-mechanical combined excavation method of rock tunnel of the present application comprises the following steps:

[0076] Step 1: Collect and analyze the engineering, hydrogeological data and rock tunnel design data of the auxiliary transport tunnel, and test and analyze the basic mechanical properties and ground stress conditions of the rock in the auxiliary transport tunnel;

[0077] Step 2, design the blasting parameters according to the data in step 1, and finally design the ultra-deep blasthole with a depth of 30m and a diameter D of 90mm;

[0078] Then, according to the weakening area of ​​a single ultra-deep blasthole, take S1 = 630D 2 , the number of super-deep blastholes N that need to be drilled on the auxiliary transport tunnel excavation section is calculated to be 5;

[0079] Step 3: Use a drilling rig to drill 5 ultra-deep blastholes on the auxiliary transport tunnel excavation section in a direction perpendicular to the excavation section;

[0080] The five ultra-deep blastholes are K1, K2, K3, K4, and K5. Figure 4 As shown:

[0081] The vertical distance between K1 and the bottom edge of the auxiliary transport tunnel is 3000mm, and the vertical distance between K1 and the left vertical wall is 1700mm; the vertical distance between K2 and the bottom edge of the auxiliary transport tunnel is 2600mm, and the vertical distance between K2 and the right vertical wall is 1400mm; the vertical distance between K3 and the bottom edge of the auxiliary transport tunnel is 2200mm, and the vertical distance between K3 and the right vertical wall is 2700mm; the vertical distance between K4 and the bottom edge of the auxiliary transport tunnel is 1500mm, and the vertical distance between K4 and the left vertical wall is 1500mm; the vertical distance between K5 and the bottom edge of the auxiliary transport tunnel is 1200mm, and the vertical distance between K5 and the right vertical wall is 1600mm.

[0082] Among them, the inscribed circle of the auxiliary transport main lane contour line is made with the center point of K1 as the center, and the radius of the inscribed circle is 1187.9mm, which is larger than 13D, and 13D is 1170mm;

[0083] The inscribed circle of the auxiliary transport lane contour line is made with the center point of K2 as the center. The radius of the inscribed circle is 1193.9mm, which is larger than 13D, which is 1170mm.

[0084] With the center point of K3 as the center, draw an inscribed circle of the auxiliary transport lane contour line. The radius of the inscribed circle is 2200mm, which is larger than 13D, which is 1170mm.

[0085] With the center point of K4 as the center, draw an inscribed circle of the auxiliary transport lane contour line. The radius of the inscribed circle is 1500mm, which is larger than 13D, which is 1170mm.

[0086] An inscribed circle is made with the center point of K5 as the center of the auxiliary transport tunnel contour line. The radius of the inscribed circle is 1200mm, which is larger than 13D, and 13D is 1170mm.

[0087] Among them, the hole spacing between K1 and K2 is 2630.6mm, which is 29.23D;

[0088] The hole spacing between K1 and K3 is 1526.4mm, which is 16.96D;

[0089] The hole spacing between K1 and K4 is 1513.3mm, which is 16.81D;

[0090] The hole spacing between K1 and K5 is 3000.0mm, which is 33.33D;

[0091] The hole spacing between K2 and K3 is 1360.1mm, which is 15.11D;

[0092] The hole spacing between K2 and K4 is 3008.3mm, which is 33.43D;

[0093] The hole spacing between K2 and K5 is 1414.2mm, which is 15.71D;

[0094] The hole spacing between K3 and K4 is 1655.3mm, which is 18.39D;

[0095] The hole spacing between K3 and K5 is 1486.6mm, which is 16.52D;

[0096] The hole spacing between K4 and K5 is 2617.3mm, which is 29.08D.

[0097] Among them, the vertical distance between the center points of K1 and K2 along the extension direction of the straight wall of the rock tunnel side is 400mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 2600mm, both of which are greater than 150mm;

[0098] The vertical distance between the center points of K1 and K3 along the extension direction of the straight wall of the rock tunnel side is 800mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 1300mm, both of which are greater than 150mm;

[0099] The vertical distance between the center points of K1 and K4 along the extension direction of the straight wall of the rock tunnel side is 1500mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 200mm, both of which are greater than 150mm;

[0100] The vertical distance between the center points of K1 and K5 along the extension direction of the straight wall of the rock tunnel side is 1800mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 2400mm, both of which are greater than 150mm;

[0101] The vertical distance between the center points of K2 and K3 along the extension direction of the straight wall of the rock tunnel side is 400mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 1300mm, both of which are greater than 150mm;

[0102] The vertical distance between the center points of K2 and K4 along the extension direction of the straight wall of the rock tunnel side is 1100mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 2800mm, both of which are greater than 150mm;

[0103] The vertical distance between the center points of K2 and K5 along the extension direction of the straight wall of the rock tunnel side is 1400mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 200mm, both of which are greater than 150mm;

[0104] The vertical distance between the center points of K3 and K4 along the extension direction of the straight wall of the rock tunnel side is 700mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 1500mm, both of which are greater than 150mm;

[0105] The vertical distance between the center points of K3 and K5 along the extension direction of the straight wall of the rock tunnel side is 1000mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 1100mm, both of which are greater than 150mm;

[0106] The vertical distance between the center points of K4 and K5 along the extension direction of the straight wall of the rock tunnel side is 300mm, and the horizontal distance along the extension direction of the bottom edge of the rock tunnel is 2600mm, both of which are greater than 150mm.

[0107] Step 4, loading explosives into each ultra-deep blast hole and plugging them.

[0108] The charge length of each ultra-deep blasthole is 20m, the plugging length is 10m, and the plugging material is expansive quick-setting cement. Figure 5 As shown. After the explosive 1 is installed in the ultra-deep blasthole, the detonator leg line 8 of the detonator 7 passes through the ultra-deep blasthole, and then a plugging bag 2 is set at the mouth of the ultra-deep blasthole. The plugging bag 2 is penetrated by a grouting pipe 3 and a return grouting pipe 4. One end of the grouting pipe 3 passing through the plugging bag 2 is connected to the outlet of the grouting pump 5. The inlet of the grouting pump 5 is connected to the expansion quick-setting cement supply tank 6. The return grouting pipe 4 is located in the plugging bag 2 and extends to the bottom of the blocked end in the ultra-deep blasthole. Start the grouting pump 5, inject the expansion quick-setting cement into the ultra-deep blasthole through the grouting pipe 3, and stop grouting when the expansion quick-setting cement emerges from the outlet of the return grouting pipe 4.

[0109] Step 5, determine the detonation sequence, detonate the explosives in each ultra-deep blasthole in turn, and blast and weaken the rocks within the excavation path.

[0110] Considering the support problem of the semicircular arch, the semicircular arch of the auxiliary transport tunnel is the surrounding rock part of the rock tunnel that needs to be protected. The vertical distance between K1 and the semicircular arch of the auxiliary transport tunnel is 1407.7mm, the vertical distance between K2 and the semicircular arch of the auxiliary transport tunnel is 1653.6mm, the vertical distance between K3 and the semicircular arch of the auxiliary transport tunnel is 2446.1mm, the vertical distance between K4 and the semicircular arch of the auxiliary transport tunnel is 2810.0mm, and the vertical distance between K5 and the semicircular arch of the auxiliary transport tunnel is 3161.3mm. Therefore, the explosions are carried out in the order of K1, K2, K3, K4, and K5, that is, the K1 blasthole is firstly exploded and the K5 blasthole is lastly detonated, so as to prevent the blasting gap zone formed by the previous detonation blasthole from hindering the seismic waves of the subsequent detonation blastholes.

[0111] The required leg line length of the electronic detonator allowed in coal mines is 15m, and the detonation method is parallel, that is, 3 detonators are connected in parallel in the hole, and in parallel between the holes; the delay interval is: the electronic detonators used in K1, K2, K3, K4, and K5 blast holes are set with delay times of 0ms, 25ms, 50ms, 75ms, and 100ms respectively.

[0112] Personnel and equipment are evacuated to a safe area for blasting, and electronic detonators are detonated using special detonators.

[0113] After the blasting, ventilation is strengthened. After 30 minutes of ventilation to remove the blasting smoke and reach the safety standard, the construction personnel enter the excavation working face to check the safety of the roof and the two sides, and deal with the pumice on the roof and the two sides.

[0114] Step 6: Use a tunnel boring machine to dig.

[0115] Specifically, in step 6, the cutting path of the tunnel boring machine is perpendicular to the expansion direction of the blasting cracks during tunneling.

[0116] The EBZ260 type of roadheader is selected according to the shape and lithology of the tunnel. The EBZ260 roadheader is driven to the tunneling working face. After reaching the working position, the scraper conveyor is turned on and tunneling begins. The cutter is fed from the middle of the tunnel arch base line from left to right, and then from right to left to cut upward in a spiral. When cutting to the top of the tunnel, the top plate is temporarily supported and supported once, and then the ground is cut and swept back and forth from top to bottom until the designed bottom plate height is reached. The tunneling process is repeated until the boundary of the ultra-deep hole blasting pre-cracking influence area is reached.

[0117] Before the tunnel boring machine starts excavation each time, check whether there are blind or residual shots within the single excavation depth of the excavation working face, observe the expansion of the blasting cracks, and the cutting head cuts in the direction perpendicular to the expansion direction of the blasting cracks.

[0118] The present invention first pre-cracks the rock within the excavation path range through ultra-deep blasting, reduces the integrity of the rock within the excavation path range, and then uses a tunneling machine to excavate. The overall investment cost is low, the excavation can be carried out according to the design, the excavation operation can be interrupted, and the average excavation speed is high; ultra-deep hole blasting is used to reduce the integrity of the rock within the excavation path range, avoiding the splashing of broken rocks, over-blasting and under-excavation in the existing blasting excavation method. At the same time, the rock pre-crack effect brought by the ultra-deep hole blasting increases the excavation footage of the rock tunnel, improves the adaptability of the tunneling machine to engineering geological conditions, effectively reduces the wear of the tunneling machine's pick, the amount of dust, and the probability of sparks generated by the collision of the pick and rock, improves the working efficiency of the tunneling machine, improves the stability of the surrounding rock, and the blasting weakening distance is long, which effectively improves the continuity of excavation.

[0119] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not a limitation of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the protection scope of the present invention.

Claims

1. A coal mine rock tunnel ultra-deep hole blasting-mechanical combined excavation method, characterized in that: The following steps are involved: Step 1: Collect and analyze the engineering, hydrogeological data and rock tunnel design data of the excavated rock tunnel, and test and analyze the basic mechanical properties and ground stress conditions of the rock of the excavated rock tunnel; Step 2, determining the number of ultra-deep blastholes to be drilled on the rock tunnel excavation section; Step 3, using a drilling machine to drill each ultra-deep blasthole on the rock tunnel excavation section in a direction perpendicular to the excavation section; Step 4, loading explosives into each ultra-deep blasthole and plugging them; Step 5, determine the detonation sequence, detonate the explosives in each ultra-deep blasthole in turn, and weaken the rock within the excavation path by blasting; Step 6: Use a tunnel boring machine to carry out excavation.

2. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 1, characterized in that: The step 2 includes the following sub-steps: Step 21, determining the diameter D and depth of the ultra-deep blasthole; Step 22, determine the weakened area S1 of a single ultra-deep blasthole, S1 = 350D 2 ~650D 2 ; Step 23, calculate the number N of ultra-deep blastholes that need to be drilled on the rock tunnel excavation section, N = [S / S1] + 1, S is the cross-sectional area of ​​the rock tunnel excavation section, and [S / S1] represents the maximum integer not exceeding S / S1.

3. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 2, characterized in that: In step 21, the diameter D of the ultra-deep blasthole is not greater than 110 mm.

4. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 2, characterized in that: In step 21, the depth of the ultra-deep blasthole is not less than 30m.

5. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 1, characterized in that: An inscribed circle of the rock tunnel excavation section contour line is drawn with the center point of the super-deep blasthole on the rock tunnel excavation section as the center, and the radius of the inscribed circle shall not be less than 13D; The line connecting the center points of any two ultra-deep blastholes on the rock tunnel excavation section is not parallel to the bottom edge of the rock tunnel and the vertical wall of the rock tunnel side; The hole spacing between any super-deep blasthole and other super-deep blastholes on the rock tunnel excavation section ranges from 15D to 35D.

6. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 5, characterized in that: The vertical distance between the center points of any two ultra-deep blastholes on the rock tunnel excavation section along the extension direction of the straight wall of the rock tunnel side and the horizontal distance along the extension direction of the bottom edge of the rock tunnel shall not be less than 150mm.

7. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 1, characterized in that: In step 4, the explosion uncoupling coefficient is not greater than 1.

5.

8. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 1, characterized in that: In step 4, the plugging length of the ultra-deep blasthole is L, L≥L0, L0 is the larger value of 90D and L1, D is the diameter of the ultra-deep blasthole, and L1 is one third of the depth of the ultra-deep blasthole; The plugging material for ultra-deep blastholes is expansive quick-setting cement.

9. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 1, characterized in that: In step 5, the method for determining the detonation sequence is: Determine the surrounding rock parts of the rock tunnel that need to be protected, and determine the distance values ​​of each ultra-deep blasthole from the surrounding rock parts of the rock tunnel that need to be protected. The order of distance values ​​from low to high is the detonation order of the ultra-deep blastholes.

10. The method for ultra-deep hole blasting-mechanical combined excavation of coal mine rock tunnels according to claim 1, characterized in that: In step 6, the cutting path of the tunnel boring machine is perpendicular to the expansion direction of the blasting cracks during tunneling.

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