Underground cavern pressure reduction structure based on shaped charge blasting

Abstract

The utility model provides an underground cavern decompression structure based on shaped charge blasting, which is characterized in that drilling sections are arranged on the walls of two sides of a cavern at equal intervals, the distance between adjacent drilling sections is 2-3m, and the depth of the drilling sections is consistent with that of a stress concentration area; the drilling section comprises a shallow consolidation section and a deep charging section, explosive is placed in the charging section, and cement or sand is plugged in the consolidation section. The underground cavern has the advantage that the safe operation of the underground cavern is effectively guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of surrounding rock excavation engineering, in particular to an underground cavern decompression structure based on concentrated energy blasting. Background Art

[0002] During the excavation of underground caverns, it is common for surrounding rocks to spall, loosen, and peel off due to stress concentration. The countermeasures taken are often timely support, and the support methods include spraying concrete, applying anchors and cables, or combined support. Hou Chaojiong believes that the application of anchor support is to strengthen the strength of the surrounding rock and enhance the bearing capacity of the surrounding rock. In order to maintain the stability of the surrounding rock, in addition to using various means to strengthen the surrounding rock, stress control can also be considered. Stress control includes two aspects. One is to excavate underground caverns in low stress areas, which can fundamentally solve the problem of surrounding rock stability; the other is to transfer stress to the depth of the surrounding rock, which can not only reduce the level of stress concentration, but also mobilize a larger and deeper range of surrounding rock bearing.

[0003] The basic principle of focused blasting is to use a focused tube to focus the blasting wave in a smaller range. Compared with traditional blasting, focused blasting can control the blasting direction and improve the blasting effect. At the same time, due to the small blasting range, it reduces the damage to the surrounding rock mass, that is, the surface rock mass. Therefore, we use focused blasting to form a weak zone in a specific direction in the stress concentration area of ​​the surrounding rock, so that the stress concentration level is reduced and the stress is transferred to the depth of the surrounding rock, thereby mobilizing a larger range of surrounding rocks to carry loads evenly. Summary of the invention

[0004] The utility model aims to provide an underground cavern decompression structure based on concentrated energy blasting, which utilizes concentrated energy blasting in the stress concentration zone of the surrounding rock to form a fissure weak zone in the depth of the surrounding rock, reduce the stress concentration degree of the surrounding rock, transfer the stress peak to the depth of the surrounding rock, and avoid the adverse effect of blasting impact on the stability of the surrounding rock.

[0005] In order to achieve the above object, the utility model is implemented through the following technical solutions:

[0006] An underground cavern decompression structure based on concentrated energy blasting, wherein drilling sections are equidistantly arranged on the cavern walls on both sides of the cavern, the spacing between adjacent drilling sections is 2-3m, and the depth of the drilling section is consistent with the depth of the stress concentration area; the drilling section includes a shallow consolidation section and a deep charging section, explosives are placed in the charging section, and cement or sand is sealed in the consolidation section.

[0007] Furthermore, the consolidation section of the drilling section is longer than the charging section.

[0008] Furthermore, the explosive is an energy-gathering tube with built-in explosives, and the explosives are externally connected to a lead wire, which extends outward to the cavern.

[0009] Furthermore, two energy-gathering holes are formed on opposite sides of the energy-gathering tube.

[0010] Furthermore, the explosive is an emulsion explosive.

[0011] Compared with the prior art, the utility model has the following advantages:

[0012] The utility model discloses an underground cavern decompression structure based on focused energy blasting. To ensure the stability of the surrounding rock of the underground cavern, the position of stress concentration is determined through numerical simulation analysis, and a hole is drilled perpendicular to the cavern wall, with the drilling depth reaching the stress concentration position. Focused energy blasting is implemented at the bottom of the borehole to generate a weak structural zone in the surrounding rock, and the stress is released toward the position of the weak structural zone, the stress peak is reduced, and is transferred to the depth of the surrounding rock, so as to achieve the purpose of reducing the stress concentration of the surrounding rock. At the same time, focused energy blasting can be used to achieve directional blasting, so that the main stress direction is offset, so as to avoid the influence of blasting shock on the surface surrounding rock, and effectively ensure the safe operation of the underground cavern. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional structural schematic diagram of the utility model.

[0014] Figure 2 It is a schematic diagram of the longitudinal section structure of the utility model.

[0015] Figure 3 It is a schematic diagram of the cross-sectional structure of the charge section of the utility model.

[0016] Figure numerals: 1, drilling section; 11, consolidation section; 12, charging section; 2, explosive; 3, energy-focusing tube; 31, energy-focusing hole; 4, lead. DETAILED DESCRIPTION

[0017] The embodiments of the present utility model are described in further detail below in conjunction with the accompanying drawings.

[0018] According to the ground stress conditions and physical and mechanical parameters of the surrounding rock in the area where the underground cavern is located, combined with the excavation size of the cavern, a numerical simulation of the underground cavern excavation process is carried out to determine the location of the surrounding rock stress concentration area caused by excavation, which is the predetermined location of the concentrated energy blasting. In the implementation plan, the circular cavern excavation is taken as an example. The diameter of the cavern is 5m. After calculation, the stress concentration area is located on the left and right sides of the cavern, about 7m away from the cavern wall.

[0019] After the stress concentration area is located, holes are arranged along the point and perpendicular to the cave wall. The drilling depth is consistent with the stress concentration area depth of 7m. Figure 1 , 2As shown, an underground cavern decompression structure based on shaped-energy blasting is shown, wherein drilling sections 1 are equidistantly arranged on the cavern walls on both sides of the cavern, the spacing between adjacent drilling sections 1 is 2.5 m, and the depth of the drilling section 1 is 7 m; the drilling section 1 includes a shallow consolidation section 11 and a deep charge section 12, explosives are placed in the charge section 12, and cement or sand is sealed in the consolidation section 11.

[0020] Preferably, the consolidation section 11 of the drilling section 1 is designed to be 5.5 m long, and the charging section 12 is designed to be 1.5 m long.

[0021] like Figure 3 As shown, the explosive is a shaped tube 3 with an explosive 2 built in, and the explosive 2 is connected to a lead 4, which extends outward to the cavern. The designed borehole diameter is 50 mm, the outer radius of the shaped tube 3 is 42 mm, the inner radius is 37 mm, and the length is 1.5 m. Emulsion explosives are used for blasting, and the diameter of a single roll is 30 mm, the length is 200 mm, and the weight is 200 g.

[0022] Two energy-gathering holes 31 are provided on opposite sides of the energy-gathering tube 3, thereby enhancing the explosion strength at the energy-gathering holes 31 and achieving successful blasting.

[0023] The operating steps of the utility model are as follows:

[0024] S1) After determining the location of the drilling hole and the concentrated blasting, the drilling operation begins. The length of the drilling section 1 is 7m;

[0025] S2) placing the explosive 2 into the energy-gathering tube 3;

[0026] S3) placing the energy-gathering tube 3 into the charge section 12 of the drilling section 1, and leading out the lead wire 4;

[0027] S4) using cement, sand and other materials to seal and reinforce the consolidation section 11 of the drilling section 1 to prevent the blasting from affecting the surface surrounding rock;

[0028] S5) After all the holes have been drilled and sealed, blasting operations begin.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the concept of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An underground cavern decompression structure based on concentrated energy blasting, characterized in that: Drilling sections are arranged equidistantly on the walls of both sides of the cavern, with a spacing of 2 to 3 m between adjacent drilling sections. The depth of the drilling section is consistent with the depth of the stress concentration area. The drilling section includes a shallow consolidation section and a deep charging section. Explosives are placed in the charging section, and cement or sand is sealed in the consolidation section.

2. The underground cavern decompression structure based on concentrated energy blasting according to claim 1, characterized in that: The consolidation section length of the drilling section is greater than the charging section length.

3. An underground cavern decompression structure based on concentrated energy blasting according to claim 1 or 2, characterized in that: The explosive is an energy-gathering tube with built-in explosives, and the explosives are externally connected to fuses, which extend outwards to the cavern.

4. The underground cavern decompression structure based on concentrated energy blasting according to claim 3, characterized in that: Two energy-gathering holes are provided on opposite sides of the energy-gathering tube.

5. The underground cavern decompression structure based on concentrated energy blasting according to claim 4, characterized in that: The explosive is an emulsion explosive.

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