Water blocking method for long fan-shaped blastholes

Abstract

The present invention belongs to the technical field of engineering blasting, and specifically relates to a water plugging method for a long fan-shaped blasthole. First, the air spacer is inflated and expanded to respond quickly, and is first inserted into the bottom of the blasthole to reduce the amount of water inflow and plug the water leakage point as much as possible in the shortest time, and then the anchoring drug roll and oily polyurethane are inserted in sequence. The plugging of the water-gushing blasthole is completed quickly and then steadily.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering blasting, and in particular relates to a water blocking method for a long fan-shaped blast hole. Background Art

[0002] Since the 20th century, engineering blasting technology has developed rapidly, especially with the advancement of the industrial revolution, the scale of mining has continued to expand, and the engineering field has also put forward many new requirements for blasting technology. People have begun to study and develop safer and more effective blasting methods.

[0003] Among them, the blasting scheme of fan-shaped layout of blastholes in rock walls or tunnel walls is widely used in mining areas or civil engineering fields due to its many advantages such as high blasting efficiency, short construction period and low construction cost. Before adopting the fan-shaped layout of blastholes, it is necessary to scientifically design according to the shape of the ore body, rock properties and blasting requirements, and then locate the position, number, angle, depth, etc. of the blastholes. In other words, in the process of fan-shaped arrangement of blastholes, the position of each blasthole is fixed and cannot be easily changed. If it is changed casually, it may not only destroy the integrity of the blasting plan, resulting in unsatisfactory blasting effect, but also affect the recovery rate and depletion rate of the ore, and even seriously increase the safety risk.

[0004] In daily construction, especially when drilling medium-deep blastholes of 5 meters or more, the deep drilling often encounters water-bearing faults and fissures inside the rock mass, which leads to water seepage in the blastholes. Once the blastholes seep water, the explosives will inevitably get damp, reducing the explosive force and detonation speed. And because the position of each blasthole in the fan-shaped blasthole group is unique, it is impossible to drill new blastholes or grout to seal them near the gushing blastholes as in traditional blasthole construction.

[0005] Because re-drilling blastholes will not only increase the drilling workload and affect the construction progress, but also change the resistance line and thus affect the blasting effect. If the blastholes are pressure-grouted, since the water-gushing blastholes are connected to the groundwater channels, it is difficult to block the water-gushing blastholes, it is difficult to fill the water-gushing blastholes with slurry, the blocking time is long, the slurry loss is also large, the quality after blocking is difficult to guarantee, the blocking effect is poor, the cost is high, and once the blocking quality is poor, it will directly affect the forming quality of other nearby blastholes, thereby affecting the charge of the blastholes and the blasting effect of the rock, and leading to a substantial increase in costs. Therefore, it is particularly important to provide a method for the engineering blasting field that can achieve rapid blocking of medium-deep water-gushing blastholes in fan-shaped hole groups in a short time and at low cost.

[0006] In view of this, in order to improve the above technical problems, the present invention provides a water plugging method for a long fan-shaped blasthole. Summary of the invention

[0007] In order to solve the problem of water gushing when drilling a fan-shaped blasthole group, especially when drilling a medium-deep hole (depth ≥ 5m), the traditional solution of abandoning the original blasthole and drilling a new one, or the solution of sealing the blasthole with pressure grouting, will cause problems such as damage to the blasting structure, increase in engineering workload, and high plugging cost. To this end, the present invention provides a water plugging method for a long fan-shaped blasthole, which forms at least a three-layer plugging structure by sequentially inserting an air spacer, an anchoring drug roll, and an oily polyurethane into the blasthole where water is gushing, thereby realizing simple, rapid, and low-cost plugging of the gushing blasthole.

[0008] In order to achieve the above technical effects, the present invention adopts the following technical solutions: The water blocking method of long fan-shaped holes includes: Use a drilling rig to drill blastholes in the surrounding rock according to the pre-determined position and angle of the long fan-shaped hole group. When the drill bit reaches the water-bearing fracture zone or fault and water seepage is found, stop drilling immediately and slowly withdraw the drill bit; Use a gun stick and / or any other tool that matches the size of the blasthole to insert the anchoring powder roll, air spacer, and oily polyurethane into the blasthole from the hole mouth to form a three-layer plugging structure to complete the plugging of the blasthole; After the blasthole stops leaking water, charge and blast the blasthole.

[0009] The specific filling order and timing of the three-layer plugging structure are: First, insert the air spacer into the bottom of the hole, and then fill the sealed bag in the air spacer with air to make it expand at the bottom of the hole; Then insert the anchoring coil into the blast hole, puncture it and compact it; Finally, when no obvious water seepage was observed in the hole, oily polyurethane was injected into the blasthole to seal the anchoring area.

[0010] The outside of the air spacer is also wrapped with a layer of woven bag.

[0011] Before the anchoring drug roll is inserted into the blast hole, a ball of flexible material is first inserted therein. When the flexible material is rammed into the blast hole, it will form a barrier layer due to its own deformation and agglomeration.

[0012] The diameter of the air spacer is 60 mm to 150 mm, the length is 500 mm to 800 mm, the inflation time is 10 s, and the inflation pressure is greater than 0.4 MPa.

[0013] The flexible material is a flexible woven bag.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention first utilizes the rapid response capability of the air spacer to expand upon inflation, and first pokes it into the bottom of the blasthole, reduces the amount of water gushing and blocks the water leakage point as much as possible in the shortest time, and then inserts the anchoring medicine roll and the oily polyurethane in sequence. The plugging of the gushing blasthole is completed quickly and then steadily. In this plugging process, first, no special equipment is required, and the three-layer plugging structure is also available on the market, which can ensure that the above-mentioned plugging method is easy to popularize and use; second, it will not damage the channel structure, and the entire plugging process only needs to insert the above-mentioned three-layer plugging structure into the blasthole in a certain order to complete the plugging, which is convenient to operate and cost-controlled; third, the plugging structure can also promote the blasting effect of the explosive, wherein the air spacer can reduce the peak value of the detonation shock pressure acting on the blasthole wall. When the shock pressure is too high, a shock wave will be excited in the rock body, resulting in excessive crushing of the surrounding rock around the blasthole to form a crushing circle, which will consume a lot of blasting energy, prolong the action time of the stress wave, and optimize the blasting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the layout of the blasthole plugging structure of the present invention; Figure 2 It is a schematic diagram of the horizontal cross-section layout of the long fan-shaped blasthole group on the rock formation of the present invention; Figure 3 It is a schematic diagram of the vertical cross-section layout of the long fan-shaped blasthole group on the rock formation of the present invention; The above drawings include the following reference numerals: 1. Blast hole; 2. Surrounding rock; 3. Hole mouth; 4. Hole bottom; 5. Air spacer; 6. Flexible woven bag; 7. Anchoring coil; 8. Oily polyurethane. DETAILED DESCRIPTION

[0016] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0017] Combination Figure 2-Figure 3 We can see that the layout of the fan-shaped blastholes 1 on the surrounding rock 2 is just as its name suggests, and is regularly arranged in a fan shape inside the rock mass. The number, position, angle, depth and other information of its arrangement are the result of scientific design based on the shape of the ore body, rock properties and blasting requirements, so the blastholes 1 in each fan-shaped hole group are unique and irreplaceable. It is under such technical requirements that the traditional practice of abandoning the blasthole 1 when water gushes in it and re-drilling the hole is first excluded.

[0018] Compared with another traditional pressure grouting method to achieve hole plugging, not to mention where the water gushing point is connected to, it is impossible to judge in advance how much mortar will be consumed. More importantly, even if the water gushing point at the bottom of the blast hole 1 is blocked, the concrete, which has a texture harder than ordinary ore, will inevitably consume most of the kinetic energy of the explosion of the explosives and reduce the blasting effect.

[0019] like Figure 1 As shown, when the present invention encounters water gushing from the blasthole 1 in the fan-shaped hole group, the drill head will be slowly withdrawn first. Then, the air spacer 5 is first inserted into the bottom of the blasthole 1 using a blasting stick or other ramming tools, and then the air spacer 5 is inflated at a pressure of 0.4Mpa for 10s to fully expand the air spacer 5 and preliminarily block the bottom of the blasthole 1.

[0020] As for why the air spacer 5 is chosen as the first plugging structure to be put into the blasthole 1, there are mainly three reasons: First, it is not afraid of water. As is well known, the main structure of the existing air spacer 5 is mostly made of double-layer polyethylene material, so it can still maintain good structural stability when facing the leak point as a "vanguard"; Second: it can be inflated after reaching the bottom of the hole 4. The operator of the present invention is a person, not a machine, so whether the operation process is labor-saving and easy becomes a problem that must be considered. Therefore, when the water pressure in the blasthole 1 is relatively large, we have to insert a fixed volume plugging structure with a diameter of the orifice 3 into the bottom of the hole 4. The pushing force of the human hand on the plugging structure will inevitably conflict with the water pressure of the gushing water, similar to a syringe or a piston structure. This will not only significantly increase the difficulty of installing the plugging structure, which is labor-intensive and time-consuming, but may also cause the plugging structure to have a gap before it is pushed into the bottom of the hole 4 due to the long-stroke friction and wear between the side wall and the hole wall, further reducing the plugging effect.

[0021] The present invention uses a cannon stick to insert the uninflated air spacer 5 into the blast hole 1. Even if the water pressure in the blast hole 1 is high, the air spacer 5 at this time will not expand. Firstly, it will not completely block the cross section of the blast hole 1. Instead, it will leave enough space for the water in the blast hole 1 to gush out, greatly reducing the water flow's propulsion resistance to the air spacer 5, making it easier for the air spacer 5 to be installed manually. Secondly, it will not be damaged by excessive wear and tear on the hole wall during the installation process. (The specific structure and use method of the above-mentioned air spacer 5 refer to the prior art and will not be described here.) Third: the price is cheap. The retail price of many air spacers 5 in the market is only 10-15 yuan each. If it is wholesaled in the mining area, the price will be even cheaper, so the cost of use is very low. Moreover, there are many types of air spacers in the market. The present invention is aimed at medium-deep blastholes 1, that is, the depth of the blastholes 1 is greater than 5 meters. Therefore, in order to ensure the blocking effect, the operator can flexibly select the standard air spacers 5 with a diameter of 60mm-150mm and a length of 500mm-800mm according to the actual size of these medium-deep blastholes 1, so as to ensure that there is enough friction coefficient and expansion volume to achieve complete blocking of the bottom of the hole 4.

[0022] At the same time, in order to prevent the air spacer 5 formed by pressing a double-layer polyethylene material from being filled with gas, a layer of woven bag is also installed on the outside of the air spacer 5. The woven bag is not only waterproof, but also has a structural strength that is significantly higher than that of polyethylene, which can effectively protect the air spacer 5 from being blown up. More importantly, the warp and weft weaving texture of the woven bag can strengthen the friction between the air spacer 5 and the side wall of the blast hole 1, thereby preventing the air spacer 5 from being pushed out by water pressure after the blast stick is withdrawn.

[0023] Therefore, the present invention utilizes the characteristics of the air spacer 5 that it is not afraid of water and responds quickly after being inflated, and first pokes it into the blasthole 1 to expand, completes the construction of the first layer of the plugging structure, and buys time and environment for the construction of the subsequent plugging structure. At this time, the water pressure and water volume in the hole will inevitably decrease rapidly or even disappear due to the complete filling of the hole bottom 4 by the air spacer 5, which is convenient for subsequent operations. However, it is still not ruled out that water will flow out from the gap between the air spacer 5 and the hole wall.

[0024] Therefore, the present invention does not directly insert the anchoring charge 7 into the blast hole 1, but first inserts a flexible woven bag 6, such as a cement bag or a sand bag, which can be found everywhere at a construction site or a blasting site. After being inserted into the blast hole 1, these almost zero-cost construction wastes will become flat due to the continuous squeezing of the blast rod. This compressed and flattened flexible woven bag 6: One is to utilize the large number of wrinkles generated by compression to form multiple waterproof partitions between the air spacer 5 and the anchoring medicine roll 7, so as to prevent water seepage from affecting the natural and rapid solidification of the extruded anchoring medicine; Second, it can protect the relatively fragile air spacer 5, and the air spacer 5 in turn provides support for the flexible woven bag 6, so that the flexible woven bag 6 can be used as an extrusion platform to cooperate with the gun stick to squeeze out the anchoring medicine in the anchoring medicine roll 7; The large number of wrinkled structures generated by compression can also prevent a small part of the anchoring medicine from leaking into the air spacer 5, which would cause the anchoring medicine to have insufficient amount and contact area and weaken the plugging effect; The four flexible woven bags 6 can also use the friction between themselves and the side wall of the blast hole 1 to further maintain the stability of the air spacer 5, so as to prevent the air spacer 5 from being pushed out by excessive water pressure when the blast rod is removed and the anchoring medicine has not yet solidified; The flat end surface formed by the five flexible woven bags 6 can ensure that the extruded anchoring medicine forms a regular cylinder under the constraints of the flexible woven bags 6, the gun stick, and the side wall of the blast hole 1, ensuring that the anchoring medicine can fully contact the hole wall, improve the utilization rate of the anchoring medicine, and enhance the anchoring effect.

[0025] Therefore, after using the flexible woven bag 6 to block the hole, the present invention squeezes the anchoring agent into the hole to complete the construction of the second layer of blocking structure.

[0026] After the anchoring agent solidifies, the plugging ability of the plugging structure will be further enhanced. At this time, the oily polyurethane 8 is introduced into the bottom of the hole 4 and waits for it to foam and solidify, and the plugging work is completely completed. At this time, the blast hole 1 will no longer have the problem of water soaking the explosives, providing a stable guarantee for the normal blasting work of the long fan-shaped blast hole 1.

[0027] In summary, the present invention forms a three-layer plugging structure at the bottom of the blasthole 1 by sequentially inserting an air spacer 5, an anchoring medicine roll 7 and an oily polyurethane 8 into the blasthole 1, and the two layers cooperate with each other. The air spacer 5 uses its own characteristic of rapid inflation response to complete the initial plugging of the bottom of the hole 4, and buys time and environment for the input and solidification of the anchoring medicine roll 7; and the air spacer 5 can also act as an extrusion platform to cooperate with the gun stick so that the anchoring medicine roll 7 can be put into the bottom of the hole 4 and then squeezed, reducing the difficulty and requirements of the anchoring medicine input; and after the anchoring medicine solidifies, it can completely block the air spacer 5 at the bottom of the hole 4, strengthen the stability of the air spacer 5, and use its own plugging ability to prevent water from overflowing; after the anchoring medicine solidifies, it also becomes a delivery platform, which is convenient for the liquid oily polyurethane 8 to be put into foaming, ensuring that the oily polyurethane 8 with excellent waterproof performance but poor structural strength can be stably plugged; the foamed oily polyurethane 8 can also react to fill the gap between the anchoring medicine and the hole wall, further strengthening the plugging effect. Therefore, the present invention can well complete the blocking of the blasthole 1 under the background of low cost, quickness and simplicity of use, which is obviously of positive significance for the blasting operation of the long fan-shaped blasthole 1.

[0028] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A water blocking method for a long fan-shaped hole, characterized in that: include A blast hole (1) is drilled in the surrounding rock (2) according to the position and angle of the long fan-shaped hole group determined in advance by a drilling machine. When the drill bit reaches a water-bearing fracture zone or fault and water seepage is found, the drilling is stopped immediately and the drill bit is slowly withdrawn; Using a gun stick and / or any other tool that matches the size of the blast hole (1), the anchoring drug roll (7), the air spacer (5), and the oily polyurethane (8) are inserted into the blast hole (1) from the hole opening (3) to form a three-layer blocking structure, thereby completing the blocking of the blast hole (1); After water seepage from the blasthole (1) stops, the blasthole (1) is charged and blasted.

2. The water blocking method of the long fan-shaped hole according to claim 1, characterized in that: The specific filling order and timing of the three-layer plugging structure are: First, insert the air spacer (5) into the bottom of the hole (4), and then fill the sealed bag in the air spacer (5) with air to make it expand at the bottom of the hole (4); Then, the anchoring charge roll (7) is inserted into the blast hole (1), punctured and compacted; Finally, when no obvious water seepage is observed in the hole, oily polyurethane (8) is injected into the blasthole (1) to seal the anchoring area.

3. The water blocking method of the long fan-shaped hole according to claim 2, characterized in that: The outside of the air spacer (5) is also wrapped with a layer of woven bag.

4. The water blocking method of the long fan-shaped hole according to claim 2, characterized in that: Before the anchoring drug roll (7) is inserted into the blast hole (1), a ball of flexible material is first inserted therein. When the flexible material is inserted into the blast hole (1), it will form a barrier layer due to its own deformation and aggregation.

5. The water blocking method of the long fan-shaped hole according to claim 2, characterized in that: The diameter of the air spacer (5) is 60 mm to 150 mm, the length is 500 mm to 800 mm, the inflation time is 10 s, and the inflation pressure is greater than 0.4 Mpa.

6. The water blocking method of the long fan-shaped hole according to claim 4, characterized in that: The flexible material is a flexible woven bag (6).

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