RU2005882C1 - Method for reconditioning and supporting of workings caved with enclosing rocks - Google Patents

Abstract

FIELD: mining. SUBSTANCE: drilled from surface over contour of caved zone are holes through overhanging rock mass above cave and charged with explosives and blasted to loose and cave overhanging rocks within boundaries of displacement. Then, formed collapse funnel is filled with loose material and compacted. Holes are drilled from surface within cave-in boundaries and cased, with casing string perforated in its lower part, and rocks are consolidated by injection through casing cementing mixture from working floor up to level of artificial roof. Then, working is driven through consolidated rocks. EFFECT: higher safety of operation and reliable support of reconditioned mine workings.

Description

 The invention relates to mining, and in particular to methods of restoration and fastening of mine workings when blocked by host rocks.

 The method is intended for restoration and fastening of horizontal and inclined workings — cross-barriers, field and formation drifts, Bremsbergs, slopes and other workings, passed near the earth’s surface, in case of arbitrary collapse of large volumes of rocks, destruction of lining and their blockage. The specific gravity of these workings is quite large when mining minerals of the upper horizon near the earth's surface. Most often, partial and complete blockages of mine workings near the earth's surface occur during mining of coal seams in the zones of their outlet under sediments. Sometimes rock caving develops to a height of 25-30 m up to the earth's surface (mines Raspadskaya, Maganak named after Shevyakov, Pervomaiskaya and others in Kuzbass). The elimination of such blockages and the fastening of workings is fraught with great danger and requires fairly large material and other means.

 There is a method of attaching voids to the support of a mine and recovering a damaged section of a mine from rock collapse, which consists in placing an elastic container in a vacuum, feeding a binder solution into it, unloading the entire collapsed rock into a mine and securing the broken section of the mine. The process of attaching and filling voids by this method is very dangerous for people, since when assembling and installing an elastic container in voids, they are not protected from accidental detachments and rock outfalls. The method does not provide a reliable connection between the binder aggregate and the surrounding rocks and requires the complete delivery of collapsed rock from the mine and filling the void with binders.

 A known method of filling the voids behind the lining of a mine working, which consists in cleaning the collapsed rock from the dump of the fixed space, introducing into the void from the collapse of the elastic container and forcing compressed air into it, installing the lining in the production and supply of cementing mortar into the elastic container with simultaneous release from it compressed air.

 The disadvantages of the method is that the elastic tank in the dump (void) is mounted without a safety fence, which is very dangerous for people engaged in the installation of the tank, there is no active connection of the aggregate with the surrounding rocks and the fact that the collapsed rocks must be completely removed from the dump and filled its astringent materials.

 There is also known a method [1], which consists in the fact that prior to harvesting the collapsed rock from a mine in a hollow, a temporary air support is installed with windows for drilling along the contour of the hole formation for installing anchor reinforcement, and an anchor reinforcement is erected under protection of the air support, from the voids remove the temporary lining and then completely remove the collapsed rock, establish a permanent lining in the excavation and fill the space of the rock outfall behind the lining with a hardening mixture solution.

 With the help of anchor-reinforcing lining installed along the contour of the dump and designed to ensure joint active work of the aggregate of the emptiness of the dump and surrounding rocks, a reliable connection between the rocks above the dump near the earth's surface and the dump aggregate cannot be achieved due to the low strength of the rocks and the impossibility of reliable fixing anchor and reinforcing rods in these rocks. The deformation and subsidence of the lining in the mine under the influence of rock pressure and the weight of the aggregate lead to the separation of the aggregate from the rocks of the ceiling, the drawing of anchors - reinforcement from the rocks. With a significant separation of the aggregate from the rocks, instantaneous collapse of the rocks of the ceiling above the dump up to the surface, dynamic impacts to the lining and destruction of the lining are possible. Instant collapse of rocks over a dump with a significant separation of the hardened aggregate from them, especially with a small thickness of the rock above the dump to the earth's surface, leads to disruption of the earth's surface, which is associated with the appearance of an additional focus of danger, i.e., with an increase in the risk of mining. Dips are formed on the earth's surface through which unexpected penetration of water into the mine workings and their significant watering up to flooding are possible. Due to the very different strength and deformation properties of the aggregate from the solution of the hardening mixture and the rocks of the ceiling above the dump, a significant separation of the aggregate of the dump from the rocks is possible without noticeable disturbance of the earth's surface. With a further increase in the gap between them, unexpected, almost instantaneous, collapse of rocks with large volumes up to the earth's surface is possible.

 In addition, this method requires the use of temporary protective lining in the dump (mounting the lining in the dump and removing it), cleaning and unloading the entire collapsed rock of the dump and filling the entire volume of the dump with binder hardening material. This is associated with large material and labor costs.

 Closest to the invention is a method of restoring mine workings [2], which consists in the fact that on both sides of the collapse zone, jumpers are erected to the level of the project roof, the dam is filled to the height of the bridge with non-bonding material, and they are formed above the level of the project roof in the sides of the log cut jumpers are built up until they reach the roof, and bonding material is supplied above the level of the design roof of the mine, after which the lintels are disassembled and pass through the incoherent rocks under the protection of artificial Rowl.

 The disadvantages of the method are as follows: the time-consuming, expensive and unproductive process of feeding non-binding and binder materials into the blockage in cramped underground conditions; requires the delivery of a significant amount of materials through a mine network from the earth's surface to the feed point. In addition, the method is quite dangerous due to the prolonged stay of people in the mine and in the development in the dam area, where additional and secondary processes of displacement and collapse of rocks can occur. In the prototype, the supply of non-binding material to the collapsed rocks within the design section of the recoverable mine is fraught with great difficulties due to the increased friction between the collapsed rocks and the material supplied to them (to fill the voids in the rocks), in particular sand. In addition, only a specific particle size distribution (small and very fine, in particular sand or crushed rocks of small sizes) can be used as a non-binding material. A big disadvantage of this method is that the void inside the dump over the collapsed rocks to the contour of the dump (its volume is equal to the volume of rocks that fell out into the section of the mine and issued from the mine when it is restored) is not filled. Therefore, after the recovery of the mine during its operation, spontaneous further development of the destruction and collapse of the rocks inside the dump is possible, especially under conditions of high rock pressure, resulting in an increase in the load on the lining and the possible blockage of the mine and the formation of a dump of much larger size than in the initial blockage . In weak rocks near the earth's surface, the abandonment of the void can lead to spontaneous collapse of rocks up to the earth's surface, disruption of the earth's surface, i.e., the formation of a failure, and unexpectedly, almost instantly. Ultimately, this can lead to an emergency on the earth’s surface in the places of its failure, to the destruction of the roof support under the action of collapsed rocks (especially when the ceiling collapses to the earth’s surface instantly) and the blockage develops.

 The method is also unsafe, since unreinforced rocks within the cross-section of the mine and the non-bonding material supplied to them during excavation are poured out and fall from the bottom and sides. The loss of unbound rocks and material from the bottom and sides is especially dangerous at a significant height of the restored mine (for safety reasons, penetration is possible with the use of a special protective lining).

 The aim of the invention is to reduce the cost of restoration and subsequent maintenance of workings and increase safety.

 The goal is achieved in that in the proposed method, which includes filling the voids of the dump with filling and bonding materials, the formation of an artificial roof and the subsequent penetration of the excavation under an artificial roof, the rock mass is pre-drilled along the contour of the dump zone from the earth’s surface at an angle equal to the angle of movement of the rock over the dump, they are charged with explosives and loosening and collapsing of the hanging rocks within the boundaries of displacement, then the filling material is filled with uyuschuyusya funnel and condense it oburivayut wells rocks within the Earth's surface with inrush, perforated cased wellbore at the bottom of the tubes and the solution was injected a hardening composition for hardening species from the soil to produce artificial roof level.

 In the proposed method, in contrast to the prototype, the void of the dump is filled from the earth's surface by drilling and exploding rocks hanging above the dump along the contour of the dump zone, followed by filling the funnel with non-bonding material from the surface and compacting it.

 In addition, the method is characterized in that the rocks are reinforced with a bonding material, including artificial roof, from the working soil by supplying cementitious materials from the earth's surface through pre-drilled and cased perforated pipes in the lower part of the pipe, after which the production passes through the strengthened rocks.

 This reduces the complexity and cost of hardening the artificial roof rocks by eliminating the descent and transport of materials through the mine workings, feeding binders into the void of the dump from the mine working upward.

 In the proposed method, work to eliminate the blockage is carried out from the earth's surface, where the transportation of materials, the cost of drilling and feeding binders are much cheaper compared to work in mine conditions. This is much safer.

 The proposed method, in contrast to the prototype, ensures the active joint work of the collapsed rocks inside the collapse with the rocks of the ceiling above the collapse to the earth's surface within the boundaries of the displacement of rocks collapsed using drilling and blasting. As a result of the forced collapse of the rocks hanging over the dump within the boundaries of their displacement and their joining in the loosened state with the collapsed rocks inside the dump, the formation of the dump aggregate is almost uniform in physical condition (loosened), the compaction and displacement of which under the influence of rock pressure during operation of the mine after its recovery occurs without noticeable separation and hovering of one part relative to another. This method eliminates the abandonment of an empty void above the collapsed rocks inside the fall to the contour of the fall and, therefore, prevents the rocks from hanging above the fall to the earth's surface (usually of low power and short-term stability), their subsequent instantaneous collapse and the resulting dynamic impacts on the lining, support bolts and possible repeated blockages of workings of significantly larger sizes and volumes than the initial blockages. In addition, the proposal provides a reliable and safe state of the earth's surface above the rock outfall in the workings, eliminates unexpected and often very dangerous failures of the earth's surface.

 Drilling a well along the contour of the collapse zone and arranging the wells parallel to the rock displacement surfaces ensures the safety of drilling operations, loading and blasting charges, destroying and collapsing hanging rocks above the collapse within the boundaries of collapse, rock displacement directly from the earth's surface. The collapse of rocks by a blasting method within the boundaries of the displacement of rocks eliminates the almost instantaneous collapse of hovering rocks over a dump within the boundaries of displacement, usually occurring after restoration of the workings. This, in turn, eliminates a sharp increase in the load on the lining (often dynamic) and repeated blockages of workings.

 The charges in the wells according to the proposed method explode with various stages of deceleration, which prevents large dynamic impacts of blasted rocks. Forced collapse of hovering rocks on destroyed rocks inside the dump contributes to a significant crushing of rocks inside the dump.

 The method does not require, as in the prototype, filling the blockage with non-bonding material to the level of the protective artificial roof of the mine, i.e. there is no need to perform technically very difficult and expensive work to fill the voids between pieces of collapsed rocks within the cross-section of the mine.

 In the proposed method, the collapsed rocks are below the design level of the artificial roof, i.e., within the design section of the excavation and on the sides of the excavation, they are hardened with a solution of cementitious substances and regenerated production is carried out on the hardened rocks. As a result of this, in comparison with the prototype, the safety of work is significantly increased, since rashes and rock outfalls in the process of sinking from the sides and bottom of the mine are excluded.

 Thus, the claimed technical solution meets the criterion of "novelty."

 Comparison of the proposed technical solution with analogues shows that it meets the criterion of "significant differences".

 In FIG. 1 shows a longitudinal section through a mine inundated over a section; in FIG. 2 - the same, with the location of the boreholes along the contour of the dump zone; in FIG. 3 is a section AA in FIG. 2 with the location of the wells in plan along the entire contour of the fall; in FIG. 4 is a section BB in FIG. 2; in FIG. 5 is the same as in FIG. 2, after the destruction and collapse of the explosives explosive hanging over the rocks in the boundaries of their movement to the earth's surface; in FIG. 6 is the same as in FIG. 5, with filling the funnel formed from explosions with incoherent materials; in FIG. 7 - drilling of rocks inside the dump wells; in FIG. 8 - a longitudinal section of the development after its full recovery; in FIG. 9 is a section BB in FIG. 8.

 The method is as follows.

After cutting in the restored development of 1 approach (approaches from both sides) to the blockage and bringing it into a safe state, determine the shape and dimensions of the dump (emptiness) and the power of the rocks hanging above the dump using the surveying instruments used at mining enterprises. Then, along the contour of the outfall zone, within the boundaries of the displacement of rocks hovering above the outfall 2, wells 4 are drilled from the earth's surface 3 by a drilling rig (s) 5 at an angle of inclination to the horizontal equal to the angle of displacement of the outlying rocks above the outfall, i.e., with their location approximately parallel to the displacement surface of 6 underworked rocks. According to numerous surveying instrumental observations, the angles of displacement of rocks near the earth's surface along strike (Fig. 2, angle δ) and across strike from the side of uprising and falling are mainly 70-80 ^about . After drilling wells 4, reinforce the support in the mine in a section (usually 4-5 m long) adjacent directly to the dump, charge the wells with explosive, detonate explosive charges, fill up the formed funnel 7 with non-bonding materials 8, for example, small rocks obtained during mining mine workings by overburden or overburden operations, and compact the rocks inside the outfall. Then they drill from the earth’s surface of the rock inside the dump with boreholes 9, casing the boreholes with pipes, the lower part of which is perforated, hardening mixture solution, for example cement-sand, is fed through boreholes 9 and hardened rocks 10 are strengthened below the artificial roof level 11, starting from the excavation soil to the level artificial roof production. The solution of the hardening mixture of the artificial roof 12 is fed from the earth's surface through the wells 9. After supplying the hardening mixture solution necessary for hardening the rocks and creating the artificial roof of the solution of the hardening mixture, pipes are removed from the wells 9 for reuse and the rocks are further compacted inside the dump from the earth's surface, for example, with a roller. Then pass generation 1 on hardened rocks and erect a permanent lining 13 in it.

 The proposed method provides a reduction in the cost of restoration and subsequent maintenance of the workings, a sharp increase in the safety of restoration work and an increase in safety during the operation of the workings. By ensuring the joint work of rocks hovering over a fall near the earth’s surface, which usually have short-term stability and collapse, as a rule, instantly in full or in large parts up to the earth’s surface, and collapsed rocks inside the fall above the mine, collapse of the hanging rocks of the ceiling is eliminated. increased loads and crashes; possible repeated blockages of production, violations of the earth's surface and the formation of failures with all the ensuing dangers and other negative consequences. The formation of almost instantaneous dips on the earth’s surface as a result of the collapse of rocks, ceilings above the mine workings near the earth’s surface is usually difficult to predict. This is evidenced by the experience of mining and mining operations near the earth's surface in the coal mines of Kuzbass. (56) 1. USSR author's certificate N 1168719, cl. E 21 D 11/00, 1980.

 2. USSR author's certificate N 1033757, cl. E 21 D 9/02, 1979.

Claims (1)

 METHOD FOR RESTORING AND FASTENING MINING WORKS NEAR THE EARTH'S SURFACE WHEN CAPACITING ROCKS, including filling the voids of the dump with filling and binding materials, forming an artificial roof and subsequent excavation, characterized in that, in order to reduce the cost of recovery and subsequent safety, preliminary, along the contour of the zone of falling out from the earth's surface, the hanging mass of rocks is drilled with wells at an angle equal to the angle of movement of the hanging rocks above with a vial, charge them with explosive and loosen and collapse the hanging rocks within the boundaries of movement, then fill the filling materials into the formed funnel, compact it and drill the rocks with wells within the fall from the earth's surface, which are cased with perforated pipes in the lower part, and pump the solution with a hardening solution mixtures for hardening rocks from working soil to the level of artificial roofing.

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