阅读说明：本技术 一种岩矸配合成形的伪采空层支护限沉回采方法 (Pseudo-goaf-layer supporting and sinking-limiting stoping method formed by matching rock waste with rock waste ) 是由 胡善超 王俊 宁建国 茹文凯 郭勇 左靖 于 2020-05-26 设计创作，主要内容包括：本发明公开了一种岩矸配合成形的伪采空层支护限沉回采方法,涉及采矿工程回采和地表沉陷防治技术领域。该方法通过加固浆液使岩层和矸石相互配合,利用回采进尺放顶时间差、浆液重力下流和矸石空间裂缝规律,在矸石层内的隔断配置输出管,并在垮落的顶板岩层内注入浆液形成分段排列稳固的支护伪层,配合架设的密闭薄形墙体进行通风；其中第一工作面采用b形开采,后续的工作面采用p形开采；在预留的阶段性巷道初步垮落后利用预留的供液管浇筑巷道悬空空间,形成完整的伪采空层,控制地层沉陷和采场积水。该回采方法减少了工作面的掘进工作量,并可以有效的控制地表沉降,在低成本、高回采率和绿色环保的条件下完成了对矿产资源的开采。(The invention discloses a pseudo-mining empty layer supporting and subsidence-limiting stoping method formed by matching rock waste rocks, and relates to the technical field of stoping of mining engineering and prevention and control of surface subsidence. The method comprises the steps of mutually matching rock strata and waste rocks by reinforcing slurry, configuring an output pipe on a partition in the waste rock stratum by utilizing the stoping footage roof-caving time difference, the gravity downflow of the slurry and the space crack rule of the waste rocks, injecting the slurry into a collapsed roof rock stratum to form a stably-arranged support false layer in sections, and ventilating by matching with an erected sealed thin wall; the first working face adopts b-shaped mining, and the subsequent working faces adopt p-shaped mining; and after the reserved periodical roadway is preliminarily collapsed, pouring the suspension space of the roadway by using the reserved liquid supply pipe to form a complete pseudo-goaf layer and control the stratum subsidence and the water accumulation in the stope. The mining method reduces the tunneling workload of the working face, can effectively control the surface subsidence, and completes the mining of mineral resources under the conditions of low cost, high mining rate and environmental protection.)

1. A pseudo-goaf-layer supporting and sinking-limiting stoping method formed by matching rock gangues is characterized by comprising the following steps:

determining working face parameters according to the mining range of a stope and the occurrence condition of a coal bed, and calculating the configuration space between a thin slurry wall and an output pipe;

arranging a track, a transportation descending hill, an air return descending hill and a connecting roadway, arranging a first working surface along the direction of the descending hill, cutting a hole, constructing a b-shaped working surface and finishing ventilation of the working surface;

thirdly, the suspended roof is controlled by using temporary supports after the working face is mined, slurry wall molds are arranged in a working face roadway one by one along the trend, and grouting is performed in the slurry wall molds to form a thin plate-shaped slurry wall;

the working face continues to be mined, the roof is forcibly jacked behind the working face to form a gangue layer, a drill hole penetrates through the gangue layer to install an output pipe, the output pipe is used for grouting into the gangue layer, and the output pipe is used as a jacking shaft to form an arch-shaped supporting section;

step five, after the working face is mined, combining a plurality of arch support sections and the slurry wall to form a support pseudo-layer;

reserving the transportation crossheading of the working face, arranging the adjacent working faces as p-shaped mining working faces, repeating the third step to the fifth step, grouting into the waste transportation crossheading through a liquid supply pipe, and cementing the collapsed waste rock in the roadway to form an in-roadway building body;

arranging a local ventilator in the roadway to blow air to the next working surface, and arranging an air door to control the ventilation air quantity to complete the ventilation of the working surface;

and step eight, repeating the step three to the step seven until the stoping within the stoping range is completed, and constructing a complete pseudo-stoping layer comprising a supporting pseudo-layer and an in-roadway building body in the stope goaf.

2. The method for supporting and limited subsidence stoping of the pseudo-mining empty layer formed by matching rock gangues and the rock gangues as claimed in claim 1, wherein the ventilation path of the b-shaped working surface is as follows: descending the rail, b-shaped working surface, transporting along the groove, connecting the lane, and returning air to descend the mountain.

3. The method for supporting and limited subsidence stoping of the pseudo-goaf layer formed by matching rock gangues and the rock gangues as claimed in claim 1, wherein the ventilation path of the p-shaped working surface is as follows: descending a rail, newly connecting an entry, p-shaped working face, newly transporting crossheading, connecting an entry and returning air to descend a mountain.

4. The method for limited subsidence recovery of rock refuse cooperatively formed pseudo-goaf-level support according to claim 1, wherein the temporary supports comprise pillars and wind shields, the pillars are supported below the roof, the wind shields have the same length as the working face and are oppositely arranged along a direction parallel to the working face.

5. The method for the limited subsidence and the stoping of the pseudo-mined empty space support formed by the rock waste in a matching manner according to claim 1, wherein the thickness of the slurry wall forms arranged in the transportation gate is 0.4-0.5m, the height of the slurry wall forms is equal to the mining height of a working face, and the length of each slurry wall form is 1-2 m; the thickness of the slurry wall forms arranged in the track lower mountain is 0.8-1m, the height of the slurry wall forms is equal to the mining height of a working face, and the length of each slurry wall form is 1-2 m.

6. The method according to claim 1, wherein liquid supply pipes are arranged in the track descending and the transportation crossheading, the liquid supply system supplies slurry through the liquid supply pipes, and each output pipe is connected with the liquid supply pipe.

7. The method for supporting and limited subsidence stoping of the pseudo-goaf layer formed by matching rock waste with the rock waste as claimed in claim 6, wherein a plurality of transfusion holes are uniformly arranged on the output pipe along two opposite side surfaces, and the output pipe is buried in the rock waste layer below the stabilizing rock mass.

8. The method of claim 7, wherein the output pipe is horizontally arranged, and the infusion holes are symmetrically arranged at the same horizontal height along the axis of the output pipe; the working face is evenly divided into a plurality of subsections along the mining direction, an output pipe is arranged in the middle of each subsection, and slurry flows out along the infusion holes to form symmetrical arch-shaped cemented gangue blocks.

9. The method for limited subsidence and recovery of a pseudo-goaf-level support formed by matching rock waste with the rock waste in claim 1, wherein a ventilation hose is connected to the local ventilator, and the ventilation hose is pushed and extended along with a working surface.

Technical Field

The invention relates to the technical field of mining engineering stoping and surface subsidence prevention, in particular to a stoping method for preventing subsidence of a pseudo-mining empty layer support formed by rock waste rock matching.

Background

With the rapid development of economy, the demand of mineral resources, especially the utilization of coal resources, is increasing. However, the exploitation of underground resources brings about a plurality of serious problems, such as the destruction of the earth surface, the serious threat to water resources, vegetation, buildings and the like, and the reduction of cultivated land, which seriously destroys the harmonious development of the nature and human beings. In addition, under the action of gradually increasing ground stress during resource exploitation, the original exploitation mode causes more safety accidents, such as rock burst, water accumulation and water burst in a goaf and the like, and casualties are caused. The low recovery rate also causes a great deal of resource waste, and further may face the dilemma of resource exhaustion. The existing coal mining method still has the problems of tension in mining continuity and high production cost, which seriously restrict the development of enterprises.

The coal mining methods are various, and the conventional coal mining methods are divided into two categories, namely a wall type coal mining method and a pillar type coal mining method. The wall coal mining method has long coal wall, and the two end tunnels of the working face are used for air inlet and return, coal transportation and material transportation respectively, and the extracted coal is transported out of the working face in the direction parallel to the coal wall. The coal wall of the pillar coal mining method is short and in a square column shape, the number of the mined working faces is large, and the mined coal is transported out in a direction perpendicular to the working faces. For the treatment of the goaf, the treatment is generally carried out according to conditions such as roof characteristics, coal seam thickness, special requirements for protecting the earth surface and the like, and the treatment methods mainly comprise a total caving method, a filling method and a coal pillar supporting method.

Most of the existing mining methods are provided with coal pillars so as to reduce the recovery utilization rate of resources, and the goaf treatment with higher filling method cost usually selects a complete collapse method, and the collapse of the goaf can cause the problems of surface subsidence and the like. The method for reserving the coal pillars to support the goaf can cause coal resource waste, along with the danger of rock burst, the coal pillars have limited supporting effect on the goaf, and the problems of water accumulation in the goaf and the like exist. Therefore, in order to improve the utilization rate of coal resources, improve the recovery efficiency of enterprises, limit surface subsidence, protect the natural environment and ensure high safety indexes, the existing mining method and goaf treatment method need to be further improved.

Disclosure of Invention

In order to reduce the tunneling workload of a working face, effectively control surface subsidence, finish mining mineral resources under the conditions of low cost, high recovery rate and environmental protection, and prevent large-area roof caving, rock burst and water inrush in old goafs, the invention provides a pseudo-goaf support subsidence-limiting stoping method formed by matching rock and gangue.

The method is characterized in that an output pipe is arranged in a caving gangue layer, a plurality of arch-shaped cemented gangue structures are built in a goaf stage by stage to form a stable pseudo-goaf layer to limit subsidence, and a thin plate-shaped slurry wall is matched to ensure ventilation of a roadway, so that transition from b-shaped mining to p-shaped mining is realized, and the mining efficiency of a working face is improved. The specific technical scheme is as follows.

A pseudo-goaf-layer supporting and sinking-limiting stoping method for rock and gangue matched forming comprises the following steps:

determining working face parameters according to the mining range of a stope and the occurrence condition of a coal bed, and calculating the configuration space between a thin slurry wall and an output pipe;

arranging a track, a transportation descending hill, an air return descending hill and a connecting roadway, arranging a first working surface along the direction of the descending hill, cutting a hole, constructing a b-shaped working surface and finishing ventilation of the working surface;

thirdly, the suspended roof is controlled by using temporary supports after the working face is mined, slurry wall molds are arranged in a working face roadway one by one along the trend, and grouting is performed in the slurry wall molds to form a thin plate-shaped slurry wall;

the working face continues to be mined, the roof is forcibly jacked behind the working face to form a gangue layer, a drill hole penetrates through the gangue layer to install an output pipe, the output pipe is used for grouting into the gangue layer, and the output pipe is used as a jacking shaft to form an arch-shaped supporting section;

step five, after the working face is mined, combining a plurality of arch support sections and the slurry wall to form a support pseudo-layer;

reserving the transportation crossheading of the working face, arranging the adjacent working faces as p-shaped mining working faces, repeating the third step to the fifth step, grouting into the waste transportation crossheading through a liquid supply pipe, and cementing the collapsed waste rock in the roadway to form an in-roadway building body;

arranging a local ventilator in the roadway to blow air to the next working surface, and arranging an air door to control the ventilation air quantity to complete the ventilation of the working surface;

and step eight, repeating the step three to the step seven until the stoping within the stoping range is completed, and constructing a complete pseudo-stoping layer comprising a supporting pseudo-layer and an in-roadway building body in the stope goaf.

Preferably, the b-shaped face ventilation path is: descending the rail, b-shaped working surface, transporting along the groove, connecting the lane, and returning air to descend the mountain.

Preferably, the p-shaped face ventilation path is: descending a rail, newly connecting an entry, p-shaped working face, newly transporting crossheading, connecting an entry and returning air to descend a mountain.

It is also preferred that the temporary support comprises a stay supported below the roof panel and a wind deflector having a length equal to the working surface and disposed oppositely along a direction parallel to the working surface.

It is also preferable that the thickness of the slurry wall forms arranged in the transportation gate way is 0.4-0.5m, the height is equal to the mining height of the working face, and the length of each slurry wall form is 1-2 m; the thickness of the slurry wall forms arranged in the track lower mountain is 0.8-1m, the height of the slurry wall forms is equal to the mining height of a working face, and the length of each slurry wall form is 1-2 m.

It is also preferable that liquid supply pipes are uniformly arranged in the track descending and the transportation crossheading, the liquid supply system supplies slurry through the liquid supply pipes, and each output pipe is respectively connected with the liquid supply pipes.

It is further preferred that a plurality of transfusion holes are evenly arranged on the output pipe along two opposite side surfaces, and the output pipe is buried in a gangue layer below the stable rock mass.

It is further preferred that the output pipe is horizontally arranged, and the infusion holes are symmetrically arranged at the same horizontal height along the axis of the output pipe; the working face is evenly divided into a plurality of subsections along the mining direction, an output pipe is arranged in the middle of each subsection, and slurry flows out along the infusion holes to form symmetrical arch-shaped cemented gangue blocks.

It is further preferred that the ventilator is connected to a ventilation hose which extends with the working surface.

The invention provides a rock waste cooperative forming pseudo-mining empty layer supporting and subsidence limiting stoping method, which has the beneficial effects that:

(1) the stoping method utilizes the distribution characteristic of waste rock after the goaf is preliminarily collapsed, slurry injected is made to diffuse to gaps of the waste rock in an arch bridge shape under the action of gravity and pipeline pressure by penetrating through the waste rock layer through the output pipe, the purpose of stabilizing the roof rock layer is achieved, the grouting cost is reduced, each arch-shaped cemented waste rock structure is cemented with a slurry wall, the stability of the structure is guaranteed, and the plugging effect is better played.

(2) According to the method, the stability of surrounding rocks of the roadway on the working face is guaranteed and the ventilation is kept through the combined action of supporting structures such as the slurry wall, the anchor rod and the anchor cable, the supporting capability of the slurry wall and the arch cemented gangue structure is enhanced, and the supporting pseudo-layer structure formed in the stope can prevent the goaf from settling and avoid water accumulation in the goaf.

(3) The method realizes the transition from b-shaped mining to p-shaped mining, perfects the ventilation path in the mining process, reduces the reservation of safe coal pillars, simultaneously can ensure the mining safety, reduces the control cost of the top plate, and is more convenient to realize mechanized coal mining.

(4) The temporary support ensures the ventilation condition of the working face at the open cut and the early mining stage, the cost for constructing the roadside supporting structure is reduced by the arrangement of the slurry wall, the longer service life of the roadway can be ensured, and the sectional arrangement can facilitate construction; the local ventilation equipment can be pushed and extended along with the working surface, so that the ventilation requirement is met.

In addition, the method constructs a complete pseudo-goaf layer, has strong integral support, can ensure the safe stoping of a single working face, can limit the integral subsidence of a stope, can avoid the water accumulation phenomenon of the stope, has simple and easy operation and strong engineering applicability, realizes the safe and efficient stoping of the working face, and has low cost for controlling the subsidence of the goaf.

Drawings

FIG. 1 is a schematic diagram of construction steps of a pseudo-mining empty-layer supporting and sinking-limiting stoping method formed by matching rock waste;

FIG. 2 is a schematic cross-sectional view A-A of FIG. 1;

FIG. 3 is a schematic diagram of the construction of the takeoff pipe;

FIG. 4 is a schematic view of a slurry wall form construction;

in the figure: 1-returning air to descend a mountain, 2-transporting to descend a mountain and 3-descending on a track; 4-transportation crossheading, 401-new transportation crossheading; 5-gangue layer, 6-output pipe; 701 a first working surface, 702 a second working surface, 703 a third working surface, 704-a fourth working surface; 8-connecting lane, 9-fresh air, 10-dirty air, 11-stope, 12-air door, 13-new connecting lane and 14-pseudo mining empty layer; 15-slurry wall, 151 slurry wall form, 152 input aperture; 16-in-lane building, 17-arch support section, 18-local ventilator, 19-infusion hole, 20 temporary support and 21 liquid supply pipe.

Detailed Description

The concrete implementation of the rock waste matched forming pseudo-mining empty layer supporting limited sinking recovery method provided by the invention is described with reference to fig. 1 to 4.

A rock-waste matched forming pseudo-goaf layer supporting and subsidence limiting stoping method is characterized in that an output pipe is arranged in a caving waste rock layer, a plurality of arch-shaped cemented waste rock structures are built in a goaf stage by stage to form a stable pseudo-goaf layer to limit subsidence, and a thin plate-shaped slurry wall is matched to ensure ventilation of a roadway, so that transition from b-shaped stoping to p-shaped stoping is realized, and the mining efficiency of a working face is improved.

The method comprises the following specific steps:

determining working face parameters according to the mining range of a stope and the occurrence condition of a coal bed, and calculating the configuration space between a thin slurry wall and an output pipe.

The reserve, hydrogeology, engineering geology, constructed roadway engineering and the like of a stope need to be considered, the division of the mining range is determined according to the actual situation of a coal field, and the occurrence situation of the coal bed comprises the dip angle, the thickness and the like of the coal bed. The working face parameters include mining height, mining direction, working face length, mining mode and the like. The thickness of the thin slurry wall is determined according to the buried depth and the service life of the roadway design, and the distance between the output pipes is determined according to the span of the arch cemented gangue.

And step two, arranging a track, a transportation descending hill, an air return descending hill and a connecting roadway, arranging a first working surface along the direction of the descending hill, cutting a hole, constructing a b-shaped working surface and finishing ventilation of the working surface.

The b-shaped working face is parallel to the track downhill for mining, the shape of the combination of the track downhill and the working face goaf is similar to the b shape, mining is carried out from bottom to top, and the working face adopts an uphill mining mode. The track of the original design roadway is used for air intake, and the ventilation path of the b-shaped working surface is as follows: fresh air enters the b-shaped working face from the lower mountain of the track, dirty air firstly passes through the transportation gate and then enters the return air lower mountain through the connecting roadway, and ventilation of the b-shaped working face is completed.

And thirdly, the suspended roof is controlled by using temporary supports after the working face is mined, slurry wall molds are arranged in the roadway of the working face one by one along the trend to the safe distance from the working face, and the slurry wall molds are grouted to form the thin plate-shaped slurry wall.

The working faces in the step comprise a first working face and working faces for subsequent mining, such as a second working face, a third working face, a fourth working face and the like, and the working faces for subsequent mining are p-shaped working faces.

Wherein interim support includes pillar and deep bead, and the pillar supports in the roof below for control roof, deep bead length equals with the working face and arranges the mutual disposition along the direction that is on a parallel with the working face, and the deep bead can form the protective screen and prevent to cross the wind, leak the wind and guarantee that the working face is opened and is cut the eye initial stage and form complete ventilation return circuit.

In addition, the thickness of the slurry wall forms arranged in the transportation gate is 0.4-0.5m, the height is equal to the mining height of a working face, the length of each slurry wall form is 1-2m, and 1m of the slurry wall forms are generally used in the transportation gate. The thickness of the slurry wall forms arranged in the track lower mountains is 0.8-1m, the height of the slurry wall forms is equal to the mining height of a working face, the length of each slurry wall form is 1-2m, and 2m slurry wall forms are generally used. The slurry wall form can be made of a hollow wooden rectangular shell, and the same slurry wall form is used in a new transportation gate way.

And fourthly, continuing the stoping of the working face, forcibly caving the working face to form a gangue layer, installing an output pipe after the drill hole penetrates through the gangue layer, grouting the output pipe into the gangue layer, and forming an arch-shaped supporting section by taking the output pipe as a top shaft.

Wherein, a plurality of transfusion holes are evenly arranged on the output pipe along two opposite side surfaces, and the output pipe is buried in a gangue layer below the stable rock mass. The output tube can be the iron material that the wall thickness is 2mm, can play certain supporting role in the waste rock layer, and evenly distributed's infusion hole is left to its outside, and its interior aperture is 40mm, and the aperture of infusion hole is 10 mm. The output pipe is horizontally arranged, and the infusion holes are symmetrically arranged at the same horizontal height along the axis of the output pipe; in addition, a semi-arch diversion trench can be arranged at the position of the liquid delivery hole, so that the slurry is left along the diversion trench after being sprayed out of the output pipe, and an arch cemented gangue structure is ensured to be formed. The working face is evenly divided into a plurality of subsections along the mining direction, each subsection is arranged adjacently, an output pipe is arranged in the middle of each subsection, and slurry flows out along a transfusion hole and then forms symmetrical arched cemented gangue blocks under the influence of self-gravity and output pressure, as shown in figure 2.

The process that the waste rock after the collecting space area caving falls to the compaction from preliminary caving has certain time difference, and the grout is injected into the waste rock layer that caving preliminarily to form the cementation waste rock structure, and this supporting construction can be fine control collecting space area subsidence.

And step five, finishing the stoping of the working face, and combining the plurality of arched support sections and the slurry wall to form a supporting false layer.

Along with the stoping of each working face, the output tubes are arranged according to the set intervals, so that a plurality of arch supporting sections which are uniformly arranged are sequentially formed, the arch supporting sections are sequentially glued with the slurry wall in the forming process, a stable supporting false layer is formed by combination, and the subsidence of the goaf can be effectively controlled.

And step six, reserving the transportation crossheading of the working face, arranging the adjacent working faces as p-shaped mining working faces, repeating the step three to the step five, grouting into the waste transportation crossheading through a liquid supply pipe, and cementing the collapsed waste rock in the roadway to form an in-roadway building body.

In particular, a transport gateway for the face is maintained, which includes a transport gateway parallel to the downhill portion of the track, and a new transport gateway for the face for subsequent mining. Working faces of subsequent mining, such as the second working face, the third working face, the fourth working face and the like, all adopt p-shaped mining. From b-shaped mining to p-shaped mining, the working face is convenient to move, and the continuation of the working face is ensured. And repeating the third step to the fifth step, specifically repeating the manufacturing process of the slurry wall and the arch support section, abandoning the original transportation crossheading within the length range pushed by the working face after the second working face starts to be mined, and grouting the collapsed waste rock through a liquid supply pipe to form a building body in the roadway. The third step to the fifth step can be repeated once until the mining of the second working face is finished; step six may also be performed until the end of production.

Liquid supply pipes are uniformly arranged in the track descending and the transportation crossheading, a liquid supply system supplies slurry through the liquid supply pipes, and each output pipe is respectively connected with the liquid supply pipes. The grout in the liquid supply pipe can be cement material, the input of the grout depends on the liquid supply system of the mine to be connected with the liquid supply pipes going down the hill and along the trough, and the liquid supply pipes can pour the grout into the grout wall model. The arrangement mode of the liquid supply pipe and the output pipe is simple and convenient to operate, and construction can be facilitated.

Wherein each p-shaped working surface ventilation path is: fresh air flow goes down the hill from the track to the new connecting roadway, passes through the p-shaped working face, then dirty air flows from the new transportation crossheading to the transportation crossheading, and returns to the return air down the hill through the connecting roadway. The new transportation crossheading is the transportation crossheading of the current mining working face and is parallel to the descending of the track; the new connecting lane is a lane for communicating the lower end of the rail and the upper end of each working surface, and the connecting lane and the new connecting lane can be parallel to each other.

And seventhly, arranging a local ventilator in the roadway to blow air to the next working surface, and arranging an air door to control the ventilation air quantity to complete the ventilation of the working surface.

And step seven is executed when the distance between the working face and the track is more than 100m, or the step seven is started after the second working face is mined in the step six, wherein the local ventilator is connected with a ventilation hose which is pushed and extended along with the working face to meet the ventilation requirement. The method mainly aims to ensure good ventilation effect of the mining of the p-shaped working face, improve the mining environment of the working face and reduce the production cost.

And step eight, repeating the step three to the step seven until the stoping within the stoping range is completed, and constructing a complete pseudo-stoping layer comprising a supporting pseudo-layer and an in-roadway building body in the stope goaf, wherein the pseudo-stoping layer can effectively limit stratum subsidence and stope water accumulation.

In step eight, when repeating steps three to seven, the part of step six that repeats steps three to five may not be executed any more, and steps three to seven are directly repeated. The ventilation requirements of all the working surfaces can be met through the seventh step, so that the ventilation environment is improved.

In order to ensure the safe stoping of the working face of the stope, in the implementation process of the method, the descending hill and the crossheading are supported by anchor cables, anchor rods and the like, so that the risk can be reduced. The trend of the working face with shorter distance is arranged during mining, so that the service life of the transportation gate way of each working face is shorter, and favorable conditions are provided for mining.

The method reduces the excavation amount of the working face, can realize the safe exploitation of mineral resources under the conditions of low cost, high recovery rate, high efficiency and environmental protection, and is favorable for the development and innovation of the anti-subsidence mining method.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.