阅读说明：本技术 竖井加固方法 (Shaft reinforcing method ) 是由 崔传杰 郭相参 安建英 于 2020-07-01 设计创作，主要内容包括：本发明公开了一种竖井加固方法,包括：在井筒设置多个钻孔位置,在每个钻孔位置钻进设定距离后,利用中空自进式锚杆继续钻进,直至中空自进式锚杆外露出设定尺寸；将中空自进式锚杆与注浆软管道连接,并同步安装压力监测装置,通过注浆软管道向中空自进式锚杆内注入设定注浆量的浆液；浆液注入完成后,对井筒进行掘进出渣处理；出渣后,进行钢筋绑扎支护；钢筋绑扎完成后,浇筑混凝土。本发明采用锚固支护加固和注浆加固相结合的方式对竖井进行加固,避免了打钻塌孔卡钻,并且,可以按需较好地控制注浆范围,保障揭露的堆积层井壁稳定、不垮塌,为竖井施工作业提供了安全保障。相比地表、工作面预注浆的高压注浆,可以节省注浆成本。(The invention discloses a vertical shaft reinforcing method, which comprises the following steps: arranging a plurality of drilling positions in a shaft, and after drilling a set distance in each drilling position, continuously drilling by using a hollow self-advancing anchor rod until the hollow self-advancing anchor rod is exposed out of a set size; connecting the hollow self-advancing anchor rod with a grouting hose pipeline, synchronously installing a pressure monitoring device, and injecting grout with a set grouting amount into the hollow self-advancing anchor rod through the grouting hose pipeline; after the slurry injection is finished, performing tunneling and deslagging treatment on the shaft; after deslagging, binding and supporting reinforcing steel bars; and after the steel bars are bound, pouring concrete. The invention adopts the mode of combining anchoring support reinforcement and grouting reinforcement to reinforce the vertical shaft, avoids drilling and collapse and drill clamping, can better control the grouting range according to the requirement, ensures that the exposed wall of the accumulation layer is stable and does not collapse, and provides safety guarantee for the construction operation of the vertical shaft. Compared with high-pressure grouting of earth surface and working surface pre-grouting, the grouting cost can be saved.)

1. A method of reinforcing a shaft, comprising:

arranging a plurality of drilling positions in a shaft, drilling a set distance in each drilling position, and then continuously drilling by using a hollow self-advancing anchor rod until the hollow self-advancing anchor rod is exposed out of a set size, wherein grouting holes are distributed in the hollow self-advancing anchor rod;

connecting the hollow self-advancing anchor rod with a grouting hose pipeline, synchronously installing a pressure monitoring device, and injecting grout with a set grouting amount into the hollow self-advancing anchor rod through the grouting hose pipeline;

after the slurry injection is finished, performing tunneling and deslagging treatment on the shaft;

after deslagging, binding and supporting reinforcing steel bars;

and after the steel bars are bound, pouring concrete.

2. A method for reinforcing a shaft according to claim 1, characterized in that the plurality of drilling locations are evenly distributed along the circumferential direction of the wall of the shaft.

3. A method for reinforcing a shaft as defined in claim 2, wherein the hollow self-advancing bolts drilled in the plurality of drilled holes are uniformly distributed in an umbrella shape, and the drilling direction is at an angle of 60 degrees to the horizontal.

4. A shaft reinforcing method according to claim 1, wherein the drilling sites are arranged at longitudinally spaced set block heights, and a cycle of shaft reinforcing construction is performed at each of the set block height shaft portions.

5. A vertical shaft reinforcing method according to claim 1, wherein the grout injected into the hollow self-advancing anchor rod is cement-water glass double-grout, wherein the weight ratio of the cement grout to the water glass is 1: 0.6 to 1.

6. A shaft reinforcing method according to claim 1, wherein when the shaft is driven to a set section height, a bolt net sheet is driven into the shaft surrounding rock to support the bolt net.

7. A method for reinforcing a shaft according to claim 1, wherein the step of performing a driving tapping process on the shaft comprises: excavating a clear path portion of the wellbore; when the height of the set section is reached, the upper is expanded according to the shaft tunneling size; and slag is discharged after the upper is expanded.

Technical Field

The invention relates to the technical field of shaft construction, in particular to a shaft reinforcing method.

Background

With the protection policy of the farmland in China, the land acquisition range and the proposed project range are strictly limited and managed in various places, which often causes the arrangement of the project system to be restricted. The simpler and more favourable the geological conditions are in terms of the shaft, which is however sometimes constrained by the above-mentioned factors, and is forced to address on very unstable sites such as waste rock heaps, backfill and the like. When a shaft is dug in the stratum, the stability of the waste stone stacking layer is very poor, so that the side wall collapse is easy to occur during construction, and the poured shaft wall is 'trousers off'.

At present, when a shaft is dug in a loose stratum such as a waste rock accumulation layer, a backfill layer and the like, the most common treatment mode is to reinforce a waste rock pile by ground pre-grouting or work surface pre-grouting. The concrete mode of reinforcing the waste rock pile by adopting ground pre-grouting comprises the following steps: before a shaft is drilled, grouting holes are drilled around the shaft, and the depth of the grouting holes penetrates through a stacking layer and a strong weathering layer and is not less than 10 m; installing a grouting pipe and a grout stopping plug; and injecting the slurry into the cracks of the accumulation layer and the strong weathering layer through the grouting holes by using a grouting pump, and reinforcing the cracks and the strong weathering layer to ensure that the accumulation layer is stable and then the shaft is dug. The concrete mode of reinforcing the waste rock pile by adopting the working face pre-grouting comprises the following steps: when a shaft is tunneled, a concrete grout stopping pad is poured or a grout stopping rock pillar is reserved in the shaft; drilling a grouting hole, installing a grouting pipe, grouting to reinforce a stacking layer and seal water, and then cutting; and circulating in such a way until the unstable stratum is penetrated. The ground pre-grouting reinforcement has the defects that the deviation of a drilled hole is not easy to control, the phenomena of hole collapse and drill blocking are easy to occur during drilling, the implementation difficulty is high, the grouting diffusion range is difficult to control, and the slurry consumption is high; after ground pre-grouting, the shaft sinking needs full-section drilling and blasting to excavate the shaft, and the excavation cost is high. The common working surface pre-grouting reinforcement has the defects that hole collapse is easy to occur in punching, and holes cannot be formed. Therefore, no matter a ground pre-grouting reinforcement mode or a working surface pre-grouting reinforcement mode is adopted, the problem that holes are punched and easy to collapse exists, and the self-stability of the well wall of the excavated pile layer is poor.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a shaft reinforcing method to solve the problems of hole collapse and drill sticking during drilling.

In order to achieve the purpose, the invention adopts the following technical scheme:

the shaft reinforcing method comprises the following steps:

arranging a plurality of drilling positions in a shaft, drilling a set distance in each drilling position, and then continuously drilling by using a hollow self-advancing anchor rod until the hollow self-advancing anchor rod is exposed out of a set size, wherein grouting holes are distributed in the hollow self-advancing anchor rod;

connecting the hollow self-advancing anchor rod with a grouting hose pipeline, synchronously installing a pressure monitoring device, and injecting grout with a set grouting amount into the hollow self-advancing anchor rod through the grouting hose pipeline;

after the slurry injection is finished, performing tunneling and deslagging treatment on the shaft;

after deslagging, binding and supporting reinforcing steel bars;

and after the steel bars are bound, pouring concrete.

Preferably, the plurality of drilling locations are evenly distributed along the circumferential direction of the borehole wall.

Preferably, the hollow self-advancing type anchor rods drilled in the plurality of drill holes are uniformly distributed in an umbrella shape, and the included angle between the drilling direction and the horizontal direction is 60 degrees.

Preferably, the drilling positions are distributed along the longitudinal direction at intervals of set section heights, and a circulation of shaft reinforcing construction is performed on each shaft part with the set section heights.

Preferably, the grout injected into the hollow self-advancing anchor rod is cement-water glass double-liquid grout, wherein the weight ratio of the cement grout to the water glass is 1: 0.6 to 1.

Preferably, when the shaft is driven to the set section height, an anchor rod hanging net sheet is driven into the shaft surrounding rock to support the anchor net.

Preferably, the step of performing a driving slag tapping process on the shaft comprises: excavating a clear path portion of the wellbore; when the height of the set section is reached, the upper is expanded according to the shaft tunneling size; and slag is discharged after the upper is expanded.

Compared with the prior art, the invention has the following advantages and beneficial effects:

when a shaft is dug in loose stratum such as a waste rock accumulation layer, a backfill soil layer and the like, the shaft is reinforced by combining anchoring support reinforcement and grouting reinforcement. By adopting the hollow self-advancing grouting anchor rod for drilling, the installation, the grouting and the anchoring are integrated, the drilling and hole collapse and drill clamping are avoided, and the anchor rod can be used as a permanent support part; the surrounding rock is reinforced by grouting through the opening on the hollow self-advancing anchor rod, the grouting range can be well controlled according to needs, the exposed wall of the accumulation layer is stable and does not collapse, and safety guarantee is provided for the construction operation of the vertical shaft. Compared with high-pressure grouting of earth surface and working surface pre-grouting, the grouting cost can be saved.

Drawings

Fig. 1 is a schematic flow chart of a shaft reinforcing method according to the present invention;

fig. 2 is a front view of the reinforced shaft structure of the present invention;

fig. 3 is a schematic top view of the reinforced shaft structure of the present invention.

Detailed Description

The embodiments of the present invention will be described below with reference to the accompanying drawings. Those of ordinary skill in the art will recognize that the described embodiments can be modified in various different ways, or combinations thereof, without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims. Furthermore, in the present description, the drawings are not to scale and like reference numerals refer to like parts.

Because surrounding rock stability in loose bodies such as waste rock accumulation layers, backfill soil layers and the like is poor, the reinforcement construction of the vertical shaft adopts a short-digging and short-building section-by-section construction mode, the vertical shaft is longitudinally divided into a plurality of parts according to the set section height, and the circulation of the reinforcement construction of the vertical shaft is carried out once on the part of the vertical shaft with each set section height. The set section height is determined according to the actual condition of the shaft, for example, the set section height can be set to be 1.7m, and if the rib caving is serious, the set section height of the circulation can be reduced. The invention will be described below by way of example in the case of shaft reinforcing construction for a shaft section of a set height.

Fig. 1 is a schematic flow chart of a shaft reinforcing method according to the present invention, and as shown in fig. 1, the shaft reinforcing method according to the present invention includes:

step S1, carrying out anchoring support construction by using the hollow self-advancing type anchor rod 2, specifically, arranging a plurality of drilling positions on the wall surface of a shaft, drilling a set distance at each drilling position, and then continuing drilling by using the hollow self-advancing type anchor rod 2 until the hollow self-advancing type anchor rod 2 is exposed out of the set size, wherein grouting holes are distributed on the hollow self-advancing type anchor rod 2, the size of the anchor rod is phi 32 x 7 x 3000mm, and the diameter of the grouting holes is 5 mm; the positions of the plurality of drill holes are uniformly distributed along the circumferential direction of the well wall 1, the horizontal distance is set to be 1.0m, the horizontal distance can be adjusted according to the actual surrounding rock condition, and if the rib caving is serious, the horizontal distance can be properly reduced. Referring to fig. 2 and 3, the drilling direction and the horizontal direction form an included angle of 60 degrees, and the hollow self-advancing type anchor rods 2 drilled in a plurality of drill holes located on the same circumference are uniformly distributed in an umbrella shape. For an integral shaft, drilling positions are distributed along the longitudinal interval set section height, so that shaft reinforcing construction is respectively carried out on the shaft with each set section height. The set distance is determined according to the bolt length, for example, when a bolt 3m long is used, the set distance may be set to 1.5 m. During construction, a 1.5m drill rod is used for drilling, then the drill rod is taken out, and then a 3m long hollow self-advancing anchor rod is used for re-drilling until the anchor rod is exposed by 0.2 m. Further, after the anchor rod is drilled, accumulated water and rock powder in the anchor rod hole are cleaned up by compressed air; because the hollow self-advancing anchor rod 2 is made of steel pipes, after the hollow self-advancing anchor rod is drilled into the shaft surrounding rock 4, the hollow self-advancing anchor rod can be used as a part of a permanent support to be left in the surrounding rock 4, so that the effect of reinforcing the surrounding rock 4 is achieved, and the phenomenon of hole collapse or drill jamming during drilling can be avoided;

step S2, grouting reinforcement construction, specifically, after drilling the hollow self-advancing grouting anchor rod 2, detaching the drilling machine, sleeving a sealing gasket and screwing, connecting the hollow self-advancing anchor rod 2 with a grouting hose pipeline, for example, connecting the hollow self-advancing anchor rod 2 with the grouting hose pipeline through threads of the anchor rod, synchronously installing a pressure monitoring device, and injecting grout 3 with a set grouting amount into the hollow self-advancing anchor rod 2 through the grouting hose pipeline, wherein the pressure monitoring device comprises a high-pressure valve and a pressure gauge which are arranged on the grouting hose pipeline so as to monitor grouting pressure;

step S3, after the grout 3 is injected, performing tunneling and deslagging treatment on the shaft;

step S4, after slag is discharged, binding and supporting steel bars;

and step S5, after the steel bars are bound, pouring concrete, and thus completing the reinforcing construction of a section of shaft.

According to the invention, the loose bodies are grouted through the hollow self-advancing grouting anchor rod, surrounding rocks around the shaft are reinforced, and the anchor rod also has the function of reinforcing the surrounding rocks, so that the well wall is ensured to be stable and not to collapse; in addition, because the strength of the wall rock after grouting is improved, the reinforced loose body can bear the weight of the well wall together with the hollow anchor rod, and the phenomenon of 'trousers falling' from the well wall is favorably prevented.

In the actual construction process, a 2TGZ-120/10.5 type grouting pump can be arranged on the working face for grouting. In one embodiment, the grout 3 injected into the hollow self-advancing bolt 2 is a cement-water glass double grout. The grouting cement is PO42.5 cement, the cement consumption of each hollow self-advancing grouting anchor rod is 0.35t, the water cement ratio is 0.5:1, and the weight ratio of cement paste to water glass is 1: 0.6 to 1, and the amount of the water glass is 0.163 to 0.217 ton. The field grouting amount control is based on orifice slurry return or pressure rise.

In one embodiment, the step of performing a driving tapping process on the shaft comprises: excavating a clear path portion of the wellbore; when the height of the set section is reached (for example, 1.7m), the upper is expanded according to the tunneling size of the shaft; and slag is discharged after the upper is expanded. Wherein, during concrete construction, tunnelling and slagging tap can adopt tools such as artifical shovel to carry out in coordination with the grab loader. For the whole shaft, the shaft is expanded by brushing the shaft section by section, so that the diameter of the shaft reaches the diameter size designed in advance.

In order to prevent the falling of surrounding rocks during concrete pouring from affecting the concrete quality of a well wall, when a shaft is driven to a set section height (for example, 1.7m), an anchor rod hanging net piece is driven into the surrounding rocks of the shaft, and anchor net supporting is carried out to further reinforce the surrounding rocks.

The invention has good use effect in the mine construction of certain iron ores. The upper part of the mine is a mining rock discharge backfill layer, the thickness of the backfill layer is 96m, and backfill mainly comprises mining waste rocks. The backfill with the particle size of 0-80 m is mainly mining waste rocks, the particle size is different, the larger is more than 500mm, and the smaller is 0.50 mm. By adopting the shaft reinforcing method to reinforce the mine construction, the mine smoothly passes through a backfill layer of 96m, and the stability of wall surrounding rock of the well wall is guaranteed.

The shaft reinforcing method is easy to operate and implement, has low cost, and can be widely applied to shaft sinking in similar loose stratum such as waste rock accumulation layer, backfill soil layer and the like.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.