EA015319B1 - Method for driving a vertical main shaft - Google Patents

Abstract

The invention relates to shaft and underground structures, in particular, to methods for construction of deep vertical main shafts in complex hydrogeological condition. The invention is aimed at lesser cost, shortening of a shaft digging in a complex hydrogeological conditions, as well as at higher safety in operation thereof in seismically-active regions. The method comprises destruction and excavation of rock to a cut value, shaft lining with a preassembly of formwork and reinforcement installation on the earth surface, hauling down and mounting formwork concrete mixture delivery into behind the formwork space, curing the concrete mixture and tear-off the workframe from concrete and its advancing to a next cut. The inventive method differs from prior art methods is characterized in that in case of water-bearing stratum being close to the ground surface and dangerous by their inflows, prior to digging a vertical shaft a calculated numbers of boreholes are drilled from the ground surface to a confining layer in one or several rows over the perimeter of the main shaft, then grouting mortar, e.g. cement mortar is injected into boreholes and radially directed jets fill porous space of the water-bearing stratum in the vicinity of boreholes zones the grouting mortar is injected from the bottom to the mouth of each borehole, providing forming a common impervious barrier, then the main shaft is dug further inside the impervious barrier and its lining to the cut depth in case digging process encounters water-bearing stratums, digging is stopped, the impervious barrier is constructed in the similar way, wherein grouting mortar boreholes are drilled from the shaft bottom, then continue shaft digging until the designed depth of the main shaft is reached.

Description

The invention relates to mine and underground construction, in particular to methods for constructing vertical shaft shafts and can be used when driving shaft shafts of great depth in difficult hydrogeological conditions.

A known method in which the construction of vertical shaft shafts includes the destruction and cleaning of the rock by the size of the entry, the installation of mobile formwork, the supply of concrete mix into the formwork space, the exposure of the concrete mixture to its hardening, separation of the formwork from concrete and its movement to the next entry [1].

The disadvantage of the analogue is the complexity of its implementation in difficult hydrogeological conditions, the high cost and duration of execution.

The closest in technical essence to the claimed invention is a method of building a shaft shaft, which includes the construction of a waterproof pillar in the form of an artificial frozen rock mass by drilling wells, installing pipes of the freezing circuit in them, passing through the pipes of the refrigerant from the cooling circuit and forming Thus, an ice-bearing pillar [2] is a prototype.

The disadvantages of this method are significant capital costs in the formation of an ice-bearing pillar over the entire depth of a deep shaft shaft and the long implementation time of this method.

The objective of the invention is to reduce costs, reduce the time of sinking, carried out in difficult hydrogeological conditions, as well as increase safety during the operation of shafts in seismically dangerous regions.

The solution to this problem is achieved by the fact that in the method of sinking a vertical shaft shaft, including breaking and excavating the rock by the size of the hole, securing the shaft shaft with assembly operations on the surface of the formwork and installation of reinforcement, lowering and installing the formwork, supplying concrete to the deck space, exposure concrete mixture before it hardens, as well as tearing off the formwork from concrete and moving it to the next in the presence of dangerous aquifers aquifers close to the earth’s surface, before When the vertical shaft shaft is drilled from the surface of the earth to the confining hole, the estimated number of wells is drilled in one or several rows along the perimeter of the shaft, then cement slurry, for example cement, is pumped through the wells under high pressure, and the pore space of the aquifer is filled with cement slurry in the near-wellbore zone, while the cement slurry is supplied sequentially from the bottom to the mouth of each well, ensuring that the compaction of the near-wellbore zones and their closure, the formation of a single anti-filtration curtain, then by excavating the rock, the shaft shaft is drilled inside the anti-filtration curtain and along the water stop, as well as its fastening to the depth of penetration, when tunneling encounters underlying aquifers dangerous for water inflows, the penetration is stopped, it is similar in them create an airtight curtain, and drilling of cement wells is carried out from the bottom of the shaft at an angle to its axis, then They dig the trunk by excavating the rock; tunneling work is carried out in this way until the shaft reaches the design depth.

After performing the operations of fastening the vertical shaft shaft with concrete roof support, if necessary, to strengthen the waterproofing of the vertical shaft shaft, a waterproofing layer of a special composition, for example, modified with polymers, is applied to the inner surface of the concrete roof support. The layer is applied by spraying.

In FIG. 1 and 2 presents a diagram of the sinking of a vertical shaft shaft according to the proposed method.

The passage of the shaft by the proposed method is as follows.

If an aquifer 1 is discovered by exploration near the earth's surface 2 before the vertical shaft 3 is drilled, an anti-filter curtain 4 is formed outside the project contour 5 of the vertical shaft 3 to the stop 6. For this purpose, the estimated number of vertical wells 7 is drilled from the surface of the earth 1 into one or more rows along the perimeter of the shaft 3. Through the wells 7 through the descent monitor 8 into the pore space of the aquifer 1 under high pressure give cement slurry and using radially directed jets 9 plug the near-wellbore space. The plugging process of the near- and downhole spaces is carried out sequentially from the bottom of the wells 10 to their wellhead 11, ensuring the formation of an anti-filtration curtain 4 during closure of the plugged areas. Then rock 12 is destroyed and excavated, the shaft 13 is fastened 13 and assembly is performed on the surface formwork and installation of reinforcement, descent and installation of formwork, supply of concrete mixture to the formwork space, holding the concrete mixture until it hardens, separation of the formwork from concrete and its moving to the next run (not shown in the drawings). In this case, the destruction and excavation of the rock 12, as well as the fastening 13 of the vertical shaft shaft 3, is carried out to the maximum, under the condition of the absence of dangerous water inflows, depth. When meeting with the tunneling of the underlying hazardous aquifer 14

- 1 015319 create a waterproofing grouting curtain 15 by treating the enclosing rocks with the plugging composition along the outer contour of the shaft 3. Grouting is carried out through wells drilled from the bottom 16 of the shaft 3 at an angle to its axis using directed jets 17 under high pressure. Then again carry out the destruction, excavation of the rock 12 and the fastening 13 of the vertical shaft shaft 3 to the maximum, under the condition of the absence of dangerous water inflows, depth. All tunneling work is carried out in a similar way until the vertical shaft shaft 3 reaches design mark 18.

As one of the options for fastening a vertical shaft shaft during sinking in difficult hydrogeological conditions, in this method, the construction of a fastening 13 of metal elements mounted on the surface can be used. At the same time, the fastening ring mounted from metal elements (not shown in the drawings) is lowered into the prepared workings of the vertical shaft shaft 3, centered, fixed in the workings and then the fastening zone is cemented through holes in the metal elements.

After the operations of fastening the vertical shaft shaft with concrete support, if necessary, enhance the waterproofing properties of the concrete fastening 13 of the vertical shaft shaft 3, a waterproofing composition is applied to the inner surface of the concrete roof support. The waterproofing composition is applied, as a rule, by spraying.

Thus, the present invention allows the sinking of the shaft in difficult hydrogeological conditions, reduce the time of sinking due to the exclusion of the preparatory period associated, for example, with the formation of ice-bearing pillar, reduce capital costs by reducing the time of sinking and the cost of the preparatory period. In addition, the method allows to increase the safety of the operation of the trunk in seismically dangerous conditions, since during tectonic movements the main impact will be taken not by the barrel attachment, but by the zone of strong, primed soils or rocks.

An example implementation of the method.

Drilling control wells at the industrial site of a mining and processing plant for the production of potash fertilizers on the basis of the Garlyk potash field in Turkmenistan showed that the geological structure of the area where the project provides for shaft shafting is quite hydrogeological: up to about 60 m aquifers are gravelly - pebble deposits with interbedding of small clay interlayers, then up to 85 m there is a water stop - dense loam, further saturated up to 88 m Fat graviynogalechnyh first layer, after which - the impermeable clay, marl and salt deposits. Given the geological structure of this section of the field, the project decided to go through the trunks with a special method. In order to reduce the terms of sinking and its cost (in comparison with the method using freezing), to increase the safety of operation of mine shafts, sinking of the shafts is as follows.

Before starting sinking from the ground to the first water stop (up to 69 m), wells are drilled in three rows along the perimeter of the mine shaft, then cement slurry is injected under high pressure through the wells using monitors and the pore space of gravel and pebble deposits is filled with cement slurry with radial directional jets in the near-wellbore zone. The filing of the grouting solution is carried out sequentially from the bottom to the mouth of each well, providing a single anti-filter curtain during plugging of the near-wellbore zones and their closure. After that, the shaft shaft is drilled inside the curtain and water-locked to a depth of 83.5 m by excavation and its fastening to the depth of penetration. From a depth of 83.5 m to a depth of 88.0 m, a new air curtain is likewise formed, but at the same time, wells are drilled from the bottom of the shaft. From a depth of 88.0 m to the design depth (~ 400 m), sinking is carried out in a similar manner.

The shaft shaft is mounted using assembly operations on the surface of the formwork and installation of reinforcing bars, lowering and installing the formwork, supplying concrete mixture to the formwork space, holding the concrete mixture until it hardens, as well as breaking the formwork from concrete and moving it to the next run. In order to enhance the waterproofing properties of concrete lining, a waterproofing composition is applied to its inner surface. The composition is applied by spraying.

When implementing the proposed method for sinking mine shafts in difficult hydrogeological conditions at the Garlykskoye potassium salt deposit, the sinking time and its cost are reduced in comparison with other special methods. In addition, the safety of operations during the operation of mine shafts in a seismically dangerous region is increased, since during tectonic movements the main blow will be taken not by the shaft mounts, but by an anti-filter curtain, which is a powerful layer of cemented rocks.

Information sources

1. Patent VI No. 2055207, IPC Е21В 5/04, publ. 1996.02.27.

2. Patent KN No. 2151292, IPC E21C 41/16, publ. 06/06/20 - a prototype.

- 2 015319

Claims (2)

CLAIM 1. The method of penetration of the vertical shaft, including the destruction and excavation of rock for the amount of stopping, mounting the shaft with the execution of assembly operations on the surface of the formwork and installation of reinforcement, descent and installation of the formwork, supplying the concrete mix to the firing space, holding the concrete mix to its hardening , as well as the separation of the formwork from concrete and its movement to the next entry, characterized in that in the presence of aquifers that are dangerous in terms of water inflow, close to the surface of the earth, before the beginning of penetration vertical shaft from the surface of the earth to the aquitard drill the estimated number of wells in one or several rows along the mine shaft perimeter, then the wells are fed under high pressure cement slurry, such as cement, and radially directed jets fill the cement layer in the near-well zone with a grouting mortar , while the supply of cement slurry carried out sequentially from the bottom to the mouth of each well, providing in the process of plugging colossal well zones and their joining to form a single impervious curtain, then, by excavating the rock, the shaft is penetrated inside the impervious curtain and along the aquitard, and also fixed to the penetration depth, when they meet with tunneling works of the aquifers that are dangerous to the water inflow, the tunnel is stopped and similarly created an impervious curtain, and the drilling of cement wells is carried out from the bottom of the shaft shaft in a direction continued driving of the barrel by recesses rock tunneling work are thus to achieve shafts design depth. 2. The method according to claim 1, characterized in that after performing the operations of fastening the shaft shaft, spray coating of the waterproofing composition is carried out on the inner surface of the concrete lining.