SU1559187A1 - Method of controlling the state of rock mass - Google Patents

Abstract

The invention relates to mining and can be used when conducting workings on strong fractured rocks, poorly cemented by minerals of secondary filling. The goal is to increase the hardening efficiency of the rocks of a highly fractured massif with the presence of minerals for the secondary filling of cracks. To do this, drill advance injection and drainage wells for the length of the bottom hole. A chemically active rock loosening solution is pumped into the injection wells and the reaction rate of the mineral fracture mineral decomposition is monitored through drainage wells. After leaching of the mineral filler, a chemical fixer is pumped into injection wells, and a chemically active solution, the pressure of which is less than the fixer pressure, is pumped into drainage wells. The method allows to organically combine the method of hardening the marginal zone around the excavation, which increases its stability, and the method of weakening the massif, which is beaten during the penetration. 3 il.

Description

The invention relates to mining, mainly to the mining industry and tunneling, and can be used when carrying out workings on strong highly fractured rocks, poorly cemented by minerals of the secondary filling.

The purpose of the invention is to increase the hardening efficiency of a highly fractured massif with the presence of secondary crack filling minerals.

FIG. 1 schematically shows the location of wells in the cross-section of production relative to its

design contour and reinforcement zones; in fig. 2 — development with injection and drainage wells, longitudinal section, and movement pattern of the chemically active solution for treatment of the bottomhole array and reinforcement zone; in fig. 3 — development in the bottomhole zone, longitudinal section, with a circuit for forcing the fastener into the reinforcement zone and the chemically active solution into the drainage wells.

The method is carried out as follows.

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When carrying out production, in a highly fractured mass of rocks with the presence of minerals of secondary filling of fractures from the bottom near the design contour of production 1, two rows of leading wells are drilled. The outer row of injection wells 2 is drilled obliquely from the design contour of the mine to the boundary of the zone 3 reinforcement of the rocks, the inner row of drainage wells 4 is horizontal to the length of the bottom hole.

Through the injection wells 2, a chemically active attenuating solution is pre-pumped into the array with the help of injectors, which, after washing the cracks, reacts with the mineral-aggregate and washes away its decomposition products through the drainage wells 4.

Control over the process of decomposition of the mineral aggregate of cracks is carried out by the number of decomposition products eluted from drainage wells, which is determined by the fracture volume of the mineral aggregate of the worked-out section of rocks according to the well-known formula

 SsiifcKJL -jib JL (1)

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where n is the effective fracture porosity of the rock mass,%; - the length of the drainage wells

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Siu cross-sectional area of the hardening zone, m2. After treating the cracks with a chemically active loosening solution to the depth of the hardening zone, the chemical keeper is fed to the injection wells, the chemical wells are fed to the wells, and the chemically active weakening solution is fed to the wells 4.

A weakening solution for the purpose of qualitative filling of cracks in a fastener in zone 3 of rock reinforcement and the ability to control its spread strictly within the zone of reinforcement is supplied under pressure less than the pressure of the fastener, since at an equal or inverse ratio of pressures there is a possibility that the weakening solution will prevent the filling of cracks in the reinforcement zone.

The ratio of the pressure of the injection of the weakening solution and the fixative is taken from the following relationship:

Р0 .РК y - 0.1, MPa, (2)

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de P and R .. - respectively pressure

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injecting a chemically active rock loosening solution and a keeper;

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a weakening solution and a fixer.

After the cracks are fully saturated with the fixer in the hardening zone, the overpressure of the fixture is transferred to the attenuating solution supplied through the drainage wells, which causes an increase in pressure in the injection system to the drainage wells. This means that the cracks in the reinforcement zone are completely filled by the fixer and its flow can be stopped.

Using the proposed method makes it possible to strengthen the marginal array of excavation by replacing a weak natural aggregate of cracks with a stronger artificial one and at the same time weakening the array within the design contour of excavation due to the weakening of bonds along fractures of rocks, thus facilitating its excavation.

Example. The development intersects a powerful zone of fractured tectonic fracture-type rock, represented by fragmented rock, with the development of carbonate group aggregate minerals in cracks in the form of veinlets and calcite adhesives along the faces of rock blocks with sliding mirrors. The collapse of rocks occurs immediately after the advancement of the development.

In this case, a 3–5% ammonium chloride solution is initially injected into the massif through the wells 2, which reacts with the crack filler, resulting in the decomposition of the carbonate aggregate with the release of CO gases. and NH and calcium chloride leached from the cracks during the subsequent flow of ammonium chloride into the wells.

A concentration of 3-5% is based on the stoichiometric ratio required by the reaction of the reaction of ammonium chloride with carbonates. In addition, a solution of ammonium chloride has such a concentration

penetrating power close to water. The concentration of ammonium chloride in the solution below 3% is impractical, since in this case the amount of reagent required by the reaction is insufficient and, therefore, the decomposition of carbonates is not complete. An increase in the concentration of ammonium chloride above 5% leads to an increase in the viscosity of the solution, and consequently, to a decrease in its penetrating ability.

Washout of decomposition products occurs through drainage wells 4, which are also used for chemical control over the intensity of the process of decomposition of the crack filler.

After treatment of the array with ammonium chloride, a solution of a chemical fixer is injected into the wells 2, for example, ED-5 epoxy resin with UP-583 hardener, and in well 4 an ammonium chloride solution of the same concentration with a pressure less than the injection pressure of the fixer is supplied. With a pumping pressure of 2 MPa, with a viscosity of 20 cP and a viscosity of ammonium chloride of 10 cP, the pressure of injection of ammonium chloride into drainage wells according to formula (2) is 0.9 MPa.

The quality control of the reinforcement zone by the hardening rocks around the excavation is monitored by changing the injection pressure of ammonium chloride in wells 4. When the fractures in the reinforcement zone are high-quality, an increase in pressure in the ammonium chloride injection system is observed in the drainage wells.

The use of the proposed method of controlling the state of the rock mass allows organically combining the method of strengthening the marginal

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the zone around the excavation, which increases its stability, and the method of weakening the array, which is fought off during penetration, which increases the efficiency of mining operations by reducing labor costs and explosives consumption.

The proposed method, in comparison with the known, allows to increase the efficiency of reinforcement of the rocks around the workings, on the fractures of which weakening minerals are developed, besides, the presence of drainage wells makes it possible to control the intensity of the mineral decomposition process and the quality of fracture filling in the reinforcement zone, and the number of agents entered into the array during processing is also reduced.

Claims (1)

Invention Formula The method of controlling the state of the rock mass, including the drilling of injection wells and sequential injection into them to the boundaries of the hardening zone of a chemically active rock loosening solution and chemical binder, is that drain holes are additionally drilled for the length of the hole, and a weakening solution is pre-pumped into the injection wells; control of drainage wells intensity-decomposition reaction of the mineral aggregate and making cracks m download binders after the last elution attenuated yuschim solution and then further attenuated developing solution is pumped into the drain well under pressure less than the pressure of the binders. X x v v x hch v X.) Ј. Lhhlh; X e AX1.TL. :. H x Lou:: .. . l -. - - wx X wx l / xxx x x xx.xx Phie.1 X Ј. :. H x Lou:: .. . l -. - - wx x x xx , / U one/ , J-A k V V - N /.-: HS: D. v ". . s / - C- / .- / -. X x /  x Sh r-xi L V.  ) L Y  y x te2 X x /  x x x xi l v. 2 X x x x x x Fi8.3