RU2748790C1 - Method for ensuring pliability of support of vertical trunk located in salt rocks - Google Patents

Abstract

FIELD: mining industry.SUBSTANCE: invention relates to the mining industry, it can be used when attaching vertical trunks in salt rocks. The method includes the erection of an external pliable support layer and a safety valve, which is adjusted to the pressure not exceeding load-bearing capacity of the support. Cast iron tubing support is constructed using tubings with safety valve. Saline solution, which does not allow dissolving salt array walls and prevents the development of rheological processes of the array, is used as a pliable layer. The displacement of the salt array leads to an increase in pressure on incompressible salt brine, which in turn transfers pressure to the valve mechanism. When the specified pressure is reached, the salt brine is dumped into the trunk section. Then, the pressure drops from the salt brine side, the valve mechanism and a channel for brine dumping are closed. The intensity of the voltage increase in rigid cast iron tubing support attenuates.EFFECT: reducing labor intensity when attaching vertical trunk due to the ease of creation of pliable support layer, providing stability of trunk tubing support.1 cl, 5 dwg

Description

The invention relates to the mining industry and can be used for fastening vertical shafts in salt rocks.

The shaft support is known (Paweł Kamiński, Piotr Czaja New structure of shafts constructed in rock mass with significantly strong rheological properties, article [Electronic resource] - access mode: https://www.researchgate.net/publication/321295865_New_structure_of_shafts_constructed_internal_withrock_massigns. (date of circulation 05.10.2020)), providing for a compensatory shell consisting of a porous material through which a solution is passed that dissolves deformed rocks.

The disadvantage of this method is the complexity of creating the structure of the structure due to the implementation of the solution supply mechanism and the introduction of monitoring systems for deformations of the salt mass, which is difficult to implement in a production environment.

There is a known method of fastening a mine shaft (Zaslavsky Yu.Z. Fastening of underground structures / Yu.Z. Zaslavsky, V.M. Mostkov - M., Nedra, 1979. - S. 138-146, Fig. 45), providing for the primary fastening of the shaft anchors and the subsequent creation of a flexible foam layer and a layer of concrete.

The disadvantage of this method is the creation of a flexible layer of foam by spraying or pouring it into the formwork, which leads to an increase in the time and money spent in the construction of the support and requires the use of additional equipment to recreate the flexible layer.

Known shaft support (copyright certificate No. 1747704, publ. 15.07.1992), providing a compensation shell with separated stiffening ribs by vertical channels filled with flexible foam material.

The disadvantage of this method is the complexity of creating vertical channels in the body of the lining, as well as preventing the destruction of the channels under the influence of rock pressure, which can lead to a decrease in the pliability of the lining.

A known method of protecting the joints of mine shafts with workings from rock pressure (USSR author's certificate No. 1368438, publ. 23.01.1988), taken as a prototype. The method includes the installation of flexible liquid cylinders equipped with safety valves with adjustable pressure parameters not exceeding the bearing capacity of the support.

The disadvantage of this method is the complexity of creating a compliant layer of support, consisting of anchors, mesh and cylinders equipped with a safety valve. As well as maintaining the working condition of the bladders throughout the entire service life.

The technical result is to reduce the complexity of the vertical shaft fastening due to the ease of creating a pliable lining layer.

The technical result is achieved by the fact that a cast-iron tubing support is constructed using tubing with a safety valve, a saline solution is used as a compliant layer, which does not allow the walls of the salt massif to dissolve and prevents the development of rheological processes of the massif, the displacement of the salt massif leads to an increase in pressure on the incompressible salt brine , which in turn transfers pressure to the valve mechanism, when the specified pressure is reached, the salt brine is dumped inside the section of the barrel, then the pressure drops from the side of the salt brine, the valve mechanism and the channel for brine discharge are closed, while the intensity of the voltage growth in the rigid cast iron tubing support.

The method is illustrated by the following figures:

fig. 1 is a diagram of a tubing with a safety valve;

fig. 2 is a diagram of a tubing with a squeezed out safety valve during deformation of the salt mass;

fig. 3 is a diagram of the principle of operation of the safety valve;

fig. 4 is a diagram of the construction of a sealed bulkhead made of a compliant material;

fig. 5 - layout diagram of cast-iron tubing lining rings, where:

1 - salt massif;

2 - salt brine;

3 - tubing with a safety valve;

4 - deformed salt mass;

5 - valve mechanism;

6 - channel for the discharge of brine;

7 - anchor;

8 - sealed jumper;

9 - cast iron tubing without a safety valve.

The method is carried out as follows. After sinking the shaft in the salt mass 1 (Fig. 1) by the amount of entry of at least 10 m. On the working soil, a sealed bulkhead 8 (Fig. 4) of a pliable material is erected, fixed with anchors 7 in the salt mass 1, and the column is erected from a cast-iron tubing lining (Fig. 5), after the installation of the first assembly ring of the tubing lining, the gap between the bulkhead and the ring is sealed. After sealing the bulkhead, the erection of the tubing column of the lining is continued by the amount of entry. The tubing column of the support for the size of the entry consists of ten rings, nine of which are without a safety valve 9, and one ring is assembled using cast iron tubing with safety valves 3. The ring with tubing with a safety valve 3 (Fig. 1) are installed ninth with a report from the soil ... A ring of cast-iron tubing lining, with tubing with a safety valve 3, is a prefabricated structure consisting of tubing without a valve mechanism and two diametrically opposed tubing with a safety valve 3 (Fig. 3), one of which is the main one, and the second is a safety one. The safety valve consists of a valve mechanism 5 and a channel for dumping brine 6. After creating a tubing column by the amount of entry, the anchorage space is filled with brine 2 (Fig. 1). When implementing deformations of the salt massif 4 (Fig. 2) brine 2 presses on the valve mechanism 5, located in a tubing with a safety valve 3. After the valve mechanism 5 is pressed by the action of the brine 2, the channel is opened to discharge the brine 6 into the barrel. After the pressure drop from the side of the brine 2, the valve mechanism 5 closes, closing the channel for the discharge of the brine 6. Thus, the lining compliance is ensured, until the supply of the brine 2 in the anchorage space of the tubing lining of the trunk is completely exhausted. Due to the discharge of the brine 2 through the safety valve, the intensity of the stress growth in the rigid cast-iron tubing lining is attenuated.

The method is illustrated by the following example. When conducting vertical shafts in the Krasny II sylvinite formation at the Ust-Yayvinsky mine of the Verkhnekamskoe potash salt deposit, the option of mounting a vertical shaft at a depth of 400-500 m with a diameter of 7 m is accepted. The pressure from the rock contour on the rigid support of the shaft is 5.2 MPa. The convergence of the borehole contour without fastening is 136 mm over 30 years. This method allows to ensure the stability of the rigid tubing lining of the trunk, made of cast iron SCh25 for the period of operation due to the safety valve calculated based on the expected flow rate of brine per day, based on the obtained value, the optimal rate of brine discharge is determined with a valve opening diameter of 1 cm.

Cross-sectional area of the trunk:

where r is the radius of the trunk in black, m.

The area of the transverse wellbore after the implementation of deformations:

– величина конвергенции, м.Where

- the value of convergence, m

The volume of the displaced brine for the entire period of operation:

where l is the amount of entry, m.

Determination of the consumption of salt brine per month:

where t is the barrel operation time, years.

Based on the daily flow rate, the rate of discharge of the brine solution is determined:

, при диаметре клапана 1 см.where n is the number of valves, structurally 2 valves;

, with a valve diameter of 1 cm.

The resulting discharge rate shows the operability of the valve mechanism and ensures the selection of the rock mass, due to the fact that the salt brine is incompressible, the load will be evenly distributed over the valves located in one section, and will allow the uniform discharge of the brine into the bore until it is completely depleted.

The use of the proposed method in comparison with known analogs has a number of advantages such as significantly reduces the time and money spent on the construction of the combined support, and also due to the incompressibility of the brine creates a resistance to the salt mass, which inhibits the development of the rheological properties of the mass.

Claims (1)

A method of ensuring the compliance of the support of a vertical shaft located in salt rocks, including the construction of an external compliant layer of support and a safety valve, which is adjusted to a pressure not exceeding the bearing capacity of the support, characterized in that a cast-iron tubing support is constructed using tubing with a safety valve, as a compliant layer, a saline solution is used, which does not allow the walls of the salt massif to dissolve and prevents the development of rheological processes of the massif, the displacement of the salt massif leads to an increase in pressure on the incompressible salt brine, which in turn transfers pressure to the valve mechanism, when a given pressure is reached, the salt brine is dumped inward section of the borehole, then there is a drop in pressure from the brine side, the valve mechanism and the channel for brine discharge are closed, while the intensity of stress growth in the rigid cast-iron tubing lining is attenuated.

Images