SU1629549A1 - Method of local expansion of shafts and large-diameter holes - Google Patents

Abstract

The invention relates to the drilling of mine shafts and can be used to expand mine workings. The goal is to increase the efficiency of expansion by eliminating the curvature of the trunk. For this, the main 1 and pilot 2 workings are drilled and the reamer 5 is lowered from the guide 6, the width of which is greater than the radius of the main production. At the top of the pilot making 2

Description

The invention relates to the drilling of mine shafts and can be used for local expansion of mine workings, including with the formation of a cross section of complex shape (with an annular gap on the bottom-).

The purpose of the invention is to increase the efficiency of expansion by eliminating the curvature of the trunk.

The essence of the method of local expansion of large-diameter shafts and wells is that coaxial main and pilot workings are drilled, and the expander is inserted with the guide, the width of which is made larger than the main work radius, through the main work. In the upper part of the pilot making create a hollow support element 35 with a cylindrical inner surface; the expander guide is made with a bevel at the lower end, and the expander radius Ry is made in co. According to the ratio ЈR + 2Rn, rfle R0 is the radius of the main output, m; Rn -1 is the radius of the internal pilot development of the support element, m, while the length of the guide is not less than the height of the expander section, and the support element is made of a material whose strength exceeds that of the expansion section.

50

FIG. 1 shows the extender. for carrying out the method after completion of the drilling process, a general view; in fig. 2 - the same, but when using the L-shaped console. 55

The method is carried out as follows.

Bur t primary 1 and pilot 2 generation. In the upper part of the pilot making 2 create the support element 3.

The support element 3 may be made of a metal or concrete pipe, the strength of which is greater than the strength of the rocks of the expansion section. Then, the expander 5 is lowered on the drill string 4. The latter has a width not greater than the diameter of the main development (2R0), must not exceed the expansion radius by an amount not less than the fracture step t and is made with guide 6 with bevel 7. Expander 5 is lowered so that bevel 7 of guide 6 has hit the upper inner edge 8 of the support member 3,

The expander may have a G shaped console 9 (FIG. 2), having porous destructive elements 10.

In order to provide the necessary radial pressing force, the bevel 7 of the guideway is carried out in the range of 35-45 °.

When the drill string 4 rotates, the bevel 7 of the guide 6 under the action of the axial force on the expander slides along the edge of the support element 3, ensuring the penetration of the rock-breaking elements 10 into the lateral surface of the main production by the magnitude of the fracture step t где, where tpЈ2Rn.

The radial feed of the expander takes place under the action of the component force from the action of the bevel of the guide against the edge of the support element in a projection on a plane perpendicular to the longitudinal axis of the main production.

As the walls of the excavation collapse, the bevel 7 of the guide 6 slides lower, and after the full exit

In support element 3, the device is stabilized and performs expansion of the output by a diameter (2R ..), which is not more than the size of the internal diameter (2Rfl) of the support element greater than the diameter of the main output.

The established expansion process corresponds to the position of the expander, in which the axis of the expander and the pilot output coincide. In this case, the guide 6 of the expander rotates in the hollow support member 3, as in a bearing.

The length of the guideway is made not less than the height of the expansion section in order to ensure the expansion of the main development to the full height.

The largest step of destruction t is related to the radius of the main step by the ratio t 2/3 R0, where

Radius of the main production.

Claims (2)

1. A method for local expansion of large-diameter shafts and wells, including drilling coaxial main and pilot workings and entering through five the production of an eccentric mounted spreader with a guide, the radial size of which is larger than the radius of the main production, characterized in that, in order to increase the expansion efficiency by eliminating the curvature of the trunk, in the upper part of the pilot production a hollow support element with a cylindrical inner surface of material is created, the strength of which exceeds the strength of the rocks of the expansion area, and the expander guide, which has a bevel at the lower end, is placed in the support element, having a bevel opposite positively to the expander, the radius of the expander C is taken in accordance with the ratio 20 25 2R0 RUJЈR0 + 2R P where R- is the radius of the main output, m; Rn is the inner radius of the reference element, m 2. A method according to claim 2, in which the length of the guideway is not less than the height of the expansion section. FIG. 2