RU2014396C1 - Method for reducing adverse effect of underground workings on ground surface - Google Patents

Abstract

FIELD: civil engineering. SUBSTANCE: to cut down expenditures for filling in aggregate, holes are arranged as a network of rectangles spaced at a certain distance from one another. Smaller sides of rectangles are disposed along the direction of workings while filling of holes with aggregate shall progress along stoping work. EFFECT: higher efficiency. 2 dwg

Description

 The invention relates to the construction and can be used to protect buildings, structures and natural objects from the harmful effects of mine workings, voids of the rock mass, as well as when lifting the surface layer of the rock mass.

 A known method of protecting objects from the harmful effects of underground workings, which includes drilling wells from the surface at the base of buildings and structures and pumping aggregate through them. In the absence of water seal through the wells, upper and lower water locks are created, and then aggregate is pumped between the water locks in such a way that, with the expected deformations of one sign, deformations of the opposite sign appear in the base. This is achieved by the fact that with the expected compression and deflection of the base of the object, wells are located directly at the object, and with stretching and bending of the base of the object at a distance of 0.5 K from the object, where K is the radius of influence equal to 55-60 m.

 The disadvantage of this method is that it is intended for individual buildings and structures. Currently, the underworking of individual objects is a special case, and the general case is the underworking and protection of built-up territories or natural objects having a significant area (floodplains, forests flooded during underground mining).

, где

- ожидаемое оседание земной поверхности от первой очистной выработки. Перед проходкой второй очистной выработки поднимают земную поверхность также на величину (0,4-0,6)

, а зону совместного влияния на величину (0,4-0,6) (

+

).Closest to the proposed invention is a method of protecting objects from the harmful effects of underground workings, which consists in raising the surface layer of rocks before each mine workings. For this, the zones of each of the treatment workings are established, as well as the zones of joint influence of these treatment workings. Before driving the first treatment mine, the surface layer from the stopper is raised by a value of (0.4-0.6)

where

- the expected subsidence of the earth's surface from the first treatment plant. Before driving the second treatment mine, the earth's surface is also raised by an amount (0.4-0.6)

, and the zone of joint influence on the value (0.4-0.6) (

+

)

 The alternation of signs of deformations caused by raising rocks during pumping of aggregate and lowering during treatment workings favorably affects underworked objects in which efforts are not accumulated, but are periodically compensated.

 The disadvantage of this method is that significant costs are required for the construction of a continuous array of aggregate.

 The aim of the invention is to reduce the cost of the construction of an aggregate array.

 To achieve this goal, the expected deformations of the earth's surface from the planned mine workings are calculated, they are compared with the permissible ones, deformations are monitored during the construction of the aggregate array and, during the underworking, they are drilled to the selected water storages, the enclosing massifs (water storages) are erected, and they are pumped into the rock mass filler, while the wells have a network of rectangles with a short side along the direction of movement of the treatment workings.

The sequence of injection of aggregate into the wells is set in the same direction as the direction of the treatment workings, and the wells are located at a distance of 2K + DH _{n + 1} / H _n , where D is the span between the aggregate masses, at which permissible total deformations occur on the earth's surface; K is the radius of influence of one well, and H _n and H _{n + 1} are the depths of adjacent spans.

, где D - пролет между массивами заполнителя, при котором на земной поверхности возникают допустимые суммарные деформации;
K - радиус влияния скважин;
H_n, H_n+1 - глубины смежных пролетов.The novelty of the method lies in the fact that the wells are arranged in the form of a network of rectangles directed with the short side along the direction of the treatment workings, the order of injection of aggregate into the wells is set in the same direction with the direction of movement of the workings, and the wells are located at a distance
2K + D

where D is the span between the aggregate arrays at which permissible total deformations occur on the earth's surface;
K is the radius of influence of the wells;
H _n , H _{n + 1} - the depths of adjacent spans.

 In FIG. 1 - shows a plan of the lines of wells on the earth's surface in the zone of influence of mining; in FIG. 2 - a vertical section of the thickness of the rocks with an indication of the zone of influence of treatment and the mass of aggregates being built.

The following notation is used in the figures and in the text:
K is the radius of influence of the well; D is the span between the placeholder arrays; H ₁ , H ₂ , H ₃ , H ₄ , H ₅ , H ₆ - the depths of adjacent spans; I, II, III, IV, V, VI - well line numbers; 1, 2, 3, 4, 5, 6, 7, 8, 9 — wellhead numbers along one line; 10 - the boundary of the zone of influence of the mine; 11 - the position of the mine working in the rock mass; 12 - wellbores in the rock mass; 13 - placeholder array; 14 - waterproofing.

 PRI me R. Under the forest within contour 10, coal is mined by treatment mine 11. The depth of the formation is 307 m, the thickness of the formation is 2.7 m, and the length of the mine is 255 m.

In accordance with these conditions, according to the "Rules for the protection of structures and natural objects from the harmful effects of underground mining in coal deposits" (M .: Nedra, 1981), we calculate the maximum deformation of the earth's surface. They comprise the following values: - subsidence of 2.1 m; - slope 13.2˙10 ^-3 ; - horizontal strains 8.4 810 ^-3 ; - curvature 1.6 ˙ 10 ^-4 m.

 With such subsidence, the groundwater level is 30 cm above the earth's surface. This leads to waterlogging and destruction of the forest. According to forestry reconstructions, the groundwater level should not rise above 1.2 m from the earth's surface. In this case, the normal conditions for the existence of the forest are preserved. In this case, it is possible to lower the earth's surface only by 0.6 m, and 1.5 m must be raised to maintain the level at 1.2 m from the earth's surface.

In accordance with the specified "Protection Rules ..." the subsidence is found from the formula
η _m = q _o m ˙cosα ˙ N ₁ ˙ N ₂ , where m is the thickness of the formation (m = 1.5 m);
α is the angle of incidence (cosα = 0.98);
N ₁ , N ₂ - functions depending on the ratio D _o / m;
D _{o the} length of the treatment output (D _o = 255);
H is the depth of the treatment plant (307 m).

=

= 0,5
Из таблиц N 21 "Правил охраны ..." находим, что при N=0,5

=0,3.In the conditions of Donbass, q _o = 0.8, and N ₂ we take equal to unity. Then from the formula we get
N ₁ =

=

= 0.5
From tables N 21 of the "Protection Rules ..." we find that with N = 0.5

= 0.3.

Then, with a depth of water storage H _in = 167-180 m, D = 40-55 mm.

 Since K, according to experimental studies, is 50-60 m, it is advisable to take the distance between the lines of the wells from 140 to 170 m in this case. After that, the places for laying the lines of the wells and the position of the wells in each line are planned on the mining plan.

 Before the impact of mining operations, all wells are numbered 1 and 2 and the earth's surface is raised by 1.5 m. Then, after ascertaining the speed of mining operations in the working face, the timing of drilling for wells N 3 and above is determined.

Drilling and creating an aggregate array should be ahead of the face at C = H _cf. ˙ctg δ _o , where C is the lead of the aggregate aggregate (13) of the face; N _cf. - the average depth of the confinement 14; δ _about - boundary angle along the strike of rocks.

When N _cf. = 170 m, ctg δ _o = 40, the advance of the aggregate array should be 680 m.

 In the process of creating the massif, observations are made of the movement of the earth's surface, with the help of which they control the rise, subsidence and deformation of the earth's surface.

 As preliminary calculations show, the use of the proposed method reduces the amount of work on the construction of aggregate by about half, which reduces costs in the production stage when moving one face to 100 m by 0.4-0.5 million rubles.

Claims (1)

METHOD FOR REDUCING THE HARMFUL INFLUENCE OF UNDERGROUND PRODUCTS ON THE TERRITORY OF THE EARTH'S SURFACE, including calculating the expected deformations of the earth's surface, comparing them with acceptable deformations, conducting observations of the deformations of the earth's surface during the construction of the aggregate mass and the part-time job, drilling wells to the selected water storage wells, pumping up aggregate rocks, characterized in that, in order to reduce the cost of constructing an aggregate array, the wells have a network of rectangles, to ROTKO side of which is arranged along the direction of clearing mines, and the sequence of injection of filler in the well is set in the direction of movement cleanup production, the well located at a distance from one another, defined by the expression
2K + D

,
where K is the radius of influence of the well, m;
D is the span between the massifs of the aggregate, in which permissible deformations occur on the earth's surface, m;
H _n , H _{n + 1} - the depth of adjacent spans, m

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