SU1703907A1 - Method of soil swelling prevention in workings - Google Patents

Abstract

The invention relates to methods for excavating mine workings in pulling rocks. The goal is to increase the reliability of the method. Simultaneously with the excavation, the thickness of the rock layers of the soil and the degree of weakening of the mechanical contact over these layers are determined. Reverse points are set at the sides of the soil at the sides of the layers and, when they approach each other, the thickness of the shrinking layer is determined by the magnitude of the degree of weakening of the mechanical contact. An anchor with a step of 0.5-1.0 m at an angle to the vertical of 20-30 & Their length is determined from the analytical expression. 2 Il.

Description

FIELD OF THE INVENTION The invention relates to mining, to methods for combating the heaving of mine workings.

There is a known method for combating soil heaving, based on the fact that inclined slots filled with a pliable material are cut in the soil. During the heaving process, due to the compaction of the compliant material, a partial release of the load occurs and the integrity of the soil is maintained.

The disadvantage of this method is the complexity of its implementation due to the lack of information about a number of characteristics of the straining rocks that are included in the calculation formula.

A known method of preventing soil stonewalls is based on drilling inclined holes, blasting explosives in them, and pumping them into a slurry solution that forms a barrier pillar outside the contact of the pulling and stable rocks. anti-swelling.

The disadvantage of this method is the unreliability of determining the contact of the straining and stable rocks and, thus, the unreliability of the barrier barrier being built.

A known method of increasing the stability of a mine working soil is based on the blasting of explosive charges in the lower part of the tubular anchors and forcing them into a trenchant solution.

The disadvantages of this method are the unreliability due to the unjustified selection of the initial parameters (output width) for estimating the parameters of the heave, the impossibility of using explosives in many coal mines.

The aim of the invention is to increase the reliability of the method.

Simultaneously with the excavation of production, the thickness of the rock layers of the soil and the degree of weakened ™ mechanical contact over these layers are determined, after which the soil is developed at its sides.

fe

Vj

About OJ Yu O VI

benchmarks, on the fact of the approaching of which judge the beginning of the process of soil heaving, to increase the degree of weakening of the mechanical contact between the layers of soil that were found when sinking, the thickness of the penetrating layer is determined, after which the working soil at the sides is fixed by anchor lining with step 0, 5 m, anchor angle 25 ± 5 ° relative to the vertical and anchor length

L (

cosa

+ la.a. + 0.1), M,

where h is the power of the pulling layer, m;

a-angle of anchor, hail;

1z.a. - the length of the lock anchor.

Thus, the determination of the power of the sheath layer is carried out and the use of this parameter in the calculation and installation of anchor lining.

FIG. 1 shows graphs; in fig. 2 is a diagram explaining the proposed method.

FIG. Figure 1 shows spectrogram 1, taken downhole, and spectrogram 2, taken down at the same point after observing the approach of reper9, in fig. 2 — bench marks 3, anchor bolt 4, a pulling layer 5, contact 6 of a layer of pulling rocks with a layer of resistant rocks, a nut 7, a stiff, a tie 8.

The presence of mine workings creates additional pressure in the adjacent areas. If the rocks of the coal seam are malleable, the soil is somewhat deformed and a horizontal component of mechanical stress appears. If the soil of the reservoir is on a non-deformable base (hard rocks), the horizontal component is the cause of the deformation of the pliable rocks with their swelling in the drift. The rate of deformation of soil rocks is determined by its strength characteristics, thickness, friction at the boundary of pulling rocks with a layer of resistant rocks.

The beginning of the deformation of soil rocks is characterized by a decrease in friction at the boundary of the transporting layer and. therefore, an increase in the degree of weakening of the contact S. Using repeated geoacoustic spectral measurements (GSI), an increase in S. can be detected.

Elimination of swelling can be done by eliminating one of the conditions for the occurrence of this phenomenon. Increasing the frictional force between the pulling layer of soil and the layer of resistant rocks reduces the possibility of deforming the rocks of the pulling layer. To do this, it is sufficient to increase the force of the rocks

0

five

0

50

an anchoring layer on the support, which can be achieved with the help of anchors, which are tightened and fixed along the contour of the working. The length of the anchors is selected from a record of the GSI results.

The method is carried out as follows.

At the time of generation with the help of -1 with the help of GSI in the bottom-hole using the Resonance Spectrogram instrumentation, the thickness of the rock layers of the soil is determined and the relative value S determines the degree of weakening of the mechanical contact by these layers (Fig. 1, curve 1) . After that, benchmarks 3 are placed in the soil at its sides. In the future, periodic benchmark measurements are made and repeated geoacoustic measurements are made (Fig. 1, curve 2) in the case of convergence of the frames, by which, in fact, an increase in the degree of weakness S ( Fig. 1, for the P2 layer 2-5) the power of the pulling layer is determined by one of the layers. After that, a hole is drilled into the soil at its sides at an angle of 25 + 5 ° relative to the vertical (this value is obtained based on mining experience) and anchor 4 is installed

one (

cosa

+ 1z.a. + 0.1), M

where h is the power of the pulling layer 5;

behind. - length of the anchor lock, m.

The anchors are installed in such a way that their locks are completely outside the sheath layer 5, i.e. below the contact of the layer of pulling rocks with the layer of resistant rocks 6. At the end of the anchor O, T m, a hex 7 is installed. The installation step of the anchors is 0.5 m. The anchor is stacked one on another with a rigid tie 8.

The use of the proposed method makes it possible to effectively predict the swelling of soil rocks and to fight against it, which reduces the cost of maintaining mine workings, and also coal mining works are carried out more rhythmically.

Claims (1)

Invention Formula A method of dealing with soil heaving of mine workings, which includes driving the mine and installing inclined anchors into the soil at its sides, characterized in that, in order to increase the reliability of the method, the thickness of the soil layers and the degree of weakening of the mechanical contact are determined along these layers , set in the soil of development at its sides bench marks and with their approach to increase the degree of attenuation ™ me-where L is the length of the anchor, m; the power contact is determined as the angle of the anchor to the verticality of the sheath layer, and the anchors are set to deg. in increments of 0.5-1.0 m at an angle to the vertical 20-I - length of the anchor lock, m; 30 ° and determine their length from the expression ccTsa + l + - power of the sheath layer, m. h - power of the pulling layer, m    Do v- .v.ir.V .-. -. - .. / .-. ;R: . : L:.:. g V;, -. ;.::. :::: ... -.- ........: ..:::. . . l t .... -, .. t ..- ... II, - --- - - .. - - V FIG. one