SU1411473A1 - Method of caving overburden - Google Patents

Abstract

The invention relates to mining. The goal is to expand the scope of application of the method and reduce the cost of the collapse of overburden during the treatment of massive mineral breakdown by taking into account the orientation of the main normal stresses in the array. To do this, in the overburden form

Description

(L

-.t:

1U

 -

y -.- .-. bifrX--,

vertical plane 3 weakening. If. Is the smallest compressive stress that has a vertical direction in the rock mass, then horizontal wells 2 will be drilled with a distance in the row that will ensure subsequent well strut 2 by hydraulic fracturing until the cleaning operation approaches them. If the smallest squeezing voltage has a horizontal direction, then wells 2 are drilled with a distance that allows them to be connected by an explosion of explosive charges with a massive collapse of the mineral. After this, drill one pd

The invention relates to mining, in particular, to methods for the partial forced collapse of resistant overburden during the development of powerful sloping fields with systems with massive collapse.

The purpose of the invention is to expand the field of application of the method and reduce the cost of the collapse of overburden during the clean-up work by the mass collapse of the mineral by taking into account the orientation of the main normal stresses in the array.

In 1 of FIG. Figure 1 shows the layout of the field's stretch, cross-section across, I, and along the horizontal plane of weakness: in fig. 2 is a diagram of the strike of a deposit, cut across and along a vertical weakening plane; Fig. 3 is a diagram of the direction of the area: birth. After the forced collapse of a volume rock element, the cross-section.

 The method is carried out as follows.

Inclined field: waiting is fulfilled by a solid front along the strike with the floor or sublevel preparation scheme. The distribution of the main normal stresses of the bulk tensor in the rocks of which the sides of a given locomotive are determined; to a depth of 30–40 m in an array. The magnitude and spatial orientation of the sought stresses are found by any known method, for example, unloading, ultrasound and others

parallel wells. If the smallest compressive stresses in the rock massif have a horizontal direction, then the wells are drilled with a distance along the grid of blastholes. If the indicated stresses have a vertical direction, then the distance between the wells should provide hydraulic fracturing between them. Thus, the explosion of explosive charges in the wells 5 or hydraulic fracturing with rock collapse on the recovered minerals creates a vertical plane of weakening. 3 il.

In advance and no later than when the front of the clearing recess approaches the drift 1 by the amount of advancement during one blasting with a massive explosion of explosive charges (Fig. 1), one row of parallel wells 2 is drilled in a horizontal plane in the rock of the side. If the smallest compressive stress has a vertical direction in the rock mass, then wells 2 are drilled with a distance of 1 to ensure the subsequent sinking of wells with a hydraulic fracture.

The value of 1 is determined from the approximate dependence

W 0,33 c, R (s + 0,33 sr,

where DUa, is the increment of the hydraulic fracturing fluid in the filtration zone, C, C, Cj are calculated coefficients that take into account the stress state of the rock mass, as well as permeability, porosity and other parameters;

R is the fracture radius of the fracture formed in the rock mass from a single well, m

Due to the fact that in the method of slinging with a fracture of parallel wells, the required distance of the wells is found by the formula:

tr

M.

Thus, a hydraulic fracture or an explosion in the side of the reservoir forms a horizontal plane {3 attenuation to a depth in the massif not less than the distance in the plan between drifts 1 and 4 of the adjacent sub-floors.

If the smallest compressive voltage is horizontal in the rock mass, then the wells are drilled with a distance of 1, ensuring their reliable alignment with explosive charges. The value of 1 is determined by the calculation method for the mode of gentle blasting, where to create a crack between the axes of two wells (the distance between them 1) is considered as a complex function of the tangential component of the blast wave voltage bc, in the stretch phase 1 f ( bu) Simultaneously with these operations or later, but before the front of the clearing recess approaches the drift 4 to the distance B, one row of parallel wells 5 is drilled from the drift 4 in the vertical plane (Fig. 2). If the smallest compressive stresses in the rock massif are horizontal in direction, then wells 5 are drilled with a depth of 1 along the grid of blast holes; if the indicated voltages have a vertical direction, with a distance of 1, which provides hydraulic fracturing between the wells. The vertical plane 6 of weakening depth not less than the height of the substage is formed by hydraulic fracturing immediately after the drilling of wells and the explosion of borehole charges simultaneously with the massive explosion of the mineral in Section A,

As a result, two intersecting planes .3 and 6 attenuations are located in the side of the deposit, which are perpendicular to one another and distinguish a bulk rock element 7 in the massif, with minimum dimensions across the strike L and bn and length

.five .

114734

along a strike equal to the length of the front of a blasting in one massive explosion. The creation of the weakening planes 3 and 6 prepares the collapse of the rock element 7, produced by a mass explosion in section A (FIG. 3). Repulsed minerals are released under the cover of the rock element 7, Q until it takes up its final position on the bottom of the site.

Claims (1)

Invention Formula A method of breaking the covering rocks, including drilling vertical wells in the hanging rocks of the sides, forming vertical planes for weakening the rocks through the said wells by exploding charges of explosives and breaking rocks of the hanging rocks on the broken minerals, in order to broaden the field of application method and reduce the cost of the collapse of covering rocks in the course of cleaning works by massive mineral breakdown by taking into account the orientation of the main normal stresses in the massif, They form horizontal weakening planes in the overburden rocks, and with the vertical orientation of the minimum compressive stresses, the horizontal weakening planes are created by drilling „.- horizontal wells and hydraulic 35 rock formation through these wells to the approach of cleaning works to them, after which they create a vertical plane for weakening rocks by an explosion of charges in Q wells simultaneously with massive collapse of the mineral, and with the horizontal orientation of the minimum compressive stresses, the vertical plane of weakening creates 4g hydraulic fracturing of rocks through the wells, after which the horizontal plane of weakening is formed by the explosion of explosive charges in horizontal wells simultaneously with the massive collapse of the mineral. 50 / 2 Г t ;; -: - .V-V, .- Fig.Z