SU1430719A1 - Method of initiating snake charges - Google Patents

Description

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(Reg. 1

114

The invention relates to the production of blasting and can be used in the mining industry and in construction when excavating rocks using explosive energy.

The aim of the invention is to increase the efficiency and directivity of the joint action of stress waves in the interval of their optimum duration, and the greatest parameters from the explosion of neighboring charges or their parts on the rock mass region between charges or parts of charges.

Fig. 1 shows a scheme for placing militants in adjacent explosive charges (BB) and connecting them with two main detonating cords (LH) in plan; figure 2 - the same section.

To implement the method, along the line of location of a simultaneously exploded row of elongated charges 1, two highways LH 2, 3 are drawn; one on one side of the charge line, and the other on the same distance on the other side. On one highway. LH there are end sections of LH 4, at the ends of which intermediate detonators-fighters 5 are placed, located in charges close to the mouth wells at a depth of h ,, to another — end sections of LH 6, at the ends of which the insurgents 7 are reinforced, located further from the wellhead at a depth of hj. In this case, the militants in a series of simultaneously exploding charges are placed at design levels different for adjacent militants by the value of h, a sections of the trunk lines l1 from the junction of their ends to the first well in the course of detonation are taken within h - a, where a - distance between wells in rows.

The end segments of the LH connecting the militants to LH highways are assembled from LHs with a diminutive weight of WB per linear meter, or segments of LH passing through the explosive charge are reliably isolated from the explosive charge if the explosive charge is easily initiated from thread LH.

When used in the charge of granulotole, alumotol, grammonites and water-filled explosives, use LH with

a reduced weight of explosives and their isolation from charge is not required.

Highways LH 2 and 3 are arranged in the area up to the first well in the course of detonation of various lengths, but their ends are joined together and they are blasting with an electric detonator or a detonator cap.

The method makes it possible to establish and with high accuracy adjust small detonation retardation intervals of militants and corresponding charges (or parts of charges) that are practically not feasible when using EDs and CPFARs, while the retarding retardation interval & t between any two adjacent militants is determined by expressions

„, & H-M + a, & h + M + a„ „0. 0.3

5 About „

five

five

where D is the detonation velocity LH, m / s; The amp 1 and dh parameters, on which the slowdown intervals depend, are easily technically regulated and changed, and the time variation of the militants ’response against the calculated slowdown interval does not exceed 2% of its value, since the explosive network is mounted from the LH of one batch that can have deviations from the nominal detonation speed in one direction only.

Example. When blasting a given volume of rock from an array, it is necessary to provide enhanced waste from the blasted rock and its intensive fragmentation. This requires intensive and uniform loading of the array by the stress field from the explosion of each pair of neighboring charges in the wells and a sufficient gradient in the displacement velocity of the blasted rock between these pairs of charges.

For this purpose, four charges are placed in the rock mass in the wells at a distance of one from the other 4 m (Figures 1 and 2). In one of the charges of each pair, two militants 5 and 7 are installed; one in the upper part of the charge at a depth of h 4 m, the second in the lower part of the charge at a depth of 12 m. In the second (neighboring) charge, one action film 8 is placed at a depth of 8 m. To create a uniform and intensive loading of the array between the charges Each couple needs

31430719

It is up to all three militants to blow up strictly at the same time in the absence of any variation in the times of their operation. To ensure the task, determine the necessary values of & 1 and h from the equations:

 §

five

DL., 4 D

h I - h "- bh - h 4. + a

L1 - Ah ,, i.,. M - yba.z + a

 oh --- -Oh

where & h ,, h; j-h, 12-4 8m;

yy7l g.

12-h

1.2

m;

whence the difference is the length of the lines 1 h ,, and the depth of installation of the action movie is 8 hj hj - and 12 - 4 8 m.

Also, without any variation in the response time, militants 5, 7, 8 in the next pair of well charges undermine, and in relation to the moment when the militants of the first pair of charges explode, the militants of the second pair detonate with a slowdown interval, ut. v equal

D

 ha + a D

2a D

those.

15

20

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At 2-4 / 6500 0.00123 c,

at the same time, the maximum variation in the values of the calculated time interval. blasting equals 0.02 x ut, O, 0000246-s.

Figure 2 shows the pattern of loading the array with stress waves at time t a / c after the undermining of the militants in the first pair of charges, corresponding to the task.

2

Claims (1)

METHOD FOR INITIATING EXTENDED CHARGES, including the formation of borehole explosive charges in the rock mass at a predetermined distance from each other with the deployment of militants with detonating cords in them, the installation of detonating lines - cords along the rows of charges on both sides of it at equal distances from it and the simultaneous undermining of charges, characterized in that, in order to increase the efficiency and directivity of the combined action of stress waves in the intervals of their optimal duration and the greatest parameters from the explosion of neighboring charges or their parts to the area of the mountain range, enclosed between the charges or parts of the charges, the militants in a series of simultaneously exploded charges are placed at different levels, which differ for inter-militants by the value of Ah, sections agistraley A1 from the junction of their ends to the first well of course, take detonation within Ah - and ίύΐ έ Ah, wherein the deceleration interval § blasting At between any two adjacent fighters determined from the relationship 0 to _t <l_i_a _& D D <0.3 ms, where a is the distance between the wells in the row, m; D is the detonation velocity of the detonating cord, m / s.