RU2375673C1 - Method of blasting foundations - Google Patents

Abstract

FIELD: blasting jobs.

SUBSTANCE: invention relates to blasting jobs to be used in construction to destruct high-rise structures, bridges, pipelines etc. Proposed method comprises exploding pressure charge 8 fitted on support side. Charges, when exploded, create through slots 3 and 4 to separate wedge-like fragment 1 from foundation. Subsequent blasting of pressure charge 8 attached on opposite side knocks wedge-like fragment 1 out.

EFFECT: higher accuracy, safety and reliability.

1 dwg

Description

The invention relates to construction, as well as to other industries, where the collapse of high-rise structures, buildings, bridges, overpasses and other objects is possible.

Known methods of collapse of high-rise structures (pipes, towers, buildings, etc.), when bore holes are drilled in supports, columns, piles, and the like, in which explosive charges and explosives are then placed, and then blasting places are covered from the possible expansion of pieces (fragments) of the destroyed object and explode [1, 2].

However, when blasting columns, supports or pipes having a small diameter or small cross-section, as well as thin walls, for example, in the case of pipes, drilling boreholes is either impossible, or inconvenient, or unsafe. In this case, as well as in cases where the enemy (during hostilities) does not leave time for special training, use overhead charges that are mounted on the side surface of the object being blown up (support, pile, pipe, etc.) [1, 3 ].

The support blasting method using an overhead charge does not guarantee the exact, specified roll direction of the structure, which is required when the structures collapse in modern urban or industrial conditions. When using an overhead charge, a padded support can collapse in almost any arbitrary direction.

The use of modern cumulative charges for a given purpose does not guarantee uniform sliding of the upper parts of the trimmed supports, which can also lead to an arbitrary direction of the roll of the structure.

The claimed invention is aimed at improving the accuracy, reliability and safety of blasting during the collapse of high-rise structures, structures and other objects.

The technical result is achieved by the fact that in the method of undermining the support, providing for the explosion of the overhead charge mounted on the side of the support, from the side of the roll by the explosion of charges, through slots are created that separate the wedge-shaped fragment from the support, and the subsequent explosion of the overhead charge located on the opposite side ensures knocking out wedge-shaped fragment.

An exemplary diagram of the implementation of the method with the designation of technical elements is presented in the drawing, where: 1 - knocked out fragment of the support; 2 - horizontal line; 3 - upper gap; 4 - lower slit; 5 - the angle between the horizontal line and the upper gap (10-15 °); 6 - the angle between the horizontal line and the bottom gap (45-60 °); 7 - left pillar in the support; 8 - charge invoice. Recommended angles relative to the horizon for the upper and lower through slots, respectively, are 10-15 ° and 45-60 °, but in principle they can be determined, selected and refined individually for each specific object.

In the proposed method for creating through the slits in the support (pos. 3 and 4 in the drawing), any of the known methods can be used, including using: linear cumulative charges, the required number of pieces of detonating cord (LH) or a powerful LH with the required weight of explosives (in one thread), hose or daisy-chain charges. The choice of explosive materials (VM) is determined by their power, the parameters of the destructible support and the preferences of a particular specialist, mining engineer, and an explosive.

To place the above VMs in the support along the contour of future slots, holes are drilled (drilled), through or not, depending on the chosen VM and the blasting method. Distances between holes or through holes are determined by calculation or experimentally. The calculation is made for the case of destruction and ejection beyond the gap not only of concrete, but also of steel reinforcement (if possible, it should be verified experimentally), i.e. the experts have a well-known task - to create through the cracks in a specific object (support, column).

In the event of undermining of sufficiently powerful supports to create through slits, hole charges with the necessary mass of explosives can be used, while the length of the holes depends on the size (mass) of the charges located in them. The mass of charges is determined by calculation or experimentally - in case of doubt, how, alas, this is often found in practice and not without reason, because each new facility for the production of special blasting is usually not the same as the previous one.

In any case, the explosive used to form the through slots should have a higher brisance than the explosive used in the overhead charge. The blast of the overhead charge provides timely and reliable knocking out (knocking out, pushing) of the contoured wedge-shaped fragment of the support in order to avoid its clamping when the upper padded part of the support is upset, because even a short delay in the collapse of the support due to the clamp of the cut fragment can cause a change in the direction of the rolls of the entire structure.

The mass of the overhead charge is selected so that it does not destroy the completely left pillar of the support, but creates a wave in it whose power would be sufficient to reliably knock out (knock out, push out) the wedge-shaped fragment of the support. To ensure this, explosive explosives or higher explosives can be used in comparison with those explosives that are used in gap charges.

In order not to list and not to describe in detail the known methods, we will dwell on the method using mixed liquid explosives (LHE). As an example, let’s consider a specific LHW - a mixture of diazot tetraoxide (N ₂ O ₄ ) with diesel fuel or other fuel; the detonation speed is ~ 6 km / s, the critical diameter is several mm, depending on the quality of the components. This fire-fighting explosive has been quite successfully used recently in the practice of special blasting, including and us. To implement the method in the support, you should drill through holes along the contour of future slots, into which to insert plastic tubes with the ends brought out, into which fill in the liquid metal. Then the ends of all the tubes must be insulated and connected to each other in a single network using a DS, to the end of which connect an electric detonator or detonator capsule for initiation. To initiate an overhead charge as an explosive, in which ammonite 6 LH can be used - a detonation speed of 3.6 - 4.8 km / s, use either the same DS through a loop to create an artificial slowdown or an electronic detonator that can provide 2- 5 ms deceleration (deceleration time depends on the size of the destroyed object). When collapsing small-sized supports (meaning the dimensions of the cross-section of the support), slowing down may not be necessary (it is specified experimentally), because the deceleration effect can be obtained due to the fact that the explosives used will detonate at different speeds.

Literature

1. Avdeev F.A., Baron V.L., Bleiman I.L. and others. Technical rules for blasting on the surface. Ed. 5th, rev. and additional., M .: Nedra, 1972, p. 84-92.

2. Etkin M.B., Azarkovich A.E. Blasting in energy and industrial construction. M .: MGGU, 2004, p.238-245.

3. Ivanov K.I. Subversion (Memo to the Fighter), 2nd edition. Military Publishing House of the NPO of the USSR, 1942.p.15-17.

Claims (1)

A method of blowing up a support, providing for the explosion of an overhead charge mounted on a side support, characterized in that through the support, explosion of charges, through slots are created in the support from the roll side, which separate the wedge-shaped fragment from the support, and the subsequent explosion of the overhead charge located on the opposite side provides knocking out a wedge-shaped fragment.