RU2847986C1 - Method for dismantling a chimney - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the construction of brick and reinforced concrete chimneys, exhaust and water towers, and other similar high-rise structures. The method of dismantling a chimney is carried out in such a way that, on the side of the chimney from which the dismantled parts are to be removed, through niches are made in the section where the parts are separated, and a pulling rope is loaded, applying overturning moments to the chimney. After the upper part of the through niche strikes the lower part of this niche, a force is applied to the chimney being overturned, creating a braking moment of forces in the direction opposite to the overturning vector.

EFFECT: reduction in the length of the rolling sector.

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Description

I. Field of application of the invention

The invention relates to the field of construction of high-rise structures and buildings, in particular brick and reinforced concrete chimneys, exhaust and water towers and other similar high-rise buildings.

Terminology used

Chimney felling vector - the planned direction of the chimney felling.

The undercut section is a horizontal or inclined plane along which the chimney is divided into parts.

The back of the chimney is the side that is the mirror opposite of the front of the chimney.

The front side of the chimney is the side where the chimney is planned to be buried.

II. State of the Art

An analogue of the proposed invention is a method for dismantling a chimney by felling it entirely (“Chimneys”, edited by S.V. Satyanov, Moscow, Stroyizdat, 2001).

Pull ropes are attached to the top of the chimney and pulled by powerful bulldozers.

Then, the chimney is trimmed by punching through niches in the base of the pipe, first at the mark of the bisector of the pipe cutting sector, and then simultaneously and evenly in both directions from the bisector of the pipe cutting sector, with a step of 500-700 mm.

Hydraulic jacks are installed in the punched niches, gradually absorbing the load from the dismantled section of the pipe. The niches are punched at a distance of 2/3 of the pipe's circumference to the left and right of the bisector of the pipe's falling direction. After all the niches are punched and the jacks are installed, the partitions between the niches are cut out, after which the broken section of the pipe rests entirely on the jacks. Then, in the remaining untouched 1/3 of the pipe's circumference on the side opposite the direction of its fall, at a height of approximately 500 mm above the level of the niches, grooves are punched 100-150 mm deep, depending on the pipe's thickness.

After the chimney is trimmed, all jacks are simultaneously turned off. By removing the support from the front, specifically by cutting a through niche, a gravity-induced crushing force is created, which forces the chimney to fall in the direction of the felling vector.

The disadvantage of this method is the increased size of the felling sector, both in angle and length.

The prototype of the proposed invention is a method for dismantling a chimney according to patent RU 2477777.

The method for dismantling a chimney is characterized by the fact that, in order to cut down the chimney, from the rear side of the chimney, in the undercut section, the vertical reinforcement and other connecting elements are completely cut in a section from one third to three quarters of the perimeter of the undercut section.

And from the front side, in the cross-section of the hem, a through niche is punched.

By removing the support from the front side, namely by cutting a through niche, a collapsing moment of gravity is also created, the action of which collapses the chimney in the direction of the felling vector.

The disadvantage of this method is the increased length of the felling sector.

The collapsed section strikes the ground along the entire length of the chimney. As the chimney collapses, the fallen chimney begins to move slightly forward, by 10-20% of its height, while the debris bouncing off the ground travels even further, almost half the height of the chimney.

Therefore, when felling a chimney, for example, 120 m high, felling sectors are prepared with a length of at least 180 m.

Due to the long fall arc of a chimney, buildings within the chimney's potential fall arc must be demolished, the chimney must be dismantled manually, or the entire structure must be felled in shorter sections. Felling in sections and dismantling by hand increases the risk of death for the workers involved.

III. Objective of the invention

The technical objective of the present invention is to eliminate the shortcomings of the prototype.

IV. Problem solution

The problem is solved by applying a force to the collapsing chimney that creates a braking moment of forces in the direction opposite to the action of the collapsing moments of forces.

VI. Description of the device in statics

Before commencing the main work of breaching the integrity of the chimney, at least one brake rope and at least one towing rope are attached to the top of the chimney. The lower end of the towing rope is secured to the towing device.

To fell a chimney, from the back side of the chimney, in the undercut section, the vertical reinforcement and other connecting elements are completely cut in a section from one third to three quarters of the perimeter of the undercut section.

In reinforced concrete chimneys, the reinforcement is weakened in places.

To weaken the reinforcement, the vertical and horizontal reinforcement is cut or partially trimmed along the entire height of the chimney.

The places where the reinforcement is weakened for each chimney are determined individually, depending on both the condition of the chimney and the size of the free area around the chimney.

Then, from the front side, in the cross-section of the hem, a through niche is punched.

In this case, the niche is punched so that the chord of the niche arc is perpendicular to the vector of the chimney shaft.

In addition, the niche is cut to such a length that the center of mass of the chimney is in close proximity to the vertical plane passing through the chord of the niche arc.

To reduce the length of the chimney stack felling sector, a braking rope is attached to the top of the chimney stack.

The lower end of the braking rope is secured from the rear side to a reliable anchor or a heavy vehicle, such as a tractor.

The length of the braking rope must be no shorter than the length that allows the chimney to freely begin tilting to the initial deflection angle specified in the demolition plan. To ensure that the braking rope does not prevent the chimney from tilting at the initial moment of tilt, the minimum deflection angle must correspond to the position of the collapsing chimney at which the upper part of the cut-through niche impacts the lower part of this niche.

The length of the braking rope must not be longer than the length of the felling sector provided for in the dismantling project.

The length of the brake cable is determined by theoretical calculations, graphically or by in-kind measurements.

VII. Description of the device in dynamics

The chimney begins to collapse in the direction of the felling, namely, the main collapsing moment of forces is applied to the chimney, which rotates the chimney around its base in the direction of the felling vector.

The main breaking moment of forces is made up of the breaking moment of the pulling rope forces and the breaking moment of the gravity forces.

By reducing the support area in the front part of the chimney, in the cross-section of the roll, a tilting moment of gravity is created.

To reduce the support area, a through niche is punched in the front part of the chimney so that the chord of the niche arc is perpendicular to the direction of the chimney roll vector.

To initiate the felling of the chimney and to reduce the deviation of the pipe during felling, the pipe is pre-tilted in the direction of the felling vector.

To do this, a pulling rope is pulled.

If the chimney does not begin to collapse, then the pull rope is loosened, the length of the through niche is increased, and the pull rope is loaded again.

These procedures are repeated until the chimney begins to fall.

To reduce the length of the felling sector, the chimney begins to be destroyed from the bottom up immediately at the moment of its tilt.

To do this, in the initial phase of felling, after the lower frontal part of the through niche is struck by the upper part of the niche, a braking moment of forces is applied to the chimney being felled, which is set in the direction opposite to the action of the main falling moment of forces.

The braking moment of forces is created by tensioning at least one braking rope.

By organizing an impact of the upper part of the through niche on the lower part of the niche, a shock wave of stress is directed upward, along the chimney, and this wave partially destroys the chimney from the bottom up.

By organizing such a blow, the strength and integrity of the chimney is reduced.

And due to the fact that the base of the pipe has lost strength, and the braking rope prevents the increase in the slope of the chimney, the chimney, having lost support, is settled vertically.

The destruction is achieved by using the potential energy of the chimney's mass, which is converted into the kinetic energy of the chimney's fall. This energy ultimately destroys the chimney from the bottom up.

As a result of the destruction of the chimney from the bottom up, the chimney is laid in a narrow and short sector in the form of a pile of construction waste.

The length of the debris trail from a destroyed chimney depends on the length of the braking rope.

VIII. Result of the problem solution

Thus, the technical problem of the present invention is solved - eliminating the shortcomings of the prototype.

Claims (2)

1. A method for dismantling a chimney characterized by the fact that in the chimney, on the side of the direction of felling of the parts to be dismantled, through niches are punched in the section of separation of the parts and a pulling rope is loaded, thereby applying collapsing moments of forces to the chimney, characterized in that after the upper part of the through niche strikes the lower part of this niche, a force is applied to the chimney being collapsed, creating a braking moment of forces in the direction opposite to the felling vector. 2. The method for dismantling a chimney according to paragraph 1, characterized in that when dismantling a reinforced concrete chimney, the reinforcement is additionally loosened above the undercut section.