A method for demolishing a high-rise frame structure building by directional collapse and aerial disintegration blasting

Abstract

The present invention belongs to the technical field of engineering blasting. A method for directional collapse and in-air disassembly blasting demolition of a high-rise frame structure building provided by the present invention includes the following steps: Step S1, determining the height of the blasting notch; Step S2, arranging blasting points; Step S3, checking the failure conditions. By setting reasonable blasting heights and detonation times for the columns, the columns within the blasting notch are detonated sequentially from the middle of one side to the periphery on the plane. During the closing process of the building's blasting notch, components such as beams, slabs, and walls undergo moment failure due to large-span instability, significantly enhancing the effect of the building's unstable disassembly. By achieving the disassembly effect during the building's collapse process, the gravitational potential energy of the building is dissipated, significantly reducing the impact intensity and ground vibration effect when the building collapses and touches the ground. It can better protect the safety of surrounding targets, with a better disassembly effect for the building, and further reducing the workload of secondary crushing of building components.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering blasting, and specifically relates to a method for directional collapse and in-air disassembly blasting demolition of high-rise frame structure buildings. Background Art

[0002] Blasting demolition technology has the advantages of safety, economy, high efficiency, etc., and is the preferred method for demolishing high-rise buildings, playing an irreplaceable and important role in the national economic construction. At present, the scale of newly built and existing buildings in China is huge. With the rapid advancement of urban renewal, industrial upgrading and transformation, and infrastructure construction, blasting demolition technology has become one of the major demands for the national economic and social development. The traditional directional blasting technology for high-rise buildings is to arrange one or more blasting cuts inside the building, so that the building becomes unstable and deflects under the action of gravity, achieving the demolition effect of directional collapse of the building. The traditional blasting technology generally designs the columns within the blasting cut range to detonate row by row in the same row, and the blasting heights of the columns in the same row are flush. This technology mainly has the following defects: the impact vibration effect is strong, and it is extremely easy to damage adjacent protected targets; the collapse and disassembly effect is poor, and the workload of secondary crushing is large. Summary of the Invention

[0003] To make up for the above deficiencies, the present invention provides a method for directional collapse and in-air disassembly blasting demolition of high-rise frame structure buildings, which can realize the directional collapse and in-air disassembly of high-rise frame structure buildings during the blasting demolition process, and significantly reduce the collapse range and ground impact vibration of high-rise buildings.

[0004] The present invention is implemented as follows:

[0005] A method for directional collapse and in-air disassembly blasting demolition of high-rise frame structure buildings, characterized by comprising the following steps:

[0006] Step S1, determining the height of the blasting cut,

[0007] When designing the directional collapse blasting demolition of a building, the height of the blasting cut is designed according to the height-width ratio of the building. By forming a "trapezoidal" or "triangular" blasting cut at the bottom of the building, the building becomes unstable and collapses under the action of gravity. The minimum height of the blasting cut should satisfy the formula:

[0008]

[0009] In the formula: r is the distance from the center of the building to the plastic hinge, in m;

[0010] H is the height of the building, in m;

[0011] h is the height of the blasting cut, in m;

[0012] L is the width of the building parallel to the collapse direction, in m;

[0013] Step S2: Arrange blasting points,

[0014] Drill blast holes and bury industrial explosives in a certain number of load-bearing columns of the building, so that the blasting heights of the load-bearing columns on the same longitudinal section are arranged in a "zigzag" shape, and the height difference is controlled within a certain range. By setting the detonation time of industrial electronic detonators, the explosives in the load-bearing columns are detonated sequentially according to the planned time sequence to blast the load-bearing columns. During the process of the blasting cut closing and touching the ground, the remaining columns collide with the ground, and the reaction force is applied to the building body, causing the beam bodies between the longitudinal "zigzags" to undergo bending-shear failure, and the walls and slabs on the cross-section to undergo impact failure, so that the beams, columns, walls and slabs on the longitudinal section of the building are disassembled in the air during the process of directional collapse;

[0015] Step S3: Check the failure conditions,

[0016] For the bending moment failure conditions of the beam bodies between the longitudinal "zigzags" and in the horizontal plane direction, blasting can only be carried out after verification and checking.

[0017] Furthermore, in the said Step S3, the checking formula for the bending moment failure conditions of the beam bodies between the longitudinal "zigzags" and in the horizontal plane direction is:

[0018]

[0019] In the formula: F0 is the load borne by a single longitudinal column, unit N;

[0020] l is the span of the beam, unit m;

[0021] q0 is the gravity distribution coefficient of the beam, unit N / m;

[0022] [M] is the ultimate bending moment of the beam body, unit N·m;

[0023] n is the number of columns demolished by blasting between the "zigzags".

[0024] Furthermore, in the said Step S2, by setting the detonation time of industrial electronic detonators, the detonation moment of the industrial explosives in the load-bearing columns is controlled, so that the load-bearing columns within the blasting cut range are detonated from the middle to both sides on the longitudinal section, and the columns within the blasting cut range are detonated sequentially from the middle position on one side to the periphery on the horizontal plane. The blasting delay time is taken as: 200 - 500 ms.

[0025] Furthermore, in the said Step S2, the height difference of the blasting heights of the load-bearing columns on the same longitudinal section arranged in a "zigzag" shape is controlled within the range of 5 - 10 meters.

[0026] The beneficial effects of the present invention are:

[0027] (1) By setting a reasonable blasting height and initiation time for the columns, the columns within the blasting cut range are initiated successively from the middle of one side to the periphery on the plane. During the closing process of the building's blasting cut, components such as beams, slabs, and walls undergo moment failure due to large-span instability, significantly enhancing the effect of the building's instability and disintegration.

[0028] (2) By achieving the disintegration effect during the building's toppling process, the present invention dissipates the gravitational potential energy of the building, significantly reducing the impact intensity and ground vibration effect when the building collapses and touches the ground. It can better protect the safety of surrounding targets, with a better disintegration effect of the building, and further reducing the workload of secondary fragmentation of building components.

[0029] (3) The present invention is not only applicable to the blasting demolition of high-rise frame structure buildings, but also applicable to the blasting demolition of buildings such as high-rise frame-shear wall structures, shear wall structures, and brick-concrete structures, realizing the disintegration of various high-rise buildings during the directional collapse process.

[0030] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present invention more obvious and understandable, the following specifically illustrates the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 is the flowchart of the method of the present invention;

[0033] Figure 2 is the schematic side view structure of the blasting cut;

[0034] Figure 3 is the schematic longitudinal section structure of the blasting cut of the present invention;

[0035] Figure 4 is the schematic plane structure of the blasting cut of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0039] Example

[0040] Specifically, as Figures 1-4 shown, a method for the directional collapse and in-air disintegration blasting demolition of a high-rise frame structure building is provided

[0041] In the first step, by drilling blast holes and burying industrial explosives in a certain number of load-bearing columns of the building, setting the detonation time of industrial electronic detonators, and detonating the explosives in sequence according to the planned time sequence to blast the load-bearing columns, a "trapezoidal" or "triangular" blasting cut is formed at the bottom of the building, causing the building to become unstable and collapse under the action of gravity, achieving the blasting demolition effect of the directional collapse of the high-rise building.

[0042] Specifically, as Figure 2 shown, when designing the directional collapse blasting demolition of the building, the height of the blasting cut is designed according to the height-width ratio of the building. The minimum height of the blasting cut should satisfy the formula:

[0043]

[0044] In the formula, r is the distance from the center of the building to the plastic hinge, in m;

[0045] H is the height of the building, in m;

[0046] h is the height of the blasting cut, in m;

[0047] L is the width of the building parallel to the collapse direction, in m.

[0048] In the second step, specifically, as Figures 3-4As shown in the figure, to achieve the disassembly of a building during the directional collapse process, the detonation time of industrial explosives in the load-bearing columns is controlled by setting the detonation time of industrial electronic detonators, so that the load-bearing columns within the blasting cut are detonated from the middle to both sides in the longitudinal section. The detonation delay time between columns generally ranges from 200 to 500 ms.

[0049] The blasting heights of the load-bearing columns on the same longitudinal section are in a "sawtooth" shape, and the height difference generally ranges from 5 to 10 m. During the process of the blasting cut of the building closing and touching the ground, the remaining columns collide with the ground, and the reaction force is applied to the building body, causing the beam bodies between the longitudinal "sawteeth" to undergo bending-shear failure, and the walls and slabs on the cross-section to undergo impact failure, so that the beams, columns, walls, and slabs on the longitudinal section of the building achieve the effect of disassembly in the air during the directional collapse process.

[0050] In the third step, the condition for the bending moment failure of the beam bodies between the longitudinal section "sawteeth" can be checked by the following formula:

[0051]

[0052] In the formula, F0 is the load borne by a single longitudinal column, with the unit of N;

[0053] l is the span of the beam, with the unit of m;

[0054] q0 is the gravity distribution coefficient of the beam, with the unit of N / m;

[0055] [M] is the ultimate bending moment of the beam body, with the unit of N·m;

[0056] n is the number of columns demolished by blasting between the "sawteeth".

[0057] By setting the detonation time of industrial electronic detonators, the columns within the blasting cut are detonated sequentially from the middle of one side to the periphery on the plane, and the detonation delay time generally ranges from 200 to 500 ms. During the closing process of the building's blasting cut, the beams, slabs, and walls in the transverse and longitudinal directions undergo bending moment failure due to large-span instability. After the remaining columns touch the ground in sequence, the reaction force is applied to the building body, causing further damage and disassembly of building components such as beams, slabs, and walls. The condition for the bending moment failure of the beam bodies in the horizontal direction of the building is also checked with reference to formula (2).

[0058] It should be understood that the specific order or hierarchy of the steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of the steps in the process can be rearranged without departing from the protection scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy.

[0059] In the foregoing detailed description, various features are combined in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention lies in less than the full scope of the features of the single disclosed embodiment. Accordingly, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0060] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but one of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Accordingly, the embodiments described herein are intended to embrace all such changes, modifications, and variations that fall within the scope of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, this term is inclusive in a manner similar to the term "including" as interpreted when used as a transitional word in a claim. Further, any use of the term "or" in the claims or specification is to be meant "non-exclusive or".

Claims

1. A method for the demolition of a high-rise framed structure building by directional collapse and in-air disintegration blasting, characterized in that, It includes the following steps: Step S1: Determine the height of the blasting notch. When designing the directional collapse blasting demolition of a building, the height of the blasting notch is designed according to the height-width ratio of the building. By forming a "trapezoidal" or "triangular" blasting notch at the bottom of the building, the building becomes unstable and collapses under the action of gravity. The minimum height of the blasting notch should satisfy the formula: （1） In the formula: r is the distance from the center of the building to the plastic hinge, in meters; H is the height of the building, in meters; h is the height of the blasting notch, in meters; L is the width of the building parallel to the collapse direction, in meters; Step S2: Arrange the blasting points. Drill blast holes and bury industrial explosives on a certain number of load-bearing columns of the building, so that the blasting heights of the load-bearing columns on the same longitudinal section are arranged in a "sawtooth" shape, and the height difference is controlled within the range of 5-10 meters. By setting the detonation time of industrial electronic detonators, the explosives in the load-bearing columns are detonated in sequence according to the planned time sequence to blast the load-bearing columns. During the process of the blasting notch closing and touching the ground, the remaining columns collide with the ground, and the reaction force is applied to the building body, causing the beam bodies between the longitudinal "sawteeth" to undergo bending-shear failure, and the walls and slabs on the cross-section to undergo impact failure, so that the beams, columns, walls and slabs on the longitudinal section of the building are disassembled in the air during the directional collapse process; Step S3: Check the failure conditions. The bending moment failure conditions of the beam bodies between the longitudinal "sawteeth" and in the horizontal plane direction must be verified and checked before the blasting can be carried out; The checking formula for the bending moment failure conditions of the beam bodies between the longitudinal "sawteeth" and in the horizontal plane direction is: （2） Wherein; is the load borne by a single vertical column, in N; is the span of the beam, in m; is the gravity distribution coefficient of the beam, with the unit of N / m; is the ultimate bending moment of the beam body, in N·m; n is the number of columns demolished by blasting between the "sawteeth".

2. A method for demolishing a high-rise frame structure building by directional collapse and aerial disintegration blasting according to claim 1, characterized in that, In step S2, by setting the detonation time of industrial electronic detonators, the detonation moment of the industrial explosives in the load-bearing columns is controlled, so that the load-bearing columns within the blasting notch are detonated from the middle to both sides on the longitudinal section, and the load-bearing columns within the blasting notch are detonated from the middle position on one side to the periphery in sequence on the horizontal plane. The blasting delay time is taken as: 200-500 ms.

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