Process of demolishing a built structure

Abstract

A method for demolishing a built structure (1) with load-bearing elements (2), comprising a weakening phase and a subsidence phase, comprising for at least one load-bearing element (2b) of the plurality of load-bearing elements (2), during the weakening phase, tensioning a first traction member (10a) exerting on said load-bearing element (2b) a traction in a first direction, and tensioning a second traction member (10b) exerting on the load-bearing element (2b) a traction in a second direction different from the first traction, the first direction and the second direction each having a main component perpendicular to the longitudinal direction, then carrying out a weakening cut in the load-bearing element (2b),the method comprising a remotely operated cutting of a part of the load-bearing element (2b) during the weakening phase as a weakening cutting and / or a remotely operated cutting of the first traction member (10a) during the sagging phase. Figure for the abstract: figure 1,

Description

Title of the invention: Method for demolishing a built structure Technical field

[0001] The invention belongs to the field of demolition of built structures with load-bearing elements, in particular for the demolition of buildings or industrial installations. Technological background

[0002] The demolition of high-rise built structures, typically over 10 m, has always represented a technical challenge to avoid exposing operators to the risk of the structure collapsing or tipping over. It is generally appropriate to tip over part of the built structure on the ground in order to reduce its height and allow demolition using conventional means.

[0003] While methods such as the use of explosives have been used, particularly for brick constructions, these methods are not suitable when the built structure to be demolished is located close to other built structures which must not be impacted by the demolition. It is then necessary to finely control the movement of the built structure. In addition, some built structures may have a very solid frame, particularly in an industrial setting, which would require quantities of explosives making any control of the movement of the built structure illusory.

[0004] It has been proposed to implement methods of demolishing buildings by jacking, which uses thrust means such as jacks intended to move / tilt certain parts of the building relative to others in order to cause an overall collapse of the building, or demolition, by the upper part of the building falling onto its lower part. Patent applications EP0973984, EP1082505, and EP2817466 provide examples of such a method. A similar approach consists of implementing cable traction means, possibly combined with the action of jacks.

[0005] All these approaches require weakening the structure, for example by removing certain load-bearing walls, and by making cuts in the partitions which are to tilt. If this weakening phase is not sufficiently thorough, then it is not possible to guarantee the movement of the load-bearing structure during the tilting phase of the supports of the built structure.

[0006] Furthermore, most of these methods are not suitable for the demolition of built structures with load-bearing beams, in which it is not walls that form the framework of the built structure, but load-bearing beams. These can extend over a large part of the height of the structure, and therefore cannot be tilted in their entirety. Presentation of the invention

[0007] The invention therefore aims to propose a method and tools for demolishing a structure with load-bearing elements, while avoiding the exposure of operators to a risk of premature collapse of the structure.

[0008] To this end, the invention proposes a method for demolishing a built structure with load-bearing elements, comprising a weakening phase and a slumping phase, the weakening phase comprising carrying out a weakening cut for each load-bearing element of a plurality of load-bearing elements extending in a longitudinal direction, the slumping phase comprising slumping the built structure in a slumping direction, the method comprising for at least one carrier element of the plurality of carrier elements: a) during the weakening phase: - al) a tensioning of a first traction member exerting on said carrier element a traction in a first direction, and the tensioning of a second traction member exerting on the carrier element a traction in a second direction different from the first traction, the first direction and the second direction each having a main component perpendicular to the longitudinal direction, then - a2) performing a weakening cut in the supporting element, the method comprising a remotely operated cut of a portion of the supporting element during the weakening phase as a weakening cut and / or a remotely operated cut of the first traction member during the sagging phase.

[0009] The invention is advantageously supplemented by the following various characteristics taken alone or according to their various possible combinations: - the remote-controlled cutting of a part of the load-bearing element and / or the remote-controlled cutting of the first traction member is carried out using a remote-controlled cutting tool that can be activated at a distance of at least 10 meters; - the remote-controlled cutting of a part of the carrier element is carried out by a remote-controlled cutting device, the cutting device comprising a mobile carriage on a rail mounted against the carrier element, the mobile carriage being provided with a cutting tool oriented towards the carrier element, the mobile carriage traveling along the rail during cutting; - the mobile carriage is provided with a motor coupled to first drive means, the guide rail being provided with second drive means complementary to the first drive means; - the rail forms an open circuit against the carrier element, the mobile carriage leaving the rail at the end of the cutting; - the first traction member comprises a hollow cylinder provided with a rod to which is fixed a cable or chain coupled to the carrier element; - the remote-controlled cutting of the first traction member comprises the cutting of the rod by a remote-controlled cutting tool; - the remote-controlled cutting of the first traction member is carried out by an oxy-cutting tool; - the weakening cut comprises a first cut of a first portion of the carrier element, and a second cut of a second portion of the carrier element, the first portion and the second portion being located at a distance from each other in the longitudinal direction.

[0010] The invention also relates to a system for demolishing a built structure with load-bearing elements, comprising: - at least two traction members capable of exerting traction forces on a load-bearing element, - a remotely operated cutting tool capable of cutting a traction member, - a remotely operated cutting device capable of making a weakening cut in the load-bearing element, wherein a first traction member exerts traction on the carrier element in a first direction, and a second traction member exerting traction on the carrier element in a second direction different from the first traction, the first direction and the second direction each having a main component perpendicular to the longitudinal direction, the remotely operated cutting device being arranged against the carrier element, and the remotely operated cutting tool faces the first traction member. Presentation of figures

[0011] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0012] - [Fig.l] shows an example of a built structure with vertical supporting beams;

[0013] - [Fig.2] shows examples of cutting beams according to one embodiment possible of the invention, in the upper zone of the beams;

[0014] - [Fig.3] shows examples of cutting beams according to one embodiment possible of the invention, in the central zone of the beams;

[0015] - [Fig.4] shows a top view of a cutting device mounted on a beam at a cutting area, according to a possible embodiment of the invention;

[0016] - [Fig.5] shows a side view of a cutting device mounted on a beam at the level of a cutting area, according to a possible embodiment of the invention;

[0017] - [Fig.6] shows an example of cutting a traction member;

[0018] - [Fig.7] shows an example of the beginning of the subsidence phase of a built structure with vertical supporting beams, according to a possible embodiment of the invention;

[0019] - [Fig.8] shows the continuation of the collapse phase of the example of [Fig.7]. Detailed description

[0020] A built structure with load-bearing elements is understood to mean any artificial construction, such as a building such as a hangar or a building, or a tower, or industrial installations, the framework of which comprises load-bearing elements supporting the weight. The load-bearing aspect of the load-bearing elements means that the weight of the structure rests mainly on these load-bearing elements. A load-bearing element is typically a beam, generally vertical, typically metallic, but can also be made of concrete, in particular reinforced concrete. A load-bearing element can also be a load-bearing wall. In particular in the case of a beam or a column, the load-bearing element can comprise a connection means mechanically coupling the beam or the column to another element of the built structure, such as for example a weld.

[0021] [Fig.l] shows an example of such a built structure 1 with vertical load-bearing elements, comprising a frame of load-bearing beams 2, for example metal. By way of illustration and not limitation, the built structure 1 here comprises six vertical load-bearing beams 2, but the number of load-bearing elements 2 can be any. The load-bearing beams 2 are distributed between front beams 2a, 2b, 2c, located in the direction of subsidence, and rear beams 2d, 2e, 2f, located opposite the direction of subsidence. Usually, the load-bearing elements 2 form alignments, and the direction of subsidence is substantially perpendicular to the direction of subsidence. The load-bearing beams 2 are equally divided between outer beams 2a, 2c, 2d, 2f, and inner beams 2b, 2e, the inner beams forming an alignment 2b, 2e with two other load-bearing beams 2.

[0022] The method first comprises a weakening phase, during which load-bearing elements 2 are cut to weaken the support of the built structure 1 in order to allow it to collapse or tip over. The weakening phase comprises carrying out a weakening cut for at least one load-bearing element 2 of a plurality of load-bearing elements 2, and preferably for all the load-bearing elements 2. The load-bearing elements 2 concerned are those whose load-bearing function is desired to be interrupted, in order to cause the collapse of the built structure 1. Typically, these load-bearing elements 2 will be those present in the same plane, in particular horizontal, such as for example the load-bearing elements 2 anchoring the structure to the ground. The weakening cutout may vary in height, size, shape or depth, particularly depending on the type of load-bearing element involved (interior, exterior, front, rear, etc.).

[0023] The weakening cut in a load-bearing element 2 has the function of creating an articulation in the load-bearing element 2, at which the load-bearing element 2 will yield during the subsequent collapse phase. By yielding, we mean the fact that a load-bearing element 2 deforms or breaks, causing a displacement of a part of this load-bearing element 2 adjacent to the cut-out area. For example, the load-bearing element may then bend or buckle. More precisely, the formation of an articulation involves a localized removal of material, which will cause at least one of the two adjacent parts of the load-bearing element 2 to tilt in a direction known as an articulation at the level of this removal of material, or cutting.

[0024] Preferably, as illustrated in [Fig.2] and [Fig.3], the weakening cutout made on a load-bearing element 2 comprises first cutouts, made on opposite sides of the load-bearing element 2: at least one cutout 4b, 4c on the side of the direction of collapse Y, and at least one cutout 6b on the side opposite the direction of collapse Y. These first cutouts are made at different longitudinal positions, i.e. different heights when the load-bearing element 2 is vertical. Two cutouts 4, 6 are typically spaced longitudinally by at least 50 cm, and preferably by at least 1 meter.

[0025] Two cutouts 4, 6 allow the carrier element 2 to be bent. It is possible, in particular for the front carrier elements 2a, 2b, 2c, and even more particularly for the interior front carrier elements 2b, to provide three weakening cutouts on the same carrier element 2 by alternating the sides, only the central cutout being in the direction opposite to the sagging. It is then possible to create a joint allowing the carrier element to buckle. It is also possible to provide cutouts 4, 6 in a direction perpendicular to the direction of sagging.

[0026] The first cutouts 4, 6 generally have a triangular shape, with two cutting lines meeting, at least one line not being perpendicular to the longitudinal direction. The first cutouts result in cutouts 4, 6 extending transversely (perpendicular to the longitudinal direction) between 70% and 30% of the thickness of the carrier element 2, and preferably between 60% and 40% of the thickness.

[0027] [Fig.2] and [Fig.3] show examples of images of first cuts 4, 6 made during the weakening phase. The direction of collapse Y is to the right. Image a) of [Fig.2] shows an upper part of an outer front beam 2c, while image b) shows an upper part of an inner front beam 2b. first cuts 4a, 4b take the form of triangles whose base is on the side of the direction of sagging Y, and which extend in the direction opposite to the direction of sagging Y. In this example, since these are metal beams, the first cuts were made in the flanges of the load-bearing beams 2. Similar cuts can be made in the rear beams 2d, 2e, 2f.

[0028] [Fig.3] shows cutouts 6b, 6c made in the intermediate part of the supporting beams 2, for example between 1 m and 3 m below the upper part illustrated in [Fig.2]. Image a) shows an outer front beam 2c, images b) and c) show an inner front beam 2b. As before, the first cutouts 6b, 6c take the form of triangles, but this time the base is on the side opposite the direction of sagging Y, and extend in the direction of sagging Y.

[0029] The first cuts can be carried out by operators equipped with cutting tools. For example, oxy-cutting tools such as blowtorches can be used, or disc tools, depending on the nature of the carrier element 2, or any other cutting means.

[0030] As seen in [Fig.l] and [Fig.6], traction members 10 are coupled to load-bearing elements in order to exert a traction force thereon. The weakening phase also comprises, for at least one of a plurality of load-bearing elements 2, tensioning a first traction member 10a exerting a traction on the load-bearing element in a first direction, and tensioning a second traction member 10b exerting a traction on the load-bearing element in a second direction different from the first traction, the first direction and the second direction each having a main component perpendicular to the longitudinal direction. Preferably, the first direction and the second direction, understood as incorporating the direction, extend away from the load-bearing element 2 from opposite sides of the load-bearing element 2.Preferably, the horizontal projections of the first direction and the second direction form an angle of at least 120° between them, so that the tractions they exert compensate for the majority in the horizontal plane.

[0031] Preferably, the first direction and the second direction each form an angle strictly greater than 45° relative to the longitudinal direction of the carrier element, and preferably greater than 70°. Typically, the longitudinal direction is vertical, and the first and / or the second direction are then close to the horizontal or at an angle.

[0032] This tensioning, just like the installation of the traction members 10, can be done at the start of the weakening phase, or after the first weakening cuts have been made. As a preferred example, a traction member 10 comprises a hollow jack 12 provided with a rod 14 to which a cable or chain is fixed. coupled to the carrier element 2. The jacks 12 may be hydraulic, with a capacity of at least 50 t at 500 bars, such as for example 100 t at 700 bars. A remote hydraulic station may be used to supply the jacks 12. The rod 14 is for example metallic, with a diameter between 30 and 70 mm, and a length between 1 m and 5 m. The rod 14 is engaged in the hollow jack 12. For example, a cable 16 is coupled to the rod 14, and to a chain 18 connected to the carrier element 2b. A hole may be made in the webs of the carrier elements in order to pass the chain 18 or the cable 16 or any other coupling means such as a shackle.

[0033] Tension members 10 may be fixed, for example to the ground. More precisely, it is the hollow cylinder 14 which is then fixed. Preferably, tension members 10 may connect two load-bearing elements 2 together. It is for example possible to take advantage of the mechanical strength of the load-bearing elements 2 to serve as a support for a tension member 10 exerting traction on another load-bearing element 2, and also to then use the same tension member 10 to exert traction on two load-bearing elements 2. Advantageously, a hole may be made in a load-bearing element 2 to pass the rod 14 of the hollow cylinder 14 therethrough, which may rest on said load-bearing element 2. It is also possible to fix the hollow cylinder 14 to a load-bearing element 2, for example using bolts. It is also possible to use a fixing shoe, fixed to the supporting element 2 for example by bolts, to which the traction member 10 can be coupled.The fixing shoe may for example comprise a hole through which the traction member 10 passes, in particular the chain 18, the cable 16 or any other coupling means such as a shackle.

[0034] In addition to the traction members 10, it is possible to have for certain load-bearing elements thrust members exerting a force opposite to the direction of articulation on a load-bearing element 2. Advantageously, a thrust support such as a metal bracket is fixed to a load-bearing element 2, for example between a low cutting zone and an intermediate cutting zone, and a hydraulic thrust cylinder is arranged under the thrust support. This arrangement makes it possible to limit the capacity of the load-bearing element 2 to be compressed in the opposite direction to the direction of articulation with loading of the thrust members before the second weakening cuts. These thrust members also allow an additional force during the collapse phase. This arrangement is particularly advantageous for the front external load-bearing elements 2a, 2b, 2c.

[0035] Once the traction members 10 are tensioned, the load-bearing elements 2 on which these tensions are exerted are maintained by these tensions, which prevent the tilting of the parts of the load-bearing elements 2 adjacent to the cutouts 4c, 4b, 6c, 6b. It is then possible to carry out second weakening cutouts in the load-bearing elements 2, complementary to the first weakening cutouts. As mentioned above, the traction members 10 can be put in place or under tension before the first cuts, or after them. The second cuts are however always carried out after the tensioning of the traction members 10, which allows the second weakening cuts to be carried out while preventing a load-bearing element 2 from giving way prematurely.

[0036] The second weakening cutouts 20c, 20b, 22c, 22b extend the first cutouts 4c, 4b, 6c, 6b, and are therefore located in the same areas. In particular, the second weakening cutouts may extend in a load-bearing element from a first cutout to an opposite limit of the load-bearing element, typically in a rectilinear manner and perpendicular to the longitudinal direction, and for example horizontally.

[0037] Thus, in the examples of [Fig.2] and [Fig.3], dashed lines 20c, 20b, 22c, 22b show the path of the second cutouts, generally straight lines starting from the vertices of the triangles forming the first cutouts. Other second cutouts can be made differently. In image b) of [Fig.2] and in image c) of [Fig.3], a second cutout comprises the transverse cutting of the rear wing 24b, 24c of the carrier element 2b, 2c, from one end to the other of the width of this rear wing 24b, 24c. In image a) of [Fig.3], the rear wing 24c which forms the uncut base of the triangle of the first cutout 6c resulting from the first cutout is cut along two parallel transverse lines.

[0038] Despite the presence of the tensioned traction members 10, the production of the second cuts may present risks for the stability of the built structure 1. In order to avoid endangering operators responsible for carrying out the weakening cuts, at least one second weakening cut is carried out by a remotely operated cutting of a part of a load-bearing element 2.

[0039] It should be noted that it is not always necessary to carry out initial weakening cuts, and that a weakening cut can be carried out entirely by a remotely operated cutting tool 36, for example over the entire section of a load-bearing element 2b. Preferably in this case, the weakening cuts are rectilinear.

[0040] The remotely operated cutting of a portion of the carrier element 2 is carried out by a remote-controlled cutting device. With reference to [Fig. 4] and [Fig. 5], the remote-controlled cutting device 30 may comprise a movable carriage 32 on a rail 34 mounted against the carrier element 2, the movable carriage 32 being provided with a cutting tool 36 oriented towards the carrier element 2, the movable carriage 32 traveling along the rail 34 during cutting. Advantageously, the movable carriage 32 may be provided with an imager 38 such as a camera, the field of vision of which is directed so that the cutting tool 36 is visible to the imager 38. It is then possible to monitor distance the operation of the cutting tool 36.

[0041] More specifically, the rail 34 forms an open circuit against the carrier element 2, the mobile carriage 32 being configured to leave for the rail 34 at the end of the cutting. In the example of [Fig.4], the carrier element 2 is a carrier beam comprising a web with a cross-shaped section, the ends of which are provided with wings 24. The guide rail 34 is fixed to the wings 24 by fixing members 42 such as flanges. Preferably, these fixing members 42 enclose the carrier element 2 in order to be able to maintain the remote-controlled cutting device 30 without requiring drilling of the carrier element 2.

[0042] In this example, the guide rail 34 runs almost around the carrier element 2, extending on four sides of the carrier element 2. The rail 34, however, has a start 34a and an end 34b, and an escape space 44 at this end 34b which allows the movable carriage 32 to leave the rail 34. The guide rail 34 may, however, have other shapes, as long as these shapes allow the movable carriage 32 to move opposite the areas to be cut.

[0043] The mobile carriage 32 is provided with a motor coupled to first drive means, the guide rail 34 being provided with second drive means complementary to the first drive means. For example, the guide rail 34 may be provided with a chain 46 or notches, and the mobile carriage 32 may be provided with a notched wheel 48 engaging in the chain 46. The mobile carriage 32 may also comprise a holding piece 40 configured to ensure the holding of the mobile carriage 32 on the guide rail 34. For example, the holding piece 40 may extend from the mobile carriage 32 towards the carrier element 2 to a side of the guide rail 34 facing the carrier element 32.

[0044] The cutting tool 36 of the mobile carriage 32 may comprise a torch 36a, 36b allowing the implementation of oxycutting, in particular when the carrier element 2 is metallic. Other cutting tools may be used, such as for example a grinder.

[0045] The cutting is remotely operated in the sense that the remote-controlled cutting device 30 is operated remotely from the built structure 1 with load-bearing elements 2, i.e. at least 10 m from the footprint of the built structure 1, preferably at least 20 m, and preferably even further. At least the movement of the cutting tool 30 is remotely controlled, as is preferably the activation of the cutting tool 36.

[0046] As illustrated in the example of [Fig.5], the mobile carriage can be provided with two cutting tools 36a, 36b oriented towards the carrier element 2, and is in this example provided with two torches at different heights, for example in order to make two second parallel cuts as in image a) of [Fig.3].

[0047] When performing a second weakening cut, the mobile carriage 32 remote-controlled travels along the rail 34. The cutting tool 36 is then activated to cut the carrier element 2 when parts of it are within cutting range during movement. It is possible to provide for activation and deactivation of the cutting tool depending on its movement. In particular, the cutting tool is preferably deactivated (e.g. the gas supply is stopped) when the mobile carriage reaches the end of the rail. The mobile carriage 32 then exits the rail 34 through the exhaust space 44.

[0048] Preferably, in order to be able to safely recover the cutting device, the latter is moored, for example by a rope 52 or a chain, to a cable 50 which prevents the mobile carriage 32 from falling to the ground when leaving the guide rail 34. The mobile carriage 32 can then be moved along the cable 50, for example by gravity (like a zip line) or by traction. It is then possible to move the mobile carriage 32 to a safe distance from the built structure 1 in order to recover it, before the collapse phase.

[0049] Preferably at this stage, at least one of the load-bearing elements 2 has been transversely cut, and this load-bearing element 2 is therefore in two parts, or at least has been cut over more than 75%, or even 90% of its section. Once the second weakening cuts have been carried out by remote-controlled cutting, it is possible to move on to the collapse phase. The collapse phase may comprise a break in the traction by the first traction member 10a exerting a traction force on a load-bearing element 2 in a first direction, while a second traction member 10b continues to exert a traction force on the same load-bearing element 2 in a second direction different from the first direction.Preferably, this breaking of traction is carried out by a remote-controlled cutting of a first traction member 10a exerting a traction force on a carrier element 2 in a first direction, while a second traction member 10b exerting a traction force on the same carrier element 2 in a second direction different from the first direction is not cut.

[0050] In order to carry out the remote-controlled cutting of the first traction member 10a, a remote-controlled cutting tool 60 of the first traction member 10a is arranged before the collapse phase, for example before the weakening phase or after the tensioning of the first traction member 10a, so as to be able to cut the first traction member. The cutting tool is remote-controlled in the sense that it is operated at a distance from the built structure 1, that is to say at least 10 m from the remote-controlled cutting tool 60, preferably from the footprint of the built structure, preferably at least 20 m, and preferably even further. It is essentially the activation of the remote-controlled cutting tool 60 which is remote-controlled, for example the ignition of the torch. The remote-controlled cutting tool 60 is chosen to be able to quickly cut the first traction member 10a. traction. In particular, the remote-controlled cutting of the first traction member 10a can be carried out by an oxy-cutting tool, the activation of which is carried out remotely. Other tools could however be used, such as discs. An oxy-cutting tool such as a blowtorch, however, has the advantage of good reliability and low cost, which makes it sacrificial.

[0051] With reference to [Fig. 6], a first carrier element 2b is coupled to a first traction member 10a and a second traction member 10b, which exert on the first carrier element 2b a traction respectively in a first direction and in a second direction, according to opposite sides of the first carrier element 2b. The first carrier element 2b has a first transverse weakening cut 6b opening towards the second direction, that is to say with a greater removal of material in this direction. The first traction member extends to a second carrier element, to which it is secured. In this example, the first traction member 10a comprises a hollow cylinder 12 and a cable 16 coupled to the rod 14 of the hollow cylinder 12. The rod 14 of the hollow cylinder 12 passes through the second carrier element 2c. The blowtorch is here configured so that its flame is at the level of rod 14, and breaks it.

[0052] While during the weakening phase the tensile forces of the two tensile members 10a, 10b mostly compensate each other, the breaking of the force exerted by the first tensile member 10a results in a traction exerted only in the second direction by the second tensile member 10b, which destabilizes the carrier element 2b. Due to the weakening cutouts 6b, 22b in the first carrier element 2b, the latter is no longer structurally able to resist, and then gives way. Depending on the weakening cutouts 6b, 22b, one or more joints appear on the carrier element, at the weakening cutouts 6b, 22b.

[0053] In the example of [Fig.7], the first traction members 10a have just been cut, while the second traction members 10b are still under tension. It can be seen that the first inner front beam 2b breaks along three articulations 50a, 50b, 50c corresponding to the three weakening cuts which have been made there. Due to the traction by the second traction member 10b, two adjacent parts of the first beam 2b tilt towards the second direction, in the direction of articulation, which is here in alignment with the other front beams, towards the left.

[0054] In some cases, it is possible that the arrangement of the load-bearing elements 2 leads to destabilization of the built structure 1 during the remote-controlled cutting of a portion of the load-bearing element 2b during the weakening phase, in which case it is passed directly to the collapse phase without it being necessary to carry out the remote-controlled cutting of the first traction member 10a. Preferably in this case, the horizontal projections of the second traction direction and the first direction traction forces are located in a horizontal angular quadrant of less than 120°, so that the traction forces of the traction members 10, instead of compensating horizontally, accumulate to destabilize the load-bearing element 2b cut by the remotely operated cutting tool 36. As soon as the cut load-bearing element 2b gives way, the remotely operated cutting of a part of the load-bearing element 2b is interrupted. For example, when the load-bearing element 2b is a strut, the remotely operated cutting of the load-bearing element 2b by the remotely operated cutting tool 36 can directly lead to the collapse of the built structure 1.

[0055] Once certain load-bearing elements 2 have given way, the built structure is destabilized. However, the weakening cuts previously made do not allow other load-bearing elements 2 to resist this destabilization, and the other load-bearing elements 2 give way in turn, as illustrated in [Fig.8]. During the collapse phase, it is possible to increase the traction of traction members 10 in order to promote the tilting of parts of the load-bearing elements 2 or to make them give way more easily. Possible thrust members mentioned above can also be used for this purpose. It is also possible to use other types of traction, for example via a vehicle. Once the structure is built on the ground, it is possible to deconstruct it conventionally.

[0056] The invention is not limited to the embodiment described and shown in the attached figures. Modifications remain possible, in particular from the point of view of the constitution of the various technical characteristics or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. A method of demolishing a built structure (1) with load-bearing elements (2), comprising a weakening phase and a subsidence phase, the weakening phase comprising carrying out a weakening cut for each load-bearing element of a plurality of load-bearing elements (2) extending in a longitudinal direction, the subsidence phase comprising the subsidence of the built structure (1) in a subsidence direction (Y), characterized in that the method comprises for at least one load-bearing element (2b) of the plurality of load-bearing elements (2): a) during the weakening phase: - al) tensioning a first traction member (10a) exerting on said load-bearing element (2b) a traction in a first direction, and tensioning a second traction member (10b) exerting on the load-bearing element (2b) a traction in a second direction different from the first traction,the first direction and the second direction each having a main component perpendicular to the longitudinal direction, then - a2) carrying out a weakening cut in the supporting element (2b), the method comprising a remotely operated cut of a part of the supporting element (2b) during the weakening phase as a weakening cut and / or a remotely operated cut of the first traction member (10a) during the sagging phase.,

2. Method according to claim 1, in which the remotely operated cutting of a part of the carrier element and / or the remotely operated cutting of the first traction member is carried out using a remotely operated cutting tool (36, 60) activatable at a distance of at least 10 meters.

3. A method according to claim 1, wherein the remotely operated cutting of a portion of the carrier element (2b) is performed by a remotely controlled cutting device, the cutting device comprising a movable carriage (32) on a rail (34) mounted against the carrier element (2), the movable carriage (32) being provided with a cutting tool (36) oriented towards the carrier element (2), the movable carriage (32) traveling along the rail (34) during cutting.

4. A method according to claim 3, wherein the movable carriage (32) is provided with a motor coupled to first drive means (48), the guide rail (34) being provided with second drive means (46) complementary to the first drive means.

5. Method according to one of claims 3 to 4, in which the rail (34) forms an open circuit against the carrier element (2), the movable carriage (32) leaving the rail (34) at the end of the cutting.

6. Method according to one of the preceding claims, in which the first traction member (10a) comprises a hollow cylinder (12) provided with a rod (14) to which is fixed a cable or chain coupled to the carrier element (2).

7. Method according to the preceding claim, in which the remotely operated cutting of the first traction member (10a) comprises the cutting of the rod (14) by a remotely operated cutting tool (36).

8. Method according to one of the preceding claims, in which the remote-controlled cutting of the first traction member (10a) is carried out by an oxy-cutting tool.

9. A method according to one of the preceding claims, wherein the weakening cut comprises a first cut of a first portion (4c, 4b) of the carrier element, and a second cut of a second portion (6b, 6c) of the carrier element, the first portion and the second portion being located at a distance from each other in the longitudinal direction.

10. System for demolishing a built structure with load-bearing elements, comprising: - at least two traction members (10a, 10b) capable of exerting traction forces on a load-bearing element (2), - a remotely operated cutting tool (60) capable of cutting a traction member, - a remotely operated cutting device (30) capable of making a weakening cut in the load-bearing element, in which a first traction member (10a) exerts traction on the load-bearing element (2) in a first direction, and a second traction member exerting traction on the load-bearing element in a second direction different from the first traction, the first direction and the second direction each having a main component perpendicular to the longitudinal direction in which the load-bearing elements extend, the remotely operated cutting device being arranged against the load-bearing element, and the remotely operated cutting tool faces the first traction member.

Images