Descending type dismantling method for high-rise building

Abstract

The descending type dismantling method comprises the steps that a cage type protection frame is erected on the periphery of a to-be-dismantled building, and sliding rails on the inner side of the protection frame abut against the outer wall of the to-be-dismantled building; an operation groove is dug in the first-layer structural beam, and a piston rod of a jack placed in the operation groove abuts against the first-layer structural beam; the top plate, the outer wall and the bearing column of the first layer are dismantled, the piston rod retracts, and the non-dismantled part of the to-be-dismantled building descends and abuts against the bottom plate; a piston rod of the jack abuts against the second-layer structural beam, the top plate, the outer wall and the bearing column of the second layer are dismantled, the piston rod retracts, and the non-dismantled part of the building to be dismantled descends and abuts against the first-layer structural beam; the rest floors are dismantled according to the method, and finally the structural beams are dismantled. By means of the protection frame, the sliding rails are in sliding connection with the to-be-disassembled building, the controllability of the non-disassembled part of the to-be-disassembled building in the descending process is ensured, finally all structural beams are stacked on the bottom plate, and then the structural beams are disassembled.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high-rise building demolition, and particularly relates to a descending demolition method for high-rise building. BACKGROUND

[0002] The demolition of high-rise buildings has always been a difficult problem in the engineering field. At present, there are two major categories: top-down layer-by-layer crushing and in-situ blasting. The layer-by-layer crushing includes manual demolition, mechanical demolition and segmented blasting demolition. For example, the patent with the publication number CN118031744A discloses a high-rise building self-top-down segmented blasting demolition method. Although this method is fast, it has a violent impact, has strict requirements on the surrounding environment, and cannot achieve efficient material recycling. Manual demolition can achieve efficient material recycling, but it is slow and has a long construction period, and requires long-term high-altitude operation. The use of manual demolition has been greatly reduced, and only a few areas are still using it. Although mechanical demolition is much more efficient than manual demolition, the self-weight of the demolition machinery is large, and when performing high-altitude operation, the building load is insufficient, which has the risk of collapse. In-situ blasting is divided into in-situ collapse blasting and directional collapse blasting. Both blasting methods will produce a large amount of dust pollution, and there is also a problem of low material recycling efficiency.

[0003] With the renewal and reconstruction of urban buildings, the demolition of urban buildings has also increased accordingly. The above-mentioned blasting demolition methods all have problems. First, the density of urban buildings is high, the space between buildings is small and limited, and traditional blasting demolition techniques cannot be applied due to insufficient collapse space. Second, individual flying objects may be produced during the blasting process, which poses a threat to the surrounding environment and passing pedestrians and vehicles. Third, the demolition of high-rise buildings by whole blasting in densely populated urban areas will have some impact on the surrounding environment. The shock wave and vibration accompanying blasting and building collapse can pose a potential threat to surrounding buildings and underground facilities, which may cause safety problems such as cracks and collapse.

[0004] Therefore, how to safely and efficiently demolish high-rise buildings in a confined space of a densely built area still needs to be studied. SUMMARY

[0005] To at least partially solve the above-mentioned problems in the prior art, the present application proposes a descending demolition method for high-rise building, which comprises the following steps:

[0006] (1) A cage-type protection frame is erected around the building to be demolished. The protection frame includes protective columns and trusses erected on the protective columns. The trusses are annular and extend around the building to be demolished. The inner side of the protection frame has a slide rail extending in the vertical direction. The inner side of the slide rail abuts against the outer wall of the building to be demolished.

[0007] (2) excavate a working slot on the bottom plate, the working slot is directly below the first layer of structural beams, place the jack in the working slot, start the jack, and make the piston rod of the jack abut against the first layer of structural beams;

[0008] (3) remove the top plate and outer wall of the first layer, cut off the load-bearing column of the first layer, and make the undemolished part of the building to be demolished supported on the jack through the first layer of structural beams;

[0009] (4) retract the piston rod of the jack, and the undemolished part of the building to be demolished is lowered synchronously until the first layer of structural beams abut against the bottom plate, excavate a working hole on the first layer of structural beams, the working hole is connected with the working slot on the bottom plate in the vertical direction, take out the jack from the working hole, and the demolition of the first floor is completed;

[0010] (5) place the jack in the working hole of the first layer of structural beams, start the jack, and make the piston rod of the jack abut against the second layer of structural beams;

[0011] (6) remove the top plate and outer wall of the second layer, cut off the load-bearing column of the second layer, and make the undemolished part of the building to be demolished supported on the jack through the second layer of structural beams;

[0012] (7) retract the piston rod of the jack, and the undemolished part of the building to be demolished is lowered synchronously until the second layer of structural beams abut against the first layer of structural beams, excavate a working hole on the second layer of structural beams, make the working hole on the second layer of structural beams connected with the working hole on the first layer of structural beams in the vertical direction, take out the jack from the working hole, and the demolition of the second floor is completed;

[0013] (8) repeat steps (5) to (7) until the demolition of all floors is completed, and the structural beams are sequentially stacked on the bottom plate in the vertical direction;

[0014] (9) disassemble the structural beams.

[0015] In step (2), the bottom of the working slot does not penetrate the bottom plate downward, and in the specific demolition process, it is recommended that the distance between the bottom of the working slot and the lower surface of the bottom plate be ≥100mm. The piston rod of the jack preferably abuts against the end of the structural beam close to the load-bearing column. The structural beam in the application is a horizontal beam.

[0016] In order to ensure the safe performance of the demolition process, the bearing capacity of the bottom plate and the structural beam of the building to be demolished needs to be evaluated. The bottom plate and the structural beam need to be able to bear the weight of the entire building. When the bottom plate or the structural beam cannot bear the weight of the entire building, if the demolition requirements can be met by simply reinforcing, the building to be demolished can be determined to be demolished by the demolition method in the present application. If the bottom plate and the structural beam cannot bear the weight of the entire building even after simple reinforcement, the demolition method in the present application cannot be used, and other mature demolition methods need to be used.

[0017] If the bottom plate cannot bear the weight of the entire building due to insufficient bearing capacity of the foundation, the bearing capacity of the foundation can be increased by grouting under the bottom plate. If the bearing capacity of the foundation cannot be met by grouting under the bottom plate, the present application cannot be used for demolition. The insufficient bearing capacity of the structural beam can be divided into two cases. One is that the connection strength between the structural beam and the load-bearing column is insufficient, resulting in insufficient bearing capacity of the structural beam. In this case, the bearing capacity of the structural beam cannot be improved by reinforcement, and the present application cannot be used for demolition. The other case of insufficient bearing capacity of the structural beam is that the contact area between the piston rod of the jack and the structural beam is too small, resulting in excessive local pressure on the structural beam, which is prone to cause the structural beam to break. In this case, the force bearing area of the structural beam can be locally reinforced to expand the force bearing area between the structural beam and the piston rod of the jack. In specific construction, steel plates, steel wrapping or carbon fiber composite materials can be used to reinforce the structural beam to expand the force bearing area.

[0018] The jacks in the present application preferably use hydraulic jacks. When the jacks use hydraulic jacks, in step (2), a pipe groove is needed to be opened on one side of the working groove to facilitate the laying of the hydraulic pipe of the jack. The pipe groove extends beyond the projection range of the first layer of structural beams to avoid the first layer of structural beams completely blocking the working groove when they are pressed against the bottom plate, which can cause damage to the hydraulic pipe. The hydraulic pipe is connected to the jack through the pipe groove. In step (5), a through groove is needed to be opened on one side of the working hole to facilitate the laying of the hydraulic pipe of the jack. The through groove extends through one side of the working hole to avoid the second layer of structural beams completely blocking the working hole when they are pressed against the second layer of structural beams, which can cause damage to the hydraulic pipe. The hydraulic pipe is connected to the jack through the through groove.

[0019] In specific operation, the hydraulic control systems of the jacks need to be integrated into the same control system to control the stroke, pressure and other parameters of the piston rod of the jack, so that the jacks can work according to the set steps.

[0020] The protective column is preferably directly opposite the load-bearing column of the building to be demolished, and the sliding rail is arranged on the inner side of the protective column and pressed against the outer wall of the outer load-bearing column.

[0021] In the present application, the top plate, outer wall and load-bearing column of the corresponding floor are removed layer by layer from bottom to top, only the structural beam is reserved, then the undemolished part of the building to be demolished is lowered by using the jack, finally all the structural beams are stacked on the bottom plate, and then the structural beams are demolished, of course, the part of the load-bearing column directly connected with the structural beam is still connected with the structural beam as the connecting point of the structural beam, but the height of the load-bearing column reserved is the same as the height of the corresponding structural beam.

[0022] In the present application, a protective frame composed of protective columns and trusses is erected outside the building to be demolished and is connected with the building to be demolished through sliding rails, so that the undemolished part can effectively resist wind load and accidental eccentric horizontal force caused by different jacking speeds or uneven load distribution during the lowering process, thereby ensuring the controllability of the undemolished part during the lowering process.

[0023] By opening operation grooves or operation holes in the bottom plate and the structural beam, it is ensured that the jack does not affect the final contact between the upper beam and the bottom plate or the lower beam after the jack is retracted.

[0024] Further, in order to avoid the operation hole being too deep, the available stroke of the piston rod of the jack is reduced, so in step (5), before placing the jack in the operation hole of the first layer of structural beams, the operation groove is first filled and leveled to form a leveling surface, and the jack is arranged on the leveling surface. When filling the operation groove, high-strength non-shrinkage grouting material can be used, or a steel column or steel plates stacked together can be directly placed into the operation groove, and the upper surface of the steel column or the uppermost steel plate needs to be horizontal.

[0025] Further, in order to improve the safety of demolition as much as possible, in steps (5) and (7), a telescopic steel sleeve is arranged directly below the truncated load-bearing column, the height of the telescopic steel sleeve decreases synchronously with the retraction of the piston rod of the jack, and the distance between the top end surface of the telescopic steel sleeve and the truncated surface of the lower end of the load-bearing column is 5-300 mm.

[0026] Specifically, the telescopic steel sleeve comprises an outer steel pipe and an inner steel piece, the outer steel pipe is sleeved on the inner steel piece, a plurality of first through holes are formed on the outer steel pipe, a plurality of second through holes are formed on the inner steel piece, and a crossbar freely passes through the coaxially arranged first through holes and second through holes, so that the outer steel pipe is connected with the inner steel piece through the crossbar; by arranging different first through holes and second through holes in a corresponding and coaxial manner and passing the crossbar through the corresponding first through holes and second through holes, the height of the telescopic steel sleeve can be adjusted.

[0027] Or the telescopic steel sleeve is composed of an outer steel pipe and an inner steel piece screwed together.

[0028] The telescopic steel sleeve is not used as a regular load-bearing component. During the operation, the top end surface of the telescopic steel sleeve always maintains a safe distance of 5-300mm from the truncated surface of the lower end of the load-bearing column. Only when the jack system fails unexpectedly, the telescopic steel sleeve provides instant falling buffer and temporary support for the undemolished part of the building to be demolished, so as to gain time and space for emergency treatment. Since there are a large number of jacks during the demolition of the building, only a single or a small number of jacks may fail, and the number of failed jacks will not exceed 1% probability, so a large number of jacks will not fail at the same time. The failure of a small number of jacks will not have a destructive impact on the entire jack system. The telescopic steel sleeve is only used as an emergency measure in extreme cases, such as a large number of jacks failing at the same time.

[0029] Further, in order to better fit on the outer wall of the building to be demolished, a plastic sliding plate is installed on the inner side of the sliding rail, and the sliding rail is pressed on the outer wall of the building to be demolished through the plastic sliding plate. Since the outer wall of the building often has many pits and is not smooth, the effective contact area between the sliding rail and the outer wall of the building to be demolished is low when the sliding rail is simply made of steel structure. After the plastic sliding plate is installed on the inner side of the sliding rail, the effective contact area with the outer wall of the building to be demolished can be effectively improved by using the elasticity of the plastic.

[0030] Specifically, in step (4), during the descending process of the undemolished part of the building to be demolished, each operation slot replaces N jacks with different telescopic amounts, N≥3; during the descending process of the undemolished part of the building to be demolished, the first jack is used first, when the retraction amount of the first jack reaches its maximum available retraction amount, the second jack is replaced, when the retraction amount of the second jack reaches its maximum available retraction amount, the third jack is replaced, and so on until the Nth jack is replaced; when the piston rod of the Nth jack is fully retracted, there is a distance between the top end surface of the piston rod of the Nth jack and the lower surface of the second layer of structural beams; according to the use order of the jacks, in at least part of the adjacent two jacks, the maximum retraction amount of the latter jack is less than that of the former jack.

[0031] In step (7), during the descending process of the undemolished part of the building to be demolished, each operation hole replaces M jacks with different telescopic amounts, M≥3; during the descending process of the undemolished part of the building to be demolished, the first jack is used first, when the retraction amount of the first jack reaches its maximum available retraction amount, the second jack is replaced, when the retraction amount of the second jack reaches its maximum available retraction amount, the third jack is replaced, and so on until the Mth jack is replaced; when the piston rod of the Mth jack is fully retracted, there is a distance between the top end surface of the piston rod of the Mth jack and the lower surface of the second layer of structural beams; according to the use order of the jacks, in at least part of the adjacent two jacks, the maximum retraction amount of the latter jack is less than that of the former jack.

[0032] The above design can smoothly make the last jack complete the last descent of the undismantled part and press against the bottom plate or the structural beam that has been stacked on the bottom plate, and when the jack is a hydraulic cylinder, the Nth and Mth jacks need to use multi-stage hydraulic cylinders to improve the operation efficiency.

[0033] Further, at least two jacks are arranged around each load-bearing column, the jacks around each load-bearing column are divided into two jack groups, and the piston rods of the jacks in the two jack groups are alternately retracted during the descent of the undismantled part of the building to be dismantled. The design can make the two jack groups serve as backup for each other, and when part of the jacks in one jack group fail, the jacks in the other jack group can be quickly switched to ensure the normal progress of the demolition. In actual operation, the piston rods of the two jack groups are controlled to alternately retract in a preset order and small steps by a hydraulic synchronous control system, to ensure stable load transfer and smooth descent of the undismantled part of the building to be measured.

[0034] Specifically, to form stable support for the undismantled part of the building to be dismantled and have greater safety guarantee, each structural beam is supported by a jack at both ends during the descent of the undismantled part of the building to be dismantled.

[0035] Specifically, during the demolition of the building to be dismantled, the cage-type protection frame is synchronously removed upward beyond the top part of the building to be dismantled, or the cage-type protection frame is removed after step (8) is completed. In specific construction, different methods are used to remove the cage-type protection frame according to needs.

[0036] In the construction process of the present application, measures such as spray dust reduction, static cutting, and local enclosure are preferably used to control dust and noise pollution.

[0037] During the entire demolition process of the building, a real-time monitoring system needs to be established, including monitoring of the pressure and displacement of each jack, monitoring of the overall inclination and settlement of the building to be dismantled, and monitoring of the deformation of the protection frame, and a warning threshold is set to realize controllable demolition.

[0038] Further, to improve the lateral displacement resistance of the protection frame, the slide rail is pressed against the outer wall of the building to be dismantled by a pre-pressing bolt that is rotatably screwed on the protection frame. Screwing the pre-pressing bolt can make the protection frame bend outward, thereby generating a pre-stress on the slide rail and improving the stability of the protection frame.

[0039] The present application also includes the following beneficial effects:

[0040] High safety: Through the cage protection frame, jack's sequence descent and telescopic steel sleeve's multiple insurance, the stability and continuity of the descent process is systematically solved, and the uncontrollable risk of the prior art is converted into controllable local failure.

[0041] Green and high recovery rate: Near-surface operation can effectively limit dust and noise pollution, and it can operate in dry environment, which can increase the material recovery rate from about 50% to more than 93%, and the concrete recovery rate can reach 99%.

[0042] Economical and efficient: The full-height scaffold and upper floor reinforcement are saved, the logistics path is the shortest, the operation is in a flow rhythm, and the comprehensive cost is significantly reduced.

[0043] Significant social benefits: Greatly reduce the interference to the surrounding community. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The top view structure diagram of the building to be demolished after setting the protection frame.

[0045] Figure 2 The enlarged view of the middle A part. Figure 1

[0046] Figure 3 The schematic diagram of the protection frame after erection.

[0047] Figure 4 The schematic diagram of the operation groove dug on the bottom plate.

[0048] Figure 5 The schematic diagram of the jack installed in the operation groove.

[0049] Figure 6 The schematic diagram of the first layer of bearing column after cutting.

[0050] Figure 7 The schematic diagram of the telescopic steel sleeve installed below the bearing column section.

[0051] Figure 8 The schematic diagram of the undemolished part of the building to be demolished during the descent process.

[0052] Figure 9 The schematic diagram of the first layer of structural beam pressing on the bottom plate.

[0053] Figure 10 The schematic diagram of the operation groove after filling and leveling.

[0054] Figure 11 The schematic diagram of each structural beam stacked on the bottom plate in the vertical direction.

[0055] Figure 12 ​The first structure diagram of the telescopic steel sleeve.

[0056] Figure 13 The second structure diagram of the telescopic steel sleeve.

[0057] Figure 14 The schematic diagram of the slide rail pressing on the outer wall of the building to be demolished by the pre-pressed bolt. DETAILED DESCRIPTION

[0058] The following describes the descending demolition method of the high-rise building in the present application. Before the building to be demolished is demolished, the bearing capacity of the bottom plate and the structural beam of the building to be demolished is evaluated. When the bottom plate and the structural beam can bear the weight of the entire building, the following steps are performed for demolition.

[0059] When the bottom plate cannot bear the weight of the entire building, if the bottom plate cannot reach the requirement after grouting and reinforcing the bottom plate, the method of the present application cannot be used for demolition. If the bottom plate can bear the weight of the entire building after grouting and reinforcing the bottom plate, the method of the present application can be used for demolition.

[0060] When the structural beam cannot bear the weight of the entire building, it is necessary to evaluate whether the bearing capacity of the structural beam can reach the requirement after reinforcing measures are taken. When the cost of the reinforcing measures is too high, it is recommended to give up the method of the present application for demolishing the building. If the cost of the reinforcing measures is within a reasonable range and the bearing capacity of the structural beam can reach the requirement after the reinforcing measures are taken, the method of the present application is used for demolishing the building after the structural beam is reinforced.

[0061] The reinforcing measures for the structural beam can specifically use the way of laying a steel plate, wrapping steel or wrapping carbon fiber composite material at the bottom of the structural beam to reinforce, or use other existing mature reinforcing measures to disperse the load and avoid excessive concentration of the load to prevent local crushing of the structural beam.

[0062] The descending demolition method includes the following steps:

[0063] (1) Please refer to Figures 1-3 In the present embodiment, the building to be demolished has ten floors, and the cross section of the building to be demolished is approximately square. A cage type protection frame 20 is erected around the building to be demolished. The protection frame 20 includes sixteen protective columns 21 erected along the outer side edges 339 of the bottom plate 330 of the building to be demolished. The sixteen protective columns are divided into four groups, and the four groups of protective columns are respectively arranged on the outer sides of the four outer walls of the building to be demolished. A truss 22 is erected on the protective columns, and the truss extends in a ring shape and surrounds the building to be demolished. In the present embodiment, the protective column specifically uses a steel lattice column, and the truss is made of H-shaped steel.

[0064] A vertical sliding rail 23 is fixedly installed on the inner side of the protection frame by means of bolts, and a plastic sliding plate 24 is installed on the inner side of the sliding rail 23, and the plastic sliding plate is pressed against the outer wall of the building to be demolished, so that the sliding rail is pressed against the outer wall of the building to be demolished through the plastic sliding plate. In the embodiment, the sliding rail is made of H-shaped steel, and the plastic sliding plate is made of polytetrafluoroethylene plate, and the plastic sliding plate is fixed on the sliding rail by means of bolts.

[0065] The protective column is opposite to the load-bearing column on the outer side of the building to be demolished, and the sliding rail is specifically arranged on the inner side of the protective column, so that the sliding rail is pressed against the outer wall of the outer load-bearing column through the polytetrafluoroethylene plate.

[0066] In order to make the polytetrafluoroethylene plate well fit the outer wall of the outer load-bearing column, it is necessary to remove the protrusions such as the eaves, bay windows and balconies on the top of the building in advance.

[0067] (2) Please refer to Figure 4 An operation groove 41 is opened on the bottom plate 330, and the bottom surface of the operation groove is leveled, and the operation groove is located directly below the first layer of structural beams 331. Please refer to Figure 5 The jack 49 is placed in the operation groove 41, and the jack is started, so that the piston rod of the jack is pressed against the lower surface of the first layer of structural beams. The thickness of the bottom plate is 500mm, and the depth of the operation groove is 300mm. After leveling the bottom surface of the operation groove, the jack is placed in the operation groove. In this application, the structural beam is a horizontal beam. In this embodiment, the jack is a hydraulic jack. In order to facilitate the laying of the hydraulic pipe of the jack, a pipe groove is formed on one side of the operation groove, and the pipe groove extends out of the projection range of the first layer of structural beams, so as to avoid that the first layer of structural beams completely block the operation groove when they are pressed against the bottom plate, and damage the hydraulic pipe. The hydraulic pipe is connected to the jack after passing through the pipe groove.

[0068] (3) Please refer to Figure 6 The top plate and the outer wall of the first layer are removed, and the load-bearing column 11 of the first layer is cut off, so that the undemolished part of the building to be demolished is supported on the piston rod of the jack through the first layer of structural beams 331.

[0069] (4) Please refer to Figure 7 and Figure 8 A telescopic steel sleeve 50 is installed directly below the truncated load-bearing column, the height of the telescopic steel sleeve is lowered synchronously with the retraction of the piston rod of the jack, and the distance between the top end surface of the telescopic steel sleeve and the truncated surface of the lower end of the load-bearing column is 5-200mm.

[0070] Please refer to Figure 12In the embodiment, the telescopic steel sleeve 50 comprises an outer steel pipe 51 and an inner steel pipe 52 which is formed as an inner steel member. Five rows of first through holes 511 are formed in the upper part of the outer steel pipe 51 in the vertical direction, each row having three pairs of first through holes 511, the two first through holes in each pair being arranged on opposite sides of the outer steel pipe, the center distance between the two adjacent rows of first through holes being 200 mm, and the center distance between the first through holes in the same row being 180 mm.

[0071] Twenty rows of second through holes 521 are formed in the inner steel pipe 52 in the vertical direction, each row having three pairs of second through holes 521, the two second through holes in each pair being arranged on opposite sides of the inner steel pipe, the center distance between the two adjacent rows of second through holes being 200 mm, and the center distance between the second through holes in the same row being 180 mm. The inner steel pipe is inserted into the inner cavity of the outer steel pipe, and by adjusting the depth of the insertion of the inner steel pipe into the outer steel pipe, the first through holes in the outer steel pipe can be coaxially arranged corresponding to different second through holes in the inner steel pipe. The horizontal rod 53 passes through the corresponding first and second through holes to connect the inner steel pipe and the outer steel pipe together. In the embodiment, the horizontal rod is a screw rod, and it can be understood that in other embodiments, the horizontal rod can also be made of a steel pipe or a steel bar.

[0072] Figure 12 In the embodiment, Figure 12 (a) is a drawing of the telescopic steel sleeve in the longest state, Figure 12 (b) is a drawing of the telescopic steel sleeve after shortening, Figure 12 (c) is Figure 12 (b) is a left view of (b).

[0073] The telescopic steel sleeve 50 is a safety redundant arrangement, which is used to support the undemolished part when the undemolished part of the building to be demolished suddenly sinks due to the failure of part of the jack pressure during the lowering process of the undemolished part. During the lowering process of the undemolished part of the building to be demolished, the depth of the insertion of the inner steel pipe into the outer steel pipe is increased synchronously to adjust the height of the telescopic steel sleeve 50, and when the height of the telescopic steel sleeve 50 cannot be lowered any more, a telescopic steel sleeve with a lower height is used to continue to protect the undemolished part. In the embodiment, the inner steel pipe and the outer steel pipe are both square pipes, and it can be understood that in other embodiments, the inner steel pipe and the outer steel pipe can also be circular pipes, or the inner steel pipe can be replaced by a round steel, but due to the large mass of the round steel, it is not convenient to move, so it is generally not recommended to use it.

[0074] Please refer to Figure 13 It can be understood that in another embodiment, the telescopic steel sleeve can also be composed of an inner circular steel pipe 56 and an outer circular steel pipe 57 which are screwed together. By screwing the inner circular steel pipe or the outer circular steel pipe, the height of the telescopic steel sleeve can be lowered. The inner circular steel pipe is used as an inner steel member, that is, the telescopic steel sleeve is composed of an inner steel member and an outer steel pipe which are screwed together.

[0075] The piston rod of the jack is retracted, and the undemolished part of the building to be demolished is lowered synchronously until the first layer of structural beams is pressed against the floor. Please refer to Figure 9 An operation hole 42 is drilled on the first layer of structural beams, which is located directly above the operation groove and vertically communicates with the operation groove on the floor. The jack is removed from the operation hole, and the demolition of the first floor is completed.

[0076] In this embodiment, the distance between the first layer of structural beams and the floor is 2.5 meters. During the lowering process of the undemolished part of the building to be demolished, 6 jacks with different extension amounts are sequentially replaced in each operation groove, i.e. N=6, and the 6 jacks include 5 single-stage hydraulic cylinders and 1 three-stage hydraulic cylinder. The strokes of the 5 single-stage hydraulic cylinders are 1.6 meters, 1.0 meter, 0.7 meter, 0.55 meter and 0.4 meter, respectively, and the stroke of the three-stage hydraulic cylinder is 0.5 meter.

[0077] During the lowering process of the undemolished part of the building to be demolished, the first jack is used first, the second jack is replaced when the retraction amount of the first jack reaches its maximum available retraction amount, the third jack is replaced when the retraction amount of the second jack reaches its maximum available retraction amount, and so on until the Nth jack is replaced. When the piston rod of the Nth jack is completely retracted, there is a distance between the top end face of the piston rod of the Nth jack and the lower surface of the second layer of structural beams. In this embodiment, the 5 single-stage hydraulic cylinders are sequentially placed into the operation groove according to the strokes of 1.6 meters, 1.0 meter, 0.7 meter, 0.55 meter and 0.4 meter, so that the undemolished part is gradually lowered, and the lowering of each single-stage hydraulic cylinder is 0.87 meter, 0.6 meter, 0.3 meter, 0.15 meter and 0.15 meter, respectively. Finally, the three-stage hydraulic cylinder is placed into the operation groove, so that the second layer of structural beams of the undemolished part is supported on the floor, and the piston rod of the three-stage hydraulic cylinder is completely retracted. When the piston rod of the three-stage hydraulic cylinder is completely retracted, the height of the three-stage hydraulic cylinder is 285 mm. An operation hole is drilled on the first layer of structural beams, and the three-stage hydraulic cylinder is removed from the operation hole.

[0078] Due to step (4), the jacks are used according to the strokes of 1.6 meters, 1.0 meter, 0.7 meter, 0.55 meter and 0.4 meter, so that the maximum retraction amount of the rear jack is less than the maximum retraction amount of the front jack among the first five jacks.

[0079] (5) Please refer to Figure 10 High-strength non-shrinkage grouting material 43 is cast and leveled in the operation groove to form a leveling surface. After the high-strength non-shrinkage grouting material solidifies and reaches the set strength, the jack is placed in the operation hole of the first layer of structural beams and supported on the leveling surface, the jack is started, and the piston rod of the jack is pressed against the second layer of structural beams. This step is similar to step (2), and details can be referred to Figure 5 .

[0080] In this embodiment, a hydraulic jack is used. To facilitate the laying of the hydraulic pipes of the jack, a through groove needs to be opened on one side of the working hole to prevent the working hole from being completely blocked when the first-layer structural beam presses against the base plate, thus avoiding damage to the hydraulic pipes. The hydraulic pipes are connected to the jack after passing through the through groove.

[0081] (6) Remove the roof slab and exterior walls of the second floor, and cut off the load-bearing columns of the second floor, so that the remaining part of the building to be demolished is supported by the structural beams of the second floor on the jacks. This step is similar to step (3), and you can refer to the following for details. Figure 6 .

[0082] (7) Install a telescopic steel sleeve 50 directly below the cut-off load-bearing column. The height of the telescopic steel sleeve decreases synchronously with the retraction of the piston rod of the jack. The distance between the top surface of the telescopic steel sleeve and the cut-off surface at the bottom of the load-bearing column is 5-200mm.

[0083] The piston rod of the jack retracts, and the undemolished part of the building to be demolished descends simultaneously until the second-floor structural beam presses against the first-floor structural beam. A working hole is then drilled in the second-floor structural beam, connecting vertically to the working hole in the first-floor structural beam. The jack is then removed through the working hole, completing the demolition of the second floor.

[0084] In this embodiment, the height of each structural beam is 400mm, and after pouring high-strength non-shrink grout into the working trench, the depth of each working hole is set to 300mm to facilitate the use of the same jacks to support the undemolished part of the building to be demolished. That is, during the descent of the undemolished part of the building to be demolished, each working hole is equipped with 6 jacks with different extension ranges, i.e., M=6. The 6 jacks include 5 single-stage hydraulic cylinders and 1 three-stage hydraulic cylinder. The strokes of the 5 single-stage hydraulic cylinders are 1.6m, 1.0m, 0.7m, 0.55m and 0.4m, respectively, and the stroke of the three-stage hydraulic cylinder is 0.5m.

[0085] In the descending process of the undemolished part of the building to be demolished, the first jack is used first, when the retraction amount of the first jack reaches its maximum available retraction amount, the second jack is replaced, the maximum retraction amount of the second jack is smaller than the maximum retraction amount of the first jack, when the retraction amount of the second jack reaches its maximum available retraction amount, the third jack is replaced, until the Mth jack is replaced; when the piston rod of the Mth jack is fully retracted, there is a distance between the top end face of the piston rod of the Mth jack and the lower surface of the second layer structure beam. In this embodiment, first, five single-stage hydraulic cylinders are placed in the work tank in the order of stroke 1.6 meters, 1.0 meters, 0.7 meters, 0.55 meters and 0.4 meters, so that the undemolished part gradually descends, and the lowering of each single-stage hydraulic cylinder is 0.87 meters, 0.6 meters, 0.3 meters, 0.15 meters and 0.15 meters respectively, and finally a three-stage hydraulic cylinder is placed in the work tank, so that the second layer structure beam of the undemolished part is supported on the bottom plate, and the piston rod of the three-stage hydraulic cylinder is fully retracted. When the piston rod of the three-stage hydraulic cylinder is fully retracted, the height of the three-stage hydraulic cylinder is 285 mm. The three-stage hydraulic cylinder is taken out through the work hole on the second layer structure beam.

[0086] This step is similar to step (4), and can refer to step (4) and Figure 7 and Figure 8 .

[0087] In step (7), the jacks are used in the order of stroke 1.6 meters, 1.0 meters, 0.7 meters, 0.55 meters and 0.4 meters, so that in the first five jacks, the maximum retraction amount of the rear jack is smaller than the maximum retraction amount of the front jack.

[0088] (8) Repeat steps (5) to (7) until the demolition of all floors is completed, and the structure beams are sequentially stacked on the bottom plate in the vertical direction, please refer to Figure 11 .

[0089] The cage protection frame 20 is demolished. It can be understood that in other embodiments, the cage protection frame can also be demolished upward beyond the top of the building to be demolished as the height of the building to be demolished continuously decreases.

[0090] (9) The structure beams are disassembled.

[0091] In step (9), before disassembling the structure beams, in order to avoid side slipping or collapse during disassembly, H steel is used as protection on both sides of the structure beams, and the H steel is inserted into the bottom plate. From top to bottom, each layer of structure layer is sequentially disassembled by static cutting, and then crushed by crushing equipment, and the steel bars and concrete blocks are respectively recycled.

[0092] In this embodiment, after each floor is demolished, high-strength non-shrinkage grouting material is poured into the working hole in the structural beam of the previous floor and leveled, and after the high-strength non-shrinkage grouting material solidifies and reaches the set strength, the jack is placed in the working hole of the structural beam that has just been demolished to avoid the working holes of the structural beams being too deep due to superposition, affecting the use of the jack. It can be understood that, according to the different thicknesses of the structural beams, without affecting the use of the jack, high-strength non-shrinkage grouting material can be poured into the working hole of the structural beam that has just been demolished after two or three floors are demolished.

[0093] It can be understood that in other embodiments, steel columns or stacked steel plates can also be used to replace high-strength non-shrinkage grouting material.

[0094] In order to make the undemolished part of the building to be demolished descend smoothly, a jack is supported at both ends of each structural beam during the descent of the undemolished part.

[0095] Please refer to Figure 1 For ease of description, the structural beam extending along the X-axis direction is referred to as the first structural beam 12, and the structural beam extending along the Y-axis direction is referred to as the second structural beam 13, wherein the X-axis direction and the Y-axis direction both extend in the horizontal direction and are perpendicular to each other, and in Figure 1 In this embodiment, the jack supported on the first structural beam is referred to as jack A 491, the jack supported on the second structural beam is referred to as jack B 492, and the jacks surrounding each load-bearing column are divided into two jack groups, in this embodiment, the jacks A are taken as one jack group, and the jacks B are taken as the other jack group, and during the descent of the undemolished part of the building to be demolished, the piston rods of the jacks in the two jack groups are alternately retracted.

[0096] During the demolition of the building, the building to be measured needs to be fenced, and spray dust suppression is used, and a static cutting machine is used when the load-bearing column is cut off to control dust and noise pollution.

[0097] During the entire demolition process of the building, a real-time monitoring system is established, including: pressure and displacement monitoring of each jack, overall inclination and settlement monitoring of the building to be demolished, deformation monitoring of the protection frame, and setting of a warning threshold to realize controllable demolition process. The real-time monitoring system uses existing mature technology and will not be described again.

[0098] In order to improve the lateral displacement resistance of the protection frame, in another embodiment, the slide rails can also be pre-pressed, please refer to Figure 14A horizontal inner threaded pipe 61 is welded on the guard column, a light pipe 63 coaxial with the inner threaded pipe is welded on the side of the slide rail 23 facing the guard column, a pre-pressing bolt 62 is screwed in the inner threaded pipe, the end of the pre-pressing bolt 62 extends out of the inner threaded pipe and is inserted into the light pipe and presses against the side of the slide rail 23, the pre-pressing bolt is screwed in the direction of the slide rail to make the protection frame produce outward bending deformation, thus pre-stressing the slide rail and improving the stability of the protection frame. The light pipe is used to improve the stability of the slide rail in the vertical direction and improve the convenience of operation, when installing the slide rail, first screw the pre-pressing bolts to make the ends of the pre-pressing bolts extend out of the inner threaded pipe in the direction of the slide rail, then move the slide rail to make each light pipe on the slide rail be sleeved on the corresponding pre-pressing bolt, continue to screw the pre-pressing bolts to make the pre-pressing bolts press against the slide rail and make the protection frame produce outward bending to pre-stress the slide rail. By using the light pipe, the slide rail can be supported during the screwing of the pre-pressing bolt, and the pre-pressing bolt can be pressed against the slide rail at the set position.

Claims

1. A method of top-down deconstruction of a high-rise building, characterized in that, It comprises the following steps: (1) erecting a cage type protection frame around the building to be demolished, the protection frame comprising protection columns and trusses erected on the protection columns, the trusses being annular and extending around the building to be demolished; the inner side of the protection frame having slide rails extending in the vertical direction, the inner side surface of the slide rails abutting against the outer wall of the building to be demolished; (2) digging a working groove on the bottom plate, the working groove being located directly below the first layer of structural beams, placing a jack in the working groove, and starting the jack to make the piston rod of the jack abut against the first layer of structural beams; (3) removing the roof and outer wall of the first layer, cutting off the load-bearing columns of the first layer, and making the undemolished part of the building to be demolished supported on the jack through the first layer of structural beams; (4) retracting the piston rod of the jack, synchronously lowering the undemolished part of the building to be demolished, until the first layer of structural beams abut against the bottom plate, digging a working hole in the first layer of structural beams, the working hole being in communication with the working groove on the bottom plate in the vertical direction, and taking out the jack from the working hole, thus completing the demolition of the first floor; (5) placing the jack in the working hole of the first layer of structural beams, starting the jack to make the piston rod of the jack abut against the second layer of structural beams; (6) removing the roof and outer wall of the second layer, cutting off the load-bearing columns of the second layer, and making the undemolished part of the building to be demolished supported on the jack through the second layer of structural beams; (7) retracting the piston rod of the jack, synchronously lowering the undemolished part of the building to be demolished, until the second layer of structural beams abut against the first layer of structural beams, digging a working hole in the second layer of structural beams, making the working hole in the second layer of structural beams in communication with the working hole in the first layer of structural beams in the vertical direction, and taking out the jack from the working hole, thus completing the demolition of the second floor; (8) repeating steps (5) to (7) until the demolition of all floors is completed, and the structural beams are sequentially stacked on the bottom plate in the vertical direction; (9) disassembling the structural beams.

2. The method of removal according to claim 1, wherein, In step (5), before placing the jack in the working hole of the first layer of structural beams, the working groove is first filled and leveled to form a leveling surface, and the jack is arranged on the leveling surface.

3. The method of claim 1, wherein, In steps (5) and (7), a telescopic steel sleeve is arranged directly below the cut-off load-bearing column, the height of the telescopic steel sleeve being lowered synchronously with the retraction of the piston rod of the jack, and the distance between the top end surface of the telescopic steel sleeve and the cut-off surface of the lower end of the load-bearing column being 5-300 mm.

4. The method of claim 3, wherein, The telescopic steel sleeve comprises an outer steel pipe and an inner steel piece, the outer steel pipe being sleeved on the inner steel piece, a plurality of first through holes being formed in the outer steel pipe, and a plurality of second through holes being formed in the inner steel piece, a crossbar being freely inserted through the coaxially arranged first through holes and second through holes to connect the outer steel pipe and the inner steel piece; by arranging the different first through holes and second through holes coaxially and correspondingly, and inserting the crossbar through the corresponding first through holes and second through holes, the height of the telescopic steel sleeve can be adjusted. Or the telescopic steel sleeve is composed of the outer steel pipe and the inner steel piece screwed together.

5. The method of claim 1, wherein, A plastic slide plate is mounted on the inner side surface of the slide rail, and the slide rail abuts against the outer wall of the building to be demolished through the plastic slide plate.

6. The method of removal according to claim 1, wherein, In step (4), each working slot is replaced by N jacks with different telescopic amounts during the descending process of the undemolished part of the building to be demolished, N≥3; during the descending process of the undemolished part of the building to be demolished, the first jack is used first, when the retraction amount of the first jack reaches its maximum available retraction amount, the second jack is replaced, when the retraction amount of the second jack reaches its maximum available retraction amount, the third jack is replaced, until the Nth jack is replaced; when the piston rod of the Nth jack is completely retracted, there is a distance between the top end face of the piston rod of the Nth jack and the lower surface of the second layer of structural beams; according to the use order of the jacks, in at least part of the adjacent two jacks, the maximum retraction amount of the latter jack is less than that of the former jack; In step (7), each working hole is replaced by M jacks with different telescopic amounts during the descending process of the undemolished part of the building to be demolished, M≥3; during the descending process of the undemolished part of the building to be demolished, the first jack is used first, when the retraction amount of the first jack reaches its maximum available retraction amount, the second jack is replaced, when the retraction amount of the second jack reaches its maximum available retraction amount, the third jack is replaced, until the Mth jack is replaced; when the piston rod of the Mth jack is completely retracted, there is a distance between the top end face of the piston rod of the Mth jack and the lower surface of the second layer of structural beams; according to the use order of the jacks, in at least part of the adjacent two jacks, the maximum retraction amount of the latter jack is less than that of the former jack.

7. The method of removal according to claim 1, wherein, At least two jacks are arranged around each load-bearing column, the jacks around each load-bearing column are divided into two jack groups, and the piston rods of the jacks in the two jack groups are alternately retracted during the descending process of the undemolished part of the building to be demolished.

8. The method of removal according to claim 1, wherein, During the descending process of the undemolished part of the building to be demolished, a jack is supported at each end of each structural beam.

9. The method of removal according to claim 1, wherein, During the demolition process of the building to be demolished, the part of the cage protection frame above the top of the building to be demolished is simultaneously removed, or the cage protection frame is removed after step (8) is completed.

10. The method of removal according to claim 1, wherein, The sliding rail is pressed against the outer wall of the building to be demolished by a pre-pressing bolt which is rotatably screwed on the protection frame.

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