JP6718392B2 - How to suspend and remove concrete slabs - Google Patents

Description

The present invention relates to a method for suspending and removing concrete slabs, and more particularly to a method for suspending and removing concrete slabs in which a large number of concrete slabs arranged in a row in a continuous direction are sequentially suspended and removed. ..

Ceiling slabs and floor slabs formed by arranging a large number of precast concrete slabs prefabricated in factories in the arranging direction are provided as constituent parts of various structures such as civil engineering structures. However, the ceiling slab and floor slab formed by using such a concrete slab made of precast concrete may need to be removed due to deterioration and renovation of a building.

These precast concrete slabs are generally manufactured so as to have a horizontally long rectangular planar shape, and in the state where both ends in the longitudinal direction are supported from below by supporting members, a large number in the lateral direction are provided. By arranging them in series, they are integrated to form a ceiling slab or floor slab. Therefore, when removing the ceiling slab or floor slab, various techniques have been developed that enable the sequential removal of a large number of these concrete slabs arranged in series (for example, See Patent Document 1).

In the method of removing a ceiling plate of Patent Document 1, as a ceiling slab or a floor slab formed by using a concrete slab made of precast concrete, for example, a tunnel ceiling slab formed by partitioning an upper part of a road tunnel, for example, a jack is used. Using a multi-axle carrier, which is a mobile special vehicle equipped with an attached lift, supports the concrete slabs from below while sequentially removing the concrete slabs from the one located at the tip in the cascading direction. Has become.

JP, 2016-142098, A

However, in the method of sequentially removing the concrete slabs that are connected while supporting it from below by a movable special vehicle equipped with a lifting platform with jacks, a control for raising and lowering while supporting a heavy concrete slab in a well-balanced manner. However, if the road surface or the like on which the special vehicle moves has a vertical gradient or a transverse gradient, the control for raising and lowering the concrete slab while supporting it in a balanced manner becomes more difficult.

It is also possible to remove the concrete slab while hoisting it from above using a mobile crane, but if the space above the ceiling slab is limited, the boom such as a crane can be removed from the concrete slab. It becomes difficult to place it above the floor, making it difficult to secure a sufficient hanging allowance, and the boom and concrete slab come into contact with existing structures when hoisting or hanging the concrete slab. It takes a lot of time and effort to avoid doing so.

Furthermore, as a simple hoisting device that can secure a considerable hoisting allowance even in a narrow space, for example, a hoist crane can be used, but when using a hoist crane, the steel material that supports the hoist crane is fixed. It is necessary to drive the anchor member to the structure above the ceiling slab, such as the top surface of the tunnel, which damages the structure and the anchor member above the ceiling slab. It is difficult to secure a sufficient supporting force only by fixing the steel material by driving it into an object.

Therefore, the development of a new technology that enables the sequential removal of a large number of concrete slabs that are arranged in a row to form a ceiling slab or floor slab in a stable state Is desired.

The present invention provides a method for suspending and removing a concrete slab capable of sequentially and efficiently removing a large number of concrete slabs that form a ceiling slab and a floor slab arranged in a row in a stable state. The purpose is to do.

The present invention is a concrete slab in which both ends are supported from below, and a large number of concrete slabs arranged in a row in the continuous direction are suspended and removed from the concrete slab on the tip side in the continuous direction. In the method of hanging and removing, a supporting stand to which an elevating device is attached, placing both ends on both ends of a concrete slab, respectively, and installing the movable stand in the continuous installation direction, The concrete slab at the tip in the continuous direction is supported by the elevating device from the support frame via the elevating device, and the concrete slab is suspended by the elevating device, and the concrete slab at the tip is suspended. After that, it is configured to include a support member removing step of removing a support member supporting both end portions of the concrete slab at the tip portion, and in the gantry installation step, the lifting device is provided from the support gantry. It is adapted to be movable along an overhanging beam portion provided on the tip side in the continuous direction, and in the concrete plate suspension step, the support platform is attached to the concrete plate of the tip portion. Installed on the concrete slab on the rear end side in the continuous installation direction, and after temporarily lifting the concrete slab at the tip by the elevating device provided in the projecting beam part, the supporting by the elevating device. By moving the concrete slab of the tip portion to a position where the member is replaced, and then by suspending and removing the concrete slab of the tip portion, the concrete slab of the tip portion is provided below the supporting member. It has been achieved.

Then, the method for suspending and removing the concrete slab of the present invention is, in the concrete slab suspension step, the concrete slab of the tip portion to be hung is a space region below the supporting member, in the longitudinal direction thereof. Is preferably rotated further along the connecting direction and then further hung down.

Further, in the method of suspending and removing a concrete slab of the present invention, it is preferable that the concrete slab forms a tunnel ceiling slab that vertically divides a space inside a tunnel.

Further, in the method for suspending and removing a concrete slab of the present invention, it is preferable that the support member is a bracket member provided so as to project inward from a side wall portion of the tunnel.

Furthermore, in the method of suspending and removing a concrete slab of the present invention, it is preferable that the tunnel has a circular or horseshoe-shaped cross-sectional shape.

Further, in the method for suspending and removing a concrete slab of the present invention, it is preferable that the support frame includes an arch-shaped support body.

According to the method of suspending and removing concrete slabs of the present invention, a large number of concrete slabs that are arranged in series to form a ceiling slab or a floor slab can be sequentially and efficiently removed in a stable state. it can.

In a tunnel in which a ceiling slab is removed by a method of suspending and removing a concrete slab according to a preferred embodiment of the present invention, (a) is a schematic cross-sectional view, and (b) is a ceiling slab viewed from above. It is a schematic plan view. A cradle installation step of a method for suspending and removing a concrete slab according to a preferred embodiment of the present invention will be described. (a) is a schematic cross-sectional view, (b) is a schematic vertical cross-sectional view inside a tunnel, (c) ) Is a schematic plan view of the inside of the tunnel. A cradle installation step of a method for suspending and removing a concrete slab according to a preferred embodiment of the present invention will be described. (a) is a schematic cross-sectional view, (b) is a schematic vertical cross-sectional view inside a tunnel, (c) ) Is a schematic plan view of the inside of the tunnel. A cradle installation step of a method of suspending and removing a concrete slab according to a preferred embodiment of the present invention will be described. (a) is an enlarged view of part A of FIG. 3(a), (b) is part B of (a). FIG. A concrete plate suspending step of a method of suspending and removing a concrete plate according to a preferred embodiment of the present invention will be described. (a) is a schematic transverse sectional view, (b) is a schematic longitudinal sectional view inside a tunnel , (C) are schematic plan views of the inside of the tunnel. A supporting member removing step of a method of suspending and removing a concrete slab according to a preferred embodiment of the present invention will be described. (a) is a schematic cross-sectional view, (b) is a schematic vertical cross-sectional view inside a tunnel, ( c) is a schematic plan view of the inside of the tunnel.

A method of suspending and removing a concrete slab according to a preferred embodiment of the present invention is a ceiling slab or a floor slab formed by arranging a large number of precast concrete slabs in the arranging direction, for example, as shown in FIG. In a road tunnel 50 having a horseshoe-shaped cross-sectional shape including an arc-shaped cross-section portion as shown in a) and (b), a tunnel ceiling slab that is formed at the top by vertically partitioning the space inside the tunnel 20 is adopted as a method for removing by sequentially suspending each of the concrete slabs 21 arranged in series. That is, the method of suspending and removing according to the present embodiment can be applied to, for example, deterioration of the tunnel ceiling slab 20 provided in the road tunnel 50, change of the ventilation system using a space above the tunnel ceiling slab 20, and the like. Accordingly, when it becomes necessary to remove the concrete slab 21, it is possible to sequentially and efficiently remove the concrete slab 21 from the one arranged on the tip side in the continuous direction X in a stable state. Was adopted as the method of.

Then, in the method of suspending and removing the concrete slab of the present embodiment, both ends 21b are supported from below, and the concrete slabs 21 arranged in a row in the continuous direction X are arranged at the front end in the continuous direction X. It is a removal method of sequentially suspending and removing from the concrete slab 21 on the side, and as shown in FIGS. 2 to 6, a support platform 30 to which a known simple lifting device 31 such as a hoist crane is attached, Both ends 30c are placed on both ends 21b of the concrete slab 21 and are installed so as to be movable in the continuous direction X (FIGS. 2A to 2C and 3A to 3C). )) and the concrete slab 21 at the tip of the continuous direction X is supported from the support frame 30 via the elevating device 31, and the concrete slab hoisting step is performed by the elevating device 31 (FIG. 5 ( a) to (c)), and a supporting member removing step of removing the supporting member 22 supporting both end portions 21b of the suspended concrete plate 21 after suspending the concrete plate 21 at the leading end. (See FIGS. 6A to 6C), and in the gantry installation step, the elevating device 31 is an overhanging beam provided to overhang from the support gantry 30 to the tip side in the continuous installation direction X. It is attached so as to be movable along the portion 30d, and in the concrete slab suspension process, the support pedestal 30 is mounted on the rear side of the concrete slab 21 on the rear end side in the continuous direction X with respect to the concrete slab 21 at the tip. The concrete slab 21 at the tip end is moved up to a position where the supporting member 22 is replaced by the elevating device 31 after the concrete slab 21 at the top is temporarily lifted by the elevating device 31 provided on the projecting beam portion 30d. After that, the concrete slab 21 at the tip is hung below the support member 22.

Further, in the method of suspending and removing the concrete slab of the present embodiment, in the concrete slab suspending step, the concrete slab 21 at the tip end to be hung down is preferably placed in a space area below the support member 22. After the longitudinal direction L (see FIGS. 5B and 5C) is rotationally moved along the continuous direction X (see FIG. 5A), it is further hung down.

In the present embodiment, the support frame 30 used in the method for suspending and removing a concrete slab has an arch shape as shown in FIGS. 2(a) to (c) and 3(a) to (c). , Both ends 30c are arranged at both ends 21b of the existing concrete slab 21 forming the tunnel ceiling slab 20 and are provided at intervals in the continuous direction X (three in the present embodiment). A support body portion 30a made of H-shaped steel or the like is provided extending above the support body portion 30a in the continuous direction X so as to connect these support body portions 30a and to attach the lifting device 31. And a connecting beam 30b made of I-shaped steel or the like. The connecting beam 30b is provided so as to extend further toward the front end side than the support body portion 30a at the front end portion in the continuous direction X, and the protruding portion is the overhanging beam to which the lifting device 31 is attached. It is part 30d.

Here, the support base 30 preferably suspends the existing concrete slab 21 forming the tunnel ceiling slab 20 of the road tunnel 50 from the concrete slab 21 on the tip side in the continuous direction X and removes it. It is a pedestal that constitutes the hanging and removing mechanism 10 for the concrete slab of the tunnel ceiling used for. The hanging and removing mechanism 10 for the tunnel ceiling concrete slab is installed on the existing concrete slab 21 that is continuously installed, and is mounted on the support pedestal 30 and the support pedestal 30 that are movable in the continuous installation direction X, and then removed. And an elevating device 31 capable of hoisting the concrete slab 21 to be suspended, and a rotating jig 32 hung from the elevating device 31 and rotatably supporting the suspended concrete slab 21 to be removed. It is configured (see FIGS. 3A to 3C and FIGS. 5A to 5C).

Further, in the present embodiment, a pair of connecting beams 30b forming the support frame 30 are provided at the same height position in the supporting main body portion 30a, and the lifting beam device is provided on the projecting beam portions 30d of the pair of connecting beams 30b. 31 are attached respectively. The lifting device 31 is a known simple lifting device such as a hoist crane. The elevating device 31 is attached to the projecting beam portion 30d of each connecting beam 30b so as to be movable in the continuous direction X along the projecting beam portion 30d.

Further, in the present embodiment, the rotary jig 32 that constitutes the suspending and removing mechanism 10 includes an upper beam portion 33 that is suspended from the elevating device 31 and a lower beam portion 34 that suspends the concrete slab 21 to be removed. , The lower beam part 34 is rotatably connected to the upper beam part 33 via the rotary connection part 34a, so that the suspended concrete slab 21 is rotated with respect to the upper beam part 33. You can do it.

In the present embodiment, as shown in FIGS. 1A and 1B, the tunnel ceiling slab 20 to be removed by the method for suspending and removing the concrete slab is a concrete made of precast concrete which is manufactured in advance in a factory or the like. It is formed by arranging a large number of plates 21 in a continuous direction X along the axial direction of the road tunnel 50. Each concrete slab 21 has a short side having a length of, for example, about 1500 mm and a long side having a length similar to the lateral width of the road tunnel 50 at a height position where the tunnel ceiling slab 20 is installed, for example, a long side having a length of 8000 mm. And has a horizontally long rectangular planar shape. The concrete slab 21 supports both ends 21b in the long side direction on a support member 22 which is provided so as to project inward from the side wall portion 51 of the road tunnel 50, and the short side direction is the continuous direction X, It is provided in a state where a large number of long side portions are in contact with each other and are arranged in series. In addition, the concrete slabs 21 arranged in succession are, for example, PC steel wires, connecting steel rods, connecting bolts (not shown) and the like, by a known method. It is provided in a state where it is appropriately integrated with X.

As shown in FIGS. 4(a) and 4(b), the support member 22 that supports both ends 21b in the long side direction of the concrete slab 21 is formed by appropriately processing various steel materials such as H-section steel. Also, a known bracket member for the road tunnel 50 can be used. The bracket member 22 is provided with a joining base portion 22a having a curved outer peripheral surface shape along the arcuate cross-sectional shape of the side wall portion 51 of the road tunnel 50, and a cradle portion 22b provided so as to project inward from the joining base portion 22a. It is formed including and. The joining base portion 22a has, for example, a joining fixing bolt (not shown) in a state where the outer peripheral surface thereof is in close contact with the inner side surface of the side wall portion 51 of the road tunnel 50 at the height position where the tunnel ceiling slab 20 is installed. , The bracket member 22 is firmly joined and fixed to a predetermined position of the side wall portion 51 of the road tunnel 50 by tightening the side wall portion 51 while the pedestal portion 22b is projected inward. You can do it.

In the present embodiment, the bracket member 22 is at a predetermined height position on the side wall portions 51 on both sides of the road tunnel 50 in the continuous direction X of the concrete slab 21, as shown in FIGS. 1( a) and 1 (b ). Along the axial direction of a road tunnel 50, the same pitch as the length of the short side of the concrete slab 21 is attached to each of a plurality of places at intervals, and these pedestals 22b are attached to both ends of the concrete slab 21. By placing the portion 21b, it is possible to support a large number of concrete slabs 21 from below.

The cradle part 22b of the bracket member 22 is provided with a flat mounting surface 22c on which the end 21b of the concrete slab 21 is mounted (see FIGS. 4A and 4B), and the mounting surface 22c is For example, it has a rectangular (square) planar shape having a size of about 400 mm in length and width (see FIG. 1B). Both end portions 21b of the concrete slab 21 are regions obtained by dividing the mounting surface 22c into two in the continuous installation direction X at the end corner portions of each pair of the adjacent concrete slabs 21 on the pedestal portion 22b of each bracket member 22. It is attached by placing each on. Thereby, each of the concrete slabs 21 is mounted with the four corners of the edge on the mounting surfaces 22c of the pedestals 22b of the bracket members 22 at the four positions, respectively. It is supported from below by the member 22 and is attached in a stable state. Each concrete slab 21 is firmly fixed to the bracket member 22 by fastening the fixed anchors 23 toward the pedestal portion 22b at the four corners of the end placed on the placing surface 22c. ing.

Then, in the present embodiment, as described above, the method for suspending and removing the concrete slab is performed by the frame installation step (see FIGS. 2A to 2C and FIGS. 3A to 3C) and the concrete. The plate suspension process (see FIGS. 5A to 5C) and the support member removal process (see FIGS. 6A to 6C) are included.

In the frame installation step in the method of suspending and removing concrete of the present embodiment, the support frame 30 to which the lifting device 31 and the like are attached is placed at both ends 30c at both ends 21b of the concrete plate 21 and the continuous direction X is set. It is installed on the existing tunnel ceiling slab 20 to be removed while being movable. That is, in the gantry installation process, the components of the support gantry 30 and the suspension removal mechanism 10 are disassembled into members of a size and weight that can be assembled manually by a worker using a simple device such as a winch. As shown in FIGS. 2A to 2C and FIGS. 3A to 3C, the transportation vehicle 55 transports the road tunnel 50 to the construction site. The components such as the lifting device 31, the rotary jig 32, and the support frame 30 that have been transported are hoisted using, for example, a small crane 56, and transported onto the existing tunnel ceiling plate 20 to be removed. In addition, other necessary devices and equipment such as a concrete cutter device and a winch are similarly lifted by using, for example, a small crane 56, and are transported onto the existing tunnel ceiling slab 20 to be removed.

Then, by the work on the existing tunnel ceiling slab 20, the worker uses the transported device or equipment from the disassembled lifting and lowering device 31, the rotary jig 32, the support platform 30, and the like, The suspending/removing mechanism 10 including the elevating device 31, the rotary jig 32, and the support frame 30 having the above-described configuration is assembled.

In the assembled support pedestal 30, it is possible to attach a well-known chill tank as a wheel member 37 for movement to both end portions 30c which are also lower end portions of each of the plurality of arch-shaped support main body portions 30a. (See FIGS. 4A and 4B). As a result, the supporting frame 30 together with the attached lifting device 31 and rotary jig 32 can be extruded by, for example, a manual operation of an operator and smoothly moved in the continuous direction X of the concrete slab 21. ..

Further, in the present embodiment, both ends 21b of the concrete slab 21 that forms the existing tunnel ceiling slab 20 that is continuously arranged are made to extend along the continuous direction X of the concrete slab 21, for example, L-shaped steel. The slip prevention guide members 36 (see FIGS. 4A and 4B) may be attached respectively. Thus, when suspending the concrete slab 21 at the tip end portion to be removed from the arch-shaped support main body 30a, both ends 30c of the support main body 30a are widened by the weight of the suspended concrete slab 21. Therefore, it is possible to effectively prevent it from being displaced to the outside, and guide both end portions 30c of the support pedestal 30 to move the support pedestal 30 more in the continuous direction X of the concrete slab 21. It will be possible to move smoothly.

Further, in the present embodiment, as described above, the pair of connecting beams 30b forming the supporting frame 30 are provided at the same height position in the supporting main body portion 30a, and the projecting beam portion 30d of each connecting beam 30b is provided. Further, the elevating device 31 is attached so as to be movable in the continuous installation direction X along the projecting beam portion 30d. With this, the concrete slab 21 to be removed can be hung from the support body 30a by the pair of lifting devices 31 while interposing the rotary jig 32, and can be hung or hung in a more stable state. become.

In the concrete plate suspending step in the method of suspending and removing concrete of the present embodiment, the concrete plate 21 to be removed at the leading end in the continuous installation direction is supported from the support frame 30 via the lifting device 31. It is hung by the lifting device 31. That is, in the concrete slab suspension process, as shown in FIGS. 5A to 5C, the support pedestal 30 is mounted on the concrete slab 21 on the rear end side of the concrete slab 21 at the front end in the continuous direction X. Installed on top of each of the connecting beams 30b, and the lifting device 31 attached to the projecting beam portion 30d of each connecting beam 30b temporarily lifts the concrete slab 21 at the tip, and then the lifting device 31 moves the bracket member 22 to a position where the bracket 22 can be replaced. After the concrete slab 21 is moved, the concrete slab 21 at the tip is hung below the bracket member 22.

In the concrete slab suspension process, for example, the support body 30a of the support frame 30 provided at the tip in the continuous direction X is located closer to the rear end than the concrete slab 21 at the front in the continuous direction X. After moving the support base 30 so that it is installed on the adjacent concrete slab 21, it is preferable to fix the support base 30 at the moved position. The support frame 30 is fixed by fixing the support body portion 30a at the rear end of the continuous installation direction X at both ends 21b of the concrete slab 21 in the continuous installation direction X (see FIG. ), (b)) or by directly fixing the support body 30a at the rear end of the continuous direction X to the concrete slab 21. As a result, when the concrete slab 21 at the tip end is lifted by the lifting device 31 attached to the projecting beam portion 30d of each connecting beam 30b, the rear end side of the support pedestal 30 rises and the support pedestal 30 becomes unstable. Can be effectively avoided.

In this embodiment, after the support base 30 is installed on the concrete slab 21 on the rear end side of the continuous installation direction X, it should be removed by the lifting device 31 attached to the overhanging beam portion 30d of each connecting beam 30b. The concrete slab 21 at the tip is lifted and lifted. In order to lift the concrete slab 21 at the tip, an anchor member (not shown) is driven into a predetermined position of the concrete slab 21, and the anchor member is struck along the beam portion 30d right above the concrete slab 21 at the tip. The lower end of the hanging wire 34b extended further downward is locked from the rotary jig 32 that is hung from the moved lifting device 31.

After that, the fixing anchor 23 that fixes the concrete slab 21 to the pedestal portion 22b of the bracket member 22 is removed, and the connecting bolts and the like that connect the adjacent concrete slabs 21 to each other are removed. After removing the slip prevention guide member 36 attached to the plate 21, by operating the elevating device 31, the concrete plate 21 at the tip end can be easily moved by the elevating device 31 with the rotary jig 32 interposed. It is possible to lift up.

Once the concrete slab 21 at the tip is lifted by the elevating device 31, the elevating device 31 is moved to the tip side in the continuous direction X along the projecting beam part 30d of the connecting beam 30b, so that the concrete of the hoisted end is lifted. The plate 21 is moved together with the rotary jig 32 to a position where the remaining front side bracket member 22 supporting the concrete plate 21 at the tip portion is replaced. As a result, the bracket member 22 that hinders the suspension does not exist below the concrete slab 21 at the tip of the hoisted end, so that the concrete slab 21 at the tip of the hoist can be smoothly suspended downward by the lifting device 31. It becomes possible to go.

Further, in the concrete plate suspending step of the present embodiment, the concrete plate at the leading end to be hung down has the lower beam portion 34 of the rotary jig 32 at the upper portion in the space region below the remaining bracket member 22. By rotating the beam part 33 (see FIG. 5(a)), preferably, the longitudinal direction L of the beam part 33 is smoothly rotationally moved along the continuous direction X and then further hung down. It has become. As a result, in the interior of the road tunnel 50, the vertically long cargo bed 57a is extended in the axial direction of the road tunnel 50 in the direction X in which the concrete plates 21 are continuously arranged, and is moved to a portion directly below the overhanging beam portion 30d. It is possible to smoothly load and unload the concrete slab 21 that is suspended and removed from the loading platform 57a of the unloading vehicle 57.

After the suspended concrete slab 21 is loaded on the loading platform 57a of the unloading vehicle 57, the lower beam portion 34 is rotated with respect to the upper beam portion 33 to return to the original position parallel to the upper beam portion 33, and also to move up and down. With the device 31, the rotary jig 32 is raised and returned to the original position, and the support frame 30 is moved to the rear side in the continuous direction X. As a result, it becomes possible to continue the work of removing the concrete slab 21 at the leading end in the next continuous installation direction X.

In the present embodiment, of the four bracket members 22 supporting the both ends 21b of the suspended concrete slab 21 after the above-mentioned concrete slab suspension step, one of the two remaining bracket members 22 on the distal end side is left. A support member removing step (see FIGS. 6A to 6C) of removing the bracket members 22 at two locations is performed. In the support member removing step, the remaining bracket member 22 can be easily removed by, for example, work performed by a worker who has boarded the work floor portion 58a of the aerial work vehicle 58.

The above-mentioned concrete slab suspension process and support member removal process are repeated a predetermined number of times to remove all the planned concrete slabs 21 and bracket members 22, and then the support frame has been moved to the rear side in the connecting direction X. 30 or the like is dismantled and removed by work by a worker who has boarded the work floor portion 58a of the aerial work vehicle 58, or work by using the small crane 56. For example, due to deterioration, change of ventilation system, or the like. The construction for removing the tunnel ceiling slab 20 that needs to be removed is completed.

Then, according to the method of suspending and removing concrete slabs of the present embodiment having the above-described configuration, a large number of concrete slabs 21 that are arranged in a row and form the tunnel ceiling slab 20 are sequentially placed in a stable state. It will be possible to remove them efficiently.

That is, in the method of suspending and removing a concrete slab of the present embodiment, the support pedestals 30 to which the elevating device 31 is attached are placed with their both ends 30c on both ends 21b of the concrete slab 21, respectively, and in the continuous direction X A pedestal installation step of movably installing, a concrete slab suspension step of suspending the concrete slab 21 at the tip in the continuous direction X by the elevating device 31 while being supported from the support pedestal 30, and a concrete slab suspension step. The supporting member removing step of removing the supporting member 22 that has been supported is included, and in the concrete plate hanging step, the support platform 30 is placed on the concrete plate 21 on the rear end side in the continuous direction X. After installation, the elevating device 31 provided on the overhanging beam portion 30d lifts the concrete slab 21 at the tip, and the elevating device 31 moves the concrete slab 21 at the tip to a position where the support member 22 is replaced, and then the tip. The concrete slab 21 is suspended below the support member 22.

Therefore, according to the present embodiment, the concrete slab 21 at the tip to be removed can be hung in a stable state by being hung from above by the support frame 30 whose both ends are supported by the existing support member 22. In addition, the concrete slab 21 to be removed is hung from the lifting device 31 attached to the support frame 30 to damage the structure even if the space above the tunnel ceiling slab 20 is limited. It is possible to remove them while securing a sufficient hanging allowance and supporting force without doing so, and by doing so, a large number of concrete slabs 21 that are arranged in series and form the tunnel ceiling slab 20 can be stably placed. , It will be possible to remove them sequentially and efficiently.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example, a concrete slab that is removed by the suspending and removing method of the present invention and has both ends supported from below and arranged in a row in the connecting direction forms a tunnel ceiling slab of a road tunnel. It is not always necessary to form the above, and other tunnel ceiling slabs or ceiling slabs constituting a building other than the tunnel may be formed. The concrete slabs, both ends of which are supported from below and arranged in a row in the arranging direction, may form not only ceiling slabs but also floor slabs. It may be a concrete slab that forms a slab and is supported by both ends thereof from below and arranged in a row in the arranging direction.

Also, the support main body of the support frame, which is placed so that both ends are respectively placed on both ends of the concrete slab and is movable in the continuous installation direction, does not necessarily have to have an arch shape, and a gate shape, etc. May be provided.

Further, in the concrete plate suspending step, the concrete plate at the tip end to be suspended is further moved downward in the space area below the support member after being rotationally moved so that the longitudinal direction thereof is along the continuous installation direction. The support member does not necessarily have to be suspended from the side wall portion of the tunnel.

10 Tunnel ceiling part concrete plate hanging and removing mechanism 20 Tunnel ceiling plate 21 Concrete plate 21b Both ends 22 Bracket member (support member)
22a Joining base 22b Receiving base 22c Mounting surface 23 Fixed anchor 30 Supporting cradle 30a Supporting body 30b Connecting beam 30c Both ends 30d Overhanging beam 31 Lifting device 32 Rotating jig 33 Upper beam 34 Lower beam 34a Rotating connecting 34b Suspended wire 37 Wheel member 50 Road tunnel 55 Transport vehicle 56 Small crane 57 Carry-out vehicle 57a Loading platform 58 Aerial work vehicle 58a Working floor X Continuous direction L Longitudinal direction of main body of concrete slab

Claims (6)

The concrete slabs with both ends supported from below and arranged in a row in the connecting direction are suspended and removed from the concrete slab on the tip side in the connecting direction. The removal method,
A support platform with a lifting device attached, with both ends respectively placed on both ends of the concrete slab, and a platform installation step of movably installing in the continuous installation direction,
A concrete slab hanging step of suspending the concrete slab at the tip end in the continuous installation direction from the support frame via the elevating device, while suspending the concrete slab by the elevating device.
After suspending the concrete slab of the tip, it is configured to include a support member removing step of removing the support member supporting both ends of the concrete slab of the tip,
In the gantry installation step, the elevating device is adapted to be movably attached along an overhanging beam portion provided to overhang from the support gantry to the tip side in the continuous installation direction,
In the concrete plate suspending step, the support base is installed on a concrete plate on the rear end side in the continuous direction with respect to the concrete plate of the tip portion, and the lifting and lowering provided on the projecting beam portion. After temporarily lifting the concrete slab of the tip part by a device, the concrete slab of the tip part is moved to a position where the supporting member is replaced by the elevating device, and then the concrete slab of the tip part is lower than the supporting member. How to hang and remove concrete slabs. In the concrete plate hanging step, the concrete plate of the tip portion to be hung down, in the space region below the support member, after the longitudinal direction of which is rotationally moved along the continuous installation direction, The method for suspending and removing a concrete slab according to claim 1, which is further suspended downward. The method for suspending and removing a concrete slab according to claim 1 or 2, wherein the concrete slab forms a tunnel ceiling slab that divides a space inside a tunnel into upper and lower parts. The method for suspending and removing a concrete slab according to claim 3, wherein the support member is a bracket member provided so as to project inward from a side wall portion of the tunnel. The method for suspending and removing a concrete slab according to claim 3 or 4, wherein the tunnel has a circular or horseshoe-shaped cross-sectional shape. The method for suspending and removing a concrete slab according to any one of claims 1 to 5, wherein the support base includes an arch-shaped support body portion.

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