JP6718391B2 - 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 margin, and the boom and concrete slab do not come into contact with existing structures when hoisting or unloading the concrete slab. It takes a lot of time and effort to do 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 concrete slabs that can be sequentially and efficiently removed from a large number of concrete slabs that are continuously arranged to form a ceiling slab or a floor slab in a stable state. The purpose is to do.

The present invention, the both ends are supported from below, a large number of concrete slabs arranged in a row in the continuous direction, a concrete slab that is sequentially suspended and removed from the concrete slab on the tip side in the continuous direction. A method of suspending and removing, in which a support stand to which an elevating device is attached is placed on both ends of a concrete slab, respectively, and the support stand is installed so as to be movable in the connecting direction. The concrete slab at the tip of the installation direction is supported by the support cradle through the elevating device, and at both end portions of the concrete slab, cut inside the both ends where the support cradle is placed. A cutting line is formed by a device, respectively, a concrete plate cutting step of separating the main body portion of the concrete plate from both end portions, and a main body portion of the separated concrete plate is suspended by the elevating device. , After the main body portion is suspended, the support frame is moved to the rear end side in the continuous installation direction to remove both end portions of the remaining concrete slab The above object has been achieved by providing a method for suspending and removing a plate.

Then, the method for suspending and removing the concrete slab of the present invention is, in the concrete slab cutting step, cut surfaces by the cutting lines at both end portions of the concrete slab are respectively formed so as to be inclined outward toward the lower side. Preferably.

Further, the method of suspending and removing the concrete slab of the present invention is, in the suspending step of the main body portion, the separated main body portion is in a space region below the left and right end portions, and the longitudinal direction thereof is After being rotationally moved along the connection direction, it is preferably 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.

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 concrete slab cutting process 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 transverse sectional view, (b) is a schematic longitudinal sectional view inside a tunnel, ( c) is a schematic plan view of the inside of the tunnel. A concrete slab cutting process of a method for 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 B of (a). FIG. A main part suspending process 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 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 method of suspending and removing a concrete slab according to a preferred embodiment of the present invention will be described. Both end portions removing steps will be described. (a) is a schematic cross-sectional view, (b), (c) is a schematic vertical section inside a tunnel It is a side view.

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 arcuate cross-sectional shape portion as shown in a) and (b), a tunnel ceiling slab formed at the upper part by vertically partitioning the space inside the tunnel. 20 is adopted as a method for removing each of the concrete slabs 21 that are continuously installed by sequentially hanging it down. 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 in which the concrete slab 21 on the side is sequentially hung and removed, 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 is A pedestal installation step (see FIGS. 2A to 2C) in which the parts 30c are respectively placed on both ends 21b of the concrete slab 21 and movably installed in the continuous installation direction X, and a tip in the continuous installation direction X. Part of the concrete slab 21 while being supported from the support pedestal 30 via the lifting device 31, inside the both ends 21c of the concrete slab 21 inside the both ends 21b on which the support pedestal 30 is placed, a cutting device A concrete slab cutting step (see FIGS. 3(a) to 3(c)) of forming the cutting lines 40 by 35 (see FIG. 4(a)) to separate the main body portion 21a of the concrete slab 21 from the end portions 21c. The main body portion 21a of the separated concrete slab 21 is suspended by the elevating device 31 to suspend the main body portion 21a (see FIGS. 5A to 5C), and after suspending the main body portion 21a, the support pedestal 30 is attached. Both ends are removed by moving to the rear end side in the continuous direction X and removing both end portions 21c of the remaining concrete slab (see FIGS. 6A to 6C).

Further, in the method of suspending and removing the concrete slab of the present embodiment, in the concrete slab cutting step, the cutting surface 40a by the cutting line 40 of both end portions 21c of the concrete slab 21 is preferably inclined downward toward the outside. Are formed on the respective surfaces (see FIG. 4A).

Further, in the method of suspending and removing a concrete slab of the present embodiment, in the main body suspending step, the separated main body portion 21a is preferably in the space region below the left and right end portions 21c, preferably the length thereof. After the direction L (see FIGS. 5B and 5C) is rotationally moved along the continuous direction X (see FIG. 5A), it is further hung down.

Further, in the present embodiment, the support frame 30 used in the method for suspending and removing the concrete slab has an arch shape as shown in FIGS. 2(a) to (c) and FIGS. 3(a) to (c). Both ends 30c are provided at both ends 21b of the existing concrete slab 21 that forms the tunnel ceiling slab 20 and are provided at least in a pair in the continuous direction X (in the present embodiment, a pair). ) Of the H-shaped steel and the like, and a support main body 30a extending in the continuous direction X above the support main body 30a for connecting the support main body 30a and a lifting device 31. And a connecting support beam portion 30b made of I-shaped steel or the like.

Here, the support frame 30 is preferably used when the existing concrete slab 21 forming the tunnel ceiling slab 20 of the road tunnel 50 is sequentially hung from the concrete slab 21 on the tip side in the continuous direction X and removed. It is a pedestal that constitutes a mechanism 10 for suspending and removing the concrete slab from the tunnel ceiling. 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).

In addition, in the present embodiment, a pair of connection support beam portions 30b forming the support pedestal 30 are provided at the same height position in the support body portion 30a, and the lifting device 31 is provided in each connection support beam portion 30b. Is movably attached along the connection support beam portion 30b.

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, for example, a short side having a length of about 1500 mm and a long side having a length similar to the lateral width of the road tunnel 50 at a position where the tunnel ceiling slab 20 is installed, for example, 8000 mm. It has a horizontally long rectangular planar shape. The concrete slab 21 supports both ends in the long side direction on a support member 22 which will be described below and is provided so as to project inward from the side wall of the road tunnel 50, and the short side is defined as the continuous direction X and the long side. It is provided in a state where a large number of parts are arranged in a row in a state where the parts are in contact with each other. 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 supporting member 22 that supports both ends of the concrete slab 21 in the long side direction is formed by appropriately processing various steel materials such as H-section steel. A known bracket member for the road tunnel 50 can be used. The bracket member 22 includes a joining base portion 22a having a curved outer peripheral surface shape along the arcuate cross-sectional shape of the side wall portion of the road tunnel 50, and a cradle portion 22b provided so as to project inward from the joining base portion 22a. Is formed. The joining base portion 22a is, for example, with a joining fixing bolt (not shown) in a state where the outer peripheral surface of the joining base portion 22a is in close contact with the inner surface of the side wall portion of the road tunnel 50 at the height position where the tunnel ceiling slab 20 is installed. By tightening the bracket member 22 toward the side wall portion, the bracket member 22 can be firmly joined and fixed to a predetermined position of the side wall portion of the road tunnel 50 in a state where the cradle portion 22b is bulged inward. ..

In the present embodiment, the bracket member 22 is in the continuous installation direction X of the concrete slab 21 at a predetermined height position on the side wall portions on both sides of the road tunnel 50, as shown in FIGS. 1(a) and 1(b). Along the axial direction of the 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 locations at intervals. By placing 21b, a large number of concrete slabs 21 can be supported from below.

The cradle part 22b of the bracket member 22 includes a flat mounting surface 22c on which the end 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 with a size of about 400 mm in length and width. Each concrete slab 21 is attached to the pedestal portion 22b of each bracket member 22 by placing the end corners of each pair of adjacent concrete slabs 21 in the two divided regions of the placement surface 22c. Has been. Thereby, each of the concrete slabs 21 is placed from the bottom by the bracket members 22 at each of these four locations by placing the four corners of the corner on the pedestals 22b of the bracket members 22 at the four locations. It is supported and mounted in a stable condition. 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, the method for suspending and removing the concrete slab is, as described above, the gantry setting step (see FIGS. 2A to 2C) and the concrete slab cutting step (FIG. 3A to ). (See (c)), a main body suspension step (see FIGS. 5(a) to 5(c)), and both end portion removal steps (see FIGS. 6(a) to 6(c)). There is.

In the gantry installation step, the support gantry 30 to which the lifting device 31 is attached is placed at both ends 30c on both ends 21b of the concrete slab 21, respectively, and the existing tunnel to be removed is movable in the continuous direction X. It is installed on the ceiling slab 20. That is, in the gantry installation step, the support gantry 30 and the hanging-up/removing mechanism 10 are disassembled in a state in which they are disassembled into constituent members of a size and weight that can be manually assembled by a worker using a simple device such as a winch. As shown in FIGS. 2(a) to 2(c), while being transported by the transport vehicle 55 to the construction site of the road tunnel 50, the transported support frame 30 and the constituent members of the suspension removal mechanism 10 are transferred to, for example, a small crane. It is lifted using 56 and conveyed on the existing tunnel ceiling slab 20 to be removed. Further, other necessary devices and equipment such as a concrete cutter device 35 as a cutting device and a winch, which will be described later, are similarly lifted by using, for example, a small crane 56 and placed on the existing tunnel ceiling slab 20 to be removed. Transport.

After that, by the work on the existing tunnel ceiling slab 20, the worker uses the transported device or equipment to remove the above-mentioned components from the disassembled support platform 30 or the components of the suspension removal mechanism 10. The supporting base 30 and the suspension removing mechanism 10 having the structure are assembled.

In the assembled support base 30, it is possible to attach a well-known chill tank, preferably as a wheel member 37 for movement, to both end portions 30c which are also lower end portions of the pair 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. ..

In addition, in the present embodiment, both ends 21b of the concrete slab 21 that are continuously arranged to form the existing tunnel ceiling slab 20 are made to extend along the continuous arranging direction of the concrete slab 21, for example, from an L-shaped steel. The slip prevention guide members 36 (see FIGS. 4A and 4B) may be attached respectively. As a result, when the concrete slab 21 to be removed from the arch-shaped support main body 30a is hung, both end portions 30c of the support main body 30a are displaced outward due to the increased weight of the concrete slab 21. It is possible to effectively prevent this from happening, and to guide the both ends 30c of the support platform 30 to move the support platform 30 more smoothly in the continuous direction X of the concrete slab 21. Will be possible.

Further, in the present embodiment, as described above, the pair of connection support beam portions 30b that configure the support pedestal 30 are provided at the same height position in the support main body portion 30a, and each connection support beam portion 30b. An elevating device 31 is attached to the. Accordingly, the concrete slab 21 to be removed can be lifted or hung in a more stable state by suspending the concrete slab 21 from the support main body portion 30a by the pair of lifting devices 31 with the rotary jig 32 interposed. become.

In the concrete slab cutting step in the method of suspending and removing a concrete slab of the present embodiment, as shown in FIGS. 3(a), 4(a) and 4(b), the concrete slab 21 at the tip portion in the continuous direction X is While being supported from the support cradle 30 via the elevating device 31, the cutting line 40 is cut by the cutting device 35 at both end portions 21c of the concrete slab 21 inside the both end portions 21b on which the support cradle 30 is placed. And the main body portion 21a of the concrete slab 21 is separated from both end portions 21c.

That is, in the concrete slab cutting step, an anchor (not shown) is driven at a predetermined position of the main body portion 21a between both ends 21b of the concrete slab 21 at the tip in the continuous direction X, and the anchor anchor is driven, By supporting the lower end portion of the hanging wire 34b attached to the lower beam portion 34 of the rotating jig 32, the concrete slab 21 is supported from the supporting main body portion 30a of the support frame 30 via the lifting device 31 and the rotating jig 32. It will be in the state where it did. In this state, as a cutting device, for example, a concrete cutter device 35 known as a device for cutting concrete is used, and the end portion 21c of the concrete slab 21 at the tip portion is located inside the both end portions 21b in the continuous direction X. And a cutting line 40 that extends across the concrete slab 21 and penetrates in the thickness direction. Thereby, the main body portion 21a sandwiched by the cutting lines 40 on both sides can be separated from both end portions 21c.

Here, in the concrete slab cutting step, it is preferable to form the cut surfaces 40a of the both end portions 21c of the concrete slab 21 by the cutting lines 40 so as to be inclined downward toward the outside (see FIG. 4A). .. As a result, in the main body portion suspending step described later, the main body portion 21a between the two end portions 21c to be left, which are separated by the cutting line 40 and sandwiched between the cutting surfaces 40a by the cutting line 40, is left. It becomes possible to smoothly separate it from both end portions 21c and easily hang it downward. The cutting surface 40a which inclines outward toward the lower side, when cutting the both end portions 21c of the concrete slab 21, for example, attaches the inclined bite member 41 on the concrete slab 21 to incline the concrete cutter device 35. It can be easily formed by moving the concrete cutter device 35 with the cutter blade 35a tilted outward.

In the main body suspension step in the method of suspending and removing the concrete slab of the present embodiment, as shown in FIGS. 5A to 5C, the main body portion 21a of the concrete slab 21 separated from both end portions 21c is With both end portions 21c left, it is hung down by the lifting device 31.

That is, in the main body suspension step, the main body portion 21a of the concrete slab 21 separated from both end portions 21c is suspended from the support main body portion 30a of the support frame 30 and supported by the concrete slab cutting step described above. The hoisting crane 31 or the like attached to the support frame 30 is operated to lower and lower the rotary jig 32 together with the rotary jig 32.

Here, in the main body suspension step, since both end portions 21c of the concrete slab 21 are left and only the main body portion 21a is suspended downward, the road tunnel 50 has a horseshoe-shaped cross-sectional shape. Even if the tunnel width of the lower portion is narrower than the tunnel width of the upper portion where the plate 21 is attached, both ends of the main body portion 21a to be hung are caught on the side wall portion of the road tunnel 50. By avoiding this, the main body portion 21a can be smoothly hung down.

Further, in the main body suspension process, the separated main body portion 21a moves the lower beam portion 34 of the rotary jig 32 to the upper beam portion 33 in the space region below the left and right end portions 21c of the road tunnel 50. By rotating it (see FIG. 5(a)), preferably, the longitudinal direction L thereof is smoothly rotationally moved along the continuous installation direction X and then further hung down. .. As a result, inside the road tunnel 50, the vertically long cargo bed portion 57a is extended in the continuous direction X of the concrete slab 21 which is the axial direction of the road tunnel 50, and moved to the portion directly below the support frame 30. It becomes possible to smoothly load and carry out the main body portion 21a of the concrete slab 21 to be hung and removed from the loading platform portion 57a of the unloading vehicle 57.

After the main body portion 21a of the concrete slab 21 that has been hung down 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. At the same time as returning, the rotating jig 32 is raised by the elevating device 31 and is moved to the rear side in the continuous installation direction X in the state where it is returned to the original position. This makes it possible to continue the work of removing the main body portion 21a of the concrete slab 21 at the leading end in the continuous installation direction X.

In the present embodiment, the concrete slab cutting process and the main body part suspending process described above are repeated a predetermined number of times while moving the support platform 30 and the concrete cutter device 35 to the rear side in the continuous installation direction X. As a predetermined number of concrete slabs 21 from the tip side in the direction X, for example, when the main body portions 21a of the concrete slabs 21 are hung down and removed, as shown in FIGS. After further moving to the rear end side in the continuous installation direction X, a work of sequentially removing both end portions 21c of the remaining concrete slab 21 from the front end side is performed in the both end portion removing step. The step of removing both end portions may be performed each time immediately after the main body portion 21a of the concrete slab 21 at the tip portion is removed and the support base 30 is moved to the rear end side in the continuous installation direction X, at six or more locations. After removing the main body portion 21a of the concrete slab 21, the two end portions 21c of the remaining concrete slabs 21 can be collectively removed.

In the step of removing both end portions in the method of suspending and removing the concrete slab of the present embodiment, for example, by the work by the worker who got on the work floor portion 58a of the aerial work vehicle 58, from both end portions 21c of the remaining concrete slab 21, Both end portions 21c of the remaining concrete slab 21 can be easily removed by removing the slip prevention guide member 36, the fixed anchor 23, and the like, and sandwiching and lifting them by, for example, the tip attachment portion 59a of the crusher heavy machine 59.

After removing both end portions 21c of the concrete slab 21 left in the both end portion removing step and removing all the planned concrete slabs 21, the support frame 30 and the concrete cutter device moved to the rear side in the continuous installation direction X 35, etc. are dismantled and removed by work by a worker who has boarded the work floor 58a of the aerial work vehicle 58, or work by using the small crane 56. For example, due to deterioration and change of ventilation system. 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. In a state where the pedestal installation step of movably installing and the concrete slab 21 at the tip portion in the continuous installation direction X are supported from the support pedestal 30, the cutting lines 40 are formed inside the both ends 21b of the concrete slab 21. Then, a concrete plate cutting step of separating the main body portion 21a of the concrete plate 21 from both end portions 21c, a main body portion hanging step of hanging the separated main body portion 21a of the concrete plate 21 by the elevating device 31, and a main body portion 21a. And the both end portions removing step of removing the both end portions 21c of the remaining concrete slab after being suspended.

Therefore, according to this embodiment, the main body portion 21a of the concrete slab 21 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 members. In addition, by suspending the main body portion 21a of the concrete slab 21 to be removed from the lifting device attached to the support base 30, even if the size of the space above the tunnel ceiling slab 20 is limited, It is possible to remove them while securing a sufficient hanging allowance and a supporting force without damaging the slab and thereby stabilizing a large number of concrete slabs 21 that are arranged in series and form the tunnel ceiling slab 20. It becomes possible to remove them efficiently in this state.

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 installed so that both ends are respectively placed on both ends of the concrete slab and is movable in the continuous direction, does not necessarily have to have an arch shape, and a gate shape or the like. May be provided.

Further, in the concrete slab cutting process, it is not always necessary to form the cut surfaces by the cutting lines at both end portions of the concrete slab so as to incline outward toward the lower side, and the main body separated in the suspension process of the main body part is cut off. The part does not necessarily have to rotate and move so that the longitudinal direction of the part is in the space region below the left end parts that are left behind.

10 Tunnel Ceiling Concrete Plate Suspension and Removal Mechanism 20 Tunnel Ceiling Slab 21 Concrete Slab 21a Body Part 21b Both Ends 21c Both Ends 22 Support Member (Bracket Member)
22a Joining base 22b Cradle 22c Mounting surface 23 Fixed anchor 30 Supporting cradle 30a Support body 30b Connection support beam 30c Both ends 31 Lifting device 32 Rotating jig 33 Upper beam 34 Lower beam 34a Rotation connection 34b Suspended wire 35 Cutting device (concrete cutter device)
35a Cutter blade 37 Wheel member 40 Cutting line 40a Cutting surface 41 Bite member 50 Road tunnel 55 Transport vehicle 56 Small crane 57 Carry-out vehicle 57a Loading platform 58 High-level work vehicle 58a Working floor 59 Crusher heavy machine 59a Tip attachment part X Direction L Longitudinal direction of the body of the concrete slab

Claims (6)

Concrete slabs with both ends supported from below and arranged in a row in the connecting direction are sequentially hung from the concrete slab on the tip side in the connecting direction and removed. 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,
The concrete slab at the tip end in the continuous direction, in a state of being supported from the support cradle via the elevating device, at both end portions of the concrete slab, inside the both ends where the support cradle is placed. A concrete slab cutting step of forming a cutting line by a cutting device to separate the main body portion of the concrete slab from both end portions,
The main body portion of the separated concrete slab, a main body portion suspending step of suspending by the lifting device,
After suspending the main body portion, the support cradle is moved to the rear end side in the continuous installation direction, and both end portions removing step of removing both end portions of the remaining concrete slab is included. How to suspend and remove. The method of suspending and removing a concrete slab according to claim 1, wherein, in the concrete slab cutting step, cutting surfaces of both end portions of the concrete slab that are cut by the cutting line are each formed to incline outward toward a lower side. In the main body portion suspending step, the separated main body portion is further rotatably moved so that the longitudinal direction thereof is along the continuous installation direction in a space region below the left end portions which are left behind. The method for suspending and removing a concrete slab according to claim 1 or 2, which is suspended downward. The method for suspending and removing a concrete slab according to any one of claims 1 to 3, 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 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 main body.

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