JP2019143430A - Scaffold construction method - Google Patents

Abstract

To provide a scaffold construction method for constructing a work scaffold around a bridge pier of a bridge installed on a water area, without using a barge.SOLUTION: A scaffold construction method for constructing a work scaffold 4 using a suspended scaffold 2 around a bridge pier 1 of a bridge installed on a water area includes: extending a suspended scaffold 2 installed continuously with a land on one side of the bridge or a carrying-in part 9 installed on the land to the bridge pier 1 along a bridge girder 6 of the bridge to form a carry-in passage 8 and the work scaffold 4 installed continuously with the carry-in passage 8 using the suspended scaffold 2 suspended on the bridge girder 6; installing a replacement beam 7 on the bridge pier 1; and replacing suspension by the bridge girder 6 with suspension by the replacement beam 7 with respect to suspension of the suspended scaffold 2 forming the work scaffold 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a scaffold construction method for constructing a work scaffold using a suspension scaffold around a pier of a bridge constructed on a water area.

  In order to repair and reinforce the piers of bridges built on water areas such as rivers, seas, lakes, etc., it is necessary to form a dry work area around these piers. A temporary closing method is known as a forming method.

  In this temporary closing method, a temporary closing structure formed of steel plates or the like is installed around the pier to partition the pier and the water area, and the water in the temporary closing structure is drained to form a dry area around the pier. Is.

  Conventionally, when repairing / reinforcing piers using this temporary closing method, a pontoon is installed from the land to the target pier, and the target pier is moved to and from the pier around the pier. A working scaffold is constructed, and a temporary closing structure is constructed and installed using this working scaffold.

  However, since this trolley is formed by connecting a large number of very large parts, it requires a lot of labor and cost for transportation to the site. Therefore, there is a problem that it cannot be used in a shallow water area.

  The present invention has been made in view of such current problems, and an object of the present invention is to provide a scaffold construction method for constructing a work scaffold around a pier of a bridge constructed on a water area without using a carriage. And

  The gist of the present invention will be described with reference to the accompanying drawings.

  In a scaffold construction method for constructing a work scaffold 4 using a suspension scaffold 2 around a pier 1 of a bridge constructed on a water area, the work is built in a land on one side of the bridge or a carry-in portion 9 provided on the land. The suspension scaffold 2 is extended to the pier 1 along the bridge girder 6 of the bridge, and the work scaffold 4 connected to the carry-in path 8 and the carry-in path 8 by the suspension scaffold 2 suspended from the bridge girder 6. And a suspension beam 7 is provided on the pier 1, and the suspension scaffold 2 forming the work scaffold 4 is suspended from the bridge girder 6 to the replacement beam 7. It is.

  The scaffolding construction method according to claim 1, wherein the replacement beam 7 is mounted and fixed on an upper portion of the pier 1.

  Also, a replacement beam forming member 7A that forms the replacement beam 7 is carried into the work scaffold 4 through the carry-in path 8, and the replacement beam forming member 7A is used from the work scaffold 4 to perform the replacement. 3. The scaffold construction method according to claim 1, wherein a beam 7 is provided on the pier 1.

  Further, after the replacement beam forming member 7A is carried into the work scaffold 4 through the carry-in path 8, a part or the whole of the work scaffold 4 is raised, and the raised work scaffold 4 is used. The replacement beam 7 is provided on the bridge pier 1 using the replacement beam forming member 7A, and the suspension scaffold 2 that forms the work scaffold 4 is suspended and suspended from the replacement beam 7 provided on the bridge pier 1. 4. The scaffold construction method according to claim 3, wherein the scaffold construction method is lowered to a predetermined position.

  Moreover, the said replacement beam 7 is a truss beam, It concerns on the scaffold construction method of any one of Claims 1-4 characterized by the above-mentioned.

  Since the present invention is as described above, it is possible to construct a work scaffold around the pier of a bridge constructed on the water area without using a trolley. Since a great deal of labor and costs can be reduced, for example, when repairing / reinforcing piers using the temporary closing method, repairing / reinforcing piers can be performed easily and at low cost. .

  Furthermore, since the land and the work platform are continuously connected via the carry-in route according to the present invention, the worker can easily go to the work platform by walking, so the materials and members necessary for the work can be made into small parts. These can be transported to the work scaffold by the operator himself, thereby making it unnecessary to use heavy equipment such as a crane and further reducing costs.

  Moreover, the present invention suspends the work scaffold from the bridge girder to the replacement beam provided on the pier, so that, for example, when a heavy load such as a temporary closing structure is constructed on the work scaffold, the load due to this heavy load is Because it does not affect the bridge and the girder, there is no concern that the bridge or bridge girder may be adversely affected by weighting, and the work can be performed with peace of mind.

It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the state before this construction method construction in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (carrying path formation process and work scaffold formation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (work scaffold suspension process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (work scaffold suspension process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (work scaffold suspension process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (work scaffold suspension process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (work scaffold suspension process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (temporary deadline structure construction and installation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (temporary deadline structure construction and installation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (temporary deadline structure construction and installation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (temporary deadline structure construction and installation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (temporary deadline structure construction and installation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (temporary deadline structure construction and installation process) of this construction method in a present Example. It is (a) explanatory drawing front sectional view and (b) explanatory side view which show the construction procedure (working dry area formation process) of this construction method in a present Example. It is a description disassembled perspective view which shows the suspension scaffold in a present Example. It is explanatory drawing which shows the work procedure at the time of forming the carrying-in route and work scaffold of this construction method in a present Example, (a) is a figure which shows the state assembled | attached in the folding state by the folding decomposition | disassembly type | formula scaffold formation frame ( b) is a diagram showing a state in which a folding and disassembling scaffold forming frame body assembled in a folded state is unfolded, and (c) is a diagram showing a state in which a scaffold plate is laid on the unfolding folding and dismantling scaffold forming frame. . It is a side view which shows the replacement beam of a present Example. It is an explanatory top view which shows the work scaffold of a present Example. It is an explanatory top view which shows the state which formed the opening part in the working scaffold of a present Example.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  The present invention provides a scaffold suspended on a bridge girder 6 from a land such as a river bank or from a carry-in portion 9 (for example, a saddle-like, stair-like or slope-like scaffold) provided on the land toward a target pier 1. 2 is extended to form the carry-in path 8 and the work scaffold 4 connected to the carry-in path 8 is formed, so that the operator can connect the land and the work scaffold 4 via the carry-in path 8. It is easy to go back and forth, which eliminates the need for a trolley installed between the land and the target pier 1 and reduces the tremendous labor and costs that are incurred when transporting this craft to the site. be able to.

  Therefore, for example, when the temporary closing method is performed using the present invention when repairing / reinforcing work for the pier 1, repairing / reinforcing work for the pier 1 can be performed easily and at low cost.

  Moreover, since the land and the work scaffold 4 can be easily moved back and forth via the carry-in path 8, for example, by making the parts and materials necessary for the work into small parts, the worker himself has these work scaffolds. Since it can be transported to 4, it is not necessary to use a heavy machine such as a crane, and the cost can be further reduced.

  Further, according to the present invention, the replacement beam 7 is provided on the pier 1, and the work scaffold 4 suspended from the bridge girder 6 (specifically, the suspension scaffold 2 forming the work scaffold 4) is suspended from the replacement beam 7. Since it is suspended, the bridge girder 6 is not loaded even if a heavy load such as the temporary closing structure 3 is constructed on the work scaffold 4, so that a large load is applied to the bridge girder 6 or the bridge itself. It is possible to eliminate the concern that a malfunction may occur, and to perform work such as building a heavy object on the work scaffold 4 with confidence.

  Specific embodiments of the present invention will be described with reference to the drawings.

  In this embodiment, the scaffold construction method of the present invention is used as a method for forming a work dry area using a temporary closing structure in repair / reinforcement work of a pier.

  Specifically, the present embodiment forms a work scaffold 4 for constructing a temporary fastening structure 3 using a suspension scaffold 2 around a bridge pier 1 to be constructed in a bridge constructed on a water area. A temporary cutoff structure 3 is constructed on the work scaffold 4 so as to surround the pier 1, and the constructed temporary cutoff structure 3 is lowered through an opening 5 formed in the work scaffold 4 into the water area. After the disposition, the space between the pier through hole at the bottom of the temporary closing structure 3 and the pier 1 is stopped, the water that has entered the temporary closing structure 3 is drained, and the temporary closing structure 3 The present invention relates to a method for forming a work dry area (hereinafter referred to as the present method) using a temporary closing structure in a pier repair / reinforcing work for forming a work dry area.

  More specifically, the construction method includes a carry-in route formation process, a work scaffold formation process, a work scaffold suspension process, a temporary closing structure construction / installation process, and a work dry area formation process. First, in the loading path formation process and the work scaffold formation process, the suspension scaffold 2 connected to the land on one side of the bridge or the loading portion 9 provided on the land is constructed along the bridge girder 6 of the bridge. The pier 1 is extended, and the loading scaffold 8 suspended from the bridge girder 6 forms the carry-in path 8 and the work scaffold 4 for constructing the temporary closing structure 3 connected to the carry-in path 8. In the work scaffold suspending step, the bridge pier 1 is provided with the replacement beam 7, the suspension scaffold 2 forming the work scaffold 4 is suspended from the bridge girder 6 to the replacement beam 7, and then the temporary closing structure. Suspended to this replacement beam 7 during body construction and installation process After constructing the temporary fastening structure 3 on the working scaffold 4 formed by the suspended scaffolding 2, an opening 5 is formed in the working scaffold 4, and the temporary fastening structure 3 is formed via the opening 5. It is lowered and placed in the water area, and in the final work dry area forming step, the water is stopped between the pier through hole at the bottom of the temporary closing structure 3 and the pier 1 and enters the temporary closing structure 3. Waste water is drained to form a working dry area in the temporary cut-off structure 3.

  Hereinafter, each process of this construction method will be specifically described along the construction procedure.

(1) Loading path formation process The loading path forming process in this construction method is a process of forming a loading path 8 (passage) connecting the loading area 9 provided on one side of the bridge or the landing site provided on the land. . In the present embodiment, a case where the carry-in unit 9 is installed will be described.

  Specifically, in the formation of the carry-in path 8, first, a carry-in part 9 (for example, a saddle-like, stepped, slope-like scaffold, etc.) is installed on the river bank on one side of the river, and is connected to this carry-in part 9. Then, an extension of the carry-in route 8 toward the target pier 1 (the pier 1 to be constructed) is formed.

  More specifically, the carry-in path 8 is formed by suspending a plurality of suspension scaffolds 2 on a bridge girder 6 and extending the carry-in path 8 along the bridge girder 6.

  Further, in this construction method, a folding and disassembling scaffold forming frame 10 that is foldable and can be assembled and disassembled on the suspension scaffold 2 that forms the carry-in path 8, and a scaffold plate 16 that is laid on the folding and disassembling scaffold forming frame 10. Suspended scaffold 2 formed by

  Specifically, the folding and disassembling-type scaffolding frame 10 that forms the suspension scaffold 2 includes a plurality of (for example, four) beam members 11, and ends of the beam members 11 are connected to each other so as to be horizontally rotatable and detachable. The beam connection member 12 and the beam member 11 are provided with a connection holding shaft 13 that serves as a rotation axis of the beam member 11 and holds the connection between the beam member 11 and the beam connection member 12, and is provided at the end of the beam member 11. By connecting the shaft insertion hole 14 and the shaft insertion hole 15 provided in the beam connecting member 12 to form a shaft insertion communication hole, the connection holding shaft 13 is inserted and disposed in the shaft insertion communication hole. The beam member 11 can be separated and removed from the beam connecting member 12 by removing the connection holding shaft 13 inserted and disposed in the shaft insertion communication hole in this assembled and formed state. It is configured as follows.

  That is, in this construction method, first, the carry-in part 9 is used as a scaffold, and the folding / disassembling-type scaffolding frame 10 that is folded by the beam member 11, the beam connecting member 12, and the connection holding shaft 13 is assembled to the carry-in part 9 and formed. Then, the folding / disassembling scaffold forming frame 10 assembled and formed in this folded state is horizontally rotated to the unfolded state, and the scaffold plate 16 is laid on the folding / disassembling scaffold forming frame 10 in the unfolded state and this folded A lifting tool 17 (for example, a scaffolding chain or the like) suspended from the bridge girder 6 is connected to the disassembly-type scaffolding frame 10 to form the first suspension scaffold 2 that becomes the loading path 8, and then this first suspension scaffold 2 is a folding and disassembling type scaffolding frame 10 that forms the first suspension scaffold 2 and a new folding and disassembling state using a beam member 11, a beam connecting member 12, and a connecting holding shaft 13. Assembling type scaffolding frame 10 A new folding and disassembling scaffold forming frame 10 formed and assembled in this folded state is horizontally rotated to be in a deployed state, and a scaffold plate 16 is laid on the folded and disassembled scaffold forming frame 10 in the deployed state. At the same time, a new suspension scaffold 2 connected to the first suspension scaffold 2 is formed by connecting a hanging tool 17 suspended from the bridge girder 6 to the folding and disassembling scaffold forming frame 10. The scaffold formation region is sequentially expanded by repeating the operation of connecting the two, and the carry-in path 8 is formed to extend along the bridge girder 6.

  In addition, when extending and forming the carrying-in path 8 using this suspension scaffold 2, as shown in the drawing, a plurality of folding and disassembling is performed in the width direction of the loading path 8 (direction perpendicular to the extending direction of the carry-in path 8). By separately forming one type of folding scaffolding frame 10 in a folded state, one of the other folding and disassembling type scaffolding frame 10 can be horizontally rotated to be in an unfolded state. Without having to unfold the individual scaffold-forming frame 10 separately, it can be simultaneously unfolded in conjunction with the unfolding operation of the folding and dismantling-type scaffold-forming frame 10 that has been horizontally rotated. 2 can be formed.

  Moreover, in this construction method, since the suspension scaffolds 2 are connected to each other and share a part of the folding and disassembling scaffold forming frame 10, the suspension fixtures 17 are not necessarily connected to all the suspension scaffolds 2 and the bridge girder. It is not necessary to suspend from 6 and the suspension scaffold 2 to be suspended is set appropriately.

(2) Work scaffold formation process The work scaffold formation process in this method is a process that is performed after the carry-in path formation process, and is connected to the carry-in path 8 formed in this carry-in path formation process. This is a process of forming a work scaffold 4 that serves as a scaffold for constructing the temporary closing structure 3 around the pier 1.

  Specifically, in the work scaffold formation process of the present construction method, the work scaffold 4 is formed by using the same suspension scaffold 2 as the suspension scaffold 2 used in the carry-in path formation process described above.

  More specifically, the carry-in path is formed at the end of the carry-in path 8 formed earlier, specifically, at the end of the folding and disassembling scaffold forming frame 10 of the suspension scaffold 2 forming the carry-in path 8. 8 is used as a scaffold, and the folding and disassembling type scaffold forming frame 10 is assembled and formed by the beam member 11, the beam connecting member 12, and the connection holding shaft 13 in the same manner as the work in the above-described work scaffold forming step. The folding and disassembling scaffold forming frame 10 assembled and formed in the state is horizontally rotated to the unfolded state, and the folding plate 16 is laid on the unfolded folding and disassembling scaffold forming frame 10 and the folding and disassembling scaffold is formed. A suspension tool 17 suspended from the bridge girder 6 is connected to the frame body 10 to form the first suspension scaffold 2 to be the work scaffold 4, and then the first suspension scaffold 2 is used as the scaffold. 2 to the folding and disassembling scaffolding frame 10 forming 2 Furthermore, a new folding and disassembling scaffold forming frame 10 in a folded state is assembled by using the beam member 11, the beam connecting member 12 and the connection holding shaft 13, and a new folding and disassembling scaffold formed by assembling and forming in this folded state is formed. The frame 10 is horizontally rotated to be in an unfolded state, and the scaffold plate 16 is laid on the unfolded folding / disassembling scaffold forming frame 10 and suspended from the bridge girder 6 on the folding / disassembling scaffold forming frame 10. A new suspension scaffold 2 connected to the first suspension scaffold 2 is formed by connecting the suspension tool 17, and the work for continuously connecting the new suspension scaffold 2 is repeated to sequentially form the scaffold formation area. The work scaffold 4 is formed.

  In this work scaffold formation process, similarly to the carry-in path formation process, a plurality of folding and disassembling scaffold forming frames 10 are continuously formed in a folded state, and any one folding and disassembling scaffold forming frame 10 is formed. It is preferable to form the work scaffold 4 efficiently by performing a horizontal rotation operation.

  Further, in the work scaffold forming process of this construction method, there is a work of lifting and moving the work scaffold 4 upward in the subsequent work scaffold suspending process. Therefore, a chain block having a lifting function is used as the lifting tool 17.

  Moreover, since the work scaffold 4 formed by this construction method has a continuous structure in which the suspension scaffolds 2 share a part of the folding and disassembling scaffold forming frame 10 like the carry-in path 8, not all It is not necessary to connect a suspension tool to the suspension scaffold 2 and suspend the suspension scaffold 2 from the bridge girder 6, and the suspension scaffold 2 to be suspended is appropriately set.

(3) Work scaffold suspension process The work scaffold suspension process in this construction method is a process performed after the work scaffold formation process described above, and the work scaffold 4 suspended and formed on the bridge girder 6 in this work scaffold formation process, It is a process of suspending to the replacement beam 7 installed on the pier 1.

  Specifically, in the work scaffold suspending step, after the replacement beam forming member 7A (with the replacement beam 7 in a disassembled state) is carried into the work scaffold 4 via the carry-in path 8, one of the work scaffolds 4 is loaded. The replacement beam 7 is provided on the pier 1 to be constructed by using the replacement beam forming member 7A and the replacement beam provided on the pier 1 by using the raised work scaffold 4. 7 is performed to suspend and suspend the suspension scaffold 2 that forms the work scaffold 4.

  More specifically, in this construction method, first, a replacement beam 7 (a truss beam is adopted in this construction method) is installed on the pier 1 to be constructed. The replacement beam forming member 7A for forming the beam 7 is transported to the work scaffold 4, and then the work scaffold 4 to be lifted is connected to the carry-in path 8 and the surrounding work scaffold 4 (work scaffold 4 that is not lifted). Release the state (separate operation), operate the lifting tool 17 (chain block) with the replacement beam forming member 7A and the operator on it, and raise the work scaffold 4 to the vicinity of the upper part of the pier 1 The replacement beam forming member 7A is assembled using the work scaffold 4 thus made as a scaffold, and the replacement beam 7 is installed (placed and fixed) on the pier 1.

  Next, a hanging tool 17 (chain block) is attached to the replacement beam 7 made of a truss beam installed on the pier 1, and the hanging tool 17 attached to the replacement beam 7 is attached to the work scaffold 4 (work scaffold 4. After connecting to the formed suspension scaffold 2), the connection between the suspension fixture 17 attached to the bridge girder 6 and the work scaffold 4 is released, and the work scaffold 4 is suspended from the bridge girder 6 to the replacement beam 7.

  When the suspension is completed, the work scaffold 4 is lowered to the original height position (the same height position as the carry-in path 8 or other work scaffolds 4) by operating the hanging tool 17 and the lowered work scaffolds. 4 and the carry-in path 8 or the surrounding work platform 4 are connected again.

  By suspending the work scaffold 4 from the bridge girder 6 to the replacement beam 7, even if the heavy temporary closing structure 3 is constructed on the work scaffold 4, no load is applied to the bridge girder 6. The temporary closing structure 3 can be constructed on the work scaffold 4 with peace of mind.

(4) Temporary Deadline Structure Construction / Installation Process The temporary deadline structure construction / installation process in this construction method is a process that is performed after the work scaffold suspension process described above. This is a process of constructing a temporary fastening structure 3 on a work scaffold 4 suspended from a replacement beam 7 installed on 1 and installing the constructed temporary fastening structure 3 in a water area. In addition, a present Example demonstrates the case where the temporary cutoff structure 3 with high height is constructed | assembled and installed.

  As in the present embodiment, when the temporary cutoff structure 3 having a high height is constructed, the temporary cutoff structure 3 is constructed and installed by dividing it vertically.

  Specifically, first, the lower side of the temporary fastening structure 3 (hereinafter referred to as the lower-side temporary fastening structure 3A) is constructed, and the constructed lower-side temporary fastening structure 3 is first installed in the water area. Then, the upper side of the temporary fastening structure 3 (hereinafter referred to as the upper-side temporary fastening structure 3B) is constructed, and the constructed upper-side temporary fastening structure 3B is first installed in the water area. The temporary cutoff structure 3 is constructed and installed by placing and connecting on the side temporary cutoff structure 3A.

  More specifically, in this construction method, first, in order to construct the lower-side temporary cutoff structure 3A, the lower-side temporary cutoff that is formed in a size that can be carried and held by an operator in advance by hand. A worker carries and carries a temporary cut-off structure forming member for a lower side such as a bottom plate forming member and a peripheral wall forming member (liner plate) for forming the structure 3A from the land to the work scaffold 4 via the loading path 8. To do. Thus, cost can be reduced by carrying in all by human power.

  Next, the lower-side temporary cutoff structure forming member carried into the work scaffold 4 is assembled on the work scaffold 4 to construct the lower-side temporary cutoff structure 3A.

  Specifically, first, a ring-shaped bottom plate portion in plan view is formed on the work scaffold 4 so as to surround the pier 1 to be constructed, and a peripheral wall portion having a predetermined height along the outer peripheral edge portion of the bottom plate portion. To form a bottomed cylindrical lower-side temporary cutoff structure 3A.

  Next, an elevating device 18 (for example, an elevating device composed of a balance balance and a chain block in this method) is provided on the pier 1 to be constructed, and this elevating device 18 is connected to the constructed lower temporary closing structure 3A. Then, the lower temporary closing structure 3 </ b> A is raised by the lifting / lowering device 18 to be in a floating state with respect to the work scaffold 4. In the present embodiment, a lifting device 18 for lifting and lowering the lower temporary fastening structure 3A (upper temporary fastening structure 3B) is provided on the bridge pier 1. However, the replacement beam 7 installed on the bridge pier 1 is provided on the bridge beam 7. It may be provided.

  Next, the opening 5 having a size through which the lower temporary cut-off structure 3 </ b> A can pass is formed in the work scaffold 4.

  Specifically, the opening 5 is formed by removing the working scaffold 4 (specifically, the suspended scaffold 2 forming the working scaffold 4) immediately below the suspended lower-side temporary cutoff structure 3A. To do.

  More specifically, first, the scaffolding plate 16 of the suspension scaffold 2 located at the center of the opening forming region (removal region) is removed to expose the folding / disassembling type scaffolding forming frame body 10, and the folding / disassembling type scaffolding forming frame is exposed. The body 10 is pulled to the scaffold side to be in a folded state, and the connection holding shaft 13 inserted through the shaft insertion hole 15 of the folded disassembled scaffolding frame 10 in the folded state is extracted, and the beam is connected to the beam connecting member 12 The member 11 is removed and removed, and then the suspended scaffold 2 connected to the removed suspended scaffold 2 is removed in the same procedure. That is, in this construction method, the suspension scaffold 2 is sequentially removed from the center side (side close to the pier 1) toward the outside to widen the opening, and the opening 5 through which the lower-side temporary fastening structure 3A can pass. Will form.

  Next, the elevating device 18 is operated, and the lower-side temporary cutoff structure 3A is first installed in the water area through the opening 5 formed in the work scaffold 4. Although not shown, when lowering the lower side temporary fastening structure 3A, a guide rail is provided on each of the pier 1 and the temporary fastening structure 3 and lowered along the guide rail, thereby lowering the lower side temporary fastening structure 3A. The cutoff structure 3A can be lowered into the water area in a straight and stable state.

  When the installation of the lower temporary fastening structure 3A is completed in this way, in order to construct the upper temporary fastening structure 3B, the opening 5 formed in the work scaffold 4 is once closed to form the lower temporary fastening structure. Similar to the construction of 3A, an upper-side temporary cut-off structure forming member formed in a size that can be carried and held by a worker in advance is transferred from the land via the carry-in path 8. Carry to work scaffold 4.

  Next, the upper-side temporary cutoff structure forming member carried into the work scaffold 4 is assembled on the work scaffold 4 to construct the upper-side temporary cutoff structure 3B.

  Specifically, the same operation as when the peripheral wall portion of the lower-side temporary fastening structure 3A is erected is performed to construct the cylindrical upper-side temporary fastening structure 3B.

  Thereafter, as in the case of installing the lower-side temporary cutoff structure 3A, the upper-side temporary cutoff structure 3B is connected to the lifting / lowering device 18 and is lifted with respect to the work scaffold 4 by the lifting / lowering device 18. An opening 5 is formed in the scaffold 4, and the upper temporary fastening structure 3 </ b> B is lowered through the opening 5, and is placed on and connected to the lower temporary fastening structure 3 </ b> A previously installed in the water area. After the temporary cutoff structure 3 is completed, a floating prevention member 19 is disposed on the upper edge portion of the temporary cutoff structure 3 to prevent the temporary cutoff structure 3 from rising.

(5) Work dry area formation process The work dry area formation process in this construction method is the final process of this construction method that is performed after the above-described provisional cut-off structure construction / installation process. In the process, a water stop treatment is applied to a gap formed between the pier through hole at the bottom of the temporary closing structure 3 installed in the water area and the pier 1, and water that has entered the temporary closing structure 3 is removed. This is a step of draining and forming a working dry area (non-water area) in the temporary cutoff structure 3.

  Specifically, in this construction method, first, a water stop means (not shown) such as a water stop sheet or a rubber water stop tube is provided between the pier through hole and the pier 1 at the bottom of the temporary cutoff structure 3. A water stop process is performed to prevent water from entering through the gap formed in the gap.

  Next, after the water stop treatment is completed, the water that has entered the temporary cutoff structure 3 is drained by using a drainage device 20 such as a pump to form a working dry area in the temporary cutoff structure 3.

  The operational effects of the present construction method performed as described above will be described below.

  Since this construction method forms a carry-in route 8 connecting the land and the work scaffold 4 in the carry-in route forming step, the worker can use this carry-in route 8 to go to the work scaffold 4 from the land. The used trolley becomes unnecessary, and a great amount of labor and cost generated when the craft is transported to the site can be reduced.

  Moreover, since this construction method uses the suspension scaffold 2 provided with the folding disassembly-type scaffolding frame 10 for the suspension scaffold 2 that forms the carry-in path 8 and the work scaffold 4, the carry-in path 8 and the work scaffold 4 are formed and removed. The work and the work of forming the opening 5 when the temporary cutoff structure 3 is lowered on the work scaffold 4 are facilitated, and these work is not a dangerous scaffold such as a beam but a properly formed scaffold. Since it can be performed above, it is possible to work safely.

  Further, in this construction method, the work scaffold 4 for constructing the temporary closing structure 3 is hung not on the bridge girder 6 but on the replacement beam 7 installed on the pier 1, so that the heavy temporary closing structure on the work scaffold 4 is provided. Even if the body 3 is constructed, no load is applied to the bridge girder 6, so there is no possibility that the bridge or the bridge girder 6 will be adversely affected by weighting, and the temporary closing structure 3 can be constructed on the work scaffold 4 with confidence.

  Note that the present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate.

DESCRIPTION OF SYMBOLS 1 Bridge pier 2 Suspension scaffold 4 Work scaffold 6 Bridge girder 7 Replacement beam 7A Replacement beam formation member 8 Carry-in path 9 Carry-in part

Claims (5)

  In the scaffold construction method for constructing a work scaffold using suspension scaffolds around the piers of the bridges constructed on the water area, a suspension scaffold connected to the land on one side of the bridge or a carry-in portion provided on the land, Extending to the bridge pier along the bridge girder of the bridge, the suspension scaffold suspended from the bridge girder forms a carry-in path and the working scaffold connected to the carry-in path, and a replacement beam is attached to the bridge pier. A scaffold construction method comprising: suspending a suspension scaffold that forms the work scaffold from the bridge girder to the replacement beam.   The scaffold construction method according to claim 1, wherein the replacement beam is placed and fixed on an upper portion of the pier.   A replacement beam forming member forming the replacement beam is carried into the work scaffold via the loading path, and the replacement beam is provided on the pier from the work scaffold using the replacement beam forming member. The scaffold construction method according to any one of claims 1 and 2.   After carrying the replacement beam forming member into the work scaffold via the carry-in path, a part or the whole of the work scaffold is raised, and the replacement beam forming member is used using the raised work scaffold. 4. The replacement beam is provided on the bridge pier, and a suspension scaffold for forming the work scaffold is suspended on the replacement beam provided on the bridge pier and lowered to a predetermined position. Scaffolding construction method.   The scaffold construction method according to any one of claims 1 to 4, wherein the replacement beam is a truss beam.

Images