JP3977400B2 - Concrete structure construction method - Google Patents

Description

  The present invention relates to a concrete structure construction method for dividing a plurality of lots of a predetermined height, placing concrete by changing the formwork for each lot in order from the bottom, and constructing a concrete structure of a target height About.

Conventionally, when constructing a large-scale concrete structure, it is divided into multiple lots of appropriate height, and the concrete is placed by rearranging the formwork for each lot in order from the bottom. Is building.
An example of a construction method for a large concrete structure such as a caisson will be described with reference to FIG.

  The caisson 1 has a plurality of inner casings 10 inside, and has an inner wall 12 that forms an inner wall surface of the inner casing 10 and an outer wall 14 that forms an outer wall surface of the caisson 1. When the caisson 1 is constructed, a formwork 18 for forming the outer wall 14 and the inner wall 12 is necessary. For this reason, a plurality of molds 18 are appropriately combined, and concrete is placed in a space formed between the facing molds 18.

  The formwork 18 for forming the outer wall 14 is formed by combining a large number of metal foams to form a flat surface, and this flat surface is pressed by a vertical material and a horizontal material. The formwork 18 for forming the inner wall 12 is formed by combining a large number of metal foams to form a plane, pressing the plane with a vertical member and a horizontal member, and stretching the support 30 between the inner surfaces to adjust the shape. It is pre-assembled on the ground.

On the inner wall 12 of the existing lot, a form holder 36 for supporting the form 18 for forming the inner wall 12 of the next lot is installed, and the inner wall 12 is formed on the form holder 36. For this purpose, the formwork 18 is supported.
The opposing molds 18 are connected to each other by a separator in a state where a concrete wall of an existing lot is sandwiched between the lower parts, and is configured to withstand a lateral pressure at the time of placing concrete. A P-con is mounted on the separator, and the interval between the molds 18 facing each other is maintained at a predetermined distance by the P-con.

  After one lot of concrete has been placed in the space formed between the opposing molds 18, the concrete 30 reaches a certain strength after a certain time, and then the support 30 is contracted to form the inner wall 12. For this purpose, the mold 18 is reduced and removed. The next rebar is added before the frame is removed, and then the mold 18 for forming the inner wall 12 is raised to the position of the next lot.

By repeating the above operation, the caisson 1 having the target height is constructed.
As a method of installing the formwork holder 36 on the inner wall 12 of the existing lot, the following method can be considered (see Patent Document 1).
That is, as shown in FIG. 11, a suspension scaffold 44 is attached to the lower part of the mold 18 for forming the inner wall 12, and in this state, the mold 18 is suspended by the crane 40 via the wire rope 38 at the upper four corners. Then, it is transported to a predetermined position. Next, the worker gets on the suspension scaffold 44 of the mold 18 suspended by the crane 40 and installs the form holder 36 on the inner wall 12 of the existing lot.

However, in the construction of the caisson 1, it is an act that is not allowed to suspend an operator with a crane and does not fall under the “inevitable case” of Article 73, Paragraph 1 of the Crane Safety Regulations.
Therefore, instead of using the above method, the frame scaffolding is assembled inside the inner casing 10 of the existing caisson 1, the worker climbs the frame scaffolding, and installs the formwork holder 36 on the inner wall 12 of the existing lot. It will be. In addition, the worker climbs on this framework scaffold and removes the P-con from the separator, and fills the hole left after the P-con is removed. The hole left after the P-con is removed is simply referred to as “P-con hole”.
Japanese Patent Laid-Open No. 10-61177 (paragraphs [0008] to [0009])

  However, the inner cage 10 of the caisson 1 is narrow, and it takes time to assemble the frame scaffolding in such an inner cage 10, and the mental and physical burden on the worker becomes very large. Moreover, since the caisson 1 has the some inner collar 10, the total number of required frame scaffolds will increase. Furthermore, in each inner rod 10, it is necessary to secure a scaffold for each lot, and the total area of the necessary scaffold becomes very wide. Therefore, the amount of materials necessary for the frame scaffold increases, and the cost increases greatly.

  Further, depending on the size of the caisson 1, the total weight of the materials necessary for the frame scaffold becomes very heavy. However, when the caisson 1 is constructed on the deck of the floating dock, the total weight of materials necessary for the scaffold is limited from the viewpoint of the loading capacity of the floating dock. For this reason, it is necessary to use a floating dock having a large loading capacity in accordance with the total weight of necessary materials, which causes an increase in work cost. In addition, if the same material is used sequentially in different inner casings 10 in order to reduce the total weight of materials required for the frame scaffold, the working time becomes very long.

  The present invention solves the above-mentioned problems, and the object of the present invention is to ensure the safety of the work, to reduce the work time, the burden on the worker and the cost, and to increase the amount of necessary materials. It is to provide a concrete structure construction method capable of preventing.

  The present invention adopts the following configuration in order to solve the problem. The concrete structure construction method according to the invention of claim 1 is divided into a plurality of lots having a predetermined height, and the concrete is placed by rearranging the formwork for each lot in order from the bottom. A concrete structure construction method for constructing a structure in which a worker who has already entered an existing lot installs a work floor support that can support the work floor on the inner wall of the existing lot. A first process, a second process in which the work floor is suspended and supported by a crane on the work floor support installed in the first process, and a mold is placed on the existing lot after the second process. The third step of standing up, placing concrete, removing the formwork, and forming a new lot on the existing lot, and the worker on the work floor newly in the third step On the inner wall of the existing lot formed in A fourth step of newly installing a work floor support capable of supporting the floor, and after the fourth step, the work floor supported on the work floor support installed in the first step is Inclined and suspended, lifted upward while passing through the working floor support installed in the fourth process, and then suspended on the work floor support installed in the fourth process, the work floor suspended by a crane And a fifth step of lowering and supporting.

  In the first step and the fourth step, the worker installs the work floor support on the inner wall of the existing lot that has already been formed. The work floor supported on the work floor support is supported on the inner wall of the existing lot, and has sufficient stability and safety for placing the worker on top. The worker can safely perform the necessary work on the work floor stably supported on the work floor support.

  In the fifth step, the work floor supported on the work floor support installed in the first step is suspended by being inclined by a crane. If the work floor is lifted upward while being inclined, the work floor support installed in the fourth step can be dodged. Therefore, the work floor can be lifted to a higher position than the work floor support installed in the fourth step while avoiding the work floor from being caught by the work floor support installed in the fourth process. When the work floor is lifted to a position higher than the work floor support installed in the fourth step, the lifted work floor is lowered onto the work floor support installed in the fourth step.

The same work floor is raised from the height position of the work floor support installed in the first process to the height position of the work floor support installed in the fourth process. It is no longer necessary to prepare and install a work floor, and it is possible to prevent an increase in the amount of necessary materials.
Also, the worker can get on the work floor and install the work floor support. Therefore, it is not necessary to assemble a frame scaffold for installing the work floor support, and the work time, cost, burden on workers, and the amount of materials are reduced.
In the fourth step, a work floor support is newly installed on the inner wall of the existing lot newly formed in the third step. The “existing lot newly formed in the third step” here refers to a lot newly formed by placing concrete in the third step.

  The concrete structure construction method according to the invention of claim 2 is the concrete structure construction method according to claim 1, wherein the existing lot in which the work floor support is installed in the first step, and the second step The working floor supported on the working floor holder in the above-described manner, and an existing lot in which the working floor holder is installed in the fourth step; and the fifth step Then, the working floor supported on the working floor receiver is coupled by a coupling means so as to be freely released.

In the unlikely event that the work floor supported on the work floor support is detached from the work floor support, the work floor is supported by the existing lot via the connecting means. The work floor will not fall. Accordingly, the work floor supported on the work floor support has higher stability and safety in order to place the worker.
When the work floor is lifted with a crane, the connecting means is released.
Examples of the connecting means include a wire rope and a chain.

A concrete structure construction method according to a third aspect of the invention is the concrete structure construction method according to the second aspect, wherein the connecting means is connected to a separator or an anchor embedded in the inner wall of the existing lot.
It is easy to embed an anchor in the inner wall of an existing lot. A large number of separators are embedded in the inner wall of the existing lot. It is easy to connect the connecting means to the separator or anchor embedded in the inner wall of the existing lot. Therefore, the work floor and the existing lot can be easily and quickly connected.
The connection between the separator or anchor and the coupling means can be performed using fastening means such as bolts and nuts, for example. Moreover, it can also connect using a shackle, a hook, etc.

A concrete structure construction method according to a fourth aspect of the present invention is the concrete structure construction method according to the second aspect, wherein the connecting means is engaged and connected to a reinforcing bar protruding from the existing lot.
Reinforcing bars protrude from the existing lot. It is easy to lock and connect the connecting means to the reinforcing bars, and the connection between the work floor and the existing lot is performed simply and quickly.
Locking of the reinforcing bars protruding from the existing lot and the connecting means can be performed using, for example, a shackle or a hook.

The concrete structure construction method according to the invention of claim 5 is the concrete structure construction method according to any one of claims 1 to 4, wherein in the third step, the work floor The working floor supported on the receiving tool and the formwork are connected so as to be freely connected by a connecting means.
In the third step, the formwork erected on the existing lot is placed on the existing lot and has high stability. The formwork and the work floor are connected by a connecting means so as to be freely released. In the unlikely event that the work floor supported on the work floor support comes off the work floor support, the work floor is supported by the formwork via the connecting means. The work floor will not fall. Accordingly, the work floor supported on the work floor support has higher stability and safety in order to place the worker.
Note that the connecting means is released when the frame is removed.
Examples of the connecting means include a wire rope and a chain.

The concrete structure construction method according to the invention of claim 6 is the concrete structure construction method according to any one of claims 1 to 5, wherein the first step and the fourth step. When the worker installs the working floor support, the worker fills the hole left after removing the P-con from the inner wall of the existing lot.
In the first step and the fourth step, when the worker installs the work floor support, the hole of the P-cone existing on the inner wall of the existing lot is filled together, so that the work efficiency is improved. Note that the P-con is removed from the separator before the P-con hole is filled.
Since it is not necessary to assemble a frame scaffold in order to remove the P-con from the separator or to fill the P-con hole, the working time, cost, burden on the worker, and the amount of materials are reduced.

A concrete structure construction method according to the invention of claim 7 is the concrete structure construction method according to any one of claims 1 to 6, wherein the first step and the fourth step. Then, when the worker installs the work floor support, the worker places the form support capable of supporting the form on the inner wall of the existing lot.
In the first process and the fourth process, when the worker installs the work floor support, the form support is installed, so that the work efficiency is improved. Since it is not necessary to assemble a frame scaffold in order to install the formwork holder, the working time, cost, burden on workers, and the amount of materials are reduced.

  The concrete structure construction method according to the invention of claim 8 is the concrete structure construction method according to any one of claims 1 to 6, wherein the second step and the fifth step. Then, after the work floor is supported on the work floor support, a worker who is on the work floor installs the form support that can support the form on the inner wall of the existing lot. To do.

If the worker gets on the work floor suspended by the crane in the second process, the worker can easily reach a high position where the hand cannot reach without climbing a stepladder or the like in the first process. Therefore, the worker can install the receiving tool for formwork safely and quickly. Similarly, if the worker gets on the work floor suspended by the crane in the fifth process, the worker can easily reach a high position where the hand cannot reach without climbing a stepladder or the like in the fourth process. Therefore, the worker can install the receiving tool for formwork safely and quickly.
In the second step, after the work floor is supported on the work floor support, the formwork support is installed. That is, when the work floor is supported on the work floor support in the second step, the formwork support is not yet installed, and the work floor may be caught by the formwork support. The work can be done easily and quickly.

In the fifth step, the work floor is lifted upward, the work floor is supported on the work floor support, and then the formwork support is installed. That is, when the work floor is lifted upward in the fifth step or when the work floor is supported on the work floor support, the formwork support is not yet installed, and the work floor is used for the formwork. The work can be performed easily and quickly without being caught by the receiving tool.
In addition, in the second step and the fifth step, when installing the formwork holder, it is possible to remove the P-con of the separator located in the upper part of the inner wall of the existing lot and to fill the P-con.

A concrete structure construction method according to the invention of claim 9 is the concrete structure construction method according to claim 7 or claim 8, wherein in the third step, after the formwork is removed, The formwork holder that has supported the formed formwork is removed from the inner wall of the existing lot.
Since the formwork holder that supported the formwork is removed, the formwork holder is not left on the inner wall of the lot after the concrete structure is constructed. The removed form holder can be used repeatedly elsewhere.

The concrete structure construction method according to the invention of claim 10 is the concrete structure construction method according to claim 7 or claim 8, wherein in the fourth step, the mold form removed in the third step is used. The support for the formwork that has been supported is removed from the inner wall of the existing lot.
Since the formwork holder that supported the formwork is removed, the formwork holder is not left on the inner wall of the lot after the concrete structure is constructed. The removed form holder can be used repeatedly elsewhere.

The concrete structure construction method according to the invention of claim 11 is the concrete structure construction method according to any one of claims 1 to 9, wherein the first step and the fourth step. The worker finishes the surface of the inner wall of the existing lot.
In the first and fourth steps, when the worker installs the work floor support, the surface of the inner wall of the existing lot is cleaned and the necessary finishing work is applied to the surface of the inner wall of the existing lot as appropriate. Work efficiency is improved. Moreover, it is not necessary to assemble a frame scaffold to finish the surface of the inner wall of the existing lot, and the work time, cost, burden on workers, and the amount of materials are reduced.

  Since it is a concrete structure construction method as described above, work safety can be ensured, work time, burden on workers, and cost can be reduced, and an increase in the amount of necessary materials can be prevented.

The best mode for carrying out the present invention will be described with reference to FIGS.
FIG. 1 is a top view of a caisson constructed by applying the concrete structure constructing method according to the present invention, FIG. 2 is an explanatory view of a space between standing molds, and FIG. 3 is a work floor support and a mold FIG. 4 is a diagram illustrating the work procedure in the first step in the concrete structure building method according to the present invention, and FIG. 5 is a diagram illustrating the work procedure in the second step in the concrete structure building method according to the present invention. 5 (i) is a work procedure explanatory diagram of the first half of the second step, FIG. 5 (ii) is a work procedure explanatory diagram of the second half of the second step, and FIG. 6 is a third diagram in the concrete structure construction method according to the present invention. FIG. 6 (i) is a work procedure explanatory diagram of the third step, FIG. 6 (ii) is a work procedure explanatory diagram of the fourth step, and FIG. 5th process in the concrete structure construction method which concerns FIG. 7 (i) is a work procedure explanatory diagram of the first half of the fifth step, FIG. 7 (ii) is a work procedure explanatory diagram of the second half of the fifth step, and FIG. 8 is a concrete structure according to the present invention. It is work procedure explanatory drawing of the process following the 5th process in a body construction method.

The concrete structure construction method according to the present invention is applied to the construction of the caisson 1 shown in FIG. This caisson 1 is constructed on the deck of a floating dock.
The caisson 1 has a plurality of inner casings 10 inside, and has an inner wall 12 that forms an inner wall surface of the inner casing 10 and an outer wall 14 that forms an outer wall surface of the caisson 1. The inner wall 12 of one inner tub 10 includes a set of inner walls 12S facing each other and a set of inner walls 12L facing each other. The lateral width of the inner wall 12S is shorter than the lateral width of the inner wall 12L. The inner casing 10 surrounded by the inner walls 12S and 12L has a rectangular shape when viewed from above.

As shown in FIGS. 2, 6 (i), and 8, when the caisson 1 is constructed, a mold 18 for forming the outer wall 14 and a mold 18 for forming the inner wall 12 are necessary. The formwork 18 is appropriately combined, and concrete is placed in a space formed between the formwork 18.
The formwork 18 for forming the outer wall 14 is formed by combining a large number of metal foams to form a flat surface, and this flat surface is pressed by a vertical material and a horizontal material. The formwork 18 for forming the inner wall 12 is formed by combining a number of metal foams to form a plane, holding the plane with vertical and horizontal materials, and stretching the support between the inner surfaces to adjust the shape. It is pre-assembled on the deck of the floating dock.

Hereinafter, the construction procedure of the caisson 1 will be described in order. The caisson 1 is constructed in order for each lot from the lowermost lot 3A upward.
First, the lowermost lot 3A shown in FIG. 4 must be constructed.
First, the reinforcing bars 20A of the lot 3A are arranged, and the mold 18 for forming the outer wall 14 and the mold 18 for forming the inner wall 12 are set up so as to surround the reinforcing bar 20A. A space 22 for placing concrete is formed between the molds 18, and the reinforcing bar 20 </ b> A is located in the space 22.

  As shown in FIG. 2, the molds 18 arranged facing each other are connected to each other by a separator 24, and are configured to withstand a lateral pressure at the time of placing concrete. A pair of P-cons 26 is attached to the separator 24. A foam tie 27 is connected to both ends of the separator 24 via each P-con 26. The P-cons 26 are located in the space 22 between the opposing molds 18, and the opposing molds 18 are kept at a constant interval by the P-cons 26. A foam tie 27 fixes the metal foam of the mold 18 and the flap material.

A plurality of anchors 28 are arranged between the reinforcing bars 20A, and the heads of the anchors 28 are exposed at various positions on the inner wall 12 after the frame 18 is removed. The anchor 28 has a bolt hole into which a bolt is screwed, and this bolt hole opens at the head of the anchor 28.
When the standing of the mold 18 is finished, the concrete of the lot 3A is placed in the space 22 between the molds 18. After placing the concrete, the rebar 20B of lot 3B is assembled on the rebar 20A of lot 3A and added. Between the reinforcing bars 20B of the lot 3B, a plurality of separators 24 to which a P-con 26 is attached and a necessary number of anchors 28 are arranged.

  When the concrete reaches a certain strength after a certain time after placing the concrete, the support of the mold 18 for forming the inner wall 12 is reduced and the foam tie 27 is released from the connection with the separator 24. Then, the mold 18 for forming the inner wall 12 is reduced, lifted with a crane, and removed from the frame. When the formwork 18 for forming the inner wall 12 is removed, the inner wall 12 of the lot 3A is exposed, and the head of the P-con 26 and the anchor 28 of the separator 24 can be seen on the exposed inner wall 12 of the lot 3A. Yes.

If the formwork 18 for forming the inner wall 12 is removed, the process proceeds to the first step (see FIG. 4).
In the first step, first, the worker enters the inner casing 10 of the lot 3A in which the worker is formed, stands on the bottom surface 16, removes the P-con 26 on the inner wall 12, and fills the hole of the P-con 26. A stepladder 42 or the like is used for the removal work of the P-con 26 located above the inner wall 12 and the hole filling work of the P-con 26.
At the same time as the removal of the P-con 26 and the filling of the P-con 26, the worker installs the work floor support 32B shown in FIG. 3 on the anchor 28 at a predetermined height on the inner wall 12L by bolting. To do.

  The work floor support 32B is made of L-shaped steel 33 cut to a predetermined length and subjected to rust prevention treatment, and the L-shaped steel 33 has two surfaces 33A and 33B adjacent to the chevron. The surface 33A of the L-shaped steel 33 has a bolt hole 33C, and is configured to be bolted to the bolt hole of the anchor 28. A steel triangular plate 33 </ b> D is welded to the longitudinal end of the L-shaped steel 33. The triangular plate 33D forms a right triangle, and at the end of the L-shaped steel 33 in the longitudinal direction, the vertex forming the right angle of the triangular plate 33D is sandwiched between the two surfaces 33A and 33B of the L-shaped steel. And in the longitudinal direction edge part of this L-shaped steel 33, the bottom end of the surface 33A and the bottom end of the surface 33B are connected by the hypotenuse 33E of the triangular plate 33D.

On each inner wall 12L, two work floor holders 32B are installed substantially symmetrically. The distance between the two work floor supports 32B is approximately half the lateral width of the inner wall 12L or slightly longer than half the lateral width of the inner wall 12L.
Each work floor support 32B is installed with the surface 33B facing upward.
The worker performs the removal operation of the P-con 26, the hole-filling operation of the P-con 26, and the installation operation of the work floor support 32 on the bottom surface 16 or the stepladder 42 placed on the bottom surface 16. Therefore, the feet of the worker are stable, and the worker can work safely in a stable state.

When the work floor support 32B is installed, the first step is completed. Next, the process proceeds to the second step (see FIGS. 5 (i) and (ii)).
In the second step, first, the work floor 34 is prepared on the deck of the floating dock. The work floor 34 has a rectangular shape. The rectangle formed by the work floor 34 is slightly smaller than the rectangle formed by the inner collar 10 viewed from above. The work floor 34 has hanging hands at its four corners. The work floor 34 has sufficient strength so that a worker can ride on it together with necessary materials.
One end of the wire rope 38S is hung on the two hanging hands on one long side of the work floor 34, and one end of the wire rope 38L is hung on the two hanging hands on the other long side, respectively. Each other end of 38L is put on the hook of the crane 40. The length of the wire rope 38S is shorter than the length of the wire rope 38L.

  As shown in FIG. 5I, when the work floor 34 is lifted by the crane 40, the work floor 34 is inclined. While the work floor 34 is tilted, the crane 40 carries the work floor 34 upward. When the work floor 34 is carried above the inner rod 10, the work floor 34 is lowered. First, the long side of the work floor 34 on the side of the wire rope 38L is placed on the surface 33B of the work floor receiving tool 32B installed on one inner wall 12L. Then, the work floor 34 is lowered by the crane 40 as it is, and the long side of the work floor 34 on the wire rope 38S side is placed on the surface 33B of the work floor support 32B installed on the other inner wall 12L. When the work floor 34 is lowered and supported on the work floor support 32 </ b> B, the wire ropes 38 </ b> S and 38 </ b> L are removed from the lifting hand of the work floor 34. The work floor 34 is supported on the inner wall 12 of the lot 3A via the work floor support 32B, and has sufficient stability and safety for placing the worker on top.

  As shown in FIG. 5 (ii), when the work floor 34 is supported by the work floor support 32B, the worker connects each suspension hand of the work floor 34 and the anchor 28 of the inner wall 12 of the lot 3A. It connects so that connection can be freely released via the wire rope 38C which is a means. Even if the work floor 34 is detached from the work floor support 32B, the work floor 34 is supported by the inner wall 12 of the lot 3A via the wire rope 38C, and the work floor 34 falls. Never do. Therefore, the work floor 34 supported on the work floor support 32B has higher stability and safety in order to put a worker.

  After connecting each suspension hand of the work floor 34 and the anchor 28 of the inner wall 12 of the lot 3A, the worker rides on the work floor 34 and attaches to the anchor 28 near the upper edge of each of the inner walls 12S, 12L of the lot 3A. Then, the form holder 36B is bolted and installed. As shown in FIG. 3, the mold holder 36B is made of an L-shaped steel 33 cut to a predetermined length and subjected to a rust prevention treatment, and the L-shaped steel 33 has two surfaces 33A and 33B adjacent to the chevron. Have The surface 33A of the L-shaped steel 33 has a bolt hole 33C, and is configured to be bolted to the bolt hole of the anchor 28.

When the form holder 36B is installed with the surface 33B facing upward like the work floor holder 32B, the second step is completed. Next, the process proceeds to the third step (see FIG. 6 (i)).
In the third step, first, the mold 18 for forming the outer wall 14 and the mold 18 for forming the inner wall 12 are stowed so as to surround the reinforcing bar 20B of the lot 3B. The molds 18 arranged to face each other are connected to each other by a separator 24 (see FIG. 2). The opposing molds 18 are kept at a fixed interval by the P-con 26 and the foam tie 27 of the separator 24.

  When the standing of the mold 18 is finished, the concrete of the lot 3B is placed in the space 22 between the molds 18. After placing the concrete, the rebar 20C of the lot 3C is assembled and added on the rebar 20B of the lot 3B. The reinforcing bar 20C is shown in FIG. 6 (ii). Between the reinforcing bars 20C of the lot 3C, a plurality of separators 24 to which the P-con 26 is attached and a necessary number of anchors 28 are arranged.

  When the concrete reaches a certain strength after a certain time after placing the concrete, the support of the mold 18 for forming the inner wall 12 is reduced and the foam tie 27 is released from the connection with the separator 24. Then, the mold 18 for forming the inner wall 12 is reduced, lifted with a crane, and removed from the frame. When the formwork 18 for forming the inner wall 12 is removed, the inner wall 12 of the lot 3B is exposed, and the head of the P-con 26 and the anchor 28 of the separator 24 are visible on the exposed inner wall 12 of the lot 3B. Yes.

When the formwork 18 for forming the inner wall 12 is removed, the worker gets on the work floor 34, removes the formwork holder 36B from the inner walls 12S, 12L of the lot 3A, and removes it. If the form holder 36B is removed, the third step is completed. Next, the process proceeds to the fourth step (see FIG. 6 (ii)).
In the fourth step, first, the worker gets on the work floor 34 supported on the work floor support 32B, removes the P-con 26 on the newly formed inner wall 12 of the lot 3B, Fill holes in Pcon 26. A stepladder 42 or the like is used for the removal work of the P-con 26 above the inner wall 12 or the hole-filling work of the P-con 26.

  Simultaneously with the removal work of the P-con 26 and the hole filling work of the P-con 26, the work floor support 32C is fixed to the anchor 28 at a predetermined height on the inner wall 12L of the lot 3B in the same manner as the work floor support 32B. Install with bolts. As shown in FIG. 3, the work floor support 32C has the same configuration as the work floor support 32B, and the work floor support 32C is installed at the work floor support 32B in the first step. The surface 33B of the work floor support 32C faces upward.

The worker performs the removal work of the P-con 26, the hole filling work of the P-con 26, and the installation work of the work floor support 32C on the work floor 34 or on the stepladder 42 placed on the work floor 34. Therefore, it can be performed safely in a stable state.
When the work floor support 32C is installed, the fourth step is completed. Next, the process proceeds to the fifth step (see FIGS. 7 (i) and (ii)).

  As shown in FIG. 7 (i), in the fifth step, first, an operator hangs one end of the wire ropes 38S, 38L on the hanging hand of the work floor 34 supported on the work floor support 32B, The other end of the wire ropes 38S, 38L is hooked to the hook of the crane 40. The position of the suspender on the work floor 34 on which the wire ropes 38S, 38L are applied is the same as when the wire ropes 38S, 38L are applied in the second step.

  When the work floor 34 is lifted by the crane 40, first, the long side of the work floor 34 on the wire rope 38S side is lifted from the work floor support 32B, and then the long side of the work floor 34 on the wire rope 38L side is the work side. The floor 34 is lifted from the floor support 32B, and the work floor 34 is inclined and suspended. As it is, the work floor 34 is lifted upward by the crane 40 and once raised to a position higher than the work floor support 32C installed in the fourth step. Since the work floor 34 is in an inclined state, the work floor support 32C can be displaced, and the work floor 34 can be prevented from being caught by the work floor support 32C.

  Further, when the work floor 34 is lifted upward by the crane 40, even if the edge of the work floor 34 touches the work floor support 32C from below, the edge of the work floor 34 is the triangle of the work floor support 32C. It only contacts the hypotenuse 33E of the plate 33D. The edge of the work floor 34 in contact with the hypotenuse 33E slides along the hypotenuse 33E. Therefore, the edge of the work floor 34 is not caught by the work floor support 32C, and the work floor 34 rises to a position higher than the work floor support 32C.

  Next, the work floor 34 of the crane 40 is lowered, and the long side of the work floor 34 on the wire rope 38L side is placed on the surface 33B of the work floor support 32C installed on one inner wall 12L. Then, the work floor 34 is lowered by the crane 40 as it is, and the long side of the work floor 34 on the wire rope 38S side is placed on the surface 33B of the work floor support 32C installed on the other inner wall 12L. When the work floor 34 descends onto the work floor support 32C and is supported, the wire ropes 38S and 38L are removed from the suspenders of the work floor 34. The work floor 34 is supported on the inner wall 12 of the lot 3B via the work floor support 32C, and has sufficient stability and safety for placing the worker on top.

  Next, as shown in FIG. 7 (ii), when the work floor 34 is supported on the work floor support 32C, the worker holds each suspension hand of the work floor 34 and the anchor 28 of the inner wall 12 of the lot 3B. Then, they are connected via a wire rope 38C, which is a connecting means, so that the connection can be freely released. In the unlikely event that the work floor 34 comes off the work floor support 32B, the work floor 34 is supported by the inner wall 12 of the lot 3B via the wire rope 38C, and the work floor 34 falls. Never do. Therefore, the work floor 34 supported on the work floor support 32C has higher stability and safety in order to put a worker.

After connecting each suspension hand of the work floor 34 and the anchor 28 of the inner wall 12 of the lot 3B, the worker rides on the work floor 34 and attaches to the anchor 28 near the upper edge of each of the inner walls 12S, 12L of the lot 3B. Then, the form holder 36C is bolted and installed. As shown in FIG. 3, the mold receiver 36C has the same configuration as the mold receiver 36B.
Once the mold receiver 36C is installed, the fifth step is completed. When the fifth step is completed, as shown in FIG. 8, the formwork 18 is set up, the concrete is placed, and the formwork 18 is removed by the same operation procedure as in the third step. Once the formwork 18 is removed, the worker gets on the work floor 34, removes the formwork support 36C from the inner walls 12S, 12L of the lot 3B, and removes it.

By repeating the procedure described above, the concrete can be sequentially placed for each lot while raising the work floor 34 sequentially, and the caisson 1 having the desired height and size can be constructed.
The worker performs the removal work of the P-con 26, the hole filling work of the P-con 26, the installation work of the work floor receivers 32 </ b> B and 32 </ b> C, and the installation work of the formwork receivers 36 </ b> B and 36 </ b> C on the work floor 34. Therefore, it is not necessary to assemble a frame scaffold in the inner frame 10, and the work time, cost, burden on workers, and the amount of materials are reduced. Further, since the same work floor 34 is sequentially raised, it is possible to reduce the amount of necessary materials, which is particularly preferable in a floating dock in which the total weight of materials necessary for the scaffolding is limited from the viewpoint of loading capacity.

In the present embodiment, the caisson 1 is constructed on the deck of a floating dock. However, it is a matter of course that the caisson 1 can be constructed in a normal dock, a quay, or the like.
In the present embodiment, the shape of the inner flange 10 viewed from above is a rectangle, but it is needless to say that the shape of the inner flange 10 viewed from above is not limited to a rectangle. For example, the shape may be a square, trapezoid, triangle, or the like. In the present embodiment, in the inner collar 10, the lateral width of the inner wall 12S is shorter than the lateral width of the inner wall 12L. However, it goes without saying that the lateral width of the inner wall 12L may be shorter than the lateral width of the inner wall 12S.

  In the present embodiment, the form 18 for forming the inner wall 12 is shaped by stretching the support between the inner surfaces. However, the shape may be adjusted by pulling between the inner surfaces with a wire rope or a chain. Moreover, although the formwork 18 for forming the inner wall 12 is assembled on the deck of the floating dock, it may be assembled in an adjacent yard or the like.

  In the present embodiment, the number of work floor holders 32B and 32C installed on one inner wall 12L is two. However, it goes without saying that the number of work floor supports 32B and 32C is not limited to two. The number and installation position of the work floor 34 are determined in consideration of the weight of the work floor 34 and the weight of materials and the like that must be loaded on the work floor 34. The same applies to the number and position of the mold holders 36B and 36C, and the number and installation position thereof are determined in consideration of the weight of the mold 18 and the like.

In the present embodiment, in the first process, the removal operation of the P-con 26 on the inner wall 12 of the lot 3A and the filling operation of the P-con 26 are performed. However, the removal work of the P-con 26 located at the high place above the inner wall 12 of the lot 3A and the filling process of the P-con 26 are carried on the work floor 34 supported by the work floor support 32B. It is also possible to do this.
Similarly, in the present embodiment, in the fourth step, the removal operation of the P-con 26 on the inner wall 12 of the lot 3B and the filling operation of the P-con 26 are performed. However, the removal work of the P-con 26 located at the high place above the inner wall 12 of the lot 3B and the hole filling work of the P-con 26 are performed on the work floor 34 supported on the work floor support 32C. It is also possible to ride.

In the present embodiment, in the second half of the second step, each suspension hand of the work floor 34 and the anchor 28 of the inner wall 12 of the lot 3A are connected via a wire rope 38C. Instead of this, a work procedure as shown in the modified examples of FIGS. 9 (i) and (ii) may be employed. That is, as shown in FIG. 9 (i), in the latter half of the second step, each suspender of the work floor 34 and the rebar 20B of lot B protruding above the lot 3A are connected via a wire rope 38C. To do. Then, as shown in FIG. 9 (ii), before the formwork 18 is stowed in the third step, the connection between the reinforcing bar 20B and the wire rope 38C is released, and the formwork supported by the formwork holder 36B. 18 and the wire rope 38C are connected.
In the present embodiment, instead of using the mold receivers 36B and 36C, the work floor receiver 32B or 32C may be used as the mold receiver.

It is a top view of the caisson constructed by applying the concrete structure constructing method according to the present invention. It is explanatory drawing of the space between the standing formwork. It is a perspective view of the receptacle for work floors and the receptacle for formwork. It is work procedure explanatory drawing of the 1st process in the concrete structure construction method concerning this invention. It is work procedure explanatory drawing in the 2nd process in the concrete structure construction method which concerns on this invention, (i) is work procedure explanatory drawing of the 2nd process first half, (ii) is work procedure explanatory drawing of the 2nd process latter half. . It is work procedure explanatory drawing from the 3rd process in the concrete structure construction method which concerns on this invention to the 4th process, (i) is a work procedure explanatory drawing of a 3rd process, (ii) is a work procedure description of a 4th process. FIG. It is work procedure explanatory drawing of the 5th process in the concrete structure construction method concerning this invention, (i) is a work procedure explanatory drawing of the first half of a 5th process, (ii) is a work procedure explanatory drawing of the latter half of a 5th process. It is. It is work procedure explanatory drawing of the process following the 5th process in the concrete structure construction method which concerns on this invention. It is work procedure explanatory drawing of the 3rd process of the concrete structure construction method which concerns on a modification, (i) is a work procedure explanatory drawing of the latter half of a 2nd process, (ii) is a work procedure explanatory drawing of a 3rd process. . It is explanatory drawing of the construction method of the conventional caisson. It is explanatory drawing of the formwork which attached the suspension scaffold.

Explanation of symbols

1 Caisson 3A, 3B, 3C Lot 10 Inner rod 12, 12S, 12L Inner wall 14 Outer wall 16 Bottom surface 18 Formwork 20A, 20B, 20C Reinforcement 22 Space 24 Separator 26 P-con 27 Foam tie 28 Anchor 30 Support 32B, 32C For work floor Receiving tool 33 L-shaped steel 33A, 33B L-shaped steel surface 33C Bolt hole 33D Triangular plate 33E Triangular plate hypotenuse 34 Work floor 36, 36B, 36C Formwork receiving tool 38, 38S, 38L, 38C Wire rope 40 Crane 42 Stepladder 44 Suspended scaffolding

Claims (11)

A concrete structure construction method that divides into a plurality of lots of a predetermined height, places the concrete by changing the formwork for each lot in order from the bottom, and constructs the concrete structure of the desired height,
A first step in which a worker who has entered an already formed existing lot installs a work floor support that can support the work floor on the inner wall of the existing lot;
A second step of hanging and supporting the work floor with a crane on the work floor support installed in the first step;
After the second step, a third step of standing a formwork on the existing lot, placing concrete, removing the formwork, and forming a new lot on the existing lot;
A fourth step in which a worker who rides on the work floor newly installs a work floor support capable of supporting the work floor on the inner wall of the existing lot newly formed in the third step;
After the fourth process, the work floor supported on the work floor support installed in the first process is suspended by tilting with a crane, and the work floor support installed in the fourth process is passed as it is. And then lifting the work floor suspended by a crane and supporting it on the work floor support installed in the fourth process after being lifted upwards. Construction method. The existing lot in which the work floor support is installed in the first step and the work floor supported on the work floor support in the second step are connected so as to be freely connected by a connecting means,
The existing lot in which the work floor support is installed in the fourth process and the work floor supported on the work floor support in the fifth process are connected so as to be freely connected by a connecting means. The method for constructing a concrete structure according to claim 1.   The method for constructing a concrete structure according to claim 2, wherein the connecting means is connected to a separator or an anchor embedded in an inner wall of the existing lot.   The method for constructing a concrete structure according to claim 2, wherein the connecting means is engaged and connected to a reinforcing bar protruding from the existing lot.   The said 3rd process WHEREIN: The said work floor supported on the said receiving tool for work floors, and the said formwork are connected so that a connection release is possible by a connection means. The concrete structure construction method according to claim 1.   In the first step and the fourth step, when an operator installs the working floor support, the worker fills a hole left after removing P-con from the inner wall of the existing lot. The concrete structure construction method according to any one of claims 1 to 5.   In the first step and the fourth step, when the worker installs the work floor support, the form support that can support the form is installed on the inner wall of the existing lot. The method for constructing a concrete structure according to any one of claims 1 to 6, wherein the concrete structure is constructed.   In the second step and the fifth step, after the work floor is supported on the work floor support, a worker who is on the work floor can support the form. Is installed on the inner wall of the existing lot, The concrete structure construction method according to any one of claims 1 to 6.   8. The method according to claim 7, wherein, in the third step, after removing the formwork, the formwork supporter supporting the removed formwork is removed from the inner wall of the existing lot. Item 9. A concrete structure construction method according to Item 8.   The said 4th process WHEREIN: The said receiving device for formwork which supported the formwork removed from the said 3rd process is removed from the inner wall of the said existing lot. Concrete structure construction method.   The concrete structure construction according to any one of claims 1 to 9, wherein in the first step and the fourth step, an operator finishes the surface of the inner wall of the existing lot. Method.

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