JPH0726473B2 - How to hang reverse winding formwork - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for suspending a reverse winding formwork.

<< Prior Art >> As is well known, the reverse winding method is a method adopted when constructing an underground tank or the like, and concrete side walls are constructed sequentially from the ground side in the depth direction.

When building a concrete side wall with this type of construction method,
Usually, a mold is used, and in the state where the mold is set at a predetermined position, concrete is poured to construct the side wall.

Then, when one side wall unit is formed, the mold is moved downward.

As a method for suspending the form at this time, particularly the bottom form, there is a method disclosed in Japanese Patent Publication No. 59-11015.

According to the suspension method disclosed in this publication, a sheet pipe having a length corresponding to a single casting height of sidewall concrete is sequentially embedded in the concrete, and the ground pipe is inserted through a wire inserted into the sheath pipe. It is a method of suspending the bottom formwork with a crane, but this method has technical problems described below.

<< Problems to be Solved by the Invention >> That is, in the method disclosed in the above publication, when the concrete side wall is constructed by the reverse winding method, the crane must be installed outside the retaining wall, but around the retaining wall. It is difficult to adopt this suspension method when there is not enough area to install a crane in.

Further, in the suspension method, since the sheath pipe is embedded in the concrete side wall, not only the construction cost is high, but it is necessary to prevent the concrete from entering the sheath pipe, for this purpose, There has been a problem in that the connecting portion of the sheath tube has to be strong and the process becomes complicated.

In addition, after the concrete side wall is constructed, a post-treatment is required because a through hole remains in the constructed concrete side wall at a portion of the sheath tube and, in some cases, this needs to be backfilled.

The present invention has been made in view of such conventional problems, and the purpose thereof is to be able to perform construction even if there is no margin on the outer circumference of the earth retaining wall, and in a simple process and after-treatment. A method of suspending a reverse winding formwork that does not need to be provided.

<< Means for Solving the Problem >> In order to achieve the above-mentioned object, the present invention, in the suspension direction of the formwork when forming the concrete side wall constructed underground by the reverse winding method, the uppermost stage constructed A movable suspending device is installed on the side wall unit, and an anchor member with one end protruding outward is sequentially installed in the upper side wall unit, and the rotary sheave attached to the formwork is attached to the anchor member. Lock the wire of the suspension device via
After the cast concrete is hardened, the hanging device is driven to feed the wire to move the mold downward.

<< Advantageous Effects of the Invention >> According to the method for suspending the reverse winding formwork having the above configuration, the formwork is suspended by feeding the wire of the movable suspending device installed on the uppermost side wall unit. Since it is moved down while being lowered, construction can be performed even if there is no room outside the retaining wall.

Further, if an anchor member having one end protruding to the outside is installed on the side wall unit side, the formwork can be hung, so that the process does not become complicated.

Furthermore, since the anchor member used for suspending the formwork is buried inside the side wall unit, there is no need to perform post-treatment.

<Example> Hereinafter, a preferred example of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show an embodiment of a method for suspending a reverse winding formwork according to the present invention.

The suspension method shown in the same figure shows a case where a concrete sidewall of a starting or reaching vertical hole of a tank or a shield machine constructed underground is formed by a reverse winding method.

The concrete side wall is divided in the circumferential direction and the depth direction, and is formed along the inner surface of the soil retaining wall 12 in the depth direction sequentially from the ground side in a plurality of times as a side wall unit 10 having a predetermined width and length.

To form the side wall unit 10, the reverse winding form 14 shown in FIGS. 2 and 3 is used.

The reverse winding formwork 14 has a substantially L-shaped side surface, and is composed of a bottom formwork 16 and a side formwork 18, and the bottom formwork 16 and the side formwork 18 are connected via pins 20. It is assembled so that it can be disassembled.

Bottom formwork 16 and side formwork 18 are formwork plates 16a and 18a, respectively.
And support members 16b and 18b.

A plurality of screw rods 22 are embedded in each side wall unit 10, and each screw rod 22 is sequentially extended in the depth direction via joint fittings.

A plurality of rotary sheaves 24 are attached to the support member 16b of the bottom mold 16, and a plurality of rotary sheaves 24a are also attached to the upper end of the support member 18b of the side mold 18.

The bottom formwork 16 is a formwork plate 16 when pouring concrete.
A nut is screwed to the lower end of the threaded rod 22 having a penetrating a through a spacer to support the threaded rod 22.

Further, the side frame 18 is similarly supported by screwing a nut to a tie rod anchor 25 embedded in the sidewall unit 10 in the radial direction.

When the placed concrete of the side wall unit 10 for one step is hardened and the construction is completed, the reverse winding formwork 14 is suspended and moved as described below.

First, the suspension device 26 is installed on the uppermost side wall unit 10.

The suspension device 26 includes an annular rail 28 laid on the side wall unit 10 and a carriage 30 movably mounted on the rail 28.
And a plurality of winches 32 installed on the carriage 30.

An arm 34 is provided in each winch 32, and the wire 36 wound around the drum of the winch 32 is paid out from the tip of the arm 34.

On the other hand, an anchor member 38, which is installed when pouring concrete to form the same and has one end protruding downward from the lower surface of the side wall unit 10, is installed on the outer side portion of the side wall unit 10.

In the hanging movement of the reverse winding form 14, first, the bottom form 16 is moved, and the tip of the wire 36 fed out is connected to the anchor member 38 through the lower side of the rotary sheave 24.

Then the threaded rod 22 that previously supported the bottom formwork 16
Is also released, and the connection with the side mold 18 is also released.

Then, another screw rod is connected to the lower end of the screw rod 22 via a joint metal fitting, and the bottom mold 16 is demolded.

When the bottom mold 16 is released from the mold, the bottom mold 16 is suspended and supported by the winch 32 via the wire 36. In this state, the winch 32 is driven to feed the wire 36. The bottom mold 16 is gradually moved downward using the screw rod 22 as a guide and is lowered to a predetermined position (see FIG. 2).

When the bottom formwork 16 has finished descending, first, by screwing a nut onto the screw rod 22, the bottom formwork 16 is supported by the screw rod 22, and the connection between the wire 36 and the anchor member 38 is released.
The suspension movement of the bottom mold 16 is completed.

When the bottom formwork 16 is installed at a predetermined position, the reinforcing bar cage is assembled on the upper part thereof, and then the side formwork 18 is suspended and moved as shown in FIG.

In the movement of the side form 18, first, the hanging metal fitting 40 is screwed to the tip of the tie rod anchor 25 located directly above the supporting member 18b, and the tip of the wire 36 wound around the hanging metal fitting 40 and the rotary sheave 24a. And are combined.

In this state, when the side mold 18 is released from the mold, the side mold 18 is supported by the winch 32 via the wire 36, and when the winch 32 is driven to feed the wire 36, the side mold 18 can move downward.

When the side formwork 18 descends to a predetermined position, a pin 20 is attached to connect it to the bottom formwork 16 and a tie rod anchor 25
Is installed and fixed to the retaining wall 12.

By the above operation, the suspension movement of one unit of the reverse winding formwork 14 divided in the circumferential direction and the installation of the formwork 14 are completed.

After that, the suspending device 26 is moved in the circumferential direction, and the above work is sequentially repeated.

Now, when the reverse winding formwork 14 is suspended and moved in the above steps, the bottom and side formwork 16 and 18 are the wires 36 of the movable suspending device 26 installed on the uppermost side wall unit 10. By moving out, it is moved downward while being hung, so construction can be performed even if there is no room outside the earth retaining wall 12.

Further, if the anchor member 38 having one end protruding outward from the lower surface thereof is installed on the side of the side wall unit 10, the bottom formwork 18 can be hung, so that the process is not complicated.

Further, the anchor member 38 used for suspending the bottom formwork 18
Will be buried inside the side wall unit 10, so there is no need for post-processing.

Although the anchor member 38 prepared separately is embedded in the side wall unit 10 in the above-described embodiment, a reinforcing bar embedded in the side wall unit 10 may be used instead.

[Brief description of drawings]

FIG. 1 is an explanatory top view of a construction state showing an embodiment of a method for suspending a reverse winding formwork according to the present invention, FIG. 2 is an explanatory view showing a suspended moving state of a bottom formwork, and FIG. It is explanatory drawing which shows the suspended movement state of a side form. 10 …… Side wall unit 14 …… Reverse winding form 16 …… Bottom form 18 …… Side form 24, 24a …… Rotating sheave 26 …… Suspension device 36 …… Wire 38 …… Anchor member

Claims (1)

[Claims] 1. A method of suspending a formwork for forming a concrete side wall constructed underground by a reverse winding method, wherein a movable suspension device is installed on the uppermost side wall unit constructed, and An anchor member with one end protruding outward is sequentially installed in the upper side wall unit, and the wire of the suspension device is locked and placed on the anchor member via a rotary sheave attached to the formwork. After the hardened concrete is hardened, the hanging device is driven to feed the wire to move the form downward, and the method for suspending a reverse winding form.