JP2003253685A - Simple temporary coffering method around column type structural body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily operate small-scale temporary coffering in a narrow space below a girder during aseismatic reinforcement work and the like for a bridge girder lower part when a column type structural body is immersed in the water. <P>SOLUTION: In this simple coffering method around the column type structural body in reinforcement work for covering the outside face of the column type structural body (a pier 3) projected on a water bottom ground 8 with a steel plate block, a coffering steel plate 5 is assembled when divided coffering steel plate members 5a and 5b are arranged at a predetermined interval to surround the pier 3 and joints of the respective members 5a and 5b are connected together, and then, the coffering steel plate 5 is pressed down by means of a press-in jack 10 in a press-in device 4 fixed in the upper part of the pier 3 to be inserted into the water bottom ground 8. When assembly of the coffering steel plate 5 and its pressing down operation are repeated, the outside of the pier 3 is hermetically coffered by means of a plurality of coffering steel plates 5. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bridge pier and a foundation (for example, concrete piles or steel pipe piles) protruding from a submarine ground.
The present invention relates to a simple temporary cutoff method around a columnar structure when carrying out a method of reinforcing (repairing) a columnar structure.

[0002]

2. Description of the Related Art For bridge piers and other columnar or pile-shaped structures of viaducts, various repairing and reinforcing methods are proposed to enhance the earthquake resistance of the columnar structures and to repair cracks caused by earthquakes. One of the proposals,
There is Japanese Patent Laid-Open No. 2000-336946 related to the present applicant.

In this reinforcing method, a plurality of steel plates are mounted by mounting a steel plate block on the outer periphery of a columnar structure by ground work and repeatedly pushing down the steel plate block with a jack of a press-fitting device fixed to the columnar structure. While press-fitting the block into the ground, the steel plate block is covered and reinforced over the required length of the outer surface of the columnar structure.The advantage of this is that the ground outside the columnar structure is deep In addition, it is not necessary to excavate widely and provide a working space.

[0004]

[Problems to be Solved by the Invention]
The reinforcement method according to 946 is a reasonable reinforcement method with good workability, but since the columnar structure is projected on the water bottom ground,
If the reinforced part exists in the water, it may be necessary to temporarily cut off the periphery of the columnar structure, drain the inside, and perform the reinforced work in the atmosphere. There was no temporary deadline construction method.

The present invention is an improvement of the above-mentioned conventional reinforcement method, and particularly in a small space under a girder in a seismic reinforcement work of a bridge substructure when a columnar structure (pier) is underwater. For simple shut-off, a simple temporary shut-off steel plate with bolts and nuts for splitting is manufactured, and the shut-off steel plate is press-fitted and installed with a small press-fitting device (SSP press-fitting device, etc.) that uses the existing pile as a reaction force. . Also, in some cases, the soil inside the deadline will be improved to stop permeated water from below.

The present invention is mainly described in Japanese Patent Laid-Open No. 2000-336.
Effectiveness is exhibited by performing the method in combination with the reinforcing method of the columnar structure according to 946, but it can also be performed in combination with various other reinforcing methods.

[0007]

In order to achieve the above-mentioned object, the present invention is constructed as follows.

The invention according to claim 1 is a simple temporary cutoff method around a columnar structure at the time of reinforcement in which the outer surface of the columnar structure projecting on the water bottom ground is covered with a steel plate block, which is divided in the circumferential direction. The cut-off steel plate is arranged so as to surround the columnar structure at a predetermined distance, and the cut-off steel plate is assembled by joining the joints of the respective members, and then the press-fitting device is press-fitted to the upper part of the columnar structure. A jack is used to push down the shut-off steel plate to penetrate into the water bottom ground, and to assemble the upper and lower shut-off steel plates and to repeat the pushing operation to watertightly shut around the columnar structure with a plurality of shut-off steel plates. Is characterized by.

According to a second aspect of the present invention, in the first aspect of the present invention, the cylinder and the operating rod of the press-fitting jack are an upper chuck for press-fitting reaction force that is detachable from the columnar structure, and a lower chuck for pressing force. A plurality of members by causing the press-fitting device to repeatedly move up and down along the columnar structure by the expansion and contraction of the press-fitting jack and the timing operation of fixing and opening the upper chuck and the lower chuck. It is characterized in that the cut-off steel plate is pushed down.

A third aspect of the present invention is characterized in that, in the first or second aspect of the present invention, the connecting means between the vertical and circumferential shutoff steel plate members is bolted through packing.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a plurality of inner end edges of the shut-off steel plate are slidably contacted with the outer surface of the columnar structure. The press-fitting guide member is detachably provided, and the shut-off steel plate is press-fitted together with the press-fitting guide member.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the interior of the deadline is drained after the deadline of the columnar structure by the deadline steel plate is completed. .

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, after the deadening around the columnar structure by the dead steel plate is completed, the ground inside the dead steel plate is improved. Let's say it is a feature.

According to a seventh aspect of the present invention, in the invention according to any one of the first to fourth or sixth aspects, after the shutoff around the columnar structure by the shutoff steel plate is completed, the outer surface of the columnar structure is covered with a steel plate block. When the press-fitting guide member according to claim 4 is removed from the shut-off steel plate, the scaffold is detachably provided inside the shut-off steel plate so as to surround the columnar structure, and the columnar structure is provided through the scaffold. It is characterized in that the work of coating the steel plate block on the outer surface of the object is performed.

[0015]

The present invention can be applied to small-scale deadlines on the outer bottom ground of columnar structures in a narrow space under girders in seismic reinforcement work of bridge substructures in which columnar structures (bridge piers) are projected in water. When doing so, a simple temporary cut-off steel plate with bolted nuts for split parts is manufactured, and the cut-off steel plate is press-fitted and installed with a small press-fitting device that uses the existing pile as a reaction force. Compared with the cut-off construction method, the river blockage rate and construction costs can be significantly reduced. In addition, in some cases, the interior of the deadline can be simply improved to stop permeated water from below, further improving workability.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The embodiments of the present invention will be described below.

FIG. 1 (A) is a front view showing a construction situation in which a simple temporary cut-off method of the present invention is applied to a bridge pier as a concrete example of a columnar structure cast on a water bottom ground, and FIG. (A)
2 is an explanatory view taken along line (a)-(a) of FIG.
It is explanatory drawing which follows the (b)-(b) line in (A).

3 is a front view of the press-fitting device, FIG. 4 is a side view of FIG. 3, FIG. 5 is a cross-sectional plan view of the press-fitting device mounted on a pier, and FIG. 6 is provided with a chuck fastening mechanism different from that of FIG. Fig. 7 is a cross-sectional plan view of the press-fitting device attached to the pier, Fig. 7 is a perspective view of the cutoff steel plate at the tip (lowermost end) and the standard cutoff steel plate connected thereabove, and Fig. 8 (A) is the press-fitting with the standard cutoff steel plate attached. The top view which shows the relationship between a guide member and a bridge pier, (B) is a longitudinal cross section of FIG. (A), (C), (D) is a side view and a top view of a press fit guide member.

The following will be described in order. In FIG. 1 (A),
The bridge girder 2 with the floor slab 1 installed on the upper surface is composed of one or more bridge piers 3 (in the figure, the left end, the middle,
It is supported by the example of the three right piers).

Prior to the work of reinforcing the bridge pier 3 projecting from the water bottom ground 8 with a steel plate block or the like (shown in FIG. 15), the periphery of the pier 3 is surrounded and the dead steel plate 5 is struck on the water bottom ground 8 outside the pier. By installing the pier 3, the outside of the pier 3 is temporarily cut off for drainage, the surroundings of the pier 3 are kept in the atmospheric state, and the above-mentioned reinforcement work is performed.

In the temporary shut-off work on the outside of the pier 3 in water, as shown in the middle pier 3 of FIG. 1, a hydraulic jack type press-fitting device 4 is fixed to the leg head of the pier 3,
By the expansion and contraction of the jack type press-fitting device 4, upper and lower shut-off steel plates 5 (shown in FIGS. 2 and 7 and below) fitted to the pier 3 are sequentially pushed down along the pier 3 and press-fitted into the ground. Although not shown, a half-divided annular reaction force receiving steel plate is attached to the pier head of the pier 3, and the hydraulic jack type press-fitting device 4 tightens the pier head through the reaction force receiving steel plate. Stuck to.

The structures of the jack type press-fitting device 4 and the shut-off steel plate 5 will be described with reference to FIGS. The jack type press-fitting device 4 is composed of an upper chuck 6 for press-fitting reaction force, a lower chuck 7 for pressurizing (combining and raising) a pressure input, and a press-fitting jack 10 for connecting the upper and lower chucks 6, 7. ing.

Since the upper chuck 6 and the lower chuck 7 have the same structure, the upper chuck 6 will be described below, and the lower chuck 7 has the same elements as those of the upper chuck 6, and the description thereof will be omitted. . In the examples shown in FIGS. 3 to 5, in the upper chuck 6, one end of each of the left and right arc-shaped divided frames 11 and 11 is hingedly connected by the connecting shaft 12, and each of the divided frames 11 and 11 is connected. A chuck jack 1 in which both brackets 13, 13 provided at the other end can be tightened and released between the two divided frames 11, 11.
4 is detachably attached to both brackets 13 and 13 via a connecting pin 15.

Therefore, the connecting pin 15 is dismounted from the pin hole, the arcuate tip portions of the left and right split frames 11, 11 are separated from each other, sufficiently opened to contact the outer surface of the pier 3, and the connecting pin 15 is attached. It is inserted into the pin hole again, and then the chuck jack 14 is expanded and contracted to tighten the outer surface of the pier 3 with the divided frames 11 and 11 and fix it to this, or release the tightening to free the pier 3. It can be in a different state. This also applies to the lower chuck 7.

Each divided frame 1 in the upper chuck 6
The cylinder side of the press-fitting jack 10 is connected to the lower surface side of the intermediate portion of the press-fitting jacks 11 by means of a connecting pin 16. The operating rod 17 side is connected by a connecting pin 18.

Therefore, the chuck jack 14 is used.
And the expansion / contraction operation of the press-fitting jack 10 are performed at a predetermined timing, so that the press-fitting device 4 is vertically moved in a predetermined range along the pier 3 in a predetermined range as described later, and this is repeated. The plurality of cutoff steel plates 5 having a predetermined length can be sequentially pushed down to surround the outside of the pier 3 and the cutoff steel plates 5 having a predetermined length can be driven vertically on the water bottom ground 8 around the pier.

As shown as another example in FIG. 6, each of the divided frames 11, 1 divided into the left and right of the upper chuck 6.
Both ends of 1 may be configured to be openable and closable by the same connection structure as the jack 14 for chuck shown in FIG. (In FIG. 6, the same elements as those in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted.)

An example of the construction of the cutoff steel plate 5 is shown in FIGS.
In FIG. 7, a cylindrical cut-off steel plate 5 is vertically divided into halves, and left and right split cut-off steel plate members 5a having a substantially semi-circular shape,
5b are combined, and this division cut-off steel plate member 5
A plurality of bolt insertion holes 20 are provided on both side edges of the arc shape of a and 5b.
A vertical joint flange 21 having a joint is provided.
The two closed steel plate members 5a and 5b are opposed to each other, and a sufficient work space (installation space for a work scaffold to be described later) is formed in the interior so as to surround the outside of the pier 3 and the joint portion is formed. Rubber packing 2 between the joint flanges 21 and 21
3, the flanges 21 and 21 are connected by a connecting bolt 22 inserted in a bolt insertion hole 20 to assemble a watertight shutoff steel plate 5 in the circumferential direction, and the outside of the pier 3 is largely held. Further, the purpose is to ensure the waterproofness of the rubber packing, and a liquid sealant or the like may be used.

In FIG. 7, the lowermost end and the cutoff steel plate 5 above the lower end contact the upper horizontal joint flange 30 and the lower horizontal joint flange 32 of each block via two semi-circular rubber packings 23, By fastening the connecting bolts to the bolt insertion holes 31, the upper and lower shutoff steel plates 5 can be joined in a watertight manner in order in the vertical direction while adding them. Further, in the example shown in FIG. 7, the upper horizontal joint flange 30 of the cutoff steel plate 5 is used.
A lower horizontal joint flange 32, a joint flange 21,
Although all 21 are projected to the outside of the division cut-off steel plate members 5a and 5b, on the contrary, each flange 30, 32,
21 may be provided so as to project inward. (However, not shown)

Further, as shown in FIGS. 7 and 8, in the second-stage cut-off steel plate 5, the left and right divided cut-off steel plate members 5a,
On the inner peripheral surface of 5b, four mounting flanges 26 are provided at equal angular intervals so as to extend vertically, and on the side surface of each mounting flange 26, the outside of the side-fitted press-fitting guide member 27 shown in FIG. The end side surface 27a is applied and both members are detachably fixed by a bolt nut 28 penetrating the bolt hole 28a of the joint portion.

Thus, the inner end edges 27b of the eight press-fitting guide members 27 radially provided on the inner peripheral surface of the cut-off steel plate 5 slidably contact the outer surface of the pier 3, whereby the pier 3
With the pier 3 as a guide, the steel plate 5
Can be pressed into the water bottom ground 8 by pressing force from above. As a result, the space around the pier 3 formed by the shut-off steel plate 5 can be made constant at all times in the radial direction centered on the pier 3.

Further, the number of press-fitting guide members 27 to be used may be adjusted or the press-fitting guide members 27 may be used depending on the nature of the water bottom ground.
It is, of course, possible to remove the from as a component.

Next, the construction procedure will be described by dividing it into items [1] to [13].

[1] As shown in FIGS. 1 (A) and 1 (B),
The press-fitting device 4 and the suspension girder 46 for assembling the shut-off steel plate 5 are installed below the bridge girder 2.

[2] As shown in FIG. 2, the upper chuck 6
And the divided frames 11, 11 in the lower chuck 7,
The press-fitting device 4 is assembled by coupling using the chuck jack 14. Temporary support at the time of assembling the press-fitting device 4 is performed by suspending it with a hoist 34 described later or a chain block (not shown).

[3] As shown in FIGS. 2 and 9, the pier 3
Is projected on the subsoil 8 and the water level 25 is high, middle, and low (HWL, MWL, LWL) at low tide and high tide.
Change to the water level. In FIG. 2 and FIG. 9, the cutoff steel plate 5 at the lowermost end is assembled in the water bottom ground 8 in water to form an annular shape by bolting. This work is performed by suspending and supporting the tip cutoff steel plate 5 with the wire 36 unwound from the hoist 34 suspended and supported by the hoist beams 35 provided at both ends of the overhead crane or the suspension girder 46.

[4] As shown in FIG. 10, the second-stage cut-off steel plate 5 is assembled in an annular shape by bolting on the cut-off steel plate 5 at the lowermost end by the same work as described above, and the upper and lower cut-off steel plates 5 are also assembled. To join.

[5] As shown in FIG. 11, a press-fit girder 29 is attached to the upper end of the second-stage shut-off steel plate 5. The installation is performed by suspending the press-fitting girder 29 with an overhead crane or the like. The press-fitting girder 29 has a reinforcing frame 29a as shown in FIG.
It is made of H-section steel reinforced with a predetermined length, and two pieces are arranged in parallel at a predetermined interval when viewed from the plane. When the press-fitting girder 29 is directly arranged on the upper edge of the shutoff steel plate 5,
Since the upper edge of the cut-off steel plate 5 made of a thin steel plate may locally bend and bend, in the illustrated example, two sets of the upper reinforcing frames 3 formed by bending the H-section steel at a predetermined angle when viewed from the plane are shown.
3 is arranged on the upper horizontal joint flange 30 of the cutoff steel plate 5 so as to face each other, and a plane arcuate reinforcing attachment plate 33a hanging from the lower surface of the upper reinforcement frame 33 is arranged along the inner peripheral surface of the upper end of the cutoff steel plate 5. Moreover, the press-fitting girder 29 is placed on the upper reinforcing frame 33.
It is arranged.

[6] Next, the operation of fixing the divided frames 11, 11 of the upper chuck 6 in the press-fitting device 4 to the head of the existing bridge pier 3 by shortening the chuck 14 for the chuck, and the division of the lower chuck 7. Frame 11, 11,
Operation of opening the chuck jack 14 by extension, operation of extending the press-fitting jack 10 and lowering the split frame 11 of the lower chuck 7, shortening of the split frames 11, 11 of the lower chuck 7 of the chuck jack 14. To fix to the head of the bridge pier 3, to open the divided frames 11, 11 of the upper chuck 6 by extension of the chuck jack 14, and to shorten the press-fitting jack 10 and lower the upper chuck 6. To do.

[7] By performing the above-mentioned operations 1 to 4, the press-fitting device 4 is lowered to the position shown in FIGS.

[8] Next, by repeating the above-mentioned steps (1) to (5), a press-fitting reaction force is applied to the upper chuck 6 when the press-fitting jack 10 is extended, and the lower chuck 7 is used as a push-down frame to form the cut-off steel plate 5 into the subsea ground 8. Press into. (Fig. 11,
(See Figure 13)

[9] When the press-fitting jack 10 is expanded to the maximum extent and the press-fitting of the one-segment shut-off steel plate 5 is completed, the press-fitting jack 10 is shortened while the lower chuck 7 frame remains open. , Lower chuck 7 is fixed. , The divided frames 11, 11 of the upper chuck 6,
The chuck jack 14 is opened by extension. The upper chuck 6 is moved upward by extending the press-fitting jack 10. , The upper chuck 6 is fixed to the pier 3. , Release the lower chuck 6 from the pier 3. ,
By shortening the press-fitting jack 10, the lower chuck 7 rises. The steps 1 to 3 are repeated until the press-fitting device 4 returns to its original position.

[10] In the above step, the left and right cut-off steel plate members 5a and 5b are assembled by bolting, and the vertical joint pipe flanges 21 of the upper and lower cut-off steel plates 5 are bolted.

[11] The same procedure as the above steps [4] to [10] is repeated, and as shown in FIG. 13, when a predetermined casting length is reached to the water bottom ground 8 with the plurality of shutoff steel plates 5 as a whole. If
Remove the press fit girder 29.

[12] After that, the entire interior of the plurality of shutoff steel plates 5 is drained. Depending on the ground conditions, water may spring out from the water bottom ground 8 surrounded by the cutoff steel plate 5, and in this case, the ground improvement portion 8a at the water bottom is simply improved as shown in FIG. For simple ground improvement, methods such as chemical injection, mortar injection, and kneading can be performed.

[13] As described above, after the temporary shutoff around the bridge girder 3 is finished and the drainage inside the shutoff steel plate 5 is finished,
As shown in FIG. 15, a scaffold 39 is provided on the inner surface of the cutoff steel plate 5, and an operator rides on the scaffold 39 and utilizes the press-fitting device 4 to move the reinforcing steel plate block 38 with the hoist 34. Suspend and temporarily support and start the reinforcement work by assembly. Note that the subsequent reinforcement work is described in JP 2000-3
It is the same as 36946.

The scaffold 39 provided on the inner surface of the cut-off steel plate 5 has three
The horizontal frame 48a of the plurality of rectangular support frames 48 is replaced with the inner peripheral annular frame 4
8b and the outer peripheral annular frame 48c are connected to each other, and the scaffolding plate 49 is placed on the horizontal frame 48a. After removing the press-fitting guide member 27 from the mounting flange 26 provided on the inner surface of the cutoff steel plate 5, the support frame 48 applies the side surface of the vertical frame 48b of the support frame 48 to the side surface of the mounting flange 26, and the contact portion Both members are detachably fixed by a bolt nut 28 penetrating therethrough. In this way, the scaffold 39 is constructed by surrounding the pier 3 in the circumferential direction and mounting the annular scaffolding plate 49 on the horizontal frame 48a of each support frame 48 radially arranged in eight directions when viewed from the plane.

The embodiment is only an example, and
Modifications of design details are included in the present invention. Further, it is of course possible to use the temporary cutoff method of the present invention when carrying out another repair method.

[0049]

EFFECTS OF THE INVENTION According to the present invention, in the seismic retrofitting work of a bridge substructure in which a steel plate block is coated on the outer surface of a columnar structure projecting on the submarine ground to reinforce it, When performing small-scale shut-off in a narrow space below girders for drainage, a simple temporary cut-off steel plate with bolts and nuts for split parts should be manufactured, and press-fitted and installed with a press-fitting device that uses the existing pile as a reaction force. As a result, the cost required to reinforce the columnar structure can be significantly reduced compared to the conventional shut-down method under girders, which can greatly reduce the hindrance factor and construction cost, and can significantly shorten the work period. There is. Further, in some cases, it is possible to improve the inside of the deadline by simple soil and stop permeated water from below, and in this respect as well, the work of reinforcing the columnar structure in water can be performed more efficiently than in the past.

[Brief description of drawings]

FIG. 1 (A) is a front view showing a construction situation in which a simple temporary cut-off method of the present invention is applied to a bridge pier as a concrete example of a columnar structure cast on a water bottom ground, and FIG. 1 (B) is FIG. It is a sectional view of (A)-(A) in (A).

FIG. 2 is an explanatory view taken along line (b)-(b) in FIG.

FIG. 3 is a front view of a press-fitting device.

FIG. 4 is a side view of FIG.

FIG. 5 is a cross-sectional plan view of a state where the press-fitting device is attached to the pier.

FIG. 6 is a cross-sectional plan view showing a state in which a press-fitting device having a chuck fastening structure different from that of FIG. 5 is mounted on a pier.

FIG. 7 is a perspective view of a tip cutoff steel plate, a standard cutoff steel plate connected to the upper side, and a rubber packing.

8A is a plan view showing the relationship between the press-fitting guide member to which the standard shut-off steel plate of FIG. 7 is attached and the pier, FIG. 8B is a vertical cross-section of FIG. 7A, and FIGS. 8] is a side view and a plan view of the press-fitting guide member.

FIG. 9 is a first construction process diagram of the present invention.

FIG. 10 is a second construction process diagram of the present invention.

FIG. 11 is a third construction step diagram of the present invention.

12 (A) is a plan view of an upper end portion of the temporarily cut steel plate in FIG. 11, and FIG. 12 (B) is an explanatory view taken along the line (c)-(c) of FIG.

FIG. 13 is a fourth construction step diagram of the present invention.

FIG. 14 is a cross-sectional explanatory view showing the state of simple ground improvement after the fourth construction step.

FIG. 15 is a diagram showing a first step in which the temporarily closed steel plate is drained after the fourth construction step and the reinforcing steel plate block is attached to the outer surface of the pier by the above-described press-fitting device.

16 (A) is a side view showing an attachment mode of the scaffolding support frame in FIG. 15, (B) is a plan view of (A), and (C).
[Fig. 4] is a plan view of a scaffold plate.

[Explanation of symbols]

1 floor slab 2 bridge girders 3 piers 4 Press-fitting device 5 Deadline steel plate 5a Division cut-off steel plate member 5b Divided cut-off steel plate member 6 Upper chuck 7 Lower chuck 8 subsoil 10 Press-fitting jack 11 divided frames 12 connecting shaft 13 bracket 14 Jack for chuck 15 connecting pin 16 connecting pins 17 Working rod 18 connecting pin 20 bolt insertion hole 21 Vertical joining flange 22 Connecting bolt 23 rubber packing 25 water level 26 Mounting flange 27 Press fit guide member 27a inner edge 28 bolt nut 29 Press fit girder 30 Upper horizontal joint flange 31 Bolt insertion hole 33 Upper reinforcement frame 33a Reinforcement attachment plate 34 hoist 35 hoist beam 36 wires 38 Steel plate block for reinforcement 39 scaffolding board 46 hanging girder 48 Support frame 49 scaffolding

Claims (7)

[Claims] 1. A simple temporary cutoff method around a columnar structure at the time of reinforcement, in which the outer surface of the columnar structure projecting from the water bottom ground is covered with a steel plate block. The structure is arranged so as to surround it by a predetermined distance, and after assembling the shut-off steel plate by joining the joints of each member, the shut-off steel plate is fixed by the press-fitting jack of the press-fitting device fixed to the upper part of the columnar structure. A columnar structure characterized by being pushed down to penetrate into the water bottom ground, assembling the upper and lower shutoff steel plates, and shutting around the columnar structure in a watertight manner with a plurality of shutoff steel plates by repeating the pushing operation. A simple temporary cut-off method for things. 2. A cylinder and an operating rod of the press-fitting jack are connected to a press-fitting reaction force upper chuck and a pressing force urging lower chuck that are detachably attached to the columnar structure, respectively, to expand and contract the press-fitting jack. By the timing operation of fixing and opening the upper chuck and the lower chuck,
The simple temporary cut-off method around a columnar structure according to claim 1, wherein a plurality of cut-off steel plates are pushed down by causing the press-fitting device to repeatedly move up and down along the columnar structure. 3. A simple temporary cutoff method around a columnar structure according to claim 1 or 2, wherein the connecting means between the vertical and circumferential cutoff steel plate members is bolted through packing. 4. A plurality of press-fitting guide members having inner ends slidably contacting the outer surface of the columnar structure are detachably provided inside the shut-off steel plate, and the shut-off steel plate is press-fitted together with the press-fitting guide members. The method according to claim 1, wherein
3. A simple temporary cutoff method around the columnar structure according to any one of 3 above. 5. The simple provisional cutoff around the columnar structure according to claim 1, wherein after the cutoff of the columnar structure by the cutoff steel plate is completed, the inside of the cutoff is drained. Construction method. 6. The columnar structure around according to claim 1, wherein after the completion of the blockage around the columnar structure by the cut-off steel plate, the ground improvement inside the cut-off steel plate is carried out. Simple temporary cutoff method. 7. The press-fitting guide member according to claim 4, when the outer surface of the columnar structure is covered with a steel plate block after the closing of the columnar structure by the shut-off steel plate is finished, the press-fitting guide member according to claim 4 is removed. A scaffold is detachably provided inside the dead steel plate so as to surround the columnar structure, and the reinforcing steel plate block is coated on the outer surface of the columnar structure through the scaffold. A simple temporary cutoff method around the columnar structure according to any one of 4 and 6.