Structure and Construction Method of Temporary Scaffolding

Abstract

To provide a structure and a construction method of a removable temporary gantry that can eliminate various disadvantages caused by leaving while taking advantage of the advantages of the method of leaving the support piles during the water discharge period. 【Solution means】 It is a structure of a temporary gantry provided with a plurality of support piles 20, a lower work unit 50, and an upper work unit 60, and is detachably connected between the pile head of the support pile 20 and the lower part of the support column 51 of the lower work unit 50 via a connection joint 30. The upper end surface of the pile head of the support pile 20 is positioned at substantially the same height as the ground surface or at a height lower than the ground surface, and a surrounding hole S is formed in the ground around the pile head of the support pile 20, and a removable filling unit is accommodated in the surrounding hole S.

Description

Technical Field

[0001] The present invention relates to a structure and a construction method of a temporary gantry that can be reconstructed.

Background Art

[0002] A temporary gantry constructed along a road or the like and used as a passage or a waiting place for vehicles or the like includes a plurality of support piles driven into the ground, a lower work unit having a plurality of support columns and girders, and an upper work unit. For example, in river improvement work or work inside the water storage area of a dam, a high water level period (flood period) and a low water level period (dry period) are defined, and no work is carried out during the high water level period from the viewpoint of safety. At a construction site with a long construction period, the temporary gantry constructed during the dry period is disassembled and removed before the flood period, and when the dry period comes again, the temporary gantry is reconstructed and the predetermined work is continued. A construction plan is established accordingly.

[0003] When carrying out the main construction work across the flood period, if all the constituent members of the temporary gantry are to be reconstructed, there are the following problems to be improved. <1>To completely rebuild the completed temporary gantry, the number of man-hours increases, workability deteriorates, and the cost burden is large. <2>It is necessary to re-survey in order to drive the support piles, and there are many additional operations. <3>The reconstruction work of the temporary gantry is prolonged, and the overall construction period including the main construction work is prolonged. <4>When constructing the support piles at the same position by the pre-boring method, since the original position is disturbed, construction becomes difficult.

[0004] Patent Document 1 discloses a construction technique that facilitates the reconstruction of a temporary trestle. This temporary trestle includes a lower leg with the pile head protruding from the ground surface, and an upper leg connected to the lower leg via a detachable connecting means. After connecting the upper leg to the lower leg via the connecting means, the upper work of the trestle is assembled. When removing the temporary trestle, the connecting means is separated and the upper leg is detached from the lower leg. Remove the upper legs and the upper structure of the temporary trestle while leaving the separated lower legs underground. When reconstructing the temporary trestle, connect the upper legs to the pile heads of the lower legs left underground via the connecting means and assemble the upper structure of the trestle. As the connecting means for the joint of both legs, bolt connection is used.

[0005] The temporary trestle disclosed in Patent Document 1 can shorten the construction period and reduce costs compared to the case of reconstructing the entire temporary trestle by using the lower legs left in the ground separated during the non-flood period and reassembling the temporary trestle again during the non-flood period.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The temporary trestle described in Patent Document 1 contains the following problems. <1> In order to improve the workability of attaching and detaching the lower legs and the upper legs via the connecting means, the connection position of both legs is at a position higher than the water level during the non-flood period. Therefore, the lower legs are left in a state where the protruding amount from the bottom ground surface of the water is large. <2> The larger the protruding amount of the lower legs protruding from the bottom ground surface of the water, the more likely the lower legs are to be damaged by the impact of floating logs and boulders during the flood period, and the lower legs protruding from the bottom ground surface of the water will also interfere with water traffic and the passage of organisms. <3> In order to reduce the influence of the lower legs protruding from the bottom ground surface of the water, countermeasures such as installing a protective fence around the lower legs can be considered, but this countermeasure not only increases the cost, but also becomes a new factor interfering with passage and requires a large occupied area, so it is not practical.

[0008] The present invention has been made to solve the above-described problems, and an object thereof is to provide a structure and a construction method of a removable temporary gantry that can eliminate various adverse effects caused by leaving while taking advantage of the advantages of a method of leaving support piles during the water discharge period.

Means for Solving the Problems

[0009] The present invention includes a plurality of support piles built in the ground, a lower work unit provided on the plurality of support piles and including a plurality of support columns and girders, and an upper work unit provided on the upper part of the lower work unit. The structure of the temporary gantry is detachably connected between the pile head of the support pile and the lower part of the support column of the lower work unit via a connection joint, and the upper end surface of the pile head of the support pile is positioned at substantially the same height as the ground surface or a height lower than the ground surface. In another aspect of the present invention, a surrounding hole is formed in the ground around the pile head of the support pile, and the periphery of the pile head of the support pile is surrounded by a filling unit removably accommodated in the surrounding hole. At this time, the upper surface of the filling unit is positioned at substantially the same height as the ground surface. In another aspect of the present invention, the filling unit includes a weight structure such as a futon cage, a bagging unit, a large sandbag, or a lightweight structure such as a styrofoam block. In another aspect of the present invention, the connection joint includes a cylinder main body having an upper cylinder and a lower cylinder that can be externally mounted across the butting portion of the support pile and the support column, a shelf plate inserted between the upper cylinder and the lower cylinder, and a plurality of fixing bolts screwed to the peripheral walls of the upper cylinder and the lower cylinder. The butting portion of the support pile and the support column can be connected through the plurality of fixing bolts. Furthermore, the present invention includes a plurality of support piles built into the ground, a lower structure unit provided on the plurality of support piles and including a plurality of support columns and girders, and an upper structure unit provided above the lower structure unit. The upper end surface of the pile head of the support pile is detachably connected to the lower part of the support column of the lower structure unit via a connection joint. When removing the temporary construction platform, the connection joint is disconnected, the support pile is left in the ground, and the lower structure unit and the upper structure unit are removed. When reconstructing the temporary construction platform, the support pile and the lower structure unit are connected via the connection joint. In the construction method of the temporary construction platform, before the connection step of connecting the support pile and the lower structure unit via the connection joint, the upper end surface of the pile head of the support pile is positioned at substantially the same height as the ground surface or at a height lower than the ground surface. In another aspect of the present invention, before the connection step of connecting the support pile and the lower structure unit via the connection joint, a surrounding hole is formed in the ground around the pile head of the support pile. In another aspect of the present invention, a filling unit is removably accommodated in the surrounding hole to surround the periphery of the pile head of the support pile with the filling unit. In another aspect of the present invention, when removing the lower structure unit and the upper structure unit, the support pile and the filling unit are left in the ground. In another aspect of the present invention, when reconstructing the temporary construction platform, the filling unit is removed to expose the surrounding hole that serves as a working space around the pile head of the support pile. In another aspect of the present invention, the removal step of the temporary construction platform in which the connection joint is disconnected, the support pile is left in the ground, and the lower structure unit and the upper structure unit are removed, and the reconstruction step of the temporary construction platform in which the support pile and the lower structure unit are connected via the connection joint are repeatedly performed. In another aspect of the present invention, it may be constructed above the water with water level fluctuations or on land.

Advantages of the Invention

[0010] The present invention has at least one of the following effects. <1>When temporarily removing the temporary scaffold, the driving process of the support pile can be omitted by leaving the support pile in the ground, and the support pile left during reinstallation of the temporary scaffold can be reused. Therefore, the working efficiency of reconstructing the temporary scaffold can be improved, and it is possible to shorten the construction period and reduce the construction cost compared with the conventional method. In particular, when the main construction work lasts for a long time, the above-described effects become remarkable in proportion to the number of times of repeating the removal work and the reconstruction work of the temporary scaffold. <2>By setting the upper end surface of the pile head of the support pile left in the ground to a height that does not protrude from the ground surface, the flow of water is not obstructed during the water discharge period. Therefore, even if collision objects such as driftwood and boulders occur, there is no concern that the pile head of the support pile will be damaged. <3>The surrounding hole formed around the pile head of the support pile can be utilized not only as a working space for connecting the support pile and the lower construction unit, but also as a storage space for the filling unit. <4>By setting the upper surface of the filling unit to a height that does not protrude from the ground surface, even if collision objects such as driftwood and boulders occur during the water discharge period, there is no concern that the filling unit will be damaged or the collision objects will be blocked. <5>When the temporary scaffold is constructed above the water level, even if the support pile and the filling unit are left on the bottom ground at a height that does not protrude from the ground surface, the support pile and the filling unit will not interfere with water traffic or the passage of organisms, and the original natural environment can be ensured as it is.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0012] The present invention will be described in detail hereinafter with reference to the drawings In this example, the temporary structure 10 applied to the upper part of the water with water level fluctuations will be described

[0013] <1>Temporary Structure This will be described with reference to FIGS. 1 and 2. The present invention is a temporary structure 10 that can be reconstructed, and is a heavy temporary structure used as a work yard or a construction traffic road in rivers, steep cliffs, etc The temporary structure 10 illustrated in this example includes at least a support pile 20 driven and installed in the ground G, a lower work unit 50 connected to the support pile 20 via a connection joint 30, and an upper work unit 60 installed on the lower work unit 50 The main constituent materials of the temporary structure 10 will be described hereinafter

[0014] <2>Support Pile This will be described with reference to FIGS. 1 and 2. The support pile 20 is a pile body that supports the temporary structure 10 In the present invention, the support pile 20 is driven into the ground and left, and is reused when reconstructing the temporary structure 10

[0015] <2.1>Examples of Materials for Support Piles In this example, the form of using a steel pipe with a circular cross-section as the support pile 20 will be described. However, the support pile 20 is not limited to a steel pipe, and may be a shaped steel such as a square steel pipe or an H-beam

[0016] <3>Lower work unit This will be described with reference to FIG. 1. The lower work unit 50 is a unit that constitutes the lower work of the temporary gantry 10. The lower work unit 50 includes at least a plurality of support columns 51 arranged parallel to each other and facing each other, and a girder member 52 horizontally spanned and integrally connected between the heads of the plurality of support columns 51. In the lower work unit 50 of this example, the upper ends of the plurality of support columns 51 arranged in parallel are connected by the girder member 52, and a brace member 53 (horizontal connecting member and cross brace) is connected between the middle portions of adjacent support columns 51, presenting a torii-shaped structure when viewed from the front.

[0017] <3.1>Support column The support column 51 is a column member that constitutes the lower work unit 50. In this example, a steel pipe with a circular cross-section having the same diameter as the support pile 20 is adopted as the support column 51, but the support column 51 may also be a shaped steel such as a square steel pipe or an H-shaped steel. The number of support columns 51 is the same as that of the support piles 20, and the arrangement interval of the support columns 51 is equal to the arrangement interval of the support piles 20.

[0018] <3.2>Girder member The girder member 52 is a steel girder member that rigidly connects between the heads of a plurality of adjacent support columns 51. The space between the head of the support column 51 and the lower surface of the girder member 52 is integrally connected by bolt connection.

[0019] <3.3>Brace member The brace member 53 is a reinforcing member of adjacent support columns 51 and includes, for example, a horizontal connecting member and a cross brace.

[0020] <4>Connection joint This will be described with reference to FIG. 3. The connection joint 30 is a connection joint that detachably connects the butting portion of the support pile 20 and the support column 51.

[0021] The socket-type connection joint 30 illustrated in FIG. 3 will be described. The connection joint 30 of this example has a cylindrical reduced-diameter cylinder body 31 that can be externally mounted across the butting portion of the support pile 20 and the support column 51. The cylinder body 31 has a lower cylinder 32 that can be externally mounted on the upper part of the support pile 20, an upper cylinder 33 that can be externally mounted on the lower part of the support column 51, and a shelf board 34 that is interposed at the boundary between the two cylinders 32 and 33 and integrated. On the outer peripheral surfaces of the lower cylinder 33 and the upper cylinder 33, a plurality of fixing bolts 35 penetrate through the cylinder body at intervals and are screwed.

[0022] Note that the structure of the connection joint 30 is not limited to this example. For example, the upper cylinder 32 and the lower cylinder 33 may have the same diameter, or when the support pile 20 and the support column 51 are shaped steel, the upper cylinder 32 and the lower cylinder 33 may be composed of square steel pipes.

[0023] Furthermore, the connection joint 30 is not limited to a socket type connection joint. For example, a bolt type connection joint in which the butting parts of the lower cylinder 33 and the support column 51 are fitted to each other and the fitting part is fixed with a plurality of connecting bolts, or a flange type connection joint in which the flanges formed at the butting parts of the lower cylinder 33 and the support column 51 are connected with bolts may be applied.

[0024] <5>Upper work unit This will be described with reference to FIG. 2. The upper work unit 60 is a unit that constitutes the upper work of the temporary construction platform 10. In this example, the upper work unit 60 includes at least a plurality of beam girders 61 arranged in parallel and a plurality of covering boards 62 arranged on the beam girders 61.

[0025] <6>Blocking unit This will be described with reference to FIG. 7. The blocking unit 80 is a substitute material for the ground that surrounds and protects the pile head of the support pile 20.

[0026] <6.1>Examples of blocking units As the blocking unit 80, for example, a known metal or fiber futon cage, a bagging unit in which a filling material is accommodated in a pouch-shaped bag body, a heavy structure such as a large sandbag (specific gravity 1.0 or more), or a lightweight structure such as a polystyrene foam block (specific gravity less than 1.0) can be applied. When the blocking unit 80 is a lightweight structure, it is advisable to drive anchor pins or the like to prevent the floating of the blocking unit 80.

[0027] Since the filling unit 80 may be any structure that can surround and protect the pile head of the support pile 20, the filling unit 80 may be in the form of an integral annular structure that can surround the pile head or a divided body obtained by dividing the annular structure into a plurality of parts.

[0028] <6.2> Purpose of using the filling unit The filling unit 80 is used to fill the filling unit 80 into the surrounding hole S where the pile head of the support pile 20 left on the ground G is exposed during the removal work of the temporary gantry 10, and to remove the filling unit 80 during the connection work between the support pile 20 and the work unit 50 to expose the surrounding hole S that serves as a working space around the support pile 20.

[0029] [Construction method of the temporary gantry] Next, the construction method of the temporary gantry 10 will be described. The following description is illustrative, and the present invention is not limited to the following construction methods.

[0030] 1. Construction of the temporary gantry (first time) In the non-water-emergence period of low water level, the temporary gantry 10 is constructed in the following manner.

[0031] <1> Driving process of the support pile (Figure 4) A plurality of support piles 20 are driven at predetermined positions on the ground G which is the water bottom surface at intervals.

[0032] <2> Pile head treatment process of the support pile The excavation work of the ground G around the support pile 20 and the adjustment work of the pile head height of the support pile 20 are carried out in the following manner.

[0033] <2.1> Excavation work of the surrounding hole As shown in Figure 4A, the ground G around the support pile 20 is excavated annularly to form a sunken surrounding hole S around the support pile 20. The surrounding hole S is formed in a size (width and depth) that can accommodate the filling unit 80 according to the three-dimensional shape of the filling unit 80. The planar shape of the surrounding hole S is not particularly restricted, and it may be any shape that allows the filling unit 80 to be immersed in the ground G around the support pile 20. In a site where it is difficult to form the peripheral wall of the surrounding hole S as a normal plane, as shown in Fig. 4(A´), the peripheral wall of the surrounding hole S is formed as a vertical wall using an earth retaining material 40 such as a liner plate.

[0034] In this example, the form of forming the surrounding hole S after driving the support pile 20 will be described. However, the support pile 20 may be driven into the surrounding hole S after the surrounding hole S is formed in advance. The driving timing of the support pile 20 and the formation timing of the surrounding hole S are appropriately selected in consideration of the properties of the ground G and the like.

[0035] <2.1.1> Exposure of the pile head By forming the surrounding hole S around the support pile 20, the pile head of the support pile 20 is exposed inside the surrounding hole S.

[0036] <2.1.2> Purpose of forming the surrounding hole Forming the surrounding hole S around the support pile 20 is to secure a working space for the connection work between the support pile 20 and the lower structure unit 50, and to secure a housing space for the filling unit 80 around the support pile 20, as will be described later.

[0037] <2.2> Height adjustment work of the support pile In the conventional construction method, the pile head of the support pile protruded upward from the ground surface. In contrast, in the present invention, the height of the pile head of the support pile 20 is adjusted by cutting it according to the height of the ground surface so that the pile head of the support pile 20 does not protrude above the ground surface.

[0038] Note that the formation work of the surrounding hole S and the height adjustment work of the support pile 20 can also be performed in the reverse order. Also, when the support pile 20 can be accurately driven according to the pile head height, the cutting work of the pile head is unnecessary.

[0039] <2.2.1> Positional relationship between the upper end surface of the support pile and the ground surface A description will be given with reference to FIG. 7. Regarding the positional relationship between the upper end surface of the support pile 20 and the ground surface by adjusting the height of the pile head of the support pile 20, the height of the pile head of the support pile 20 is adjusted so that the upper end surface (pile head end surface) of the support pile 20 is approximately at the same height as the ground surface or is slightly lower than the ground surface.

[0040] <3>Connection process of the lower part unit As shown in FIG. 4(B), the support column 51 of the lower part unit 50 is connected to the upper part of the support pile 20 via the connection joint 30. Specifically, the lower part unit 50 is hoisted above the support pile 20 and fixed via the connection joint 30 pre-assembled at the end of the support pile 20 or the support column 51. In the connection process of the lower part unit 50, since the surrounding hole S around the support pile 20 can be utilized as a working space, the connection work between the support pile 20 and the support column 51 can be efficiently carried out in a short time.

[0041] <4>Assembly process of the upper part unit (FIG. 2) After completing the connection of the lower part unit 50, the upper part unit 60 is installed on the upper part of the lower part unit 50.

[0042] 2. Use of the temporary construction platform The main construction work is carried out using the temporary construction platform 10 constructed during the non-water discharge period.

[0043] 3. Demolition work of the temporary construction platform (FIG. 5) In the following process, the temporary construction platform 10 is removed leaving the support pile 20.

[0044] <1>Demolition process of the upper part unit The upper part unit 60 constituting the temporary construction platform 10 is disassembled and removed.

[0045] <2>Demolition process of the lower part unit While utilizing the surrounding hole S formed around the support pile 20 as a working space, the lower part unit 50 is separated from the support pile 20 and removed. The details of the disconnection operation of the lower work unit 50 are as follows.

[0046] <2.1>Disconnection of the connection between the support pile and the lower work unit (Fig. 5(A)) Loosen the fixing bolts 35 of the connection joint 30 connecting between the support pile 20 and the lower work unit 50, and disconnect the connection between the support pile 20 and the connection joint 30.

[0047] <2.2>Separation and removal of the lower work unit (Fig. 5(A)) After disconnecting the connection between the support pile 20 and the connection joint 30, lift and remove the lower work unit 50. At this time, the connection joint 30 is also removed together with or separately from the lower work unit 50.

[0048] <2.3>Retention of the support pile By removing the lower work unit 50, the support pile 20 remains in the ground G. If necessary, provide a lid on the upper end opening of the support pile 20 to prevent foreign matters such as earth and sand from entering the inside of the support pile 20.

[0049] <3>Installation of the filling unit (Fig. 5(B)) After removing the temporary gantry 10 and finishing the retention of the support pile 20, accommodate the filling unit 80 in the surrounding hole S, and surround the pile head of the support pile 20 with the filling unit 80. Since the filling unit 80 accommodated in the surrounding hole S functions as substitute earth and sand for the ground G, there is no worry that the surrounding earth and sand will enter the surrounding hole S and be backfilled. The support pile 20 and the filling unit 80 remain in the surrounding hole S.

[0050] <3.1>Positional relationship between the filling unit and the upper end surface of the support pile (Fig. 7) When installing the filling unit 80 around the support pile 20, in order to protect the pile head of the support pile 20, make the upper end surface of the support pile 20 substantially at the same height as the uppermost surface of the filling unit 80, or make the upper end surface of the support pile 20 slightly lower than the uppermost surface of the filling unit 80.

[0051] <3.2>Position relationship between the height of the filling unit and the ground surface (Fig. 7) The top surface of the filling unit 80 shall be in a position relationship approximately the same height as the ground surface. In actual construction, considering the influence of the laying accuracy of the filling unit 80, there is no particular problem even if the top surface of the filling unit 80 is slightly higher than the ground surface.

[0052] <3.3>Protective effect of the filling unit on the support pile The pile head of the support pile 20 does not protrude upward from the upper surface of the filling unit 80 and the ground surface, and the upper end surface of the support pile 20 is located at approximately the same height as the upper surface of the filling unit 80 and the ground surface. Therefore, even if driftwood, boulders, etc. occur during the water discharge period, the pile head of the support pile 20 can be spared from damage.

[0053] Furthermore, since the filling unit 80 surrounding the pile head of the support pile 20 functions as a protective material, it becomes more difficult for the pile head of the support pile 20 to be damaged.

[0054] Furthermore, since the filling unit 80 does not protrude upward from the ground surface either, there is no worry that the filling unit 80 will be damaged or that a collision object will hit the filling unit 80 and be blocked.

[0055] Also, even if the support pile 20 is left unattended during the water discharge period, the support pile 20 will not interfere with water traffic or the passage of organisms, and the original natural environment can be ensured as it is.

[0056] <3.4>Proportionality of the installation of the filling unit For example, even in a form where the surrounding hole S is not provided around the pile head of the support pile 20 and the filling unit 80 is arranged to a height where the pile head of the support pile 20 protruding above the ground surface is hidden, it is possible to protect the pile head of the support pile 20. In this protection form, since the filling unit 80 bulges upward with respect to the ground surface, problems such as the filling unit 80 becoming a new obstacle and collision objects such as driftwood and boulders colliding with the bulging filling unit 80, or the collision objects being blocked, will occur. In the present invention, in order to avoid such problems, the height of the uppermost surface of the filling unit 80 is set to be approximately the same as the ground surface.

[0057] 4. Reconstruction work of the temporary gantry (Fig. 6) When entering the non-water intake period after the water discharge period, reconstruct the temporary gantry 10 in the following manner.

[0058] <1> Omission of the driving process of the support piles In the present invention, when reconstructing the temporary gantry 10 during the non-water discharge period, the support piles 20 left in the ground G are reused. Therefore, the process of driving new support piles 20 can be omitted.

[0059] <2> Removal process of the filling unit When the upper end surface of the support pile 20 is set to be approximately the same as the ground surface, it is necessary to secure a working space around the pile head of the support pile 20 for connection work.

[0060] As a method of securing a working space without using the filling unit 80, a method of excavating the ground G around the pile head of the support pile 20 to expose the pile head of the support pile 20 can be considered. Although construction is possible with this method, the excavation work becomes an additional process, imposing a heavy burden of time and cost. Therefore, it is desirable to adopt a more efficient method.

[0061] In contrast, in the present invention, as shown in Fig. 6(A), by simply removing the filling unit 80, a surrounding hole S serving as a working space can be formed at the removal trace of the filling unit 80. The surrounding hole S, which was the accommodation space of the filling unit 80, is restored as a working space with the removal of the filling unit 80.

[0062] In the present invention, since the surrounding hole S restored at the removal trace of the filling unit 80 serves as a working space, it is not necessary to excavate the ground G around the pile head of the support pile 20 again to form a working space after the second time. Therefore, it is possible to efficiently and inexpensively form the surrounding hole S serving as a working space around the head of the support pile 20 in a short period of time.

[0063] <3>Connection process of the support pile and the lower unit As shown in FIG. 6(B), the head portion of the support pile 20 is exposed and positioned within the surrounding hole S at the removal trace of the filling unit 80. The surrounding hole S serves as a working space during the connection operation between the support pile 20 and the lower unit 50. Using the surrounding hole S, the support pile 20 is connected to the support column 51 constituting the lower unit 50 with the connection joint 30 interposed therebetween.

[0064] <4>Assembly process of the upper unit (FIG. 2) The upper unit 60 is assembled on the upper part of the lower unit 50 to complete the temporary construction platform 10.

[0065] As described above, in the present invention, with the support pile 20 remaining in the ground, the lower unit 50 and the upper unit 60 are removed, and the driving and extraction processes of the support pile 20 during the non-water discharge period are omitted, and the temporary construction platform 10 can be reconstructed through the connection process of the lower unit 50 again.

[0066] 5. Repeated removal and reconstruction of the temporary construction platform When the present construction work lasts for a long time, the removal work of the temporary construction platform 10 involving the remaining of the support pile 20 and the filling unit 80 in the ground G as described above, and the reconstruction work of the temporary construction platform 10 involving the removal of the filling unit 80 are repeatedly performed.

[0067] [Other embodiments] In the previous embodiment, the form in which the temporary construction platform 10 is applied to the above-water part with water level fluctuations has been described. However, the temporary construction platform 10 may also be applied to the construction site on the land part without water. Even when the temporary construction platform 10 is applied to the land part, the utilization method of the support pile 20 and the filling unit 80 is basically the same as that in the previous embodiment.

[0068] Also in this example, similar to the previous embodiment, the temporary platform 10 can be reconstructed by utilizing the support piles 20 left in the local ground G. Furthermore, also in the land area, since the pile heads of the support piles 20 and the filling units 80 do not protrude from the ground surface, even if these are left in the local ground G, the support piles 20 and the filling units 80 will not obstruct the passage of vehicles and people.

Explanation of Reference Numerals

[0069] G ····· Ground S ····· Surrounding Hole 10 ····· Temporary Platform 20 ····· Support Pile 30 ····· Connection Joint 31 ····· Cylinder Body 32 ····· Lower Cylinder 31 ····· Cylinder Body 32 ····· Lower Cylinder 33 ····· Upper Cylinder 33 ····· Shelf Board 34 ····· Fixing Bolt 40 ····· Earth Retaining Material 50 ····· Lower Structure Unit 51 ····· Support Column 52 ····· Girder Member 53 ····· Brace Member 60 ····· Upper Structure Unit 61 ····· Girder Member 62 ····· Covering Board

Claims

1. A temporary structure that can be reconstructed, comprising a plurality of support piles built into the ground, a lower work unit provided on the plurality of support piles and having a plurality of support columns and girders, and an upper work unit provided above the lower work unit, wherein the head of the support pile is detachably connected to the lower part of the support column of the lower work unit via a connecting joint, a surrounding hole serving as a working space during the connection operation between the support pile and the lower unit is formed in the ground around the head of the support pile, the surrounding hole detachably accommodates a filling unit that surrounds the head of the support pile during the removal operation of the lower work unit, the upper end surface of the head of the support pile, which is the connecting surface with the lower part of the support column of the lower work unit via the connecting joint, is positioned at substantially the same height as the ground surface or at a height lower than the ground surface, Structure of the temporary structure.

2. The structure of the temporary structure according to claim 1, wherein the upper surface of the filling unit is positioned at substantially the same height as the ground surface.

3. The structure of the temporary structure according to claim 1 or 2, wherein the filling unit is a heavy structure or a lightweight structure.

4. The connecting joint includes a cylindrical body having an upper cylinder and a lower cylinder that can be externally mounted across the butting portion between the support pile and the support column, a shelf plate inserted between the upper cylinder and the lower cylinder, and a plurality of fixing bolts screwed to the peripheral walls of the upper cylinder and the lower cylinder, and the butting portion between the support pile and the support column can be connected through the plurality of fixing bolts. The structure of the temporary structure according to claim 1.

5. A construction method of a temporary structure that can be reconstructed, comprising a plurality of support piles built into the ground, a lower work unit provided on the plurality of support piles and having a plurality of support columns and girders, and an upper work unit provided above the lower work unit, wherein the head of the support pile is detachably connected to the lower part of the support column of the lower work unit via a connecting joint. When removing the temporary structure, the connecting joint is disconnected, the support pile is left in the ground, and the lower work unit and the upper work unit are removed. When reconstructing the temporary structure, the support pile and the lower work unit are connected via the connecting joint. The method includes adjusting the height of the head of the support pile so that the upper end surface of the head of the support pile, which is the connecting surface with the lower part of the support column of the lower work unit via the connecting joint, has a positional relationship at substantially the same height as the ground surface or at a height lower than the ground surface, and adjusting the height of the head of the support pile so that the upper end surface of the head of the support pile, which is the connecting surface with the lower part of the support column of the lower work unit via the connecting joint, has a positional relationship at substantially the same height as the ground surface or at a height lower than the ground surface. Before the connecting step of connecting the support pile and the lower work unit via the connecting joint, a surrounding hole serving as a working space during the connection work between the support pile and the lower unit is formed in the ground around the pile head of the support pile. When removing the lower work unit and the upper work unit, the filling unit is removably accommodated in the surrounding hole, and the periphery of the pile head of the support pile is surrounded by the filling unit. Construction method of a temporary platform.

6. The construction method of the temporary platform according to claim 5, characterized in that when removing the lower work unit and the upper work unit, the support pile and the filling unit are left in the ground.

7. The construction method of the temporary platform according to claim 5, characterized in that when reconstructing the temporary platform, the filling unit is removed to expose a surrounding hole serving as a working space around the pile head of the support pile.

8. The removal step of the temporary platform in which the connecting joint is disconnected and the support pile is left in the ground to remove the lower work unit and the upper work unit, and the reconstruction step of the temporary platform in which the support pile and the lower work unit are connected via the connecting joint are repeated. The construction method of the temporary platform according to claim 5.

9. The construction method of the temporary platform according to any one of claims 5 to 8, characterized in that the construction is carried out above the water surface accompanied by water level fluctuations.

Images