JP2017210865A - Temporary cut-off method, temporary cut-off structure, supporting, supporting unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temporary cut-off method that contributes to improvement of workability during construction of a structure in water area and quality of the structure.SOLUTION: A water area 3 is cut off by a well-like steel pipe sheet pile 4, then the inside of the well formed of the steel pipe sheet pile 4 is bored underwater. After a truss supporting 1 is installed in the well and dried up, a structure is constructed. The truss supporting 1 has an annular flat surface in substantially hollow square shape along the inner periphery of the well formed of the steel pipe sheet pile 4, an opening 15 at its central part, and a truss structure in flat. The truss supporting 1 is installed in vertically plural steps. The truss supporting 1 formed of upper and lower two steps is vertically connected by the truss structure.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a temporary closing method and a temporary closing structure for a water area, and a support and a support unit used for these.

  When constructing a structure such as a pier in a water area, a temporary cutting body such as a steel pipe sheet pile is placed in a tubular shape to cut off the water area, and after the ground is excavated to a predetermined depth and dried up, May build. A support is installed inside the temporary cut-off body to resist the surrounding water pressure (see, for example, Patent Documents 1-3).

  In this case, the upper support is installed while lowering the water level inside the temporary cut-off body, and then the ground is excavated to a predetermined depth while keeping the water level constant. In many cases, support works are installed according to the installation procedure.

  Fig.23 (a) is a figure which shows the outline of the support work 100, FIG.23 (b) looks at Fig.23 (a) from the top. FIGS. 23A and 23B show a state where the installation of all the support works 100 has been completed.

  In the example of FIG. 23, intermediate piles in which support structures 100 are arranged in a plurality of upper and lower stages inside the water area 3 closed by a steel pipe sheet pile 4 and the upper and lower support works 100 are embedded in the bottom 2 of the bottom of the water. 110. The flat surface of the support 100 has a shape in which a bulge 101 is arranged along the inner periphery of the well formed by the steel pipe sheet pile 4 and a cut beam 102 is provided between the bulges 101 at the opposite positions. The cut beams 102 are provided in a grid pattern in the vertical and horizontal directions, and a fire-strike 103 is provided at a connection portion between the cut beams 102 and the uplift 101.

JP-A-4-155010 Patent No.2949341 Japanese Patent No. 3051321

  However, in the structure of such a support work 100, since the interval between the cut beams 102 is narrow and there is no large opening, other work is likely to be hindered. For example, long rebars cannot be carried in when constructing a structure, and short rebars are often connected by joints. In addition, it is necessary to limit the length of materials such as single pipes used for the formwork when placing concrete. Further, in other work such as excavation, the cut beam 102 and the fire hitting 103 are obstructed, and work efficiency is deteriorated.

  In addition, interference between the intermediate pile 110 and the cut beam 102 and the rebar of the structure is likely to occur, and in such a place, a hole is made in the steel material such as the intermediate pile 110 and the cut beam 102 to pass the rebar, or the rebar is cut. However, in either case, it may be a cause of structural problems such as insufficient concrete filling. Moreover, in the location where the intermediate pile 110 penetrates the structure, measures such as unboxing the structure are required. Although this section is repaired later, it can be a weak point in durability.

  This invention is made | formed in view of said problem, and it aims at providing the temporary closing method etc. which contribute to the improvement of the workability at the time of construction of the structure of a water body, and the quality of a structure.

  1st invention for solving the subject mentioned above comprises the process of shutting off a water area by the closed area by a temporary cut-off body, and the process of installing a support work in the inside of the temporary cut-off body, The support work Is a temporary closing method characterized in that it is annularly arranged along the inner periphery of the temporary closing body, has an opening at the center, and has a truss structure in a plane.

  In the present invention, the support work has a truss structure in the plane, the rigidity is increased, and it becomes possible to provide a large opening at the construction center of the structure in the center of the temporary cut-off body, eliminating the interference between the structure and the support work. . In addition, long rebars and large formwork can be inserted from the large opening, the size limit of the input material is small, and the work environment is greatly improved by using other large openings. Can be achieved. As a result, workability at the time of construction of the structure and the quality of the structure are improved, and the construction period is shortened.

The support works are preferably installed in a plurality of stages. Further, it is desirable that at least two stages of the support works are connected vertically by a truss structure.
By installing a plurality of support works up and down inside the temporary cut-off body, it is possible to resist a large water pressure. In addition, by connecting the upper and lower support works with a truss structure, the rigidity is increased, and the intermediate pile as described above is not required and interference between the structure and the intermediate pile does not occur, so the workability of the structure is improved and the structure The quality of the product is improved and durability can be easily secured.

It is desirable to lower a support unit in which at least two stages of the support work are previously connected to each other in advance by a truss structure and install the support work unit inside the temporary cut-off body.
Even when there are many support stages, it is possible to shorten the work period by shortening the work period by installing the support units assembled in advance on the ground etc. I can do it.

In addition, the support unit having a truss structure pre-mounted on or below the support is lowered and installed inside the temporary cut-off body, and then another support is added to the truss structure of the support unit. It is also desirable to install.
In this case as well, effects such as shortening the work period can be obtained by using the support work unitized.

It is also desirable that the support work be used as an annular shape by joining portions of the plane.
In this way, by using the support work divided on the plane in the field, the burden at the time of carrying in the support work is reduced.

It is desirable to construct the bottom plate at the bottom of the excavation after underwater excavation of the ground inside the temporary cut body while leaving the guide frame when the temporary cut body is placed on the ground.
By performing underwater excavation before the water level inside the temporary cut-off body is lowered, deformation of the temporary cut-off body during excavation can be suppressed and large-scale reinforcement is not necessary. Therefore, it is easy to realize a large opening at the time of excavation by using the guide frame at the time of placing the temporary cut-off body for the reinforcement work, the risk of damage to the reinforcement work due to contact with the excavator is reduced, and underwater excavation is difficult. There is no part to be improved, and work efficiency during excavation is improved. In addition, after the bottom plate is constructed, the temporary fastening body can be held by the guide frame and the bottom plate, so that deformation and the like can be suppressed, and the risk that deformation of the temporary fastening body increases due to variations in ground physical properties is also reduced.

Preferably, a partition wall is formed inside the temporary fastening body, and after excavating the ground inside the temporary fastening body, a predetermined position of the partition wall is cut and an upper portion is removed.
By providing the partition wall, the stability of the temporary cut-off body is increased. Further, since the partition wall is cut after excavation, not before excavation of the ground, there is no risk of damaging the head of the partition wall after cutting, and the partition wall can be suitably used as the foundation of the structure. Moreover, since it is not necessary to pull out the partition wall from the soil, it can be easily removed.

The second invention has a temporary cut-off body that forms a closed region and closes the water area, and a support work installed inside the temporary cut-off body, and the support work is an inner periphery of the temporary cut-off body. Is a temporary closing structure characterized by having a truss structure in a plane and being arranged annularly along the center.
The support works are preferably installed in a plurality of stages. Further, it is desirable that at least two stages of the support works are connected vertically by a truss structure.

  A third invention is a support used for a temporary closing structure in which a water area is closed by a closed area by a temporary closing body, the plane is annular, the center is an opening, and the plane has a truss structure. It is a support work characterized by.

4th invention is the support unit characterized by providing the truss structure on or under the support work of 3rd invention.
Further, it is desirable that at least two stages of the support works are connected vertically by a truss structure.

  According to the present invention, it is possible to provide a temporary closing method and the like that contribute to improvement of workability at the time of construction of a structure in a water area and the quality of the structure.

Diagram explaining deadlines of water area 3 The figure explaining excavation etc. of the ground 2 Diagram showing truss support 1 and support unit 10 Diagram explaining installation of truss support 1 Diagram explaining installation of truss support 1 and construction of pier 74 etc. Diagram explaining construction of pier 74 etc. The figure which shows the temporary deadline structure 20 ' The figure which shows the support work unit 10 ' The figure explaining the installation procedure of the support work in 2nd Embodiment The figure which shows the attaching part of the support material 7, and the support material receiving part 4a The figure explaining the installation method of bracket 8 ' Diagram explaining the filling method The figure which shows truss support work 1a and support work unit 10a The figure explaining the installation procedure of the support work in 3rd Embodiment The figure explaining the installation procedure of the support work in 3rd Embodiment The figure explaining the installation procedure of the support work in 4th Embodiment The figure explaining the installation procedure of the support work in 4th Embodiment The figure explaining the installation procedure of the support work in 5th Embodiment The figure explaining the installation procedure of the support work in 5th Embodiment The figure explaining the installation procedure of the support work in 6th Embodiment The figure explaining the installation procedure of the support work in 6th Embodiment Diagram showing alignment of truss support 1 The figure which shows the outline of the support work 100

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, the procedure of the temporary closing method according to the first embodiment of the present invention will be described. In this embodiment, first, as shown in FIG. 1 (a), a steel pipe sheet pile 4 which is a temporary cut-off body is placed on the ground 2 at the bottom of the water to form a closed area in the plane, and the water area 3 to be constructed is closed. . The steel pipe sheet pile 4 is provided in a well shape as shown in FIG. FIG.1 (b) is the figure which looked at Fig.1 (a) from the top.

  In this example, the steel pipe sheet pile 5 is driven into the bottom 2 of the bottom of the water pipe (closed region) by the steel pipe sheet pile 4 to form a partition wall. The steel pipe sheet piles 5 are provided in a row so as to connect a pair of opposite sides of the well formed by the steel pipe sheet piles 4. If necessary, the steel pipe sheet piles 4 and 5 are placed in the vertical direction of the steel pipe sheet piles 4 and 5 (for example, the section from the top concrete described below to the vicinity of the paving stone layer, the lower end of the steel pipe sheet piles 4 and 5), and reinforcing bars are placed in the steel pipe to make concrete It is also possible to reinforce it by filling it. Moreover, although illustration is abbreviate | omitted, the adjacent steel pipe sheet piles 4 and 5 are connected by a joint, and the water stop process is given to the joint part of the steel pipe sheet pile 4 which forms a well.

  The steel pipe sheet piles 4 and 5 are driven using a guide frame 6. The guide frame 6 includes an outer frame 6 a disposed along the outer periphery of the well by the steel pipe sheet pile 4, and two inner frames 6 b disposed along both sides of the inner periphery of the well by the steel pipe sheet pile 4 and the partition wall by the steel pipe sheet pile 5. Consists of Diagonal members 61 are arranged at the corners of each inner frame 6b. After placing the steel pipe sheet piles 4 and 5, the guide frame 6 is attached to the tops of the steel pipe sheet piles 4 and 5.

  Thereafter, as shown in FIG. 2A, the ground 2 inside the well by the steel pipe sheet pile 4 is excavated underwater to a predetermined depth while maintaining the water level, and a paving stone layer 71 and a bottom concrete 72 are constructed at the bottom of the excavation. Underwater excavation is performed by installing an excavator such as a grab on a crane of a dredger (not shown). After excavating the ground 2 and placing the bottom concrete 72, the steel pipe sheet pile 5 is cut at a position (predetermined position) where it hits the upper surface of the bottom concrete 72, and the upper part thereof is removed.

  In the present embodiment, excavation of the ground 2 is performed with the guide frame 6 left, and after excavation, the inner frame 6b is removed so as not to hinder support installation described later. Thereby, at the time of excavation of the ground 2, the guide frame 6 is caused to function as a reinforcement for suppressing deformation or the like of the steel pipe sheet pile 4 with respect to a traveling wave or the like generated by a vessel navigating the periphery. After the bottom base concrete 72 is constructed and the inner frame 6b is removed, the steel pipe sheet pile 4 is held by the outer frame 6a and the bottom base concrete 72, and deformation of the steel pipe sheet pile 4 is suppressed.

  In addition, in order to install a support work, which will be described later, a bracket 8 of the first stage (referred to as the number of stages when counted from the bottom; the same shall apply hereinafter) is formed. The bracket 8 is made of steel. As shown in FIG. 2B, a substantially bracket-shaped bracket body 82 is bolted to a linear bracket receiving member 81 joined to the steel pipe sheet pile 4 by underwater welding or the like. By attaching using (not shown), it is formed in a substantially right triangle shape. A bracket receiving material 81 is attached in advance to a formation position of a second-stage bracket 8 described later.

  After this, a support work is installed. In this embodiment, a truss support work 1 shown in FIG. 3A is used as the support work. The truss support 1 has a substantially square-shaped annular plane, and has a large-area opening 15 in the center. The plane of the truss support 1 has a truss structure in which a plurality of vertical members 11 and cross members 12 are combined in a lattice shape, and diagonal members 14 are provided in the lattice. The diagonal members 14 are also provided at the four corners of the opening 15.

  In the present embodiment, as shown in FIG. 3B, the support unit 10 in which the truss support 1 is combined in two upper and lower stages is assembled and manufactured in advance on the ground or on the water. The upper and lower two-stage truss support works 1 are connected by a truss structure composed of a plurality of vertical members 16 and diagonal members 17. The diagonal members 17 are arranged in an approximately X shape between adjacent vertical members 16. Steel materials such as H-section steel are used for the vertical members 16 and the diagonal members 17, and the longitudinal members 11, the transverse members 12, and the diagonal members 14.

  The support unit 10 is brought into the site, suspended from above by a hoist crane (not shown), etc., and lowered and installed on the first bracket 8 as shown in FIG. 4 (b), it arrange | positions cyclically | annularly along the inner periphery of the well by the steel pipe sheet pile 4. As shown in FIG. FIG. 4B is a top view of FIG. 4A. Moreover, between the truss support work 1 and the steel pipe sheet pile 4 is filled with concrete or mortar (not shown). Although omitted in the following description, the above-mentioned filling is performed when each truss support work (support work unit) described later is installed.

  Next, as shown in FIG. 5A, a second-stage bracket 8 is formed above the support unit 10. As described above, the bracket receiving member 81 is attached at this position, and the bracket 8 is formed by attaching the bracket body 82 to the bracket receiving member 81.

  Thereafter, as shown in FIG. 5B, the support unit 10 is installed on the second-stage bracket 8 in the same procedure as described above. As a result, a temporary closing structure 20 is formed in which the upper and lower four-stage truss support 1 is divided into two units and installed inside the well by the steel pipe sheet pile 4. In the example shown in the figure, the lower truss support 1 of each support unit 10 is mounted on the bracket 8 and supported. However, the bracket 8 is placed at a position corresponding to the upper truss support 1 of each support unit 10. It may be provided and further supported by the bracket 8.

  After the provisional deadline structure 20 is thus formed, the construction of the structure is started. In this embodiment, a pier is constructed on top concrete as a structure. Therefore, as shown in FIG. 5 (c), the well inside the well is drained by the steel pipe sheet pile 4 to dry up, and the slab concrete top plate concrete 73 is constructed on the bottom concrete 72.

  Thereafter, in the opening 15 of the truss support 1 (see FIG. 3A), a pier 74 made of reinforced concrete is constructed on the top concrete 73 as shown in FIG. 5D. The support unit 10 is removed according to the progress of the work. FIG. 5D shows a state after the lower support unit 10 is removed. Thereafter, as shown in FIG. 6A, water is poured into the steel pipe sheet pile 4, and the support unit 10 and the outer frame 6a are all removed.

  Hereinafter, the earth and sand are backfilled inside the well with the steel pipe sheet pile 4 and the steel pipe sheet pile 4 is removed. The steel pipe sheet pile 4 can be used as a pier foundation in combination with the steel pipe sheet pile 5 by cutting at a position where it hits the upper surface of the top concrete 73 and removing only the upper part. This state is shown in FIG.

  As described above, in the present embodiment, the truss support 1 having a truss structure in the plane is used as the support to increase the rigidity, and the construction site of the structure such as the bridge pier 74 at the center of the inside of the well by the steel pipe sheet pile 4 is used. A large opening can be provided, and the interference between the structure and the truss support 1 is eliminated. In addition, long rebars and large formwork can be inserted from the large opening, the size limit of the input material is small, and the work environment is greatly improved by using other large openings. Can be achieved. As a result, the workability at the time of construction of the structure in the water area 3 and the quality of the structure are improved, and the construction period is shortened.

  Moreover, in this embodiment, it can resist a big water pressure by installing the truss support 1 in the upper and lower steps in the well by the steel pipe sheet pile 4. In addition, by connecting the upper and lower truss support 1 vertically by the truss structure, the rigidity is increased, and the intermediate pile as described above is not necessary, and the structure such as the pier 74 and the top slab concrete 73 interferes with the intermediate pile. Does not occur. As a result, the workability of the structure is improved, the quality of the structure such as the concrete filling property is improved, and the durability can be easily secured.

  Moreover, in this embodiment, the support unit 10 which connected the truss support work 1 up and down beforehand with the truss structure is dropped, and it installs in the inside of the well by the steel pipe sheet pile 4. Therefore, even when the truss support 1 has many installation stages, by installing the support units 10 assembled on the ground in advance, it is possible to eliminate underwater joint work and reduce the number of on-site work times. It can be shortened. In addition, the risk of accidents due to work at high places and up and down work can be reduced.

  Furthermore, in this embodiment, by performing underwater excavation before the water level inside the well is lowered by the steel pipe sheet pile 4, deformation of the steel pipe sheet pile 4 at the time of excavation can be suppressed, and large-scale reinforcement is not necessary. Therefore, it becomes easy to realize a large opening at the time of excavation by using the guide frame 6 at the time of placing the steel pipe sheet piles 4 and 5 for the reinforcement work, the risk of damage to the reinforcement work due to contact with the excavator is reduced, and underwater excavation. There are no places where it becomes difficult to improve work efficiency during excavation. In addition, after the construction of the bottom concrete 72, deformation and the like can be suppressed by holding the steel pipe sheet pile 4 with the outer frame 6a and the bottom concrete 72 of the guide frame 6, and the deformation of the steel pipe sheet pile 4 increases due to variations in ground physical properties. Risk is also reduced.

  Moreover, in this embodiment, by providing the partition by the steel pipe sheet pile 5, the stability of the well by the steel pipe sheet pile 4 is increased, and the steel pipe sheet pile 5 is cut not after excavation of the ground 2 but after excavation. The possibility of damaging the head during excavation is eliminated, and the steel pipe sheet pile 5 can be suitably used as the foundation of a structure such as a bridge pier 74. Moreover, since it is not necessary to pull out the steel pipe sheet pile 5 from the soil, the steel pipe sheet pile 5 can be easily removed, and for example, it is possible to reduce the specifications of the hoist ship when lifting it with a crane or the like.

  However, the present invention is not limited to this. For example, in the present embodiment, the dry-up is performed after the truss support 1 is installed, but the water level may be lowered before all the truss support 1 is installed. For example, it is possible in some cases to install the truss support 1 in order from the top each time the water level is lowered by a predetermined depth. In the present embodiment, the ground 2 is excavated with the guide frame 6 left, but either the outer frame 6a or the inner frame 6b of the guide frame 6 or both can be removed before excavation. In some cases, excavation of the ground 2 may be omitted.

  Further, in this embodiment, the upper and lower truss support 1 is connected by the truss structure of the vertical member 16 and the diagonal member 17, and the upper and lower four-stage truss support 1 is installed. There is no limit. For example, as shown in the temporary closing structure 20 ′ in FIG. 7, each of the plurality of stages of truss supporters 1 can be installed independently without being connected. In this example, the truss support 1 of each step is suspended individually and the truss support 1 is supported by the bracket 8 formed in the same manner as described above at the installation position of the truss support 1 of each step. Further, the number of stages of the truss support 1 can be set to an arbitrary number of one or more.

  Moreover, the steel pipe sheet pile 4 should just form the closed area | region in the plane, and is not restricted to what cuts off the water area 3 in a well shape. For example, the water area 3 may be cut off in a cylindrical shape. In this case, the truss support plane may be a substantially circular annular plane. Furthermore, instead of the steel pipe sheet pile 4, a steel sheet pile or other member may be used as a temporary cut-off body.

  Hereinafter, other examples of the present invention will be described as second to sixth embodiments. Each embodiment will be described with respect to differences from the embodiments described so far, and the same points will be denoted by the same reference numerals in the drawings and the like, and description thereof will be omitted. In addition, the configurations described in the embodiments including the first embodiment can be used in combination as necessary.

[Second Embodiment]
As a second embodiment, a temporary closing method for further reducing underwater work at the time of installation of a support work will be described. In this embodiment, as shown in FIG. 8, the upper and lower truss supporters 1 are connected by a truss structure in which horizontal members 18 are provided above and below the vertical member 16 and the diagonal member 17, and used as a support unit 10 ′. As the horizontal member 18, a steel material such as H-shaped steel is used. The plane of the horizontal member 18 has a rectangular frame shape.

  In this embodiment, as shown in FIG. 9A, the support unit 10 ′ is hung from a crane or the like (not shown) of the hoist ship with the rod-like support member 7 attached to the support unit 10 ′. Lower and lower. The support member 7 is a steel rod having a total thread and is inclined so as to go inward as it goes down. When the support unit 10 ′ is lowered, a positioning guide (not shown) in the plane of the support unit 10 ′ is also attached to the steel pipe sheet pile 4.

  10 (a) and 10 (b) are diagrams showing the attachment portion of the support member 7. FIG. FIG. 10A is a view showing a cross section perpendicular to the longitudinal direction of the longitudinal member 11 (see FIG. 3A) of the outer peripheral portion of the truss support 1 at the upper part of the support unit 10 ′. ) Is a view showing a longitudinal section of the longitudinal member 11. 10A is a cross section taken along line BB in FIG. 10B, and FIG. 10B is a cross section taken along line AA in FIG.

  As shown in the figure, in this embodiment, the support member 7 is a horizontal structure of a truss structure that connects the vertical member 11 of the outer peripheral portion of the truss support 1 at the top of the support unit 10 ′ and the upper and lower truss support 1. It is attached to the material 18.

  The support member 7 is passed through the web of the above-described vertical member 11 (H-shaped steel) and the holes (not shown) of the washer 111 provided above and below the web, and on the lower surface of the lower washer 111 and the upper surface of the upper washer 111. The nut 112 is tightened.

  The lower end portion of the support member 7 protrudes downward from the vertical member 11 and is passed through the web of the horizontal member 18 (H-shaped steel) and the hole (not shown) of the washer 181 provided above and below the web. The nut 182 is tightened on the lower surface of the washer 181 and the upper surface of the upper washer 181. The lower surfaces of the vertical members 11 and the horizontal members 18, the lower surfaces of the washers 111 and 181, and the upper surfaces of the vertical members 11 and the horizontal members 18, the upper surfaces of the washers 111 and 181 are inclined surfaces orthogonal to the inclination of the support material 7.

  FIGS. 10A and 10B are attachment parts in which the support member 7 is attached to the vertical member 11 of the outer peripheral part of the truss support 1, but the cross member 12 (FIG. With respect to a), the support member 7 is attached with the same configuration. Further, in the vertical member 11, the horizontal member 12, and the horizontal member 18, reinforcing ribs (not shown) connected to both the flanges of the H-shaped steel and the web are provided in the vicinity of the mounting portion of the support member 7 as necessary. Provided.

  In the present embodiment, the support unit 10 ′ is lowered to a predetermined position as shown in FIG. 9B while sequentially adding a plurality of steel bars as the support member 7 with a coupler (not shown) or the like. The position (height) of the support unit 10 ′ can be grasped by the measuring tape (not shown) attached to the support unit 10 ′, the length and number of the steel bars that have been added, and the like.

  When the support unit 10 ′ is disposed at a predetermined position, the upper end portion of the support member 7 is held by the support member receiving portion 4 a provided at the upper end of the steel pipe sheet pile 4. FIG. 10C shows the support material receiving portion 4a. As shown in FIG. 10C, the support material receiving portion 4a includes a transfer steel material 41, a height adjusting material 42, a center hole jack 43, and the like.

  The passing steel material 41 is an H-shaped steel bridged between adjacent steel pipe sheet piles 4, and a notch portion 412 is provided in the upper and lower flanges at a portion corresponding to the gap between the steel pipe sheet piles 4. The upper end portion of the support member 7 is disposed between the adjacent steel pipe sheet piles 4 and passed through the notch portion 412.

  A washer 413 is disposed on the upper flange of the transfer steel member 41 so as to straddle the notch 412. The washer 413 is fixed on the flange by a non-slip (not shown) or the like. The upper surface of the washer 413 is an inclined surface orthogonal to the inclination of the support member 7, and a pedestal 414 for installing the center hole jack 43 is provided on the upper surface. The transfer steel 41 is also provided with reinforcing ribs (not shown) connected to both flanges of the H-shaped steel and the web as required.

  The height adjusting member 42 is for adjusting the height of the transfer steel member 41 and is attached to the side surface of the upper end portion of the steel pipe sheet pile 4. For the height adjusting member 42, a grooved steel or the like is used, and is provided so as to support the lower flange of the transfer steel member 41.

  The center hole jack 43 is for holding the support material 7 and adjusting its tension in order to support the support unit 10 ′ by the support material 7. The upper end of the support member 7 is passed through a hole (not shown) in the washer 413, the pedestal 414, and the center hole jack 43, and is fastened to the plate 431 on the upper surface of the jack with a nut 432.

  In the present embodiment, the support unit 10 ′ is supported by the support material 7 from a plurality of locations (for example, about 20 locations). At this time, the tension force of the support member 7 is appropriately managed so as not to exceed the management value, and finally adjusted so as to be equal for all the support members 7.

  After the support unit 10 'is thus installed, the bracket 8' is installed above the support unit 10 'as shown in FIG. 9C.

  FIG. 11 shows an installation method of the bracket 8 '. In the present embodiment, as shown in FIG. 11 (a), the bracket receiving member 81a is a long one using grooved steel or the like, and a bracket body 82 similar to the above is joined to the lower end thereof in the air by welding or the like. Has been. The bracket receiving member 81a is temporarily supported by a hook 83 such as a hook provided at the upper end of the steel pipe sheet pile 4.

  The bracket 8 'is suspended by a wire (not shown) or the like and lowered along the steel pipe sheet pile 4. As shown in FIG. 11B, the bracket body 82 is disposed at a predetermined position, and the bracket receiving member 81a is placed on the water. The welded portion 84 is welded and fixed to the steel pipe sheet pile 4. When the bracket 8 'is lowered, by measuring the height of the upper end of the bracket receiving member 81a, the position (height) of the bracket body 82 is grasped from the measured value and the member length of the bracket receiving member 81a. Work can be done.

  After the bracket 8 'is thus installed, the new support unit 10' is suspended and lowered in the same manner as described above, and placed on the bracket 8 '(bracket body 82) as shown in FIG. 9 (d). . For safety reasons, it is possible to form a bracket similar to the bracket 8 at a position where the uppermost truss support 1 is supported.

  In this embodiment, the space between the truss supporter 1 and the steel pipe sheet pile 4 at each stage is finally packed. Except for the uppermost truss support 1, in this embodiment, the padding is performed underwater. Fig.12 (a) is a figure shown about the filling method in water. In the present embodiment, as shown in the left diagram of FIG. 12A, the precast block 31 is hooked and arranged on the flange surface of the vertical member 11 on the outer peripheral portion of the truss support 1 with a hook 32. The precast block 31 is arranged across the flange surface of the vertical member 11 and the flange surface of the horizontal member 18 described above, and a bag body 34 having an opening at the top is provided on the front surface thereof. As shown in the right figure, when the bag body 34 is filled with a filler 33 such as mortar or concrete, the bag body 34 expands so as to be in close contact with the shape (cylindrical shape) of the steel pipe sheet pile 4.

  Thereby, as shown in FIG.12 (b), between the vertical material 11 (and above-mentioned horizontal material 18) of the outer peripheral part of the truss support construction 1 and the steel pipe sheet pile 4 is performed. Thickening is also performed on the cross member 12 on the outer peripheral portion of the truss support 1 by the same method, and a plurality of such clogged portions are provided between the truss support 1 and the well formed by the steel pipe sheet pile 4.

  As described above, a temporary closing structure 20 ″ (see FIG. 9D) is formed in which the upper and lower four-stage truss supporter 1 is annularly arranged along the inner periphery of the well with the steel pipe sheet pile 4. The work procedure before and after installation is the same as that of the first embodiment, and this embodiment can provide the same effects as those of the first embodiment. Use has the advantage that the burden of underwater work can be further reduced.

  The filling method is not limited to the example shown in FIG. 12. For example, a formwork is installed between the longitudinal member 11 or the transverse member 12 and the steel pipe sheet pile 4 on the outer periphery of the truss support 1 underwater to fill the filler. Alternatively, a bag body similar to the bag body 34 may be attached to the longitudinal member 11 or the transverse member 12, and the bag member may be filled with a filler. However, the former method requires installation of the formwork underwater, and the workability is low, and the latter method may cause the bag body to hang down when filling with the filler and cannot be satisfactorily filled, and the above method does not solve these problems. This is advantageous in terms of reduction.

[Third embodiment]
In 3rd Embodiment, as shown to Fig.13 (a), a part of these planes are joined in the process mentioned later using a pair of truss support work 1a which divided the said truss support work 1 in the plane. Let it be a substantially square-shaped annular plane.

  As shown in FIG. 13 (b), each truss support 1a is formed with a pair of support units 10a by attaching a truss structure with vertical members 16 and diagonal members 17 to the upper part. The support unit 10a is assembled and manufactured in advance on the ground or on the water, and is carried to the site for use.

  14 and 15 are diagrams for explaining the installation procedure of the support work in the third embodiment. In the present embodiment, when the support is installed, first, as shown in FIG. 14 (a), a work trolley 9 is placed on the water, and the pair of support units 10a are grounded, and welding, bolts, and the like are arranged. Are joined in the air to form a substantially square-shaped annular plane similar to that of the first embodiment. A temporary bracket 8a is provided on the top of the steel pipe sheet pile 4, and the support unit 10a is installed thereon. The bracket 8a can be installed by hooking it on the top of the steel pipe sheet pile 4 with a hooking portion (not shown).

  Further, the first-stage bracket 8 is formed in the same manner as in the first embodiment, and a bracket receiving member 81 (see FIG. 2B) is attached to the formation position of the second-fourth-stage bracket 8 described later. Keep it.

  The support unit 10a is suspended by a wire using a suspension mechanism (not shown) such as a winch provided at the top of the steel pipe sheet pile 4, and the top of the first-stage bracket 8 as shown in FIG. 14 (b). Install in. When the support unit 10a is suspended, the temporary bracket 8a is temporarily moved to a position that does not hinder the suspension, and after the support unit 10a is suspended, it is returned to its original position.

  Then, as shown in FIG.14 (c), a pair of support unit 10a is grounded and joined similarly to the above on the trolley 9. Further, the second stage bracket 8 is formed in the same manner as in the first embodiment.

  The ground support unit 10a is suspended by the same procedure as described above, and is installed on the second-stage bracket 8 as shown in FIG. 14 (d). Thereafter, the truss supporter 1a (another supporter) of the support unit 10a is attached to the upper end portion of the vertical member 16 of the lower support unit 10a by welding or bolting in water.

  Thereafter, the support unit 10a is grounded in the same procedure and installed on the third-stage bracket 8 as shown in FIG. 15A, and the above-described joining is performed in the same manner. Finally, as shown in FIG. 15 (b), the truss support 1a is joined to the upper end of the vertical member 16 of the uppermost support unit 10a in the air, and four steps are provided at a position to support the truss support 1a. An eye bracket 8 is formed. Thereby, the temporary closing structure 20a in which the upper and lower four-stage truss support works 1a are annularly arranged along the inner periphery of the well by the steel pipe sheet pile 4 is formed.

  The work procedure before and after the support is installed is the same as that of the first embodiment, and the same effect as that of the first embodiment can be obtained in this embodiment by using the support unit 10a. Further, in the present embodiment, since the support unit 10a divided on the plane is joined and used in the field, each support unit 10a is light in weight, and the burden at the time of carrying in is reduced. In the present embodiment, the truss support 1 according to the first embodiment is divided into half the support unit 10a in a plane, but the size and the number of divisions are not limited thereto, and the capacity of the crane or the like to be used. Can be determined according to

[Fourth Embodiment]
16 and 17 are diagrams for explaining the installation procedure of the support work in the fourth embodiment. Also in the fourth embodiment, as shown in FIG. 16A, a pair of support units 10a are grounded and joined on the carriage 9 as in the third embodiment, and the first-stage bracket 8 is joined. However, the bracket 8 is at a higher position than the third embodiment.

  Therefore, when the support unit 10a is suspended as in the third embodiment and installed on the first-stage bracket 8 as shown in FIG. 16 (b), the vertical members 16 and the like of the support unit 10a The upper end is on the surface of the water.

  Thereafter, as shown in FIG. 16 (c), a pair of support work units 10 a is newly ground and joined on the carriage 9. In this embodiment, at this time, the truss support work 1a (another support work) of the ground support work unit 10a is in the air by welding, bolts, or the like on the upper end of the vertical member 16 of the lower support work unit 10a. Join and install.

  Next, the bracket 8 is removed and the bracket 8 is formed below the bracket 8 as shown in FIG. 16 (d). The support unit 10a is suspended in the same manner as described above, and the bracket 8 is shown in FIG. 17 (a). 8 Install on top. At this time, since the upper ends of the vertical members 16 and the like of the upper support unit 10a are on the surface of the water, a new ground structure of the support unit 10a and the vertical members 16 of the lower support unit 10a and Are installed on the bracket 8. This state is shown in FIG.

  At this time, since the upper end of the vertical member 16 of the uppermost support unit 10a is on the water, as shown in FIG. 17C, the truss supporter 1a is joined to the upper end of the vertical member 16 in the air. At the same time, the bracket 8 is formed at a position for supporting the truss support 1a at the second to fourth stages. Also by this, the temporary closing structure 20a in which the upper and lower four-stage truss support works 1a are annularly arranged along the inner periphery of the well by the steel pipe sheet pile 4 is formed.

  The work procedure before and after the support is installed is the same as that of the first embodiment, and the same effect as that of the third embodiment can be obtained in this embodiment by using the support unit 10a. Moreover, since all the joining can be performed in the air in the present embodiment, the operation becomes easier as compared with the third embodiment.

[Fifth Embodiment]
18 and 19 are diagrams for explaining the installation procedure of the support work in the fifth embodiment. In the fifth embodiment, as shown in FIG. 18 (a), the truss support work 1a corresponding to the required number of steps (four in the example in the figure) is vertically moved using a truss structure composed of a vertical member 16 and a diagonal member 17. The support unit 10b connected to the is used. The support unit 10b is assembled and manufactured in advance on the ground or on the water, and is used by being carried to the site.

  In the present embodiment, the support unit 10b is suspended by a crane (not shown) of a hoist ship and disposed at a predetermined position inside the well by the steel pipe sheet pile 4 as shown in FIG. It is supported from above by suspending it with a wire or the like from a suspending device (not shown) provided on the top of the. Then, the other support unit 10b is suspended in the same manner, arranged next to the previous support unit 10b as shown in FIG. 19A, and supported from above in the same manner as described above.

  After that, the pair of support units 10b are joined in water by welding, bolts, or the like to form a substantially square-shaped annular plane similar to the first embodiment. Then, as shown in FIG. 19 (b), the well inside the steel pipe sheet pile 4 is drained and dried up, and then the bracket 8 is formed at a position where the truss support work 1 a of each stage is supported. Thereby, the temporary closing structure 20b in which the upper and lower four-stage truss support works 1a are annularly arranged along the inner periphery of the well formed by the steel pipe sheet pile 4 is formed.

  The work procedure before and after the support is installed is the same as that of the first embodiment, and the same effect as that of the first embodiment can be obtained in this embodiment by using the support unit 10b.

  In the present embodiment, the truss support unit 1a is connected to the upper and lower four stages, but the number of stages is not limited to this, and the number of stages can be determined according to the capacity of the crane or the like to be used as described above. . In addition, the plane of the truss support 1a is a half of the truss support 1 of the first embodiment, but is not limited to this, and uses a total of four parts divided into two vertically and two horizontally. It is good also as a substantially square-shaped annular plane similar to 1st Embodiment by joining in water.

[Sixth Embodiment]
20 and 21 are diagrams for explaining the installation procedure of the support work in the sixth embodiment. 6th Embodiment is an example which arrange | positions the truss support work 1 of 8 steps | paragraphs.

  That is, in the sixth embodiment, first, as shown in FIG. 20 (a), after forming the first stage bracket 8, the truss support 1 is suspended from a crane (not shown) such as a hoist ship. Installed on the bracket 8 to be the first stage truss support 1. A bracket receiving member 81 (see FIG. 2B) is attached in advance to the formation positions of the remaining second to fourth brackets 8 to be described later.

  Next, as shown in FIG. 20 (b), the second stage truss support 1 is similarly suspended by a crane or the like and installed on the first stage truss support 1.

  Thereafter, as shown in FIG. 20 (c), the second-stage bracket 8 is formed in the same manner as in the first embodiment, and a truss structure including the vertical member 16 and the diagonal member 17 is provided below the truss support 1. The support unit 10c is suspended by a crane or the like. The support unit 10c is assembled and manufactured in advance on the ground or on the water, and is carried into the site for use.

  When the truss support 1 of the support unit 10c is installed on the second stage bracket 8 as shown in FIG. 20 (d), the lower end of the vertical member 16 of the support unit 10c is the second stage truss support 1. The second truss support 1 (another support) is joined and attached to the lower end of the vertical member 16 at this position.

  Next, on the truss support 1 (third truss support 1) of the support unit 10c, the fourth truss support 1 is suspended by a crane or the like as shown in FIG. 21 (a). Install. In this way, truss support 1 for four stages is installed.

  Thereafter, in the same procedure, as shown in FIG. 21B, the third and fourth brackets 8 are formed, and the four-stage truss support 1 is newly installed. As a result, a temporary cutoff structure 20 c is formed in which a total of eight stages of truss supporters 1 are annularly arranged along the inner periphery of the well with the steel pipe sheet pile 4.

  The work procedure before and after the installation of the support is the same as that of the first embodiment. In this embodiment, the same effect as that of the first embodiment can be obtained by using the support unit 10c and the like.

  In this embodiment, the truss support 1 is installed on the truss support 1, but at this time, as shown in FIG. 22A, the guide plate 811 of the guide member 81 provided on the lower truss support 1 is provided. Alternatively, the projecting member 82 provided on the upper truss support 1 may be guided to align both trusses 1. The tip of the protruding member 82 protrudes downward from the upper truss support 1, and the guide plate 811 of the lower truss support 1 is arranged so as to match the tip shape of the protruding member 82.

  Further, in this embodiment, the vertical member 16 of the support unit 10c is attached to the lower truss support 1, but also in this case, a guide member 91 is provided on the truss support 1 as shown in FIG. The vertical member 16 of the support unit 10c may be lowered along the member 91 to perform alignment. In the example of FIG. 22B, a box 92 opened upward is arranged in the truss support 1 and a guide member 91 is provided therein, and the support unit 10 c is provided in the box 92 along the guide member 91. After the vertical material 16 is arranged, the box 92 is filled with mortar 93 or the like to fix the vertical material 16 to the lower truss support 1.

  Or as shown in FIG.22 (c), the receiving plate 93 is arrange | positioned on the truss support work 1, the guide member 91 is provided on it, and the vertical member 16 is guided by the guide plate 911 of the guide member 91. Also good. In this example, a screw 94 projects upward from the receiving plate 93, and the nut 94 is tightened by passing the screw 94 through a hole (not shown) of the bottom plate 161 provided at the bottom end of the vertical member 16, thereby 16 is fixed to the lower truss support 1.

  In the example of FIG. 22D, guide members 91 a and 91 b are provided on the receiving plate 98 disposed on the truss support 1. The guide member 91a and the guide member 91b are disposed on both sides of the vertical member 16, and the vertical member 16 of the support unit 10c is guided along the guide plates 911 of the guide members 91a and 91b. Further, in this example, the pin 96 is disposed on the flange 162 provided at the bottom end of the vertical member 16, and the vertical member 16 is fixed to the lower truss support 1 by pressing the flange 162 from above. Both ends of the pin 96 are pressed from above by pressing plates 97 provided on the guides 91b on both sides of the vertical member 16 (only the pressing plate 97 on the front side is shown in FIG. 22D). Except when the material 16 is fixed, it is stored in a notch 912 provided in the guide 91a (see reference numeral 96 'in the figure).

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

DESCRIPTION OF SYMBOLS 1, 1a; Truss support 2; Ground 3; Water area 4, 5; Steel pipe sheet pile 4a; Support material receiving part 6; Guide frame 6a: Outer frame 6b; Inner frame 7: Support materials 8, 8 ', 8a; ; Carrier 10, 10 ', 10a, 10b, 10c; support unit 11; longitudinal member 12; transverse member 14, 17, 61; diagonal member 15; opening 16; vertical member 18; horizontal member 20, 20', 20a 20b, 20c; temporary closing structure 31; precast block 32; hook 33; filler 34; bag 71; paving stone layer 72; bottom concrete 73; top concrete 74; bridge pier 81, 81a; 83; hook part 84; welded part 100; support work 101; erection 102; cut beam 103;

Claims (14)

A process of shutting off the water area by a closed area by a temporary closing body;
A step of installing a support in the temporary closing body;
Comprising
The temporary closing method, wherein the support is annularly arranged along the inner periphery of the temporary closing body, the central portion is an opening, and has a truss structure in a plane.   The temporary closing method according to claim 1, wherein the supporting works are installed in a plurality of upper and lower stages.   The temporary closing method according to claim 2, wherein at least two stages of the supporting works are vertically connected by a truss structure.   The temporary closing method according to claim 3, wherein a supporting unit in which at least two stages of the supporting works are connected in advance vertically by a truss structure is lowered and installed inside the temporary closing body.   Lowering a support unit with a truss structure pre-mounted on or below the support work and installing it inside the temporary cut-off body, and then attaching another support work to the truss structure of the support work unit The temporary closing method according to claim 3.   The temporary closing method according to any one of claims 1 to 5, wherein the supporting work is used as an annular shape by joining a part of planes.   The bottom base is constructed at the bottom of the excavation after underwater excavation of the ground inside the temporary cutoff body while leaving a guide frame when the temporary cutoff body is placed on the ground. The temporary closing method according to claim 6. Forming a partition wall inside the temporary cut-off body,
The temporary closing method according to any one of claims 1 to 7, wherein after excavating the ground inside the temporary closing body, a predetermined position of the partition wall is cut and an upper portion is removed. A temporary cut-off body that forms a closed area and cuts off the water area;
A supporting work installed inside the temporary cut-off body,
Have
The temporary closing structure is characterized in that the supporting work is annularly arranged along the inner periphery of the temporary closing body, has an opening at the center, and has a truss structure in a plane.   The temporary closing structure according to claim 9, wherein the support works are installed in a plurality of upper and lower stages.   The temporary closing structure according to claim 10, wherein at least two stages of the supporting works are vertically connected by a truss structure. A supporting work used for a temporary closing structure in which a water area is closed by a closed area by a temporary closing body,
A support work characterized in that the plane is annular, the center is an opening, and the plane has a truss structure.   A truss structure provided with a truss structure above or below the strut according to claim 12.   The support unit according to claim 13, wherein at least two stages of the support are vertically connected by a truss structure.

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