JP4543359B2 - Box-type steel sheet pile for temporary cut-off method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a box-type steel sheet pile used for a temporary closing method for temporarily closing a water area to create a construction air space.
[0002]
[Prior art]
For example, when a new intake is installed in an existing dam and power generation facilities are added, it is necessary to temporarily cut off the front water area of the existing dam dam body with a water barrier to create a construction air space. As a temporary closing method performed for such a purpose, there is one described in JP-A-9-88044.
FIG. 5 shows the temporary closing method described in the above publication. The water blocking wall indicated by reference numeral 1 is constructed in an arch shape (semi-circular shape) with respect to the dam dam body 2 and should be opened. The front water area W of the mouth 3 is cut off. The water blocking wall 1 is formed by a double sheet pile wall 6 constructed by continuously placing steel sheet piles along a guide frame 5 provided on a gantry 4 installed on the bottom of the water, and in the double sheet pile wall 6. The construction air space S appears by draining the inside of the concrete layer 7 provided.
[0003]
In such a temporary closing method, the double sheet pile wall 6 is connected to box-shaped steel sheet piles 10, 10... Via a joint 11 having a rigid fitting structure as shown in FIG. . This box-shaped steel sheet pile 10 has a structure in which the inside of a rectangular cross-section frame 12 is divided into a plurality of chambers A, A in the long side direction by a plurality of partition plates (partition walls) 13. The concrete layer 7 is placed inside. Here, one of the partition plates 13 is composed of two plates 14 and 15 that are separated from each other, and the concrete layer 7 in the box-shaped steel sheet pile 10 is formed of the two-layered plates. The body is cut between the bodies 14 and 15. In addition, a plurality of communication holes (not shown) that communicate with each other between the chambers A are formed in the other partition plates 13 except for the two stacked plates 14 and 15, and a plurality of communication holes (not shown) are also formed in the side plate portion 12 a of the frame body 12. (Not shown) are provided, and the concrete layer 7 in the double sheet pile wall 6 is adjacent to each other, including the inside of the chamber B closed by the joint 11 between the adjacent box-shaped steel sheet piles 10. The box-shaped steel sheet pile 10 is integrated between the two stacked plates 14 and 15. The joint 11 includes a cylindrical female joint member 16 having a longitudinal slit 16a and a cylindrical male joint member 17 that can be inserted into the female joint member 16. Between the two, mortar or the like is provided. It is rigidly bonded by a solidified material.
[0004]
Since the water blocking wall 1 constructed in this way has its concrete layer 7 edged between the two stacked plates 14 and 15 in each box-shaped steel sheet pile 10, both plates 14 and 15 If the steel sheet pile 10 is cut | disconnected longitudinally between, the water stop wall 1 will be in the one box-shaped steel sheet pile 10 and the other box-shaped steel sheet pile 10 which were placed adjacent to each other. The other plate body 15 is divided into a plurality of parts and can be easily disassembled in units of the divided blocks. In this dismantling, the cutting lines L1 and L1 are set so that the space between the adjacent box-shaped steel sheet piles 10 is as narrow as possible on the inner peripheral side of the water blocking wall 1, while the water blocking wall 1 By setting the cutting lines L2 and L2 so as to be as wide as possible on the outer peripheral side of the wall (FIG. 6), the lateral force F is applied from the inner side to the outer side of the water blocking wall 1, and the first block cut first Can be easily removed, and the whole can be easily disassembled.
[0005]
[Problems to be solved by the invention]
By the way, the double-layered plates 14 and 15 in the box-shaped steel sheet pile 10 are each welded to the inner wall surface of the frame 12 as shown in FIG. It was set as the bending-shaped part 14a, 15a which bent the both-side edge part from the mating surface to the opening direction. However, this type of box-shaped steel sheet pile 10 is subjected to a large internal pressure as the concrete is placed after the construction of the double sheet pile wall 6 described above, and the internal pressure is applied to the double-layered plates 14 and 15 by this internal pressure. A large tensile force acts, and as a result, the bent portions 14a and 15a extend, and there is a possibility that the frame 12 of the box-shaped steel sheet pile 10 and thus the double sheet pile wall 6 may be deformed.
As a countermeasure against the above-mentioned deformation, there is a concept of using a thick plate as the double-layered plates 14 and 15, but in this case, it is difficult to bend the bent portions 14a and 15a, and the processing is very costly. As a result, a new problem of increased cost burden arises.
The present invention has been made in view of the above-described technical background, and the problem is that the allowable width of cutting between two stacked plates is not so narrow and the strength is not increased without causing an increase in cost. It is to provide a box-type steel sheet pile that contributes to the stable construction of the temporary closing method.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a temporary partition formed by separating one of a plurality of partition walls that divide the inside of a rectangular cross-section frame body in the long side direction from a double-layered plate body separated from each other. a box-shaped steel sheet pile for deadlines method, a plate of the two-ply, respectively formed as bent shaped portion bent in the opening direction against the mating surface of the opposing one side edge portion, the respective curved-shaped portion of the mating The inner wall surface of the frame body is brought into surface contact and welded, and the opposite side edge portions are each formed into a flat plate shape and welded by abutting against the inner wall surface of the counterpart frame body .
In the box-type steel sheet pile configured in this way, the inner double-layered plate body has only one opposite side edge portion as a bent shape portion, so even if tensile force due to concrete placement acts, the amount of elongation is As a result, the deformation of the frame is suppressed. In addition, the double-layered plate body is welded by bringing the opposite bent side bent portions into contact with the inner wall surface of the opposite frame body, so that the inner peripheral side and the outer peripheral side of the water blocking wall. In addition, a desired allowable width necessary for cutting can be ensured.
[0007]
In the present invention, a plurality of reinforcing members that reinforce the frame body are disposed on at least one side adjacent to the double-layered plate body, and both ends of the reinforcing member are disposed on the frame. In this case, the deformation of the frame can be surely prevented.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 3 show an embodiment of a box-type steel sheet pile for a temporary closing method according to the present invention. The overall structure of the box-type steel sheet pile and the temporary closing method to which the box-type steel sheet pile is applied are not different from the contents described with reference to FIGS. 5 and 6. The same parts as those shown in FIG.
[0009]
The box-shaped steel sheet pile 10 is a two-layer stack in which one of a plurality of partition walls (partition plates) 13 partitioning the inside of the rectangular cross-section frame 12 in the long side direction is separated from each other. The plate bodies 21 and 22 are formed. Thus, the double-layered plates 21 and 22 are bent-shaped portions 21a obtained by bending one opposite side edge portion of both side edge portions welded to the inner wall surface of the frame body 12 in the opening direction from the mating surface. Therefore, the opposite side edge portions of the plate bodies 21 and 22 have a flat plate shape. Further, the two-layered plate bodies 21 and 22 are overlapped so that the respective bent shape portions 21a and 22a are superposed on the side edge portions of the mating flat plate shape. A space 23 (FIG. 2) having a predetermined width w provided for cutting is secured on both the inner and outer peripheral sides of the water blocking wall 1. Each of the two stacked plate bodies 21 and 22 has the flat side edge portions butted against the inner wall surface of the frame body 12, and the bent shape portions 21a and 22a are brought into surface contact with the inner wall surface of the frame body 12. It is welded in the state.
[0010]
In the present embodiment, a plurality of reinforcing members 24 and 25 are disposed inside the box-shaped steel sheet pile 10 adjacent to the double-layered plate bodies 21 and 22 and on both sides thereof. Each reinforcing member 24, 25 has both end portions extending through the frame body 12 and extending to the outside. In this state, the penetration portion is welded to the frame body 12 from inside and outside. ing.
[0011]
In order to temporarily cut the front water area W of the dam body 2 using the box-shaped steel sheet pile 10, the box-shaped steel sheet pile along the guide frame 5 (FIG. 5) of the gantry 4 installed on the water bottom as described above. The double sheet pile wall 6 is constructed by connecting 10 with the joint 11 connected to each other, and then the concrete is placed in the double sheet pile wall 6 to complete the water blocking wall 1. Since the box-shaped steel sheet pile 10 has the double-layered plates 21 and 22 with only one side edge as the bent-shaped portions 21a and 22a, a tensile force acts on the concrete by placing the concrete. However, the amount of elongation becomes small, and the deformation of the frame 12 is suppressed. In addition, in the present embodiment, since the plurality of reinforcing members 24 and 25 are disposed adjacent to the two-layered plates 21 and 22, the deformation of the frame body 12 is more reliably prevented.
[0012]
On the other hand, when the water blocking wall 1 is dismantled after the opening work of the intake port 3 is completed, the concrete layer 7 is edged between the two stacked plates 21 and 22 in the box-shaped steel sheet pile 10. If the box-shaped steel sheet pile 10 is cut in the longitudinal direction at a location corresponding to the space 23 (FIG. 2) between the two plates 21 and 22, one box shape is placed adjacent to each other. It will be in the state divided | segmented into multiple between the one plate body 21 in the steel sheet pile 10, and the other plate body 22 in the other box-shaped steel sheet pile 10, and can be easily disassembled by this division unit.
By the way, at the time of disassembling, it is advantageous in terms of improving work efficiency that the block first cut as described above is removed by applying a lateral force F from the inner side to the outer side of the water blocking wall 1. Therefore, in the present embodiment, as shown in FIG. 4, a box-shaped steel sheet pile 10A having a structure in which the two-layered plate bodies 21 and 22 are inverted by 180 ° is separately prepared. These box-shaped steel sheet piles 10 connected to each other are used in place of one another. Thereby, it becomes the form where the bending shape part 14a of one board 14 opposes between the box-shaped steel sheet piles 10 and 10A, Therefore, the space | interval of the cutting lines L1 and L1 in the inner peripheral side of the water stop wall 1 is carried out. It becomes possible to set narrower than the interval between the cutting lines L2 and L2 on the outer peripheral side of the water blocking wall 1. That is, the first block cut along the cutting lines L1 and L2 can be easily removed in the lateral direction by the lateral force F, and as a result, the water blocking wall 1 can be efficiently disassembled. Become.
[0013]
In addition, in the said embodiment, although the application to the temporary closing method which temporarily cuts the front water area of the dam body 2 was shown, the application range of this invention is arbitrary and various temporary closing methods other than a dam lake are shown. Of course, it can be applied to.
[0014]
【The invention's effect】
As described above in detail, according to the box-type steel sheet pile for temporary closing method according to the present invention, even if concrete is placed inside, the extension of the double-layered plate body is suppressed, so that the overall deformation is suppressed. Therefore, it will greatly contribute to the stable construction of the temporary closing method. In addition, since an allowable width of cutting performed when the water blocking wall is disassembled is sufficiently secured, the water blocking wall dismantling is not hindered. In addition, it is not necessary to increase the thickness of the plate body, and the side edge portion bending process is also halved, which is advantageous in terms of cost and generally has a large effect.
[Brief description of the drawings]
FIG. 1 is a plan view showing the main structure of a box-type steel sheet pile for a temporary closing method according to the present invention.
2 is an enlarged plan view showing a Q portion in FIG. 1. FIG.
FIG. 3 is an enlarged plan view showing a part of a water blocking wall constructed using the box-type steel sheet pile.
FIG. 4 is a plan view schematically showing an arrangement form and disassembling procedure of the box-type steel sheet piles on the water blocking wall.
FIG. 5 is a plan view showing an overall installation mode of a water blocking wall by a temporary closing method.
FIG. 6 is an enlarged plan view showing a part of a water blocking wall constructed using a conventional box-type steel sheet pile.
7 is an enlarged plan view of a P part in FIG. 6. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stop wall 2 Dam dam body 5 Conductor frame 6 Double sheet pile wall 7 Concrete layer 10, 10A Box-shaped steel sheet pile 12 Frame body 13 Partition plate (partition wall)
21, 22 Double-ply plates 21a, 22a Bent parts 24, 25 Reinforcing members

Claims (2)

One of a plurality of partition walls that partition the inside of the rectangular cross-section frame in the long side direction, is a box-shaped steel sheet pile for a temporary fastening method formed from two stacked plates separated from each other,
Plate member of said two-ply are contradictory each formed as bent shaped portion bent in the opening direction with respect to a mating surface on one side edge, by the respective bent-shaped portion contacting the surface with the inner wall surface of the mating of the frame body A box-shaped steel sheet pile for a temporary closing method , wherein welding is performed and the opposite side edge portions are each formed into a flat plate shape and are welded while being abutted against the inner wall surface of the counterpart frame . A plurality of reinforcing members that reinforce the frame body are provided on at least one side adjacent to the double-layered plate body, and both ends of the reinforcing member penetrate the frame body. The box-type steel sheet pile for a temporary closing method according to claim 1, wherein the box-type steel sheet pile is extended to the outside .

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