JP4636298B2 - Underwater concrete placement equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for placing concrete in an underwater structure, and more particularly, an underwater concrete placement for placing concrete in each chamber of an underwater structure having a plurality of independent chambers partitioned by a partition wall. Relates to the device .
[0002]
[Prior art]
For example, when installing a new intake port in an existing dam and adding power generation facilities, it is necessary to create an air space for construction by cutting off the water area in front of the existing dam body with a water barrier. As a deadline method (temporary deadline method) performed for various purposes, there is one described in JP-A-9-88044.
FIGS. 5 to 7 show the temporary closing method described in the above publication. The water blocking wall indicated by reference numeral 1 is constructed in an arch shape with respect to the dam dam body 2 and should be opened. The front water area W of 3 is cut off. The water blocking wall 1 includes a double sheet pile wall 7 constructed by continuously placing steel sheet piles 6 along the guide frame 5a of the guide frame mount 5 installed on the water bottom ground 4, and the double sheet pile wall. 7 and a concrete layer 8 placed in the wall 7, and both end portions of the double sheet pile wall 7 are joined to the dam body 2.
[0003]
Here, as the steel sheet pile 6, for example, a box formed from two plate bodies 12, 13 in which one of a plurality of partition walls 11 partitioning the inside of the frame body 10 is separated and overlapped with each other. Shaped steel sheet piles are used, and the steel sheet piles 6 are connected to each other via joints 16 including male joint members 14 and female joint members 15 provided on both sides thereof. A plurality of through holes (not shown) are provided in the left and right side plates 10a of the other partition wall 11 and the frame body 10 except for the two stacked plate bodies 12 and 13, and the concrete layer 8 in the double sheet pile wall 7 is The sheet piles 12 and 13 in the adjacent steel sheet piles 6 are integrated with each other, and the sheet piles 12 and 13 in each steel sheet pile 6 are bordered. Therefore, if the steel sheet pile 6 is cut | disconnected longitudinally like L1 and L2 after the construction in the water stop wall 1 as shown in FIG. The wall 1 is divided into a plurality of parts between the two stacked sheet bodies 12 and 13 in the adjacent steel sheet piles 6 and can be easily disassembled in units of the divided blocks.
[0004]
[Problems to be solved by the invention]
By the way, the inside of the double sheet pile wall 7 is the partition wall (12, 13) because the double-layered plate bodies 12, 13 in each steel sheet pile 6 serve as partition walls for restricting the flow of concrete as described above. ) Is divided into a plurality of independent chambers A in the direction in which the steel sheet piles 6 are arranged, whereby the placement of the concrete (underwater non-separable concrete) into the double sheet pile wall 7 is performed as described above. It must be done in units.
However, since the box-shaped steel sheet pile 6 has a plate thickness of the partition wall 11 including the frame body 10 and the two stacked plate bodies 12 and 13 of about 10 mm at most, the strength (rigidity) is not sufficient. When trying to finish placing concrete in each room in the double sheet pile wall 7 using a general-purpose tremy tube, coupled with the use of highly fluid underwater non-separable concrete, the double sheet pile There is a risk that a large internal pressure is partially applied to the wall 7 and the double sheet pile wall 7 is deformed or broken.
In other words, in order to prevent such deformation or breakage of the double sheet pile wall 7, the concrete must be placed so that there is no significant difference in the height of the concrete in each chamber. To achieve this, each room is filled with a specified amount of concrete in order to ensure the safety of underwater structures, and this cycle is repeated several times. Must be cast.
[0005]
However, the double sheet pile wall 7 after construction is naturally filled with water, and if a specified amount of concrete is introduced from above, the separation of the concrete components due to dropping in water will occur. become.
Therefore, conventionally, in order to intermittently place concrete while avoiding underwater separation, it is necessary to rely on a method of intermittently raising it using a tremy tube with a bottom lid (open / close lid). Was in the situation.
[0006]
However, according to the use of the tremey pipe with the bottom cover, the tremy pipes must be prepared by the number of the independent chambers A in the double sheet pile wall 7, and the double water constituting the water blocking wall 1 described above. In view of the fact that the sheet pile wall 7 has a large number of independent rooms A (for example, 12 rooms) and has a length (height) exceeding 50 m, the construction becomes large and the pipe after use As the cleaning of the house is difficult, the construction period will be extended and the construction cost will be inevitably increased. Also, during the interruption of the concrete driving cycle described above, the slump flow value of the concrete remaining in the tremmy pipe decreases and its use becomes impossible, and in addition, when the water temperature falls, its fluidity It was also expected that the concrete would drop and the concrete could not be discharged. Further, the concrete poured into each independent chamber A of the double sheet pile wall 7 flows out into the adjacent sub chamber a (FIG. 7) through the through holes provided in the partition wall 11 and the left and right side plates 10a of the frame body 10. However, according to the use of this type of tremy pipe, the pressure inside the pipe increases due to the high pressure in the pipe, and the concrete falls into the sub chamber a.
The present invention has been made in view of the technical background described above, and the problem is that the height of the driven surface does not vary so much with respect to the plurality of independent chambers in the underwater structure. To provide an underwater concrete placement device that can make concrete placement smoothly and with high quality and easy construction so that it does not drop underwater, thereby contributing greatly to shortening the construction period and reducing construction costs. is there.
[0009]
An underwater concrete placing apparatus according to the present invention is used for carrying out the above-described construction method, and includes a placing pipe having a bottom cover that can be opened and closed, a support frame having a locking part for a lifting tool at an upper end, and the bottom cover. The support frame has a transmission structure in which a base end portion connected to the placement pipe opens the opening end of the placement pipe to the outside, and the drive means includes the support means. It is arranged on the upper end side of the frame.
In the underwater concrete placing apparatus configured as described above, concrete can be arbitrarily supplied to the placement pipe through the base end portion of the transmission structure of the support frame, and the placement pipe can be easily suspended by hanging the support frame. Can be moved into the room.
In the apparatus of the present invention, the configuration of the driving means is arbitrary, but it is composed of a cylinder and a connecting wire that connects the piston rod and the bottom lid, and the connecting wire is extended in the driving tube. This can simplify the area around the placement tube.
Further, in this apparatus, the placing pipe has a relatively small cross-section that is similar to a chamber of an underwater structure in which concrete is to be placed and has a slightly smaller cross-sectional shape than the chamber, and a lower section continuously provided below the body portion. It is possible to adopt a structure in which a bottom cover is provided on the nozzle part. By adopting such a structure, the main body part becomes a resistance and the rise of the concrete pouring surface is suppressed, and even if there is a sub chamber communicating with the chamber through a through hole, it falls into the sub chamber. Will disappear.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 4 show an underwater concrete placing method according to the present invention and an underwater concrete placing apparatus used for carrying out this method. This construction method is applied to the construction of the water blocking wall 1 for temporarily closing the front water area W of the dam dam body 2 described above, and the concrete is contained in the double sheet pile wall 7 constructed using the box-shaped steel sheet pile 6. Since there is no difference from the contents described with reference to FIGS. 5 to 7, only the main part of the double sheet pile wall 7 including the box-shaped steel sheet pile 6 is shown here. In the double sheet pile wall 7, as described above (FIG. 7), the double stacked plate bodies 12 and 13 in each box-type steel sheet pile 6 serve as a partition wall to form a plurality of independent chambers A in the connecting direction of the steel sheet pile 6. In addition to being partitioned, each independent chamber A is partitioned into a plurality of sub chambers a by a partition wall 11 having a through-hole 17 (FIG. 2) and the left and right side plates 10 a of the frame body 10, and into the double sheet pile wall 7. When the concrete is placed, concrete is poured into one of the sub chambers a, and the concrete flows out to the adjacent sub chamber a through the through holes 17.
[0011]
The underwater concrete placement device 20 is for placing concrete in one of the sub chambers a in the double sheet pile wall 7 described above, and includes a placement pipe 22 having a bottom lid 21 that can be opened and closed, and a suspension. A support frame 24 having a tool locking member (locking portion) 23 at its upper end and a drive means 25 for opening and closing the bottom lid 21 are schematically configured.
The casting tube 22 has a cross-sectional shape similar to one of the sub chambers a in the double sheet pile wall 7 into which concrete is to be poured and slightly smaller than the sub chambers a, as well shown in FIGS. The main body part 26 and a nozzle part 27 having a relatively small cross section provided under the main body part 26 are provided. The bottom lid 21 is disposed at the lower end opening of the nozzle part 27. The outer wall of the main body portion 26 is provided with a plurality of buffer members 28 for alleviating the impact when contacting the wall surface of the double sheet pile wall 7.
[0012]
1 and 3, the support frame 24 has a rectangular plate-shaped base 30 having an opening at the center, and the suspension member locking member 23 is placed on the base 30 at the upper end. A pair of brackets 31 that are pivotally attached to each other are disposed together with a reinforcing plate 32, and a column 33 that serves as a connecting portion for the placement tube 22 is disposed under the base 30. The struts 33 are made of an angle material here, and four of them are arranged so as to connect the four corners of the base 30 and the main body portion 26 of the placing tube 22. That is, the support pillars 33 of the support frame 24 have a transmission structure, whereby the upper end opening of the placing tube 22 is largely opened to the outside.
[0013]
On the other hand, the driving means 25 connects the cylinder 35 positioned between the pair of brackets 31 and supported by the brackets 31, and the piston rod 36 of the cylinder 35 and the bottom cover 21 of the placing tube 22. The connecting wire 37 is provided. The connecting wire 37 has an upper end connected to the piston rod 36 via a shackle 38 and a lower end connected to the bottom lid 21 via a socket 39. The cylinder 35 always shortens its piston rod 36, whereby the bottom lid 21 is pulled up via the connecting wire 37 and maintains the state in which the opening of the nozzle portion 27 of the placement tube 22 is closed. Yes.
[0014]
Hereinafter, the concrete placing method in the double sheet pile wall 7 performed using the concrete placing apparatus 20 configured as described above will be described in detail.
As described above, the double sheet pile wall 7 is installed with the box-shaped steel sheet pile 6 continuously along the guide frame 5 a of the guide frame mount 5 after the guide frame mount 5 (FIG. 5) is installed on the water bottom ground 4. In this construction, prior to the placement of the steel sheet pile 6, an excavator forms an arching groove 40 (FIG. 1) in the water bottom ground 4, After the box-shaped steel sheet pile 6 is installed in the groove 40 with the guide frame 5a as a guide, a mortar 41 (FIG. 1) is placed in the groove 40 to solidify the bottom of each steel sheet pile 6. .
[0015]
Then, after completion of the above-described root hardening, concrete (underwater non-separable concrete) is placed in the double sheet pile wall 7 using the present underwater concrete placement device (hereinafter simply referred to as a placement device) 20. At the time of placing the concrete, the suspension member 23 is hung on a suspension wire 42 (FIG. 1) extending from a crane (not shown), and the entire placing device 20 is lifted, which is a double sheet pile to be placed. The wall 7 is moved above the sub chamber a in one independent chamber A. First, as shown in FIG. 4 (1), only the placement tube 22 of the placement device 20 is inserted into the sub chamber a, and in this state, the support frame 24 positioned above the placement tube 22 is inserted. The injection hose 43 is inserted into the opening end portion of the placing tube 22 through the gap between the columns 33, and the concrete 44 is supplied into the placing tube 22.
[0016]
After supplying the concrete 44 into the placing pipe 22, the placing apparatus 20 is lowered by a crane operation. At this time, as shown in FIG. 4 (2), when the concrete 45 previously placed in the bottom of the sub chamber a in the double sheet pile wall 7 already exists, the nozzle part on the lower end side of the placing pipe 22 27 is inserted into the concrete 45.
Next, the piston rod 36 is extended by the operation of the cylinder 35, and the bottom cover 21 of the placing tube 22 is opened. Then, as shown in FIG. 4 (3), the concrete 44 in the placement pipe 22 flows out from the nozzle portion 27, and the concrete placement surface in the sub chamber a gradually rises. At the same time, the concrete in the sub chamber a flows out into the adjacent sub chamber through the through-hole 17 (FIG. 2) provided in the partition wall 11 and the left and right side plates 10a of the frame body 10, and the concrete is placed in the adjacent sub chamber. Increasing surface also rises gradually. In the present embodiment, the driving device 20 is raised in accordance with the rising of the driving surface, but the main body 26 of the driving tube 22 and the inner wall of the steel sheet pile 6 forming the sub chamber a Therefore, the concrete flowing out to the adjacent sub chamber through the through-hole 17 does not fall underwater in the sub chamber, so that the separation is not caused. To be prevented.
[0017]
In this way, the entire amount of the concrete 44 in the placing pipe 22 is discharged, and then the bottom lid 21 is closed by shortening the piston rod 36 of the cylinder 35 as shown in FIG. The whole is pulled up from the double sheet pile wall 7. At the time of this pulling up, since the bottom lid 21 is closed, the casting tube 22 is filled with water. In the present embodiment, the driving device 20 filled with water is moved to the inside of the guide frame 5a by a crane operation, and the bottom lid 21 is opened there for draining and cleaning the driving tube 22. . Thereafter, the placing device 20 is moved above the sub chamber in the other independent chamber A of the double sheet pile wall 7 to be placed next, and thereafter, the above procedure is repeated to put concrete into the sub chamber. I do.
[0018]
There are 12 independent chambers A in the double sheet pile wall 7 as an example, and in this embodiment, concrete is sequentially placed in each independent chamber A according to the above-described procedure, and this cycle is repeated to double. The concrete is placed on the entire length (total height) of the sheet pile wall 7, thereby completing the water blocking wall 1. Thus, in the present embodiment, the ascending distance of the concrete placing surface in the independent chamber A by one discharge of the concrete 44 in the placing pipe 22 is set to about 1.0 to 1.5 m. The internal pressure generated by one-time concrete driving into the independent chamber A in the double sheet pile wall 7 is not so large, and the deformation or damage of the steel sheet pile 6 and consequently the double sheet pile wall 7 is prevented.
[0019]
In addition, in the said embodiment, although applied to construction of the water stop wall 1 which temporarily cuts off the front water area of the dam dam body 2, this invention can be applied besides construction of such a water stop wall 1. Of course. Moreover, the kind of underwater structure is also arbitrary, and various things other than the said double steel sheet pile 7 can be made into object.
[0020]
【The invention's effect】
As described above in detail, according to the underwater concrete placing method and apparatus according to the present invention, there is no significant difference in height on the driven surface with respect to the plurality of independent chambers in the underwater structure. In addition, the concrete can be placed smoothly, with high quality and with ease of construction so as not to drop underwater, and the construction period is shortened and the construction cost is greatly reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an implementation status of an underwater concrete placing method according to the present invention and a structure of an underwater concrete placing apparatus used for carrying out the method.
FIG. 2 is a cross-sectional view showing the implementation status of the present underwater concrete placement method and the structure of the underwater concrete placement device used for the implementation of the method.
FIG. 3 is a side view showing an upper structure of the underwater concrete placing device.
FIG. 4 is a sectional view showing the underwater concrete placing method in the order of construction.
FIG. 5 is a plan view showing an installation mode of a water blocking wall that temporarily cuts off a front water area of a dam body.
6 is a side view showing an installation mode of the water blocking wall shown in FIG. 5. FIG.
FIG. 7 is a plan view showing a structure of a double sheet pile wall constituting a water blocking wall.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stop wall, 2 Dam dam body 5 Guide frame mount, 5a Guide frame 6 Steel sheet pile (box-type steel sheet pile)
7 Double sheet pile wall, 8 Concrete layer 11 Partition wall 12, 13 Double-ply plate (partition)
17 Through-hole 20 Underwater concrete placing device 21 Bottom cover 22 Placed tube 23 Locking member (locking portion)
24 Support frame 25 Drive means 33 Support frame support (transmission structure)
35 Cylinder, 36 Piston rod 37 Connecting wire A Independent chamber a Sub chamber

Claims (3)

A casting tube having a bottom lid that can be opened and closed;
A support frame having a hook locking part at the upper end and a driving means for opening and closing the bottom lid,
The support frame has a transmission structure in which a lower part connected to the placement pipe opens the opening end of the placement pipe to the outside, and a drive source of the drive means is mounted on the upper part. Underwater concrete placement equipment. Driving means, the cylinder and consists of a connection wire for connecting its piston rod and bottom cover, underwater concreting device according to claim 1, wherein the connecting wire is characterized by being extended through the striking設管. The placing pipe is composed of a main body portion having a cross-sectional shape which is similar to a chamber of an underwater structure on which concrete is to be placed and is slightly smaller than the chamber, and a nozzle portion having a relatively small cross section provided continuously below the main body portion. , underwater concreting device according to claim 1 or 2, characterized in that the bottom lid is provided on the nozzle portion.

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