JP2004204579A - Construction method for hybrid structural box body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method for a hybrid structural box body made of steel sheets and concrete by improving the fluidity of concrete at the time when concrete is placed. <P>SOLUTION: In this construction method, when a box body 10 having a hybrid structure is constructed, a steel plate structural case body 1A composed of a floor plate 1a, a bottom plate 1b, and side plates 1c are slanted together with a form 9 for placing concrete to the bottom plate 1b and the side plate 1c arranged so as to surround the case body 1A with a specified distance by a specified angle, concrete is placed in the external face of the bottom plate 1b and the side plate 1c of the box body and the box body 1A is returned to the horizontal state together with the form 9 and then, concrete is placed in the outside face of the uncast part of the side plate 1c and the outside face of the floor plate. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of building a box having a composite structure of a steel plate and concrete (hereinafter referred to as a “hybrid structure”), and more particularly to a method of building a box having a hybrid structure suitable for, for example, a floating pier or a floating breakwater.
[0002]
[Prior art]
Generally, a floating body 10 having a structure as shown in FIG. 2 is used for a floating pier connected to a quay or the like. The floating body 10 is provided on a box 1A formed of the steel sheet 1, a longitudinal rib 4 for reinforcement attached inside the steel sheet 1 (the box 1A), and an outer surface of the steel sheet 1 (the box 1A). The hybrid structure is composed of the stud dowel 5 and the reinforcing bar 3 and the concrete part 2 cast around the outer periphery of the steel plate 1 so as to embed the stud dowel 5 and the reinforcing bar 3. Reference numeral 6 denotes a fender attached to the outer wall of the floating body 10. Such a hybrid structural body made of steel plate and concrete is strong in tension and compression and lightweight. In addition, since the steel sheet is not exposed and is covered with concrete, it is resistant to corrosion by seawater and the like.
[0003]
Conventionally, the floating body 10 having the above structure is constructed according to the procedure shown in FIGS. 3A to 3F as a construction method requiring no joint processing of concrete and having a short working time. That is, a box 1A comprising a floor plate 1a, a bottom plate 1b, and both side plates 1c is formed from the steel plate 1, and the inside of the steel plate 1 (the floor plate 1a, the bottom plate 1b, and both side plates 1c) forming the box 1A is formed with vertical ribs 4 and the like. And a plurality of stud dowels 5 are grown on the outer periphery, and a plurality of concrete support bases 11 are welded to the outer surface of the bottom plate 1b (FIG. 3 (a)).
[0004]
Next, after being temporarily placed on the gantry 7, reinforcing bars 3a are arranged around the outer periphery of the bottom plate 1b and the lower periphery of both side walls 1c, and are welded to the tip of each stud dowel 5 [FIG. 3 (b)]. Next, a formwork 9a for placing concrete for a bottom plate is previously laid on a base 15 whose surface is solidified flat with soil cement or the like, and the box 1A is transferred onto the formwork 9a [FIG. 3 (c)].
[0005]
Next, a reinforcing bar 3b following the reinforcing bar 3a is arranged around the outer periphery of the upper portion of the both side walls 1c and the outer periphery of the floor plate 1a, and the reinforcing bar 3b is welded to the tip of each stud dowel 5 (FIG. 3D).
Next, a formwork 9b for placing concrete on both sides 1c and the floorboard 1a, the lower end of which is connected to the formwork 9a, is assembled [FIG. 3 (e)].
[0006]
Next, high-fluidity concrete 2a is cast between the form 9a and the bottom plate 1b, and then normal concrete 2b is cast between the form 9b and both side walls 1c and on the upper surface of the floor plate 1a. By casting the high-fluidity concrete 2a, the bottom plate portion of the hybrid structure is formed, and by casting the ordinary concrete 2b, the floor plate portion and both side walls of the hybrid structure are formed.
[0007]
In this manner, a concrete portion 2 having a predetermined thickness can be formed on the entire periphery of the box 1A by casting concrete once (see FIG. 3 (f)) (for example, see Patent Document 1).
[0008]
[Patent Document 1]
JP-A-9-254868 (paragraphs 0008 to 0015, FIGS. 1 and 3)
[0009]
[Problems to be solved by the invention]
In the conventional method, in the case of a large box, the fluidity at the time of casting concrete on the bottom plate portion is poor, and the size of the hybrid structure box that can be built is limited. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of constructing a hybrid structural box with improved fluidity at the time of placing concrete.
[0010]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
The invention according to claim 1 is a method for constructing a hybrid structural box, comprising: a steel plate box comprising a floor plate, a bottom plate and a side plate; and the bottom plate and the side plate arranged so as to surround the box at a predetermined interval. There is a concrete casting formwork, and after the box is inclined together with the formwork by a predetermined angle, concrete is poured on the outer surface of the bottom plate and the side plate, and then the box is After returning to the horizontal state together with the formwork, concrete is poured into the unplaced portion of the side plate and the outer surface of the floor plate.
[0011]
With this configuration, the concrete is cast on the outer surface of the bottom plate by casting the concrete by inclining the box together with the form by a predetermined angle, so that the concrete on the form corresponding to the bottom plate is subjected to its own weight. A horizontal component force is generated, the fluidity in the horizontal direction is improved, and the concrete easily spreads on the outer surface of the bottom plate.
[0012]
According to a second aspect of the present invention, in building a hybrid structural box, after forming a steel plate box with a floor plate, a bottom plate and a side plate, a plurality of stud dowels are implanted on the outer surface of the box. After arranging a plurality of reinforcing bars on the outer surface of the box, or implanting a plurality of stud dowels on one side of the steel plate, the stud dowels are located on the outside of the steel plate as a floor plate, a bottom plate and a side plate. After forming a steel plate box, a plurality of reinforcing bars are arranged on the outer surface of the box, and then, on a form for concrete placing on the outer surface of the bottom plate, at a predetermined interval, the box is And then assembling a formwork for placing concrete on the side plate, and then, after inclining the box with the formwork by a predetermined angle, placing concrete on the outer surfaces of the bottom plate and the side plate. Then, the box is After returning with the frame in the horizontal state, characterized in that the concrete on the outer surface of the non-striking portion and the floor plate of the side plate so as to pouring.
[0013]
With this configuration, construction can be done efficiently, so that the work time can be shortened.Furthermore, the concrete can be cast on the outer surface of the bottom plate by casting the concrete by tilting the box by a predetermined angle. The horizontal component force due to its own weight is generated in the concrete on the forming form, and the fluidity in the horizontal direction is improved, and the concrete easily spreads on the outer surface of the bottom plate.
[0014]
According to a third aspect of the present invention, in the method for constructing a hybrid structural box according to the first or second aspect, the box has a longitudinal direction and a lateral direction, and the box is formed by the formwork. When tilted by a predetermined angle, the short direction is tilted.
[0015]
With this configuration, concrete can be easily spread on the outer surface of the bottom plate in a short time as compared with the case where the longitudinal direction is inclined.
[0016]
According to a fourth aspect of the present invention, in the method for constructing a hybrid structural box according to any one of the first to third aspects, the projecting portion is provided on a bottom surface of the box. Further, the formwork for placing concrete on the bottom plate is provided with a fitting portion that can be fitted to the projecting portion, and the box is placed on the formwork for placing concrete on the bottom plate. It is characterized in that, when it is installed in the device, it is installed so that the protruding portion coincides with the fitting portion.
[0017]
With this configuration, when the box is tilted by a predetermined angle together with the mold, the projecting portion is fitted with the fitting portion, so that the box is unlikely to be shifted laterally with respect to the mold.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
A method for building a hybrid structural body as one embodiment of the present invention will be described with reference to the drawings. The hybrid structural body in this embodiment exemplifies the method of constructing the floating body for a floating pier as shown in FIG. 2 described in the prior art. In FIG. 2, for convenience of explanation, the front and rear sides of the drawing are hollow, but side plates are provided on both the front and the rear sides of the drawing, so that a closed structure is provided. The outer surface of the side plate is provided with a stud dowel, a reinforcing bar, or concrete, like the other side plates. However, if necessary, there is an opening provided with a flange, and a lid is fixed to the flange with bolts or the like, and the airtightness of the floating body is maintained.
[0019]
During the process of the method of constructing the floating body, the process is partially the same as that described with reference to FIGS. 3A to 3E as the related art, but the description will be repeated again. Subsequent steps will be described with reference to FIGS.
[0020]
<Process before tilting>
It is built according to the procedure shown in FIGS. That is, the steel plate 1 is formed into a box 1A composed of a floor plate 1a corresponding to the upper surface, a bottom plate 1b corresponding to the lower surface, and a side plate 1c. While reinforcing with the ribs 4 and the like, a large number of stud dowels 5 are melted on the outer periphery, and a plurality of concrete support bases 11 are welded to the outer surface of the bottom plate 1b [FIG. 3 (a)].
[0021]
Although only the left and right side plates 1c appear in the figure, the side plates 1c also have side plates on both the front side and the opposite side in the figure, and the box has a structure that can be hermetically sealed as a whole. Also, a disk with a hole in the center is provided at a plurality of locations on the outer surface of the floorboard in a state of standing upright. The movement and posture of the box can be changed by pulling the hole with a rope or hook.
[0022]
Next, after being temporarily placed on the gantry 7, the reinforcing bar 3a is arranged around the outer periphery of the bottom plate 1b and the lower periphery of the side plate 1c, and is welded to the tip of each stud dowel 5 [FIG. 3 (b)].
Next, a formwork 9a for placing concrete for the bottom plate is previously laid on a base 15 whose surface is solidified flat with soil cement or the like, and the box 1A is transferred onto the formwork 9a.
[0023]
The base 15 is a movable base, and functions as a movable base described later. [FIG. 3 (c)]. Since the plurality of concrete support bases 11 are provided on the outer surface of the bottom plate 1b, a predetermined interval can be maintained between the outer surface of the bottom plate 1b and the formwork 9a. The predetermined interval is an interval corresponding to the thickness required for the concrete portion 2.
[0024]
Next, reinforcing bars 3b following the reinforcing bars 3a are arranged around the upper periphery of the side plate 1c and the outer periphery of the floor plate 1a, and the reinforcing bars 3b are welded to the tips of the stud dowels 5 (FIG. 3D). The reinforcement to the upper outer periphery of the side plate 1c and the outer periphery of the floor plate 1a is performed in the earlier step of FIG. 3B, that is, when the reinforcing bar 3a is arranged on the outer periphery of the bottom plate 1b and the lower periphery of the side plate 1c. They may be performed together.
[0025]
Next, the formwork 9b for placing concrete for the side plate 1c and the floorboard 1a is opposed to the outer surface of the side plate 1c at a predetermined interval, and the lower end thereof is connected to the formwork 9a for placing concrete for the bottom plate [FIG. 3 (e)].
[0026]
The concrete casting form 9b for the floor plate is formed by extending the concrete casting form 9b for the side plate 1c to a position higher than the height of the reinforcing bar 3b of the floor plate 1a. As a result, concrete having a predetermined thickness can be cast on the outer surface of the floor panel 1a. The upper part of the floorboard is open so that a person can stand and work, and the concrete dropped on an appropriate place on the floorboard can be spread over the entire floorboard 1a.
[0027]
The summary up to this point is as follows. A steel plate box 1A composed of a floor plate 1a, a bottom plate 1b, and a side plate 1c is formed, a plurality of stud dowels 5 and reinforcing bars 3 are attached to the outer peripheral surface thereof, and the box is placed on a pre-installed bottom plate form 9a. The body 1A is placed. Here, the box 1A is placed on the bottom plate form 9a at a predetermined interval corresponding to the height of the concrete support base 11. A formwork 9b for the bottom plate 1b and the side plate 1c is assembled facing the bottom plate 1b and the side plate 1c of the box 1A. Further, the mold 9b for the floor panel 1a is formed by extending the mold 9b for the side panel 1c above the surface facing the side panel 1c. The box 1A and the mold 9 in this state are placed on a horizontal base 15, a movable base 15 described later.
[0028]
<Inclination process>
In this state, as shown in FIG. 1A, the box 1A together with the mold 9 is inclined by a predetermined angle θ. As a means for inclining, the bottom frame 9a is supported by the movable base 15, and one end of the movable base 15 is set as the rotation center 17 and the other end is lifted by the jack 16.
[0029]
After tilting in this manner, concrete is poured in from the side plate form 9b (the left side in the figure) on the side that is at a higher position, that is, from the side of the arrow B in the figure, and the casting is performed [FIG. 1 (a)]. . Since concrete is introduced through a large-diameter hose, the opening of the hose is moved to the introduction point.
[0030]
After the concrete poured from the side of arrow B reaches the bottom plate form 9a below, the bottom plate form 9a is inclined downward, so that a horizontal component force occurs due to the weight of the concrete. As a result, the fluidity in the horizontal direction is improved, and the concrete spreads on the outer surface of the bottom plate. In addition, since concrete is poured from the side plate form frame 9b (left side in the figure) at the higher position, that is, the side of the arrow B in the figure, the height difference from the charging position to the inclined lower part of the bottom plate form 9a. The force of flowing the concrete is increased due to the head difference, and the concrete is easily spread. Further, due to the head difference, the concrete can easily reach the upper side of the side plate form frame 9b (the right side in the figure) on the lower side.
[0031]
By this casting, the concrete portion 2 on the side of one side plate form 9b (right side in the figure) is almost completed, but a part of the upper side of the other side plate form 9b (left side in the figure) and the floor plate 1a. An unplaced portion is formed on the side [FIG. 1 (b)].
[0032]
This box 1A has a substantially rectangular parallelepiped shape, and has a longitudinal direction and a lateral direction. The mold 9 and the movable base 15 correspond to this shape, and have a shape having a longitudinal direction and a transverse direction. The shape of the movable base 15 is also a thin and substantially rectangular parallelepiped. The other end lifted by the jack 16 and the one end serving as the rotation center 17 are located on the long sides of the movable base 15, and the short side of the movable base 15 is inclined.
[0033]
In this manner, by inclining the lateral direction, the distance over which the concrete flows on the bottom plate form 9a is shorter than inclining the longitudinal direction, so that the concrete can be spread quickly. In addition, the box 1A is not limited to a substantially rectangular parallelepiped shape, and may have a protruding portion in a part thereof. The same applies to the case of
[0034]
The inclination angle θ is appropriately set according to the size of the box 1A, the properties of the cast concrete, and the like. At this time, the work efficiency can be improved by automating the angle adjustment of the jack 16. The jack is preferably a hydraulic jack.
[0035]
When the inclination angle θ is increased, the box 1A may be shifted laterally. For this reason, a concave portion (corresponding to a “fitting portion” in the claims, not shown) in which the lower end of the support base 11 (corresponding to a “projecting portion” in the claims) can be fitted to the bottom plate form frame 9a. ) Is provided, and the box 1A is placed on the bottom plate form 9a such that the lower end of the support base 11 is fitted into the recess.
[0036]
Thus, even if the inclination angle θ of the movable base 15 is slightly increased, the projecting portion and the fitting portion are fitted to each other, so that it is possible to prevent the case 1A from laterally displacing the mold frame 9. In this case, the support base for maintaining the predetermined interval is also used as the protruding part, but may be separate ones. In addition, the fitting portion of the bottom frame 9a is not concave, but is convex, and the tip of the projecting portion is concave so that it can be fitted. Various forms can be applied as long as they can be fitted.
[0037]
<Process to return to horizontal>
Next, by lowering the jack 16 to level the movable table 15, the box 1A and the formwork 9 are also returned to the horizontal state. After that, concrete is cast on the non-placed portion on the side plate form frame 9b side and the floor plate 1a side to form the respective concrete portions 2 (FIG. 1 (c)).
[0038]
Thus, the concrete portion 2 having a predetermined thickness is formed on the entire circumference of the box 1A to complete the floating body 10 having a hybrid structure of steel and concrete [FIG. 1 (d)].
[0039]
In the above example, the high flowable concrete is charged from the side plate form 9b (the left side in the figure) on the side at the high position, that is, from the side of the arrow B in the figure, and the side plate form 9b on the opposite side is placed. It is poured by flowing to the upper side (right side in the figure). The present invention is not limited to this, and high-fluidity concrete may be used only for forming the concrete portion 2 of the bottom plate 1b, and ordinary concrete may be used for other portions.
[0040]
In this case, high fluidity concrete is charged from the side plate form 9b (the left side in the figure) on the side at the higher position, that is, from the side of the arrow B in the figure, and the space between the bottom plate 1b and the bottom form 9a is formed. After flowing and filling, the inclination of the box 1A and the formwork 9 is returned to be horizontal, and concrete is usually introduced from the side of each side plate formwork 9b to form the concrete portion 2 of each side plate 1c. do it.
[0041]
The specific gravity of concrete is about 2.3, which is larger than water, so that when the concrete is in a fluid state, buoyancy larger than water can be generated. For this reason, water is put into the box so that the box does not come up.
[0042]
When a concrete support 11 is used as a means for keeping a predetermined interval between the concrete casting form 9a on the bottom plate 1b and the box 1A, the support and the concrete part 2 are completed after completion. Although it is preferable because it is integrated, other means may be used as long as it can support the box 1A at a predetermined interval. For example, a support base other than concrete may be used, or the box 1A may be suspended from above and supported.
[0043]
In addition, although this hybrid structure box was described as a floating body used on the sea such as a floating pier, the present invention is not limited to such a floating body, and any other hybrid structure box that can be constructed by such a method is used. May be used.
[0044]
【The invention's effect】
The present invention described above has the following effects.
According to the first aspect of the present invention, when constructing a hybrid structural box, a steel plate box including a floor plate, a bottom plate and a side plate, and the bottom plate arranged so as to surround the box at a predetermined interval and There is a formwork for placing concrete on the side plate, and after tilting the box together with the formwork by a predetermined angle, concrete is placed on the outer surface of the bottom plate and the side plate, and then the box is formed. After returning the body to a horizontal state together with the formwork, concrete was cast on the outer surface of the unplaced portion of the side plate and the floor plate, so that the box was inclined at a predetermined angle together with the formwork. By placing concrete, the concrete on the formwork corresponding to the bottom plate generates a horizontal component force due to its own weight, which improves the fluidity and makes it easy for the concrete to spread over the outer surface of the bottom plate. Can. Therefore, it is possible to construct a hybrid box having a size that was difficult to construct conventionally.
[0045]
According to the second aspect of the present invention, when constructing the hybrid structural box, a steel plate box is formed by the floor plate, the bottom plate and the side plate, and then a plurality of stud dowels are implanted on the outer surface of the box. Then, after arranging a plurality of reinforcing bars on the outer surface of the box, or implanting a plurality of stud dowels on one side of the steel plate, the stud dowels are positioned on the outside as the floor plate, bottom plate and side plate. After forming a steel plate box, a plurality of reinforcing bars are arranged on the outer surface of the box, and then placed on a form for concrete casting on the outer surface of the bottom plate at a predetermined interval. After installing the body, assembling a formwork for placing concrete on the side plate, then, after inclining the box with the formwork by a predetermined angle, placing concrete on the outer surfaces of the bottom plate and the side plate. And then replace the box After returning to the horizontal state together with the formwork, concrete is cast on the unplaced portion of the side plate and the outer surface of the floor plate, so that it is possible to build efficiently, shorten the working time, and furthermore, The concrete on the formwork corresponding to the bottom plate has a horizontal component force due to its own weight, and the fluidity is improved. Concrete can be spread. Therefore, it is possible to construct a hybrid box having a size that was difficult to construct conventionally.
[0046]
According to the invention of claim 3, in the method of constructing a floating body according to claim 1 or 2, the box has a longitudinal direction and a lateral direction, and the box and the formwork are combined. Since the short direction is inclined when inclining by a predetermined angle, this configuration makes it possible to spread concrete over the outer surface of the bottom plate in a shorter time than in the case where the long direction is inclined.
[0047]
According to a fourth aspect of the present invention, in the method for constructing a hybrid structural box according to any one of the first to third aspects, a protrusion is provided on a bottom surface of the box, and concrete is cast on the bottom plate. The formwork is provided with a fitting portion which can be fitted to the projecting portion. When the box is placed on a concrete casting formwork on the bottom plate, the projecting portion is fitted. Since it is installed so as to coincide with the mating portion, when the box is tilted by a predetermined angle together with the mold, the box is less likely to be laterally displaced with respect to the mold by fitting the projecting portion and the fitting portion. .
[Brief description of the drawings]
FIG. 1 is a schematic view showing a procedure of a method of constructing a floating body according to an embodiment of the present invention. FIG. 2 is a perspective view of a conventional floating body and a floating body according to an embodiment of the present invention. And a schematic diagram showing a procedure of a method of building a floating body according to an embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 ... Steel plate 1A ... Box 1a ... Floor plate 1b ... Bottom plate 1c ... Side plate 2 ... Concrete (concrete part)
2a: Highly fluid concrete 2b: Normal concrete 3: Reinforcing bar 3a: Reinforcing bar 3b: Reinforcing bar 4: Vertical rib 5: Stud dowel 6 ... Fender 7 ... Stand 9: Concrete casting form 9a ... Concrete casting form 9b for bottom plate) Concrete casting form 10 for floor and side plate (for floor plate and side plate) Floating body 11 Concrete support base 15 Base (movable table)
16 Jack 19 Rotation center

Claims (4)

When building a hybrid structural box,
A box made of a steel plate including a floor plate, a bottom plate, and a side plate; and a formwork for placing concrete on the bottom plate and the side plate arranged so as to surround the box at a predetermined interval. After tilting a predetermined angle together with the formwork, concrete is poured on the outer surface of the bottom plate and the side plate,
Then, after the box is returned to a horizontal state together with the formwork, concrete is poured into the non-placed portion of the side plate and the outer surface of the floor plate. . When building a hybrid structural box,
After forming a steel plate box with the floor plate, bottom plate and side plate, implanting multiple stud dowels on the outer surface of the box, arranging multiple reinforcing bars on the outer surface of the box,
Alternatively, after implanting a plurality of stud dowels on one side of the steel sheet, forming a steel sheet box on which the stud dowels are located on the outer side of the steel sheet as a floor plate, a bottom plate, and a side plate, and then forming an outer surface of the box. Arrange multiple rebars in
Then, on a formwork for placing concrete on the outer surface of the bottom plate, at a predetermined interval, the box is installed,
Next, assembling a formwork for placing concrete on the side plate,
Next, after inclining the box with the formwork by a predetermined angle, concrete is poured on the outer surfaces of the bottom plate and the side plates,
Then, after the box is returned to a horizontal state together with the formwork, concrete is poured into the non-placed portion of the side plate and the outer surface of the floor plate. . In the method of building a hybrid structure box according to claim 1 or 2, when the box has a longitudinal direction and a short direction, and when tilting the box by a predetermined angle together with the formwork, A method for constructing a hybrid structural box, characterized by inclining the transverse direction. The method for constructing a hybrid structural body according to any one of claims 1 to 3, wherein a projecting portion is provided on a bottom surface of the box, and a formwork for placing concrete on the bottom plate is provided on the projecting portion. A fitting portion that can be fitted is provided, and when the box is placed on a formwork for placing concrete on the bottom plate, the projecting portion is installed so as to match the fitting portion. A method for building a hybrid structural box characterized by the following.

Images