JPH09177087A - Gravity type concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly fix a rubber member to the bottom of a skeleton by adhering and fixing a fixing nut to the through-hole of the rubber member, and burying the head part of a fastening member inserted and screwed to the through-hole into a concrete skeleton bottom plate. SOLUTION: A fixing nut 6 having a washer 10 concentric to a through-hole 4 is adhered and fixed to a nut hole 5. A fastening member 13 formed of a hexagon bolt 11 and a fastening nut 12 screwed to the middle part of its screw part 11a is inserted to the through-hole 4. After the bolt 11 is supported in standing state with the bolt head part 11b up, the fastening nut 12 is fastened, whereby the bolt 11 is firmly fixed to a rubber member 3. After this work, the rubber member 3 is enclosed by a form, and concrete is pored thereto from above followed by curing and drying, whereby the upper part of the fastening member 13 is buried in the bottom plate 1a of a caisson skeleton 1, and the rubber member 3 can be firmly connected to the caisson skeleton 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravity type concrete structure in which a plate-shaped rubber member is provided on the bottom surface of a concrete skeleton, and more specifically to a fixing structure for fixing the rubber member to the bottom surface of the concrete skeleton. It is a thing.

[0002]

2. Description of the Related Art The caisson method is one of the methods for constructing a breakwater body that divides the water surface side from the land side, such as a breakwater, a land revetment, and a quay wall. This construction method floats the hollow caisson structure built on the ground on the water surface and tows it to the installation position with a ship etc., injects water into the hollow part of the caisson structure to let it sink, then sand in the hollow part, The caisson skeleton is fixed to the seabed by filling it with gravel, concrete, etc. (this type of fixing is called "gravity type"). In this case, simply placing the caisson frame on the installation surface may cause the caisson frame to start moving due to the pressure of waves, etc.Therefore, a slip prevention structure is usually provided between the caisson frame and the seabed to allow the caisson frame to slide. Is being prevented.

This slip prevention structure, as shown in FIG.
After laying a base (20) made of asphalt pavement, etc. on the seabed at the planned installation site, a plate-shaped rubber member (23) called a caisson mat is attached to the bottom plate (21a) on this base (20). The caisson skeleton body (21) is placed, and the base (20) and the rubber material (23) are brought into close contact with each other to prevent the caisson skeleton body (21) from sliding due to the frictional force acting between them.

[0004]

By the way, in such a slip prevention structure, the caisson frame (21) and the caisson mat (23) must be firmly fixed. As a conventional fixing structure, for example, Japanese Utility Model Publication No. 5-22635, Japanese Patent Publication Sho
The structures described in JP-A-56-51246 and JP-B-60-20662 are known.

One of these technologies (Actual Kaihei 5-22635
7), as shown in FIG. 7, a through hole (24) is formed in a rubber mat (23) and a counterbore part (25) is provided in an opening portion of a lower surface of the rubber mat (23). (26a) is accommodated and the dowel (26) is inserted into the through hole (24) from the lower surface side of the mat, and the tip of the dowel is fixed from the upper surface of the mat with the stopper (27), and concrete is poured to give the dowel tip. The part is embedded in the bottom plate (not shown) of the caisson frame.

On the other hand, the remaining two technologies (Japanese Patent Publication No. 56-51246)
8 and No. 60-20662), as shown in FIG. 8, a mounting bracket (30) and a mounting bracket (31) protruding from the mounting plate (30) ( 32) is embedded in the rubber block (23) and integrally molded, and the rib (31) is projected on the upper surface of the rubber block (23), and the bottom bar arrangement (33) of the caisson body (21) is attached to this rib (31). The rubber mat (23) is integrated with the bottom plate (21a) of the caisson frame (21) by inserting concrete after inserting the rubber mat (23).

However, in the construction shown in FIG. 7, it is necessary to turn the heavy rubber mat inside out, insert the dowel into the through hole, and then turn the rubber mat inside out and pour concrete into the construction site. Become.

It is also possible for the operator to hang the rubber mat and, in this state, slip under the mat and insert the dowel, but this would impair the safety of the operator. Further, the parts cost tends to increase because the special part, the gibbel, is used.

Further, in the fixing structure shown in FIG. 8, each reinforcing bar (33) has to be inserted into the holes provided at a plurality of positions of the rib (31) before the concrete is driven, so that the construction procedure is complicated. However, there is a drawback that the construction cost also rises accordingly.

Therefore, in the present invention, the rubber material can be firmly fixed to the bottom surface of the caisson frame, and the construction can be performed by a simple procedure without using any special parts.
An object of the present invention is to provide a fixing structure that can be safely installed without imposing an excessive burden on an operator.

[0011]

In order to achieve the above object,
In the present invention, in the one in which the rubber member is provided on the bottom surface of the concrete skeleton, the through hole is formed in the rubber member, the fixing nut is arranged in the lower opening portion of this through hole, and the fastening member is attached to the through hole from the upper surface side. The head part of the fastening member was embedded in the bottom plate of the concrete skeleton by inserting it and screwing it into the fixing nut.

The fixing nut is preferably attached to the rubber member by an adhesive or by vulcanization adhesion.

The fixing nut may be housed in a nut hole formed in the lower surface of the rubber member.

The fixing nut may be integrated with a square nut or square washer, and the nut hole may have a square hole shape.

The inner corner portion of the nut hole is preferably formed into a curved surface having a radius of 1.5 mm or more.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, a rubber member (3) is attached to the bottom plate (1a) of the caisson frame (1) through a fixing structure (2). The rubber member (3) is a single plate-shaped rubber plate that covers the entire surface of the bottom plate (1a) of the caisson frame (1), and has a plurality of through holes (4) formed in its thickness direction. At the lower opening of each through hole (4), a plurality of nut holes (5) are formed by scooping the lower surface of the rubber member (3).
Is depressed. The depth of the nut hole (5) is set to be larger than the thickness of the fixed nut (6) so that the fixed nut (6) described later does not protrude below the lower surface of the rubber member (3). The nut hole (5) can be formed by providing a convex portion on the mold when molding the rubber member (3) or by cutting the rubber member (3) after molding.

On the lower surface of the rubber member (3), a groove (7) for releasing water is formed. The recessed groove (7) is formed by opening both ends thereof to both end surfaces of the rubber member (3), and is enclosed between the rubber member (3) and the ground when the caisson frame (1) is installed. The caisson body (1) is prevented from slipping by letting out the released water to the outside.

A fixing nut (6) with a washer (10) arranged coaxially with the through hole (4) is adhesively fixed to the nut hole (5). The fixing work of the fixing nut (6) is performed by using an adhesive, or by vulcanizing and adhering the rubber member (3) and the fixing nut (6) at the time of vulcanization molding of the rubber member (3). Can be done.

In the through hole (4), a hexagon bolt (11),
A fastening member (13) consisting of a fastening nut (12) screwed into a substantially middle portion of the screw portion (11a) is inserted. The fastening member (13) includes a fastening nut (12) and a rubber member (3).
Insert a washer (14) between the
Insert the tip into the through hole (4) with b) facing up,
Further, the tip portion is screwed into the fixing nut (6) in the nut hole (5) and is supported in an upright state. After that, when the tightening nut (12) is tightened, the bolt (11) is attached to the rubber member (3).
Firmly fixed to When the fastening member (13) is screwed into the fixing nut (6), since the fixing nut (6) is fixed to the rubber member (3), the fixing nut (6) does not rotate together with the screwing. Both can be easily screwed together.

After performing the above work, the rubber member (3)
Enclose with a formwork and pour concrete from above to cure
When dried, as shown in FIG. 2, the upper part of the fastening member (13) is embedded in the bottom plate (1a) of the caisson body (1), so that the rubber member (3) and the caisson body (1) are firmly fixed. It becomes possible to connect. At this time, since the bolt head (11b) having a larger diameter than the screw portion (11a) is embedded in the bottom plate (1a), the bolt (11) is surely prevented from coming off the bottom plate (1a). It

Thus, according to the present invention, the through hole (4)
The fixing nut (6) is adhesively fixed to the nut hole (5) provided in the lower opening of the, and the fastening member (13) inserted into the through hole (4) from the upper surface side is screwed with the fixing nut (6). Therefore, the assembly work can be performed easily and safely. That is, if the fixing nut (6) is bonded and fixed to the nut hole (5) in advance, it is not necessary to turn over the rubber member (3) many times on site, unlike the conventional structure shown in FIG. Also,
It is not necessary to lift the rubber member (3). Therefore, it is possible to ensure the safety while reducing the burden on the operator.

Further, as shown in the structure of FIG.
Since it does not require troublesome work such as inserting 3) into the hole of the rib (31), it can be installed by a simple procedure,
The construction cost can also be reduced.

The term "fastening member" as used herein means a member that can be screwed to the fixed nut (6), and is limited to the combination of the hexagon bolt (11) and the tightening nut (12) described above. Not a thing. For example, if not necessary, the tightening nut (12) may be omitted and the "fastening member" may be configured only by the hexagon bolt (11), or the "fastening member" may be configured by a screw member other than the hexagon bolt. You may.

Further, the nut hole (5) may be a square hole (rectangular hole) and the fixing nut (6) may be a square nut (square nut) engaging with the fixing nut (6), or the fixing nut (6). The square washer (10) may be fixed by welding to the square washer (10) to engage with the nut hole (5) having a square hole shape. By doing so, the fixing nut (6) is prevented from rotating, so that the fixing nut (6) and the bolt (11) can be prevented from falling off for a long period of time. Also, the bolt (1
If the fixing nut (6) and the fixing nut (6) are engaged with each other even a little, the fixing nut (6) is prevented from falling off, so that the adhesive strength between the fixing nut (6) and the rubber member (3) can be reduced.

3 (a) and 3 (b) show an example of a structure in which the retaining function of the fastening member (13) is further strengthened. Of these, FIG. 3 (a) shows the upper end of the fastening member (13). Is bent downward, and in the figure (b), the upper end of each fastening member (13) is horizontally embedded in the bottom plate (1a).
The fastening members (13) are connected to each other by screwing into 6).

As shown in FIG. 4, the corners (17) in the circumferential direction of the inner part of the nut hole (5) are preferably formed in a curved shape with no corners. The curved surface portion (17) alleviates stress concentration at the corner portion (17) even when a force in a separating direction acts between the caisson frame (1) and the rubber member (3), and the rubber member (3) It is possible to prevent the fastening member (13) from coming off due to the crack of (1). According to the experiment, as shown in FIG. 5, if the curvature radius (R) of the curved surface part (17) is 1.5 mm or more,
It was revealed that a good pulling force (about 350 kg) can be exerted, and that it effectively functions as a retainer.

In the above description, the rubber member (3) is used.
Is a single plate that covers the bottom of the caisson frame,
Even if the rubber member (3) is subdivided into blocks and each of the subdivided rubber members (3) is attached to the bottom surface of the caisson frame (1) with the same fixing structure (2) as in FIG. 1, the same effect can be obtained. Played.

The fixing structure (2) is not limited to the caisson skeleton (1), but can be widely applied to gravity concrete structures such as concrete blocks and L-shaped blocks used for the same purpose.

[0030]

As described above, according to the present invention, the rubber material can be firmly fixed to the bottom surface of the concrete structure, and the sliding of the concrete structure due to the pressure of waves or the like can be reliably prevented. . Further, since it is not necessary to turn over the rubber member many times on site and it is not necessary to lift the rubber member, it is possible to reduce the burden on the operator and sufficiently secure the safety. Furthermore, it does not require the troublesome work of inserting the reinforcing bar into the hole of the rib, and the bolt,
Since it can be easily manufactured using only commercially available members such as nuts and washers, the construction cost can be reduced.

If the fixing nut is attached to the rubber member by an adhesive or by vulcanization adhesion, co-rotation of the fixing nut when screwing the fastening member can be prevented, and workability is improved.

If the fixing nut is housed in the nut hole formed in the lower surface of the rubber member, the lower surface of the rubber member can be made flat, and the stability of the caisson body after installation on the seabed can be enhanced.

If the fixing nut is integrated with the square nut or the square washer and the nut hole is formed into a square hole, the fixing nut is prevented from rotating, so that the fastening member can be easily screwed into the fixing nut. be able to.

If the inner corner portion of the nut hole is formed into a curved surface with a radius of 1.5 mm or more, stress concentration at the inner corner portion can be relieved and the fastening member can be prevented from coming off due to cracking of the rubber member. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a fixing structure of a rubber member in a gravity concrete structure according to the present invention.

FIG. 2 is a cross-sectional view of the fixing structure after placing concrete.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an embodiment of a nut hole.

FIG. 5 is a diagram showing experimental results.

FIG. 6 is a cross-sectional view showing a structure for preventing slippage of a concrete structure.

FIG. 7 is a sectional view of a conventional fixing structure.

FIG. 8 (a) is a front view showing a conventional fixing structure in a half section, and FIG. 8 (b) is a plan view showing a state before placing concrete.

[Explanation of symbols]

 1 Concrete skeleton (caisson skeleton) 1a Bottom plate 2 Fixed structure 3 Rubber member 4 Through hole 5 Nut hole 6 Fixed nut 13 Fastening member

Claims (5)

[Claims] 1. A concrete skeleton provided with a rubber member on a bottom surface thereof, wherein a through hole is formed in the rubber member, a fixing nut is arranged in a lower opening portion of the through hole, and a fastening member is attached to the through hole from an upper surface side. A gravitational concrete structure, characterized in that the head of the fastening member is embedded in the bottom plate of the concrete skeleton by inserting the screw into the fixing nut. 2. The gravity type concrete structure according to claim 1, wherein the fixing nut is attached to the rubber member by an adhesive or by vulcanization adhesion. 3. The gravity-type concrete structure according to claim 1, wherein the fixing nut is housed in a nut hole formed by recessing the lower surface of the rubber member. 4. The gravity type concrete structure according to claim 3, wherein the fixing nut is a square nut or is integrated with a square washer, and the nut hole has a square hole shape. . 5. The gravity-type concrete structure according to claim 3, wherein the inner corner portion of the nut hole is formed into a curved surface having a radius of 1.5 mm or more.