JP4451177B2 - Inter-block joint structure - Google Patents

Description

The present invention relates to an inter-block joint structure for connecting precast blocks such as a sinking box and a culvert box.

When constructing underwater tunnels and underpass tunnels, there is a method of constructing a plurality of precast blocks side by side. Usually, the arranged blocks are joined to ensure unity or water-stopping.
For example, in a submergence method in which a precast box is arranged on the bottom of the water to construct a submarine tunnel, a shear key is provided to transmit a shearing force between the adjacent submerged boxes a and a. FIG. 4 shows a conventional inter-block joint structure. In a conventional structure, the vertical shear key b and the horizontal shear key c are separately arranged.
A steel structure is generally used for the vertical shearing key b. After the sinking boxes a and a are joined together, the water in the box is drained, and the sinking box a facing the end surface of the vertical shearing key b. Weld to the end face. In addition, it is common to use a reinforced concrete structure for the horizontal shearing key c, and by forming a recess and a protrusion on a part of the roadbed concrete that is constructed on the floor slab after draining the box, Transmits horizontal shear force.
Japanese Patent Laying-Open No. 2003-213709 (FIG. 3)

The above-described conventional inter-block joint structure has the following problems.
<1> The joining and construction of the vertical shear key and the horizontal shear key involve a lot of work to be performed at the site after draining the inside of the box, which causes the construction period to be prolonged.
<2> A vertical shear key is installed on a temporary receiving bracket provided in an opposing sinking box, and both are joined. For this reason, high installation accuracy is required, and installation work takes time.

In order to solve the above-described problems, the inter-block joint structure of the present invention is an inter-block joint structure for transmitting a shear force between precast blocks, which is fixed to one block and the other block side. A rod that protrudes on the surface of the rod, an edge cutting material that is arranged on the protruding surface of the rod, a buffer material that is arranged on the outer periphery of the edge cutting material, and a cylindrical tube with a bottom that is arranged on the outer periphery of the buffer material And a filler filled between the bottomed cylindrical tube and the concave portion of the other block, wherein the rod body is formed by a steel tube having a hollow portion filled with a filler. Is. Here, the pre-Symbol edge cutting member formed by unbonded tape, the cushioning material can be formed of an elastic material.

The inter-block joint structure of the present invention can obtain at least one of the following effects by means for solving the above problems.
<1> Joining can be performed by inserting a rod projecting from one block into the recess of the other block formed larger. For this reason, a strict installation precision is not required but a block can be joined rapidly.
<2> The edge of the one block and the rod is cut by the edge cutting material, and there is almost no restriction in the axial direction of the rod and the rotational direction around the axis. For this reason, even if the force of these directions generate | occur | produces by an earthquake etc., the joint structure between blocks is not damaged.
<3> Since the cushioning material is arranged between the one block and the rod, the fulcrum of the rod acts as a shear elastic spring, and it is possible to prevent excessive stress from being generated in the joint structure.

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

<1> Inter-block joint structure The blocks 11 and 12 are precast blocks made of reinforced concrete, steel, a composite of steel plate and concrete, or the like. The blocks 11 and 12 can be used for a submerged box to be submerged in the bottom of the water to construct a submarine tunnel, a culvert box to construct an underpass, or the like. The cross-sectional shape of the blocks 11 and 12 can be arbitrarily selected, such as a rectangle or an ellipse.
The joint structure between blocks is a structure of a joint part that connects between the blocks 11 and 12 facing each other. The joint portion is provided with a rod body 2 for transmitting a shearing force, a cushioning material 3 disposed on the outer periphery of the rod body 2, an edge cutting material 4 disposed between the cushioning material 3 and the rod body 2, and a block 11. The filler 5 to be filled is disposed between the recessed portion 111 and the buffer material 3.

<2> Rod Body The rod body 2 is a member that is disposed across the two blocks 11 and 12 and counters the shearing force. The rod body 2 can be a rod-shaped member such as a steel pipe, a cast iron pipe, or a steel bar. The material, shape, and arrangement number of the rods 2 can be arbitrarily set according to the shearing force acting between the blocks 11 and 12.
For example, the rod 2 can be formed using a cylindrical steel pipe. The hollow portion of the steel pipe can be filled with a filler 21 such as concrete as necessary to improve the yield strength.
The rod 2 is fixed to one block 12. For example, when the block 12 is made of concrete, it is fixed by embedding a part of the rod 2. Moreover, when the joining side end surface of the block 12 is a steel material, the rod body 2 can also be fixed by welding.

<3> Edge Cutting Material The edge cutting material 4 cuts the edges of the buffer material 3 and the rod body 2 that are finally fixed to the block 11 via the filler 5 to release the rod body 2 from axial restraint. It is a member for. By arranging the edge cutting member 4, the movement of the rod body 2 in the axial direction is locally unconstrained.
The edge cutting member 4 can be arranged by, for example, attaching an unbonded tape having a small surface friction coefficient to the surface of the rod 2. It can also be arranged by applying a low friction material. A buffer material 3 to be described later is disposed after the edge cutting material 4 is pasted. The edge cutting member 4 is disposed only in a portion protruding from one block 12.

<4> Buffer Material The buffer material 3 is an elastic member disposed between the rod 3 and the block 11. The buffer material 3 behaves as a shear elastic spring by deforming the buffer material 3 when a strong force is temporarily applied between the blocks due to an earthquake or a wave, and excessive stress is generated in the joint structure. Is to prevent. Moreover, when the buffer material 3 is elastically deformed, the rotation angle around the axis of the rod body 2 can be absorbed, and the generation of a restraining moment can be suppressed. That is, it can be said that it is a very weak rotation spring.
If the cushioning material 3 is arranged too thick, it may cause a relative displacement that causes a step between the blocks 11 and 12, so the thickness of the cushioning material 3 is not limited so as not to affect the structure of other joint portions. Is preferred.
For the buffer material 3, for example, a rubber filler having a hardness of about 40 degrees can be used. For example, a bottomed cylindrical tube 31 having an inner diameter larger than the outer shape of the rod body 2 on which the edge cutting member 4 is disposed is installed as a mold, and a gap between the bottomed cylindrical tube 31 and the edge cutting member 4 is filled with a rubber filler. The buffer material 3 is formed.

<5> Filler Filler 5 is a consolidated material filled between the recess 111 formed in the block 11 and the buffer material 3. For example, grout mortar, cement milk, concrete, adhesive and the like can be used.
The block 11 is previously formed with a recess 111 for accommodating the protruding portion of the rod 2. If the recessed part 111 is formed larger than the protrusion part of the rod body 2, even when the installation precision of a block is low or the construction error has arisen, the two blocks 11 and 12 can be joined easily.

  Hereinafter, the Example at the time of using the submerged box sunk in the water bottom as the blocks 11 and 12 is described.

<1> Manufacture of rod body The edge cutting material 4 and the buffer material 3 are attached to the rod body 2 at a factory. A steel pipe is used for the rod 2, and concrete is filled into the steel pipe as a filling material 21.
An unbonded tape is attached to the protruding portion of the rod body 2 as the edge cutting material 4. And the part which stuck the edge cutting material 4 of the rod 2 to the position spaced apart from any inner surface of the cylindrical tube 31 with a bottom is inserted, and is temporarily placed. If the rubber-based filler is filled into the bottomed cylindrical tube 31 in this state, the cushioning material 3 is disposed around the rod body 2.
Since the above-described processing of the rod body 2 can be performed at a factory, it can be performed accurately and efficiently.

<2> Production of blocks The blocks 11 and 12 are made of reinforced concrete in a production yard on land. For example, at the four corners of the end surface of the block 12 in the joining direction, a portion of the rod body 2 where the cushioning material 3 is not disposed is embedded. As an attachment method, for example, a mold frame for forming the end face of the block 12 is fixed with the side on which the cushioning material 3 of the rod 2 is fixed, the mold frame is set, and concrete is placed inside the mold frame. As a result, the rod 2 and the block 12 are integrated. In addition, a recess 111 is formed in the block 11 on the side that receives the rod 2 at the time of joining at a position where the rod 2 is inserted.

Moreover, in order to improve the water-stopping property of the junction part between blocks, the primary water-stopping material 61 and the secondary water-stopping material 62 are arrange | positioned in the end surface of the blocks 11 and 12 (refer FIG. 2). The primary water-stop material 61 is a linear water-proof seal disposed on, for example, an end surface where the blocks contact each other, and is attached to the end surface of the block 12 in an annular shape. As the primary waterproof material 61, a known waterproof material such as a rubber seal or a gasket can be used. When the block 12 is pressed against the existing block 11, the primary water blocking material 61 is deformed by its own weight, inertial force, pulling force, or the like, and exhibits water blocking properties. The secondary water stop material 62 is a water stop material that is attached from the inside after, for example, temporary joining is completed and the inside of the block 1 is drained. For example, a waterproof rubber with a Ω cross section can be used. The secondary waterproof material 62 is attached so as to straddle between the blocks 11 and 12.
It is preferable to form, for example, a protruding guide portion 7 and a recessed portion for receiving the guide portion 7 at the end portions of the blocks 11 and 12 in the penetration direction. For example, a part of one end face of the block 12 is protruded and constructed, and a cushioning material such as a rubber sheet is attached to the surface to form a rectangular shear key type guide portion 7 (see FIG. 2).

<3> Joining of Boxes A block 12 to which the rod body 2 is fixed is sunk next to an existing block 11 that has been sunk in advance at the bottom of the water. Then, the rod body 2 wrapped in the buffer material 3 is inserted into the recess 111 of the block 11. Here, by forming the concave portion 111 with a margin according to the installation error, the blocks 11 and 12 can be joined to each other regardless of the installation accuracy. Moreover, the guide part 7 provided in the end surface of the block 12 is also fitted and joined.
When the block 12 is pulled by a pulling jack or the like and collides with the block 11, the primary water blocking material 61 is deformed to complete the primary water blocking. And after draining the water in the blocks 11 and 12 and being in an air state, the secondary water stop material 62 is attached.
Then, grout mortar is injected as the filler 5 into the recess 111, and the gap between the recess 111 and the buffer material 3 (or the bottomed cylindrical tube 31) is filled with the filler 5. FIG. 3 shows a filling method of the filler 5. When the filler 5 is injected from the injection pipe 51 into the recess 111 and the filler 5 is discharged from the discharge pipe 52 for bleeding air, it is confirmed that the gap of the recess 111 is filled with the filler 5. it can.

Explanatory drawing of the Example of the joint structure between blocks of this invention. The perspective view of the Example of the joining state of a block. Sectional drawing of the Example at the time of construction | assembly of the joint structure between blocks. Explanatory drawing of the Example of the conventional block joint structure.

Explanation of symbols

11 ··· Block 12 ··· Block 111 · Recess 2 · · · Rod 21 · · Filling material 3 · · · Buffer material 4 · · Edge cutting material 5 · · · Filler

Claims (2)

An inter-block joint structure for transmitting a shear force between precast blocks,
A rod that is fixed to one block and is arranged to protrude to the other block;
An edge cutting material disposed on the protruding surface of the rod,
Cushioning material disposed on the outer periphery of the edge cutting material;
A bottomed cylindrical tube disposed on the outer periphery of the cushioning material;
A filler filled between the bottomed cylindrical tube and the recess of the other block;
The rod is formed by a steel pipe having a hollow portion filled with a filler.
Inter-block joint structure. In the inter-block joint structure according to claim 1,
The previous Symbol edge cutting material is formed by the unbonded tape,
An interblock joint structure, wherein the cushioning material is formed of an elastic material .

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