JP4652009B2 - Structure - Google Patents

Description

The present invention, box culverts, tunnels lining, GenShin and immune also piles or caissons other underground structures relates to an underwater structure, component itself based on its own shear deformation in particular forming part of the structure section It relates to structures with earthquake function.

  Improvement of the earthquake resistance of structures is demanded, and the design and construction of structures excellent in earthquake resistance while ensuring safety, durability, economy and workability are desired. Recently, in order to ensure seismic performance against large-scale earthquakes, structures tend to be more rigid, so the cross-sectional area is larger, the amount of reinforcing bars is increased, the details of reinforcement arrangements such as road bridge specifications, etc. As a result, severe conditions are imposed on the design and construction of the structure, resulting in a problem that the structure becomes expensive.

On the other hand, the seismic isolation device is interposed between the ground and the structure, or at the structural change point such as the connection between the substructure and the superstructure, and the seismic motion exceeding a certain value is exempted. Techniques for preventing transmission to structures and members on seismic devices are also well known.
However, since this seismic isolation device is an object interposed between the ground and the structure, or a structural change part of the structure (for example, between the foundation beam and the column), it can be installed on the structure. It is difficult to obtain a sufficient seismic isolation function due to the limited number of components, and therefore the cross-sectional force generated in the structure or its members does not decrease sufficiently, so it is necessary to increase its strength and increase its rigidity. There is a problem that.
In addition, since the number of seismic isolation devices is limited, the load of the individual seismic isolation devices increases due to the increase in load due to the improvement in rigidity, so the size of the seismic isolation devices themselves must be increased, As a result, there is a problem that the cost is increased.

  Therefore, the present invention eliminates the above-mentioned problems while ensuring safety, durability, and workability by changing the members constituting the structure from a rigid structure to a flexible structure, and is also economical and earthquake resistant. The problem is to provide an excellent structure.

To solve the above problems, the present invention is the axial direction in which the components forming a part constituted by a plurality of blocks of continuous, each block successive blocks said consecutive by tendons of the structure The rubber is elastically bonded between the adjacent blocks so as to be relatively movable between the adjacent blocks, and the adjacent blocks are subjected to shear deformation of the constituent members. Are joined so as to be relatively movable so as to be superior to axial displacement and bending deformation, and a plurality of joints between the adjacent blocks are arranged in the ground or in water.
The component is at least one of a column, a beam, a wall, a plate, an arch, and a shell, and the axis of the column, the beam, and the arch is formed in the member axis direction, and the axis of the wall is formed in the vertical direction. The plate and shell axes are formed in these principal axis directions.

Rubber-like elastic material, that the material is shear deformation, allowing the shear deformation to the joint portion between adjacent blocks, the low-friction sliding member is sliding between at least one of the adjacent blocks To cause shear deformation between adjacent blocks. Furthermore, by tensioning the tendons each block in the axial direction, the axial displacement and bending deformation occurs between the blocks can be controlled to below a predetermined allowable value.

  Further, when the opposing surfaces between adjacent blocks are formed in parallel to the predicted shear direction and used as a guide surface for relative movement of the blocks, the shear deformation is facilitated. In many cases, the facing surface is preferably a horizontal surface. Furthermore, it is preferable to form a stopper for restricting the relative movement distance to be within a predetermined value between the adjacent blocks.

  Thus, each block constituting the component member is joined so as to be relatively movable so that the shear deformation of the component member is excellent, and the elastic joint portion of the shear deformation is formed in the component member at a plurality of axial positions. Has been. For this reason, a structure including such a structural member is made flexible, and if this structure is an underground structure, it is seismically isolated by deformation following the shear deformation of the surrounding ground due to the earthquake. It can be a structure. Also, if this structure is a ground structure or an underwater structure, the flexible structure will make the natural period longer with respect to the input of seismic motion and realize higher seismic isolation of the entire structure. can do.

According to the present invention, in the underground structure or the foundation structure, by causing the plurality of elastic joints installed in a parallel direction to the shear deformation of the surrounding ground at the time of the earthquake to follow the shear deformation of the ground. In addition, the cross-sectional force generated in the structure can be greatly reduced, and at the same time, the structure can be reduced in seismicity or isolated. Therefore, it can be designed and constructed as a more rational flexible structure from the conventional rigid structure, and a large cost reduction can be expected while improving safety.
In addition, for ground structures, the installation of multiple elastic joints facilitates seismic isolation of the entire structure, so sufficient seismic performance can be ensured even during large-scale earthquakes. There is an effect.

The structure of the present invention is intended to improve the earthquake resistance of the structure by installing predetermined constituent members in the underground or underwater structure where it is difficult to ensure the earthquake resistance required for an earthquake.
Here, the component member is constituted by two or more blocks that are continuous in the axial direction of the component member, the continuous block is tensioned in the axial direction by a tension material, and the shaft is adjacent between the adjacent blocks. This is a member joined so that the shear deformation is superior to the displacement / bending deformation and the relative movement in the shear direction is possible so that the shear force is transmitted, and this joint is called an elastic joint. In addition, the joint part of several places between adjacent blocks is arrange | positioned in the ground or underwater.

And in the case of constituting a column, a beam and an arch member, or a wall or a plate and a shell, shear deformation is performed at a plurality of locations along the member axial direction, the vertical direction of the wall, or at least two directions perpendicular to each other of the plate and the shell. It is preferable to form the elastic joint portion.
Further, the axial tension in the component member predominates shear deformation at the elastic joint during the action of seismic load, suppresses axial displacement (opening) and bending angle, and at the same time improves the yield strength of the member as necessary. Therefore, it is preferable to load by an unbond method. As the tension method, an out cable method, an out belt method, and an out membrane method can be considered in addition to the method of penetrating the inside of the member.
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the structure of the present invention. A box culvert A constructed in the ground by a top plate 1, a bottom plate 2, a side wall 3 and a middle wall 4 supporting them. It is a schematic perspective view which shows the whole. FIG. 2 is an enlarged view showing a main part of the elastic joint 5 in the side wall 3 which is a constituent member forming a part of the box culvert A. FIG.
This box culvert A (underground structure) is constructed by joining a divided top plate 1, bottom plate 2, side wall 3 and middle wall 4 made of precast concrete. In this case, an elastic joint portion 5 is installed at a joint portion between the top plate 1 and the bottom plate 2 and the side wall 3 and the middle wall 4. Thereby, a flexible structure in the transverse direction of the box culvert A is possible.

  Further, in order to easily follow the shear deformation of the surrounding ground at the time of the earthquake, the side wall 3 and the middle wall 4 are divided into four blocks 31, 41, respectively, and the adjacent blocks 31, 31, 41 , 41, the elastic joint 5 is installed along the longitudinal direction of the box culvert A. Moreover, the tension material 6 is penetrated through the side wall 3 and the middle wall 4 over the top plate 1 to the bottom plate 2, and both ends of the tension material 6 are fixed by an unbonding method or the like (not shown). Further, depending on the required strength, instead of the middle wall 4, middle pillars 4 (not shown) may be employed at a predetermined interval. And the said elastic junction part 5 is installed in this center pillar 4 in the member axial direction at predetermined intervals.

  On the other hand, in the elastic joint portion 5, as shown in FIG. 2 (a), a pair of concave portions 51 and convex portions 52 to be fitted are formed at the center portions of the opposing surfaces of the blocks 31, 31, respectively. A rubber-like elastic material 53 is interposed between the flat portions 32 and 32 of the surface. In this case, a gap 54 is formed between the concave portion 51 and the convex portion 52 to restrict the shear deformation of the elastic material 53 within a predetermined value, and the left and right surfaces sandwiching the gap 54 function as a stopper. . The flat portions 32, 32 of the facing surface are formed in parallel to the shear direction of the surrounding ground and guide the shear displacement of the block. In this embodiment, the flat portions 32 and 32 are horizontal surfaces.

Further, as shown in FIG. 2B, a sheet-like sliding material 55 having a lower friction than the block 31 may be interposed instead of the rubber-like elastic material 53. Further, the shear deformation performance between the blocks can be controlled by changing the friction characteristic of the sliding member 55. As the sliding material 55, a metal plate such as stainless steel is suitable.
FIG. 3 is an explanatory diagram showing the seismic reduction / isolation effect of the underground structure according to the present invention. 3 (a), (b), and (c), respectively, a part (side wall 3) of the box culvert A, the horizontal displacement distribution g according to the depth of the surrounding ground at the time of the earthquake, and the side wall 3 corresponding thereto. Horizontal displacements w, w ′ of 3B and 3C respectively indicate the horizontal displacement of the side wall 3 provided with the elastic joint portion 5 and the side wall having a normal rigid joint.

  As shown in the figure, the horizontal displacement w of the side wall 3 (or the middle wall 4) is a piecewise shear deformation caused by a plurality of elastic joints 5 with respect to the horizontal displacement (shear deformation) g of the surrounding ground at the time of the earthquake. Then, since it follows the ground displacement, it is possible to reduce the relative displacement r between the two. On the other hand, it is clear that the horizontal displacement w ′ of the side wall in the case of the normal rigid joint in which the elastic joint portion 5 is not installed does not follow the shear deformation of the surrounding ground, and the relative displacement r ′ with the surrounding ground is large. It is.

  By installing the elastic joint 5 as described above, the box culvert A can be made flexible in the transverse direction, and the cross-sectional force acting on the side wall 3 and the middle wall 4 can be greatly reduced. In addition, it is possible to improve the seismic energy absorption capacity by the shear deformation of the elastic joint 5 and to obtain a superior seismic reduction and seismic isolation performance than the prior art.

  FIG. 4 shows an arch tunnel lining body B according to the second embodiment of the present invention. The arch tunnel lining body B is constituted by a concrete arch 7 and a bottom slab 8 using an open-cut tunneling method. The arch 7 is characterized in that a plurality of blocks 71 are tensioned in the axial direction of the arch by a tension material 72 and an elastic joint 73 is interposed between the adjacent blocks 71 in the horizontal direction. The elastic joint 73 may be arranged in an optimal direction not only in the horizontal direction but also in accordance with the curvature of the arch 7 and the characteristics of the input ground motion. In this embodiment, an elastic joint having the same configuration as that of the first embodiment is employed.

  As described above, by installing the elastic joint 73 at a predetermined interval in the axial direction of the arch 7, it is possible to appropriately transmit bending and shearing force between the blocks 71 when a large horizontal load is applied during an earthquake. It is possible to expect an effect that buckling does not occur in the arch 7 by controlling the tension force of the tendon at the same time as suppressing to a wide range and transmitting the axial force.

FIG. 5 shows a triple arch tunnel lining body C according to a third embodiment of the present invention. The triple arch tunnel lining body C is constructed by connecting three arch tunnel lining bodies B of the second embodiment in the lateral direction. In this case, the arch 7 and the bottom slab 8 have the same structure as that of the second embodiment, but an inner wall 9 is provided between adjacent arch tunnels. On the inner wall 9, a block 91 is tensioned in the vertical direction by a tension material 92, and an elastic joint portion 93 is installed between adjacent blocks 91. The end portion of the tendon material 92 is fixed by an unbond method or the like. The structures of the elastic joint portions 73 and 93 are the same as those of the elastic joint portion of the first embodiment.
With the above configuration, in addition to the effects of the first and second embodiments, the entire structure can easily follow the horizontal deformation of the surrounding ground during an earthquake, and sufficient seismic performance can be ensured even during a large-scale earthquake. It becomes possible.

FIG. 6 shows a bridge D according to a fourth embodiment of the present invention, and is a conceptual diagram illustrating a case where the bridge D is used as a bridge pier 10 that supports the upper structure 11. In this embodiment, the pier 10 is constructed in a circular cross section by cast-in-place reinforced concrete or precast concrete block 10a by the PC well method.
Here, when the block 10a is assembled, between the adjacent blocks 10a and 10a, a plurality of elastic joint portions 10b having the same structure as the elastic joint portions of the first to third embodiments described above are provided in the horizontal direction. It is installed. In this case, the elastic joint portion 10b is installed not only in the ground but also in the water or on the ground. Further, prestress is introduced by inserting unbonded tension members 10c in the vertical direction at predetermined intervals in the circumferential direction of the pier 10.
By installing the elastic joint portion 10b as described above, it becomes easy to achieve a flexible structure of the entire structural object while considering the earthquake resistance performance of the upper structure 11, so that the earthquake resistance performance of the entire structure is further improved. Can be improved. Moreover, it is advantageous for reducing workability and cost.

FIG. 7 shows an underground structure E according to a fifth embodiment of the present invention, and is a conceptual diagram illustrating a case where the underground structure E is used as a starting and reaching shaft 12 such as a shield tunnel. Here, the shaft 12 is a structural member that forms part of the underground structure E, and is a kind of shell.
The shaft 12 is assembled by press-fitting the segment 12a (block) on the ground, inserting tension members 12b and 12c such as stranded wires of PC steel in the circumferential direction and the vertical direction, and introducing pretres. It is constructed by excavating the soil inside and sinking it to a predetermined depth. In this case, in assembling the segment 12a, elastic joint portions 12d and 12e are installed between the segments 12a adjacent in the circumferential direction and the vertical direction. In addition, what is necessary is just to employ | adopt the same structure as the elastic junction part in 1st-4th Example as these elastic junction parts 12d and 12e. In addition, you may install the said elastic junction part in the opening part 13 vicinity of the said shaft 12. FIG.

By installing the elastic joints 12d and 12e as described above, the shaft 12 can easily follow not only the horizontal deformation of the surrounding ground at the time of the earthquake but also the vertical deformation. And seismic isolation can be achieved more effectively. And since it can construct with the conventional construction method, it is advantageous to safety and economical efficiency.
The present invention is not limited to the structure according to the above-described embodiment, but can be applied to other structure types, for example, a foundation structure such as a pile or a caisson, or a shell-like structure such as a tank. In addition, the arrangement, number, structure, and the like of the elastic joints shown in the above embodiments are merely examples, and various changes can be made based on design requirements and the like.

It is a schematic perspective view which shows the whole precast box culvert concerning 1st Example of this invention. It is an enlarged view which shows the elastic junction part of FIG. It is explanatory drawing which shows the seismic reduction and seismic isolation effect of an underground structure. It is a schematic cross-sectional view which shows the arch tunnel lining body which concerns on 2nd Example of this invention. It is a schematic cross-sectional view which shows the triple arch tunnel lining body which concerns on 3rd Example of this invention. It is a schematic cross-sectional view which shows the pier which concerns on 4th Example of this invention. It is a schematic perspective view which shows the shaft which concerns on 5th Example of this invention.

Explanation of symbols

1 Top plate 2 Bottom plate 3 Side wall 31 Block 4 Middle wall 41 Block 5 Elastic joint 6 Tension material

Claims (4)

The components forming part of the structure constituted by a plurality of blocks of continuous, rubber between the respective consecutive blocks tense in the axial direction in which the blocks are continuous with the tendon, adjacent block The elastic deformation member or the low friction sliding member is interposed so as to be relatively movable between the blocks so that the shear deformation of the constituent members of the adjacent blocks is superior to the axial displacement and bending deformation. To be relatively movable,
The structure characterized by arrange | positioning the junction part of the several places between the said adjacent blocks in the ground or water.   The structure according to claim 1, wherein the component member is at least one of a column, a beam, a wall, a plate, an arch, and a shell. 2. The structure according to claim 1, wherein opposing surfaces of the adjacent blocks are formed in parallel to the predicted shear direction and are used as guide surfaces for relative movement of the blocks . The structure according to claim 1 or 3 , wherein a stopper is formed between the adjacent blocks to restrict the relative movement amount to be within a predetermined value .

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