JP2000096517A - Pier structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pier structure, in which a wasteful cross section can be omitted and the weight of pier structure can be reduced while damage by the repeated external force of the whole pier can be restrained to be small. SOLUTION: This pier structure has a column material 15, in which an upper section has a top member 21 and a lower section is disposed in upright to a foundation member 11, and a plurality of cables 17 being arranged around the column material 15 and connecting the top member 21 and the foundation member 11. The pier structure is constituted so that the column material 15 bears axial compressive force and shear force while a plurality of the cables 17 bear tensile force with the bending deflection of a pier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pier structure.

[0002]

2. Description of the Related Art As prior art related to the present invention, for example, the invention of a pier structure described in Japanese Patent Application Laid-Open No. Hei 6-313303 and the construction of a concrete-filled steel pipe multi-column pier described in Japanese Patent Application Laid-Open No. 7-42114. There is a method invention. Japanese Unexamined Patent Publication No. Hei 6-313303 discloses a structure in which a plurality of pier forming blocks 50 are arranged at intervals in the front-rear width direction or the left-right width direction as shown in FIG. The pier forming unit 51 is formed by being connected by a connecting body having a supporting performance, and a plurality of the pier forming units 51 are integrally stacked upward.

[0003] In Japanese Patent Application Laid-Open No. 7-42114, as shown in Fig. 17, a fine steel pipe 55 in which a horizontal structure and a brace are attached to a short hollow steel pipe, and a long hollow steel pipe column 57 are provided. Using a steel pipe, the steel pipe 55 and the steel pipe column 57 are alternately connected to the upper part of the base steel pipe embedded vertically in the base, and the pier is started up. This is a concrete-filled steel pipe multi-column pier constructed by filling concrete and filling concrete inside the formwork of the bridge seat.

In each of the conventional examples, the cross-sectional area can be made smaller than that of a single-post type pier, so that the weight of the pier can be reduced and the foundation is not relatively burdened. Is obtained.

[0005]

However, in the above-mentioned conventional pier structure, the pier-forming block or the steel pipe column disposed at the center of the pier and the steel pipe columns disposed therearound have the same cross section. There is such a problem. That is, when the pier is bent and deformed by an external force such as seismic force, a larger compressive force and a larger tensile force are applied to the pier forming block or the steel pipe column arranged outside the center, but all of the piers have the same cross section. Since it is formed, if the outer part is designed to withstand the compressive force and the tensile force, the central part is excessively designed and the mechanically useless cross-sectional portion is increased.

In addition, since all the pier-forming blocks or steel pipe columns bear all the forces of axial force, bending and shearing, when the pier-forming blocks or steel pipe columns cause local buckling due to bending deformation, the axial direction is reduced. The compression force cannot be supported. For this reason, when a repeated load such as seismic force is applied, local buckling occurs due to bending in order from the steel pipe column far from the pier center axis, and eventually the axial compression force cannot be supported, and the entire pier becomes Has the potential to lead to destruction.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and can eliminate unnecessary cross-sections, reduce the weight of a pier structure, and reduce damage to the entire pier due to repeated external forces. The purpose is to obtain a pier structure.

[0008]

According to the present invention, there is provided a bridge pier structure having a top member on an upper part, a lower part standing on a base member, and a top member disposed around the pillar member. And a plurality of cables for connecting the base member and the base member, wherein the column member bears an axial compressive force and a shearing force, and the plurality of cables are pulled by bending deformation of the pier. It is designed to bear power.

[0009] Further, the cable is radially arranged downward from an upper end of the pillar.

[0010] Further, a stiffener is disposed around the column member and connects the top member and the base member, and the stiffener bears a shearing force. Is what you do.

Further, the stiffener is formed of a tubular member, and the cable is inserted through the tubular member.

Further, the stiffener and the column are connected by a plate.

[0013] Further, the column member is formed of a steel pipe column, and concrete is filled inside the steel pipe column.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 is a partial perspective view of a bridge having a pier structure according to Embodiment 1 of the present invention, FIG. 2 is a side cross-sectional view of the pier structure shown in FIG. 1, and FIG. 3 is a cross section taken along line AA in FIG. FIG. Hereinafter, FIGS. 1 to 3
Embodiment 1 will be described based on FIG. In the figure, reference numeral 1 denotes a bridge having a pier structure according to the present invention, which is composed of a bridge substructure 5 constructed on the ground 3 and a bridge superstructure 7 constructed on the bridge substructure 5.

The substructure 5 comprises a footing 11 constructed on a foundation pile 9 installed on the ground 3 and a pier 13 constructed on the footing 11. The pier 13 is a steel pipe column 15 installed on the pier center axis.
And a plurality of cables 17 arranged around the steel pipe column 15. The lower end of the steel pipe column 15 is joined to the anchor frame 19 and is embedded in the footing 11. The upper end of the steel pipe column 15 is a haunch 2
1 so as to be able to bear the axial compressive force and the shear force.

The upper and lower ends of the plurality of cables 17 are fixed to the upper surface of the haunch 21 and the lower surface of the footing 11 by a fixing member 23, respectively, and are installed with a tension sufficient to stretch the cables. Therefore, the cable 17 is configured to bear the tensile force.

Next, the operation of the pier structure configured as described above will be described by taking as an example a case where a repeated load such as seismic force is applied. When seismic force is applied from the left side in FIG. 2, the pier 13 bends and deforms rightward around the steel pipe column 15, the cable 17 installed on the left side in FIG. Be on the side. At this time, on the tension side, since the upper end and the lower end of the cable 17 are fixed, a tensile force acts on the cable 17 to resist bending. On the other hand, on the right compression side,
The tension of the cable 17 is loosened or slightly bent. The steel pipe column 1 installed on the center axis of the pier
5 hardly generates bending stress due to bending deformation.

Next, in the case of the seismic force from the right in the figure, the situation is completely opposite to the above. A tensile force acts on the cable 17 disposed on the right side, and the cable 17 resists the bending deformation of the pier 13. . As described above, since the cable 17 is made to resist the bending deformation in the case of receiving the repeated load such as the seismic force by the tensile force of the cable 17, even if the external force is repeatedly applied, the buckling occurs when the member is compressed. Since the tensile strength does not deteriorate, damage to the entire pier can be kept small.

As described above, since the compressive load is borne only by the steel pipe column 15 at the center where the bending stress hardly occurs due to the bending deformation, the compressive load accompanying the bending deformation is hardly applied to the steel pipe column 15. It is possible to design without considering it, it is possible to make it thinner,
Also, the entire foundation can be made smaller. Further, since the cable 17 arranged around the steel pipe column 15 is not subjected to a compressive load but only has a tensile force, there is no deterioration due to buckling, so that damage to a repeated load is reduced.

Embodiment 2 FIG. 4 is an explanatory diagram illustrating Embodiment 2 of the present invention. In the present embodiment,
Instead of the cable 17 of the first embodiment, the lower end is arranged around the central steel column 15 and the upper end is formed of the steel column 15.
The inclined cable 18 is disposed near the upper end of the cable. The inclined cable 18 as a whole has a structure in which the upper ends of the steel pipe columns 15 are arranged radially. By installing the inclined cable 18 in this way, the bridge pier 13 has a large resistance to bending deformation.

Embodiment 3 5 is an explanatory view for explaining Embodiment 3 of the present invention, FIG. 6 is a side sectional view of the pier structure shown in FIG. 5, and FIG. 7 is a sectional view taken along line AA in FIG. 5 to 7, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals, and only the characteristic parts of the present embodiment will be described below.

In the present embodiment, a plurality of steel pipes are erected around a steel pipe column 15, and a cable 17 is connected to the steel pipe 25.
, And the steel pipe column 15 is filled with concrete 27 as shown in FIG. Steel pipe 25
Is fixed to the anchor frame 19 and is embedded in the footing 11. The upper ends of the plurality of steel pipes 25 are inserted into the haunch 21 so as to be vertically movable, and the upper ends of the elastic pipes 2 made of, for example, hard rubber are provided.
9 are installed.

Here, the meaning of installing the elastic body 29 will be described. Originally, for the purpose of the present invention, it is sufficient to provide a certain space between the upper end of the steel pipe 25 and the haunch 21, but the haunch 21 is usually constructed by forming a mold and pouring concrete. Therefore, it is difficult to provide a certain gap between the upper end of the steel pipe 25 and the haunch 21. Therefore, if the elastic body 29 is previously installed at the upper end of the steel pipe 25, it is almost the same as providing a certain gap between the upper end of the steel pipe 25 and the haunch 21 when the haunch 21 is constructed as described above. A similar situation can be achieved in a very simple way.

Next, the operation of the pier structure configured as described above will be described. When the seismic force is received from the left side in FIG. 6, the pier 13 bends and deforms rightward around the steel pipe column 15, and the steel pipe 25 installed on the left side in FIG. Be on the side. At this time, the point that a tensile force acts on the pull-side cable 17 to resist bending deformation is the same as in the first embodiment. Further, since the upper end of the steel pipe 25 is not fixed to the haunch 21, no tensile force acts on the steel pipe 25, and only a shear force acts on the steel pipe 25.

On the other hand, on the right compression side, the steel pipe 25
An elastic body 29 that can expand and contract is provided at the upper end of the steel pipe 25. Since the steel pipe 25 and the haunch 21 are not fixed and can move relative to each other, the elastic body 29 contracts when the haunch 21 moves downward due to bending deformation. Thus, no compressive force acts on the steel pipe 25 and local buckling does not occur. In the case of the seismic force from the right in the figure, the situation is completely opposite to the above, the right side is the tension side, and the left side is the compression side. No shear force only acts.

As described above, according to the present embodiment, the provision of the steel pipe 25 can increase the resistance of the pier in the shear direction. At this time, since only the shearing force acts on the steel pipe 25 and the compressive force does not act, the steel pipe 25 does not locally buckle even when the external force is repeatedly applied. In addition, since the cable 17 is inserted through the steel pipe 25, the cable 17 is protected by the steel pipe 25 and generation of rust and the like is suppressed. Further, even if the cable 17 is broken, the cable 17 does not jump and is safe.

Although not shown, the inclined cable 18 of the second embodiment shown in FIG. 4 is inserted into the steel pipe 25 of the present embodiment (provided to be inclined). Also, the same effects as in the present embodiment can be obtained.

Embodiment 4 FIG. 8 is an explanatory diagram illustrating Embodiment 4 of the present invention. In the present embodiment,
The steel pipe column 15 and each steel pipe 25 of the third embodiment are connected by a connection support member 31. By providing the connection support member 31, the entire buckling of the steel pipe column 15 can be prevented. The fourth embodiment is particularly effective for a tall pier.

Embodiment 5 FIG. 9 is an explanatory diagram illustrating Embodiment 5 of the present invention. In the present embodiment,
An inclined steel pipe 33 is installed around the steel pipe column 15, and the same inclined cable 18 as shown in FIG. 4 is inserted through the inclined steel pipe 33, and the lower end is further installed around the central steel pipe column 15. In addition, a plurality of supporting steel pipes 35 whose upper ends are joined in the middle of the steel pipe column 15 are installed. By arranging the supporting steel pipes 35 in this manner, the overall buckling of the steel pipe columns 15 can be prevented, and the resistance to shearing force can be increased.

Embodiment 6 FIG. FIG. 10 is an explanatory diagram illustrating Embodiment 6 of the present invention. In the present embodiment, each steel pipe 25 and steel pipe column 1 of the third embodiment shown in FIG.
5 are joined by a steel plate 37. With such a structure, in addition to the effect of the third embodiment, the overall buckling of the steel pipe column 15 can be prevented and the resistance to the shearing force can be increased.

Embodiment 7 FIG. 11 is an explanatory diagram illustrating Embodiment 7 of the present invention. In the present embodiment, an inclined steel pipe 33 is installed around the steel pipe column 15 and the same inclined cable 1 as shown in FIG.
8, and each inclined steel pipe 33 and the steel pipe column 15 are joined by a steel plate 39. With such a structure, it is possible to prevent buckling of the steel pipe column 15 as a whole and to increase the resistance to shearing force.

Embodiment 8 FIG. FIG. 12 is an explanatory diagram illustrating Embodiment 8 of the present invention. In the present embodiment, each inclined steel pipe 33, the supporting steel pipe 35, and the steel pipe column 15 of the fifth embodiment shown in FIG. With such a structure, in addition to the effect of the fifth embodiment, the overall buckling of the steel pipe column 15 can be further prevented, and the resistance to the shearing force can be increased.

Embodiment 9 FIG. 13 is an explanatory view for explaining the ninth embodiment of the present invention, and FIG. 14 is an enlarged view of the leg portion of FIG. In the present embodiment, an inclined steel pipe 33 similar to that of the fifth embodiment shown in FIG. 9 is installed between each steel pipe 25 and the steel pipe column 15 of the third embodiment shown in FIG. Each steel pipe 25, each inclined steel pipe 33, and the steel pipe column 15 arranged in the direction are joined by a steel plate 43.

According to the present embodiment, the overall buckling of the steel tube column 15 can be further prevented, and the resistance to shearing force can be further increased. The shape of the steel pipe column 15 and the steel pipe 25 may be all round as shown in FIG. 14, or only the steel pipe column 15 may be square as shown in FIG. Both may be square as shown in FIG.

In each of the above-described embodiments, the example in which the steel pipe column 15 is installed as the column member installed on the center axis of the pier is shown. However, the present invention is not limited to this. It may be a rod or a reinforced concrete column. Note that, from the spirit of the invention, it is necessary to minimize the occurrence of bending stress due to bending deformation in the column material, and for that purpose, a member that can set the second moment of area to be small is preferable.

Further, in the above-described third to ninth embodiments, the example in which the cable 17 or the inclined cable 18 is inserted through the steel pipe 25 or the inclined steel pipe 33 has been described. However, the case where the cable 17 or the inclined cable 18 is not inserted is not excluded, and the insertion is not performed. Even in this case, it is needless to say that the effect of preventing the overall buckling of the column material or increasing the resistance in the shear direction is obtained.

[0037]

Since the present invention is constructed as described above, the following effects can be obtained.

Since the column members are configured to bear the axial compressive force and the shear force, and the plurality of cables are configured to bear the tensile force accompanying the bending deformation, the mechanical roles of the members constituting the pier are divided. It becomes clearer, wasteful cross sections can be omitted, and the weight of the pier structure is greatly reduced.

In addition, since the cables are arranged radially downward from the upper end of the pillar, a large resistance can be exerted against bending deformation.

In addition, a stiffener is provided around the column member to connect the top member and the base member, and the stiffener bears a shear force. Can be increased.

Further, since the stiffening member is formed of a tubular member, and the cable is inserted through the tubular member, deterioration of the cable can be prevented, and the cable can jump even if the cable is broken. Is safe.

Further, since the stiffener and the column member are connected by the plate member, the entire buckling of the column member can be prevented, and a large resistance to bending deformation and shear deformation can be exhibited.

Further, since the column member is made of a steel tube column, and concrete is filled in the inside of the steel tube column, the concrete prevents local buckling of the steel tube column, and the steel tube restrains the concrete to realize high compressive strength. An excellent composite structure can be realized.

[Brief description of the drawings]

FIG. 1 is a partial perspective view of a bridge provided with a pier structure according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of the pier structure shown in FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is an explanatory diagram of Embodiment 2 of the present invention.

FIG. 5 is an explanatory diagram of a third embodiment of the present invention.

FIG. 6 is a side sectional view of the pier structure shown in FIG. 5;

FIG. 7 is a sectional view taken along line AA in FIG. 6;

FIG. 8 is an explanatory diagram of Embodiment 4 of the present invention.

FIG. 9 is an explanatory diagram of Embodiment 5 of the present invention.

FIG. 10 is an explanatory diagram of Embodiment 6 of the present invention.

FIG. 11 is an explanatory diagram of a seventh embodiment of the present invention.

FIG. 12 is an explanatory diagram of Embodiment 8 of the present invention.

FIG. 13 is an explanatory diagram of Embodiment 9 of the present invention.

FIG. 14 is an enlarged view showing a part of FIG. 13 in an enlarged manner.

FIG. 15 is an explanatory diagram of another mode of the ninth embodiment of the present invention.

FIG. 16 is an explanatory diagram of a conventional example.

FIG. 17 is an explanatory diagram of another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bridge 13 Bridge pier 15 Steel pipe column 16 Concrete 17 Cable 18 Inclined cable 19 Anchor frame 21 Haunch 23 Fixing member 25 Steel pipe 33 Inclined steel pipe 37, 39, 41, 43 Steel plate

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuaki Takeda 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 2D059 AA03 GG55

Claims (6)

[Claims] 1. A pillar having a top member at an upper part and a lower part standing upright on a base member, and a plurality of cables arranged around the pillar member and connecting the top member and the base member. A pier structure comprising: the column material bears an axial compressive force and a shear force, and the plurality of cables are configured to bear a tensile force accompanying bending deformation of the pier. Pier structure. 2. The pier structure according to claim 1, wherein the cables are arranged radially downward from an upper end of the pillar. 3. A stiffener arranged around the column member to connect the top member and the base member, and the stiffener bears a shearing force. The pier structure according to claim 1 or 2, wherein 4. The pier structure according to claim 3, wherein said stiffener is formed of a tubular member, and said cable is inserted through said tubular member. 5. The pier structure according to claim 3, wherein the stiffener and the column are connected by a plate. 6. The pier structure according to claim 1, wherein the pillar member is made of a steel pipe column, and concrete is filled in the steel pipe column.