JP5069713B2 - Basic structure of buildings over railway tracks - Google Patents

Description

  The present invention relates to a foundation structure of an over-track building in which a building is built in an upper part of a platform.

  Conventionally, as a foundation structure of a building, a plurality of piles supporting pillars of the building are connected by a foundation beam. This has the effect of reducing the bending moment generated in the pile head during an earthquake due to the restraint of the foundation beam. In order to improve the performance of the pile, a method of increasing the rigidity of the pile head in which the pile diameter is increased or the bending moment acts greatly is employed (for example, see Patent Document 1).

  Patent Document 1 is a configuration in which four blades attached on the outer peripheral surface of a pile body and extending downward in the axial direction from the upper end of the pile body are arranged in a cross-sectional shape in a cross shape, , Strengthening the pile, ensuring the horizontal resistance of the pile, and increasing the ground reaction force.

By the way, as a building, there is an over-the-track building constructed in the upper part of the platform. In this sky building, there are many structural forms without foundation beams for construction reasons.
FIG. 6 is a view showing the foundation of such a building 10 above the railway track. That is, the support pillar 10a of the building 10 is joined on the pile 11, and a plurality of support pillars 12a, 12a,... Supporting the platform 12 are supported with respect to the ground G. That is, in this building 10 above the track, the plurality of piles 11, 11,... Are not connected to each other, and the support pillar 10 a of the single building 10 is supported by the single pile 11.

JP 2006-193958 A

  However, in the foundation structure in the conventional building above the railway, each pile is independent, so there is no constraint of the pile head by the foundation beam, and the foundation is supported by connecting multiple piles by the foundation beam as described above. Compared with the structure, the effective input motion of the pile is large, and the bending moment at the joint portion between the column and the pile is increased. Furthermore, the dissipation attenuation is reduced because the contact area with the ground is small. For this reason, the pile diameter has been increased, or the reinforcement of the joint between the column and the pile, where the bending moment is increased, has been carried out. However, there have been problems in its workability and economic efficiency. In response to this, it is not certain that the blade head is provided with a blade body as disclosed in Patent Document 1, and there is room for improvement in that respect.

  The present invention has been made in view of the above-described problems, and reduces the effective input motion, increases the dissipation attenuation, and reduces the bending moment acting on the joint between the column and the pile, thereby reducing the pile head. An object of the present invention is to provide a foundation structure for an over-track building capable of suppressing the destruction of the rail and reducing the response of the superstructure.

  In order to achieve the above object, in the foundation structure of the building above the railway according to the present invention, the foundation structure of the building above the railway constructed on the platform is provided with the first support pillar of the building above the railway. A pile foundation comprising a pile body to be supported and an enlarged portion projecting radially outward from the pile head of the pile body is provided, and the second support pillar of the platform is integrally joined to the enlarged portion. Yes.

  In the present invention, by providing the enlarged portion, the contact area with the ground can be increased, and the effect of dissipation attenuation can be enhanced. And the 2nd support pillar of a platform is integrally joined to the enlarged part projected on the diameter direction outside from the pile head, and an enlarged part can be made to function as a foundation of a platform.

  Moreover, in the foundation structure of the building above the railway according to the present invention, the enlarged portion is preferably a blade member that partially protrudes outward in the outer diameter direction from a part of the pile head.

  In the present invention, for example, when the enlarged portion provided on the pile head is a blade member having a cross shape in a sectional view, the amount of the member can be reduced as compared with the enlarged portion having a circular shape in the sectional view. The blade member can be arranged according to the position of the support pillar.

  Moreover, in the foundation structure of the building above the railway according to the present invention, the blade member is more preferably formed from a precast concrete member.

  In this invention, since the joining operation | work of a pile main body and a blade member is easy, and since an enlarged part has the role of the foundation of a platform, the concrete placement work by site construction can be reduced.

  Further, in the foundation structure of the building above the railway according to the present invention, the joint portion between the pile head and the enlarged portion, and the joint portion between the pile head and the first support column may be formed of a high-strength material. preferable.

  In the present invention, since the joint portion between the pile head and the enlarged portion and the joint portion between the pile head and the first support column are joined by a high strength material such as high strength fiber reinforced concrete, the joint portion. Damage to the can be suppressed.

  According to the foundation structure of the building above the railway of the present invention, the effective input motion is reduced, the dissipation attenuation is increased, and the bending moment acting on the joint between the pile head and the supporting column of the building is reduced, It is possible to suppress the pile head breakage and reduce the response of the superstructure.

It is a sectional side view which shows the basic structure of the building above a track by embodiment of this invention. It is a top view of the basic structure shown in FIG. It is an AA arrow directional view shown in FIG. It is a perspective view of the pile foundation shown in FIG. It is a top view of the pile foundation shown in FIG. It is a sectional side view which shows the basic structure of the conventional building above a track.

Hereinafter, an embodiment of a foundation structure of a building over a track according to the present invention will be described with reference to FIGS. 1 to 5.
As shown in FIG. 1, the foundation structure 1 according to the present embodiment is applied to a building 3 that forms a building above the railroad that is built on a platform (hereinafter simply referred to as “home 2”). The track floor has a structure in which homes 2A and 2B are provided on both sides of a two-lane track (railway 5 shown in FIGS. 1 and 2) laid on the ground G. And the building support pillar 31 (1st support pillar) is provided in the appropriate position, and the building support pillar 31 is joined to the pile main body 41 of the pile foundation 4 mentioned later. Here, as shown in FIG. 2, the building 3 is provided with six building support columns 31, and six piles (three per home 2) corresponding to each of the building support columns 31. A foundation 4 is provided.

  As shown in FIGS. 2 and 3, the homes 2A and 2B are supported from below by a plurality of home support columns 21, 21,... (Second support columns), respectively. ... are partly joined to the blade member 42 of the pile foundation 4 described later. In addition, the home support column 21 in the following description means what was joined to the blade member 42 of the pile foundation 4.

  As shown in FIGS. 4 and 5, the pile foundation 4 includes a pile main body 41 that supports the building support pillar 31 of the building 3, and a blade member 42 (an enlarged portion) that projects radially outward from the pile head 4 a of the pile main body 41. ). The blade member 42 partially protrudes outward in the outer diameter direction from a part of the pile head 4a, and is formed in a substantially cross shape in a sectional view. The building support column 31 of the building 3 is joined to the pile head 4a, and the home support column 21 of the home 2 is integrally joined to the blade member 42. In addition, although the protrusion length to the radial direction of the blade member 42 can be set arbitrarily, it is set to the length which the home support pillar 21 can support with the blade member 42 as mentioned above.

  As shown in FIG. 5, in the blade member 42, a part 42A near the pile head 4a is constructed by concrete placement at the same time as the pile body 41, and the other projecting tip side part 42B is formed by a precast concrete member. .

  And the joint part of the pile head 4a and the building support pillar 31, ie, the pile head 4a of the pile main body 41, and the concrete placement part (said part 42A) of the blade | wing part 42 are high-strength materials, such as high-strength fiber reinforced concrete. It is formed by.

Next, the operation of the foundation structure 1 used for the building 3 composed of the above-track building constructed as described above will be described based on the drawings.
As shown in FIG. 1, in the present basic structure 1, by providing the blade member 42, the contact area with the ground G is increased, and the effect of dissipation attenuation can be enhanced. Further, the effective input motion can be reduced by the restraining effect of the pile head by the blade member 42. In addition, the home support pillar 21 of the home 2 is integrally joined to the blade member 42 projecting radially outward from the pile head 4 a, and the blade member 42 can function as the foundation of the home 2.

  Moreover, since the expansion part provided in the pile head 4a is the blade member 42 which becomes a cross shape by sectional view, it can reduce a member amount compared with the expansion part which makes circular section view, and also the home support pillar 21 The blade member 42 can be arranged according to the position.

Furthermore, since a part of the blade member 42 is made of a precast concrete member, the joining work between the pile body 41 and the blade member 42 is facilitated, and there is a construction failure point as in the case of performing concrete placing work by on-site construction. Since there is no problem that it occurs, the foundation structure that connects the pile foundations 4 with the platform 2 as the foundation beam can be realized with high quality.
Moreover, since the building support column 31 and the blade member 42 have a joint structure formed of a high-strength material such as high-strength fiber reinforced concrete, damage to the joint can be suppressed.

  In the foundation structure of the building above the railway according to the present embodiment described above, the effective input motion is reduced, the dissipation attenuation is increased, and the bending moment acting on the joint between the pile head 4a and the building support column 31 is reduced. Thereby, destruction of the pile head 4a can be suppressed and the response of the superstructure can be reduced.

As mentioned above, although embodiment of the basic structure of the building over the track by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, in the present embodiment, the enlarged portion forming the blade member 42 formed in a substantially cross shape in a cross-sectional view of the pile head 4a is used, but is not limited to this shape, for example, a circular shape or a polygonal shape in the cross-sectional view. An enlarged portion having a shape such as the above may be used. The point is that the contact area of the pile head 4a with the ground G is increased, and the enlarged portion may be joined to the home support column 21.

  In addition, the radial projecting dimension and the axial dimension of the enlarged portion (blade member 42) with respect to the pile head 4a depend on the pile diameter (diameter dimension of the pile body 41), the supporting force, the geological conditions of the ground G, and the like. It can be set arbitrarily.

1 Basic structure 2 Home (platform)
3 buildings (buildings above the railway track)
4 Pile foundation 4a Pile head 5 Railway track 21 Home support pillar (second support pillar)
31 Building support pillar (first support pillar)
41 Pile body 42 Blade member (enlarged part)
G ground

Claims (4)

It is the basic structure of the building above the railway track that is built above the platform,
A pile foundation comprising a pile body supporting the first support pillar of the building above the railway track, and an enlarged portion projecting radially outward from the pile head of the pile body,
The foundation structure of the building above the railway, wherein the second support pillar of the platform is integrally joined to the enlarged portion.   The foundation structure of an over-the-rail building according to claim 1, wherein the enlarged portion is a blade member that partially protrudes outward in the outer diameter direction from a part of the pile head.   The foundation structure of an over-track building according to claim 2, wherein the blade member is formed of a precast concrete member.   The joint portion between the pile head and the enlarged portion and the joint portion between the pile head and the first support column are formed of a high-strength material. The basic structure of the building above the railway line.

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