JP2018204172A - Structure of joint between pile and foundation beam - Google Patents

Abstract

To provide a structure of a joint of a pile and a foundation beam which makes it possible to reduce the size of the spacing between the pile and the foundation beam.SOLUTION: A structure (10) of the joint part between a pile (12) and a foundation beam (14) contains a first cylindrical body (30) and a second cylindrical body (32) respectively extending in the vertical direction, and concrete (34) charged into the first and second cylindrical bodies. The second cylindrical body (32) surrounds the periphery of a head part (12a) of the pile, and surrounds the whole or a part of the periphery of the first cylindrical body below the upper end of the first cylindrical body, and having a space with the first cylindrical body.SELECTED DRAWING: Figure 2

Description

  It relates to the structure of the joint between the pile installed in the ground and the foundation beam installed on the ground.

  Conventionally, the structure of the junction part of a pile and a foundation beam including the concrete with which the steel pipe which supports a foundation beam on the head of a pile, and the inside of a steel pipe were filled is proposed.

  By the way, the magnitude of the bending moment generated in the pile at the time of the earthquake depends on the magnitude of the distance between the pile and the foundation beam. In the conventional structure, a space is required in the steel pipe for arranging a transmission mechanism for transmitting the shearing force generated in the steel pipe and the concrete in the steel pipe to the pile during an earthquake. For this reason, there was a limitation on reducing the length of the steel pipe and hence the size of the gap between the pile and the foundation beam.

JP 2017-8543 A

  The objective of this invention is providing the structure of the junction part of a pile and a foundation beam which enables reduction of the magnitude | size of the space | interval between a pile and a foundation beam.

  The present invention relates to a structure of a joint portion between a pile and a foundation beam, and the structure includes a first cylindrical body and a second cylindrical body that extend in the vertical direction, and the second cylindrical body is the above-described structure. Surrounding the periphery of the head of the pile, and all or part of the periphery of the first cylindrical body is spaced below the upper end of the first cylindrical body and from the first cylindrical body. And the first cylindrical body and the second cylindrical body, and the concrete filled in the first and second cylindrical bodies.

  According to the present invention, the first cylindrical body and the second cylindrical body are integrated with each other, and both the first and second cylindrical bodies and the pile are integrated with each other through the concrete. The pile through the composite body (first composite body) composed of the cylindrical body and the concrete inside thereof and the composite body (second composite body) composed of the second tubular body and the concrete inside thereof. And the foundation beam are joined together. In the present invention, the second cylindrical body has the whole or a part of the periphery of the first cylindrical body below the upper end of the first cylindrical body and the first cylindrical body. The second cylindrical body and the concrete filling the space existing between the first and second cylindrical bodies reinforce the first composite body. This reinforcement can increase the shear strength of the first composite during an earthquake, thereby eliminating the need for the arrangement of the shear force transmitting member in the first cylindrical body and the arrangement space therefor. As a result, it is possible to reduce the length of the first composite, that is, the size of the interval between the pile and the foundation beam.

  The foundation beam has a bracket made of one H-shaped steel and two H-shaped steels joined to the one H-shaped steel and perpendicular to the H-shaped steel, and the first cylindrical body is joined to the bracket. The four plate members are located between one H-shaped steel and two H-shaped steels of the bracket, and the cylindrical member is located immediately below the four plate members. Can be. Alternatively, the first cylindrical body is composed of a cylindrical member joined to the bracket, and the cylindrical member receives one H-shaped steel and two H-shaped steels of the bracket and allows the insertion of these H-shaped steels. It can have four recesses with open tops to allow. According to this, a part of the bracket can be embedded in the concrete filled in the first cylindrical body.

  The second cylindrical body is formed of a cylindrical member, and the cylindrical member receives one H-shaped steel and two H-shaped steels of the bracket, and has four recesses open at the upper end that allow insertion of these H-shaped steels. It can have. According to this, still another part of the bracket can be embedded in the concrete filled in the second cylindrical body. Or the said 2nd cylindrical body shall have an upper end located in the height below the said foundation beam.

1 is a schematic plan view of a structure according to an embodiment of the present invention. It is sectional drawing obtained along line 2-2 of FIG. It is a schematic plan view of the structure which concerns on other embodiment of this invention. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

  Referring to FIGS. 1 and 2, an example of a structure of a joint portion between a pile 12 installed in the ground and extending in the vertical direction and a foundation beam 14 installed on the ground is indicated by a reference numeral 10 as a whole.

  The illustrated pile 12 is a cast-in-place pile having a circular cross-sectional shape, and its head 12 a extends to the ground via abandoned concrete 18 formed on the ground 16. The pile 12 may be a ready-made pile.

  The base beam 14 includes a bracket 14a composed of one H-section steel 22 joined to each other and a pair of H-section steels 24 orthogonal thereto, and a plurality of other H-section steels 26 joined to the bracket 14a (see FIG. 2). ). The foundation beam 14 supports the superstructure, and in the illustrated example, the pillar 28 of the building, at the joint portion of the H-section steels 24 and 26 constituting the bracket 14a.

  The joint structure 10 is filled in the first cylindrical body 30 and the second cylindrical body 32 made of steel, each extending in the vertical direction, and inside the cylindrical bodies 30 and 32. Concrete 34 is included.

  The first cylindrical body 30 includes four plate members 36 and one cylindrical member 38 joined to the bracket 14a. The four plate members 36 are respectively positioned between one H-section steel 22 and two H-section steels 24 constituting the bracket 14 a, and the cylindrical member 38 is positioned immediately below the four plate members 36.

  Each plate member 36 has an arc-shaped cross section of about ¼ circle and extends in the vertical direction. Each plate member 36 defines an approximately 1/4 partial cylindrical space 40 between one H-section steel 22 and H-section steel 24 adjacent to each other. More specifically, each plate member 36 includes a pair of upper and lower flanges 22a and 22b of the H-section steel 22 and a pair of flanges of the H-section steel 24 (only the upper flange 24a is shown), and the H-section steel. A partial cylindrical space 40 is defined between the web 22 c connected to both flanges 22 and the web 24 c connected to both flanges of the H-shaped steel 24. The four partial cylindrical spaces 40 constitute a cylindrical space substantially corresponding to one cylindrical space.

  The cylindrical member 38 positioned immediately below the four plate members 36 defines one cylindrical space 42 that communicates with the four partial cylindrical spaces 40. The cylindrical member 38 extends downward from the lower flange 22b of the one H-section steel 22 and the lower flanges of the two H-section steels 24 constituting the bracket 14a to the height position of the head 12a of the pile 12, and the head in part thereof. It is in contact with the portion 12a. Instead of the illustrated example, the cylindrical member 38 can extend from the lower flange of the H-shaped steels 22 and 24 to a height position just before reaching the height position of the head portion 12a of the pile 12. . The cylindrical member 38 has an inner diameter larger than the outer diameter of the head 12a of the pile 12 instead of the illustrated example, and surrounds the periphery of the head 12a of the pile 12 and is in contact with the discarded concrete 18. Can do. The plate member 36 and the cylindrical member 38 preferably have the same thickness dimension, and have the same inner diameter and the same outer diameter. The first cylindrical body 30 is arranged so that its axis is on the extension of the axis L1 of the column 28 of the building.

  The bracket 14a of the foundation beam 14 and the first cylindrical body 30 are preferably manufactured in advance in a factory and transported to the building construction site.

  The 2nd cylindrical body 32 consists of one cylindrical member. The second cylindrical body 32 is disposed on the discarded concrete 18 and surrounds the periphery of the head 12a of the pile 12 preferably over the entire circumference of the head 12a with a space from the head 12a. The second cylindrical body 32 surrounds the entire periphery of the first cylindrical body 30 below the upper end 30a of the first cylindrical body 30 and at a distance from the first cylindrical body 30. ing. The cylindrical member constituting the second cylindrical body 32 preferably has the same thickness as the plate member 36 and the cylindrical member 38 constituting the first cylindrical body 30, and the plate member 36 and the cylindrical member The member 38 has an inner diameter and an outer diameter larger than the inner diameter and the outer diameter.

  The second cylindrical body 32 receives the mounting of the bracket 14a at its upper end 32a, or, as in the example shown in the figure, is provided in the second cylindrical body 32 and opens to the upper end 32a. It is possible to receive the mounting of the bracket 14 a in the recess 44. In the four recesses 44, a part of one H-section steel 22 and two H-section steels 24 constituting the bracket 14a, that is, a part of the lower flange of these H-section steels 22, 24 and Each part of the web is received and inserted. A gap existing between the second cylindrical body 32 and a part of the web of the H-shaped steels 22 and 24 received in the respective recesses 44 provided in the second cylindrical body 32 is, for example, a suitable steel plate member. (Not shown) can be temporarily closed, thereby preventing leakage when placing the concrete 34 to be filled. The second cylindrical body 32 has an upper end 32a (shown by an imaginary line (two-dot chain line) in FIGS. 2 and 4) positioned at a lower level than the bracket 14a, instead of the illustrated example, and the upper end 32a. The bracket 14a may not be mounted. The 2nd cylindrical body 32 is arrange | positioned so that the axis line may exist on extension of the pile 12 axis line L2.

  The concrete 34 filled in the first cylindrical body 30 and filling the four partial cylindrical spaces 40 and the cylindrical spaces 42 is a flat surface located at the same level as the surfaces of the upper flanges 22a and 24a of the H-shaped steels 22 and 24. Is specified.

  According to this, the 1st cylindrical body 30 and the 2nd cylindrical body 32 are mutually integrated via the concrete 34, and both the 1st and 2nd cylindrical bodies 30 and the pile 12 are combined. The bracket 14 a and the first and second cylindrical bodies 30 and 32 are integrated with each other through the concrete 34. Thereby, the pile 12 and the foundation beam 14 are joined to each other via the structure 10.

  In the illustrated example, the first cylindrical body 30 and the composite body (first composite body) made of concrete 34 filling the inside thereof is a second cylindrical body surrounding the entire periphery of the first cylindrical body 30. Concrete satisfying a space having an annular cross-sectional shape between the body 32 and the first and second cylindrical bodies 30, 32 (denoted by reference numeral 34a for the purpose of distinction from concrete in other spaces) )) Is reinforced by the composite (second composite), and the shear resistance of the first composite is increased. According to this, when a shear external force acts on the first composite, the shear external force is transmitted to the second composite integrated with the first composite. More specifically, the first cylindrical body 30 constituting the first composite body is sequentially transmitted to the concrete 34c and the second cylindrical body 32 constituting the second composite body. Accordingly, it is possible to eliminate the need for installing a shearing force transmission member required for increasing the shear resistance force in the first cylindrical body 30, and thereby the first cylindrical body. It is possible to reduce the length between the head 12a of the pile 12 and the foundation beam 14 in the vertical direction of 30.

  By the way, when the foundation including the pile 12 is formed, the pile 12 is located immediately below the column 28 of the superstructure constructed on the foundation, that is, the axis L2 of the pile 12 is an extension of the axis L1 of the column 28. It is supposed to be above. However, in particular, in the case where the pile 12 is composed of a built-up pile, the axis L2 of the pile 12 is relatively large in the horizontal direction with respect to the extension of the axis L1 of the column 28. It may take. In the present embodiment, the first cylindrical body 30 has the axis of the first cylindrical body on the extension of the axis L1 of the column 28, and the second cylindrical body 32 has the second cylindrical body 32. By installing so that the axis of the cylindrical body is on the extension of the axis L1 of the pile 12, it is possible to avoid the rebuilding of the pile.

  The first cylindrical body 30 can be composed of one cylindrical member instead of the illustrated example. In this case, as in the second cylindrical body 32, the one cylindrical member constituting the first cylindrical body 30 is provided with four recesses (not shown) opened at the upper end thereof. These four recesses accept and allow part of one H-section steel 22 and two H-section steels 24 constituting the bracket 14a. Similarly, the one cylindrical member constituting the first cylindrical body 30 and the portions of the H-shaped steels 22 and 24 received in the respective recesses provided in the cylindrical member, more specifically, A gap existing between a portion of the web and the web is temporarily closed with a suitable steel plate member (not shown), thereby preventing leakage when the concrete 34 to be filled is placed. Alternatively, four H-section steels (not shown) constituting the base beam bracket are joined to the circumferential surface of the cylindrical member constituting the first cylindrical body 30 at an angular interval of 90 degrees. can do.

  Further, as shown in FIGS. 3 and 4, the first cylindrical body 30 and the second cylindrical body 32 may have the same inner diameter and outer diameter. In this example, the cylindrical member 38 of the first cylindrical body 30 and the cylindrical member constituting the second cylindrical body 32 are each provided with a part of the other cylindrical member at each of these two intersections. Two slits (not shown) for receiving, or one slit (not shown) for receiving a part of one of the cylindrical members at each of the two intersecting points, and the first 1 is different from the example shown in FIGS. 1 and 2 in that the cylindrical member 38 of the cylindrical body 30 is arranged so as to surround the periphery of the head 12a of the pile 12.

  One of the two slits provided at each intersection extends from the lower end of the cylindrical member 38 of the first cylindrical body 30 upward to more than half of the height of the cylindrical member 38. The other one of the two slits extends downward from one of the two concave portions 44 of the second cylindrical body 32 facing each other to the lower end of the second cylindrical body 32 from the bottom of the concave portion 44. Has stretched more than half of the distance between.

  In the example shown in FIG. 3 and FIG. 4, the first cylindrical body 30 and the composite body (first composite body) made of the concrete 34 filling the inside thereof are arranged around the first cylindrical body 30. Concrete that fills a space having a crescent-shaped cross-sectional shape between the second cylindrical body 32 that surrounds a part and both the first and second cylindrical bodies 30 and 32 (differentiation from concrete in other spaces) In order to increase the shear resistance of the first composite, the composite is composed of the second composite.

DESCRIPTION OF SYMBOLS 10 Structure of connection part 12 Pile 14 Foundation beam 14a Bracket 22 which comprises a foundation beam 1 H-section steel 24 Two H-section steel 28 Column 30 1st cylindrical body 32 2nd cylindrical body 32a 2nd cylinder Top end 34 of the body 44 Concrete 44 Recess

Claims (5)

The structure of the joint between the pile and the foundation beam,
A first cylindrical body and a second cylindrical body each extending in the vertical direction, the second cylindrical body surrounding the periphery of the head of the pile, and the periphery of the first cylindrical body A first cylindrical body and a second cylindrical body that surround all or part of the first cylindrical body below the upper end of the first cylindrical body and at a distance from the first cylindrical body;
The structure of the junction part of a pile and a foundation beam including the concrete with which the inside of both the 1st and 2nd cylindrical bodies was filled. The foundation beam has a bracket composed of one H-section steel and two H-sections bonded to and orthogonal to the one H-section steel,
The first cylindrical body includes four plate members and a cylindrical member respectively joined to the bracket, and the four plate members are located between one H-shaped steel and two H-shaped steels of the bracket. The structure of a joint portion between a pile and a foundation beam according to claim 1, wherein the cylindrical member is located immediately below the four plate members. The foundation beam has a bracket composed of one H-section steel and two H-sections bonded to and orthogonal to the one H-section steel,
The first cylindrical body is formed of a cylindrical member joined to the bracket, and the cylindrical member receives a part of one H-section steel and a part of two H-sections of the bracket, and these H-shapes. The structure of the joint part of the pile and foundation beam of Claim 1 which has four recesses of the upper end opening which accept | permit insertion of steel.   The second cylindrical body is formed of a cylindrical member, and the cylindrical member accepts a part of one H-section steel and a part of two H-section steels of the bracket and permits the insertion of these H-section steels. The structure of the junction part of the pile and foundation beam of Claim 2 or 3 which has four open recesses.   The structure of a joint portion between a pile and a foundation beam according to claim 1, wherein the second cylindrical body has an upper end located at a height below the foundation beam.

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