JP5456627B2 - Connection structure and method of connection between pile and steel column - Google Patents

Description

  The present invention relates to a joining structure between a pile and a steel column and a joining method between the pile and a steel column, and more particularly, a joining structure and joining suitable for directly joining a pile and a column without providing a foundation beam or a footing. Regarding the method.

  Conventionally, pile foundations in steel buildings have been constructed with multiple piles in the ground so that the pile heads are located at a position below the slab surface of the lowest floor, and footing is performed so that the pile heads of each pile are involved. In general, the footings are connected and integrated with underground beams, and then the pillars of the building are joined to the footings. However, in recent years, a structure in which a pile and a column are directly joined without providing a footing and an underground beam has begun to be adopted. According to this structure, it is possible to greatly shorten the construction period and reduce the cost.

  As such a direct connection structure between a pile and a pillar, a base plate is provided at the bottom of the pillar, and a pile head joint with an anchor bolt on the top surface is used to prevent horizontal construction errors with respect to ready-made piles embedded in the ground. Welded to the position to absorb, and with the connecting part below the base plate inserted into the pile head, the base plate was supported while absorbing the vertical construction error of the pile by the anchor bolt (see Patent Document 1) )It has been known.

  On the other hand, if the legs of the steel column are inserted into the pile head, the pile diameter may become larger than necessary, so as a joint structure to improve this, the connecting part below the base plate is connected to the pillar body. Also has a small cross section, and the anchor bolts are projected on the upper surface of the ready-made piles embedded in the ground, and the anchor bolts are used to support the base plate while absorbing vertical construction errors of the piles (see Patent Documents 2 and 3) In addition, in order to be able to determine the pile diameter regardless of the fit of the pillar, the base plate of the steel column is supported on the pile head joint plate welded to the pile head so that the height can be adjusted with bolts. (Refer patent document 4) etc. are also proposed.

Japanese Patent No. 4405539 Japanese Patent No. 3671342 JP 2002-194748 A JP 2002-188154 A

  However, in the invention described in Patent Document 1, since the pile head joint hardware must be welded after the pile is buried in the ground, the work conditions are severe, such as the work depends on the weather, and stable. Quality assurance is difficult. In addition, since it is necessary to secure a space for welding work, the amount of ground excavation may be increased. Such a problem also exists in the invention described in the cited document 4. On the other hand, in the inventions described in the cited documents 2 and 3, such a problem does not occur because the base plate is joined to the pile head by the bolt, but the construction error in the vertical direction of the pile position can be absorbed by the bolt, It cannot absorb horizontal construction errors. Here, in order to absorb the construction error in the horizontal direction, it is conceivable to process the base plate after installing the piles. However, in this case, there is a possibility that the construction period may be extended due to the delay in the steel frame production.

  The present invention has been made in view of such a background, and directly joins a pile and a steel column without using on-site welding, and absorbs construction errors in the vertical and horizontal directions of the pile to make the steel column appropriate. It is an object of the present invention to provide a method for joining a pile and a steel column and a pile head joint hardware that can be arranged at various positions.

  In order to solve the above problems, the present invention provides a base plate (1) having a cylindrical shape and having a metal portion (12) on the upper surface (1a) and a plurality of bolt insertion holes (23). 22) is a joining method of a pile and a pillar for joining a steel column (2) provided at the lower end, a metal plate portion (31) having a substantially circular shape, and one end of one of the plate portions A step of preparing a pile head joint hardware (3) having a plurality of legs (32) which are welded to the surface (31b) and spaced apart from each other along the peripheral edge of the plate portion; The pile head fitting is attached to the upper end of the pile so as to face the upper surface of the pile and cover the hollow portion (1C) of the pile as viewed in the axial direction, and an opening (35) formed between the adjacent leg portions A step of communicating the hollow portion with the upper outside of the pile, and the ground (G The soil cement is poured into the excavation hole (6) and the soil and sand are stirred and mixed to form the soil cement (7), and the pile to which the pile head joint hardware is attached is filled with the soil cement. Inserting into the drilling hole and sinking while discharging the air in the hollow part from the opening to the outside, and aligning the bolt holes in the base plate when the steel column is placed in place after the pile is set Next, a step of forming a plurality of bolt insertion holes (36) in the plate portion, a steel column is disposed above the pile, and the bolt (8) is inserted into the bolt insertion hole of the plate portion and the bolt insertion hole of the base plate. And a step of joining the pile head joint and the steel column while adjusting the height of the steel column with the nut (9) screwed to the bolt.

  Moreover, according to one aspect of the present invention, the step of filling the non-shrink mortar (45) between the pile head joint hardware and the steel column after joining the pile head joint hardware and the steel column, After joining a hardware and a steel column, it is set as the structure further equipped with the step which constructs | assembles the reinforced concrete structure (4) which winds the head (1H) of a pile, a pile head joining hardware, and the leg (1F) of a steel column. Can do.

  In order to solve the above problems, the present invention provides a drilling hole (6) formed in a cylindrical shape and having a metal portion (12) on the upper surface (1a) and a soil cement (7) formed therein. In order to join the pile (1) to be laid inside and the steel column (2) having a base plate (22) having a plurality of bolt insertion holes (23) at the lower end, A pile head fitting (3) to be attached, which is opposed to the upper surface of the pile, and has a substantially circular metal plate portion (top plate 31) covering the hollow portion (1C) of the pile as viewed in the axial direction, and one end Are welded to the surface of the plate portion on the pile side and are spaced apart from each other along the periphery of the plate portion, and communicate with the hollow portion of the pile and the upper exterior of the pile while attached to the upper end of the pile. A plurality of legs (foot) forming openings (35) to be Providing pile joint fittings comprising a plate 32) and.

  According to one aspect of the present invention, the pile head joint hardware further includes a metal ring-shaped plate portion (33) connected to the other end side of the plurality of leg portions and connecting the plurality of leg portions. be able to.

  According to the present invention, since the pile head joint hardware is welded before the pile is set in the ground, stable quality can be ensured regardless of the working conditions such as the weather. Moreover, since it is not necessary to secure the welding work space around the buried pile, it is possible to avoid an increase in the amount of ground excavation. In addition, after setting up the pile, by forming the bolt insertion hole of the plate part at the position that matches the bolt insertion hole of the base plate, the construction error in the horizontal direction of the pile position is absorbed and the bolt passed through the bolt insertion hole The steel column can be arranged at a predetermined position by absorbing the construction error in the vertical direction of the pile position with the nut. Furthermore, since it is not necessary to process the base plate after installing the pile, there is no possibility that the construction period will be extended due to the delay in the steel frame production.

  In addition, it should be constructed so that a non-shrink mortar is filled between the pile head joint hardware and the steel column, or a reinforced concrete structure in which the pile head, the pile head joint hardware, and the steel column leg is wound is constructed. Thus, the axial force of the steel column can be reliably transmitted to the pile 1, and the bonding strength between the pile and the steel column can be increased.

  In addition, by configuring the pile head joint hardware to have a metal ring-shaped plate portion, the entire circumference of the ring-shaped plate portion can be welded to the metal portion of the pile. Bonding strength can be increased.

  As described above, according to the present invention, the pile and the steel column are directly joined without using on-site welding, and the steel column is arranged at an appropriate position by absorbing the vertical and horizontal construction errors of the pile. Can do.

The side view which shows the joint structure of the pile and steel column which concern on embodiment through a reinforced concrete structure see-through | perspective The longitudinal cross-sectional view of the joining structure of the pile and steel column which concerns on embodiment Sectional drawing showing the reinforced concrete structure seen through along line III-III in FIG. Sectional view showing the reinforced concrete structure seen through line IV-IV in FIG. Perspective view of pile head joint hardware according to an embodiment Explanatory drawing of the joining method of the pile and steel column concerning an embodiment

  Hereinafter, an embodiment of a method for joining a pile 1 and a steel column 2 according to the present invention and a pile head fitting 3 used for the method will be described with reference to the drawings. In addition, in FIG.1, FIG3 and FIG.4, the reinforced concrete structure 4 is shown through.

  As shown in FIG. 1 and FIG. 2, the connection structure between the pile 1 and the steel column 2 according to the present invention is such that one steel column 2 is supported by one pile 1. The joint portion constituted by the reinforced concrete structure 4 is set at a position lower than the floor surface 5 of the lowest floor (here, the first floor).

  The pile 1 is an SC pile (Steel and Concrete composite pile: high-strength concrete pile with outer shell steel pipe), and is a ring-shaped unit formed by welding a steel pipe 11 disposed on the outer peripheral surface and upper and lower ends of the steel pipe 11 by welding. It is comprised by the end plate 12 and the high strength concrete 13 with which the inside of the steel pipe 11 was filled cylindrically. That is, the pile 1 extends along the axial direction and forms a hollow portion 1C having both ends opened inside the high-strength concrete 13, and the upper surface (hereinafter referred to as the pile head surface 1a) by the metal end plate 12. ) Is defined. Further, a J-shaped groove is formed at the upper end of the peripheral surface of the upper end plate 12 over the entire circumference.

  As shown in FIG. 3, the steel column 2 is welded to a column main body 21 made of a hollow quadrangular column having a substantially square cross section and a lower end of the column main body 21, and is larger than the cross-sectional shape of the column main body 21. The base plate 22 has a similar planar shape, and the base plate 22 is disposed so as to be located immediately above the pile head surface 1a. Bolt insertion holes 23 are formed in the vicinity of the four corners of the base plate 22.

  The pile 1 and the steel column 2 are connected to the pile 1 by welding all around, and the steel column 2 has a head without a head and formed with a male thread over the entire length (hereinafter referred to as the bolt). A pile head joint 3 fastened by a bolt 9 and a nut 9 is disposed.

  As shown in FIGS. 2, 4, and 5, the pile head metal fitting 3 includes a metal top plate 31 having a substantially circular shape, and a surface of the top plate 31 on the pile 1 side (hereinafter referred to as a lower surface 31 b). ) And a plurality (eight in this case) of foot plates 32 that are spaced apart from each other along the periphery of the top plate 31, and the other end of the foot plate 32. And a metallic ring-shaped plate 33 for connecting the two.

  The top plate 31 is substantially circular having an outer diameter substantially the same as the pile diameter. The foot plate 32 is a metal plate having the same shape, that is, the same height, and is arranged at an equal distance from the center of the top plate 31 and at an interval of 45 degrees so as to have a constant interval, and is perpendicular to the top plate 31 Be joined. The ring-shaped plate 33 has the same outer diameter as the pile diameter, and has an inner diameter smaller than the inner diameter of the pile 1.

  The pile head fitting 3 is such that the top plate 31 faces the pile head surface 1a, covers the hollow portion 1C in the axial direction of the pile 1, and the plurality of foot plates 32 are on the periphery of the pile head surface 1a. It is attached to the upper end of the pile 1 so that the opening 35 which connects the hollow part 1C of the pile 1 and the upper exterior of the pile 1 may be formed between the footplates 32 which are arrange | positioned along and adjacent. In addition, the opening 35 plays the role which discharges the air and soil cement of the hollow part 1C of the pile 1 outside when the pile 1 is embedded so that it may mention later.

  At the lower end of the circumferential surface of the ring-shaped plate 33, a J-shaped groove forming a U-shaped groove is formed over the entire circumference in cooperation with the J-shaped groove formed in the upper end plate 12. The pile head joint 3 is firmly attached to the upper end of the pile 1 by welding all around the groove.

  On the other hand, in the top plate 31, four bolt insertion holes 36 are formed at positions facing the bolt insertion holes 23 formed in the base plate 22 of the steel column 2. One bolt 8 is inserted into each of the pair of bolt insertion holes 23, 36 of the top plate 31 and the base plate 22, and two nuts 9 are screwed up and down with respect to each bolt 8. Is joined to the pile head joint 3 so that the relative separation distance with respect to the pile head joint 3, that is, its height can be adjusted.

  A non-shrink mortar 45 is filled between the pile head joint 3 and the steel column 2, and the axial force of the steel column 2 is transmitted to the pile head joint 3 through the non-shrink mortar 45. ing.

  In addition, a reinforced concrete structure 4 can be constructed around the head 1H of the pile 1, the pile head joint hardware 3, and the leg 2F of the steel column 2 so as to involve them, and the stress ( Axial force, bending, and shear) can be transmitted to the pile head joint 3 through the reinforced concrete structure 4 as well.

  The reinforced concrete structure 4 has a circular cross section having a diameter larger than the pile diameter, and concrete 41 is placed upward from a height that is lower than the pile head surface 1a by a predetermined dimension, and a rebar cage 42 provided therein. Consists of. The rebar cage 42 extends in the vertical direction and is formed in a circular shape so as to surround the main bars 43 with a plurality of main bars 43 arranged in a circle at predetermined intervals in the horizontal direction, with a predetermined interval in the vertical direction. And a plurality of hoop muscles 44 arranged horizontally. Each main reinforcement 43 is arrange | positioned so that it may protrude below the pile head surface 1a, and may protrude above the upper surface of the base plate 22 of the steel column 2. As shown in FIG. Note that most of the hollow portion 1 </ b> C of the pile 1 is filled with the soil cement 7, and the concrete 41 is filled inside the pile head joint 3.

  Next, a method of joining the pile 1 and the steel column 2 according to the embodiment will be described with reference to FIG.

  First, a top plate 31 having a substantially circular shape, a plurality of foot plates 32 having one end welded to the lower surface 31 b of the top plate 31 and spaced apart from each other along the periphery of the top plate 31, A pile head metal fitting 3 having a ring-shaped plate 33 that is welded to the other end side and connects all the foot plates 32 is prepared (see FIG. 5).

  Next, in the manufacturing factory of the pile 1 and the like, the top plate 31 faces the pile head surface 1a and covers the hollow portion 1C of the pile 1 as viewed in the axial direction. A pile head joint 3 is placed at the upper end of the pile 1 so that an opening 35 is formed along the periphery of 1a and between the adjacent foot plates 32 to communicate the hollow portion 1C of the pile 1 with the upper outside of the pile 1. Install (see Figs. 1 and 2). And the pile 1 by which the pile head joining metal fitting 3 was attached to the upper end in this way is carried in to the spot.

  On the other hand, as shown in (A), the ground G is excavated to a predetermined depth while appropriately discharging the drilling liquid using an auger screw 51 having an enlarged head at the tip and a notch in the spiral portion as shown in FIG. As shown in (B), the auger screw 51 is lifted upside down while the enlarged head at the tip is enlarged, and the ground G is excavated so that the diameter of the lower portion of the excavation hole 6 is increased. Next, as shown in (C), the auger screw 51 is moved up and down and rotated forward and reverse while pouring cement milk into the excavation hole 6, and the excavated earth and sand is stirred and mixed to form the soil cement 7.

  Then, as shown in (D), after constructing a root-solidifying part 71 having higher strength than the other parts of the soil cement 7 at the bottom of the excavation hole 6, the auger screw 51 is pulled up, and shown in (E). As described above, the pile 1 to which the loaded pile head joint 3 is attached is inserted into the excavation hole 6 filled with the soil cement 7, and the air of the hollow portion 1 </ b> C of the pile 1 is passed through the opening 35 of the pile head joint 3. It is sunk while being discharged to the outside, and the tip of the pile 1 is plunged into the root hardening part 71 and fixed on the supporting ground. In addition, with the sedimentation of the pile 1, the soil cement 7 will be filled in the hollow part 1C of the pile 1 and the outer peripheral part of the pile 1, and when there is much soil cement 7, the soil in the hollow part 1C of the pile 1 The cement 7 is discharged to the outside through the opening 35 of the pile head joint hardware 3.

  Here, when it demonstrates with reference to FIG. 2, when the installation error arises in the pile 1, it will be in the state which the pile head surface 1a shifted | deviated to the horizontal direction and the perpendicular direction with respect to the predetermined position. Therefore, after the pile 1 is laid, four bolt insertion holes 36 are formed in the top plate 31 so as to align with the bolt insertion holes 23 of the base plate 22 when the steel column 2 is disposed at a predetermined position. Thereafter, the steel column 2 is arranged above the pile 1, and the bolts 8 are inserted into the bolt insertion holes 36 of the top plate 31 and the bolt insertion holes 23 of the base plate 22, and the four nuts 9 are screwed to the bolts 8. By joining the top plate 31 and the base plate 22 while adjusting the height of the steel column 2, the steel column 2 is joined to the pile head joint 3, that is, the pile 1.

  Thereafter, the non-shrink mortar 45 is filled between the pile head joint hardware 3 and the steel column 2, and the reinforced concrete structure around the head 1 H of the pile 1, the pile head joint hardware 3, and the leg 2 F of the steel column 2. Build body 4. In constructing the reinforced concrete structure 4, the ground G around the pile 1 is excavated to the extent that does not hinder the rebar assembly work and the formwork assembly work, and the soil cement 7 is placed inside the pile head joint hardware 3. When the pile is filled, the soil cement 7 inside the pile head joint 3 is removed after the pile 1 is set and before the bolt insertion hole 36 is formed.

  According to such a pile head joint fitting 3 and a method of joining the pile 1 and the steel column 2 using the same, before the pile 1 is set in the ground G, the pile head joint fitting 3 is attached to the pile 1 at a factory or the like. Because it is welded to the upper end, stable quality can be ensured regardless of the working conditions such as the weather. In addition, since it is not necessary to secure a space for welding work around the buried pile 1, the amount of excavation of the ground G is not increased. Moreover, after the pile 1 is laid, by forming the bolt insertion hole 36 of the top plate 31 at a position aligned with the bolt insertion hole 23 of the base plate 22, the horizontal construction error of the buried pile 1 is absorbed, Moreover, the construction error in the vertical direction of the pile 1 can be absorbed by the bolt 8 and the nut 9 passed through the bolt insertion holes 23 and 36, and the steel column 2 can be arranged at a predetermined position. Furthermore, since it is not necessary to process the base plate 22 after the pile 1 is installed, there is no possibility that the construction period will be extended due to the delay in steel frame production.

  In addition, a non-shrink mortar 45 is filled between the pile head joint hardware 3 and the steel column 2 and the reinforced concrete structure is formed so that the head 1H of the pile 1, the pile head joint hardware 3 and the leg 2F of the steel column 2 are involved. By constructing 4, the axial force of the steel column 2 can be reliably transmitted to the pile 1, and the joint strength between the pile 1 and the steel column 2 can be increased.

  In addition, since the pile head joint hardware 3 includes the ring-shaped plate 33, the entire circumference of the pile head joint hardware 3 can be welded to the metal portion of the pile 1. Can be increased.

  This is the end of the description of specific embodiments, but the present invention is not limited to these embodiments. For example, in the said embodiment, although SC pile is used as the pile 1, if it is a pile which has a metal part in the pile head surface 1a, for example, PC pile, PHC pile, PRC pile, joint pile, etc. other than SC pile Pile may be used. Moreover, in the said embodiment, although the pile head joining metal fitting 3 is provided with the ring-shaped plate 33, you may comprise so that the ring-shaped plate 33 may not be provided. Moreover, in the said embodiment, although the outer diameter of the top plate 31 and the ring-shaped plate 33 of the pile head joining metal object 3 is made the same as the outer diameter of the pile 1, of course, it can be made smaller than the outer diameter of the pile 1. If the pile 1 can be laid, it may be larger than the outer diameter of the pile 1. Moreover, in the said embodiment, although the fixing method to the support layer of the pile 1 is not specifically limited, In addition to being able to employ | adopt the method by striking and press-fitting, it equips the tip of a pile with the metal fitting and inserts in the hollow part 1C of the pile 1 Alternatively, a method may be employed in which the ground G is softened by rotating the rod and the water ejected from the metal fitting at the tip, and the pile 1 is rotationally press-fitted into the support layer, and then the root consolidation portion 71 is formed. Moreover, in the said embodiment, although the reinforced concrete structure 4 is constructed | assembled in the junction part of the pile 1 and the steel column 2, it is also possible to set it as the form which does not provide this. Moreover, in the said embodiment, although the foundation beam is not provided, it is also possible to provide a foundation beam and it is also possible to provide a footing around a junction part. Furthermore, the shape of the steel column 2, the number and position of the bolt insertion holes 23 and 36, the number of bolts 8 and nuts 9, the shape, and the like are not limited to those of the above embodiment. In addition to these, the specific shape, arrangement, and quantity of each member are not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

1 Pile 1C Hollow part 1H Head 1a Pile head surface (upper surface)
2 Steel column 2F Leg 3 Pile head joint 4 Reinforced concrete structure 6 Drilling hole 7 Soil cement 8 Bolt 9 Nut 12 End plate 22 Base plate 23 Bolt insertion hole 31 Top plate (plate part)
31b Bottom surface (Pile 1 side surface)
32 Foot plate (leg)
33 Ring-shaped plate 35 Opening 36 Bolt insertion hole 45 Non-shrink mortar G Ground

Claims (5)

A method of joining a pile and a column for joining a pile formed in a cylindrical shape and having a metal portion on at least an upper surface, and a steel column provided with a base plate on which a plurality of bolt insertion holes are formed at the lower end,
Pile head joint hardware having a metal plate portion having a substantially circular shape and a plurality of leg portions, one end of which is connected to one surface of the plate portion and spaced apart from each other along the peripheral edge of the plate portion. Steps to prepare,
The plate portion faces the top surface of the pile and covers the hollow portion of the pile as viewed in the axial direction, and a plurality of leg portions run along the periphery of the top surface of the pile and between adjacent leg portions. Attaching the pile head joint hardware to the upper end of the pile so that an opening for communicating the hollow portion of the pile and the upper outside of the pile is formed;
Excavating the ground, stirring and mixing earth and sand while pouring cement milk in the excavation hole, and creating a soil cement;
Inserting the pile to which the pile head joint hardware is attached into the excavation hole filled with the soil cement, and laying down while discharging the air of the hollow portion to the outside from the opening;
Forming a plurality of bolt insertion holes in the plate portion so as to align with the bolt insertion holes of the base plate when the steel column is disposed at a predetermined position after the pile is sunk;
The steel column is disposed above the pile, the bolt is inserted into the bolt insertion hole of the plate portion and the bolt insertion hole of the base plate, and the height of the steel column is adjusted by a nut screwed to the bolt. A method of joining a pile and a column, comprising: a step of joining the pile head joint hardware and the steel column while performing.   2. The method according to claim 1, further comprising a step of filling a non-shrink mortar between the pile head joint hardware and the steel column after joining the pile head joint hardware and the steel column. A method of joining piles and columns.   The method further comprises the step of constructing a reinforced concrete structure in which the head of the pile, the pile head joint hardware and the legs of the steel column are wound after joining the pile head joint hardware and the steel column. The method of joining a pile and a column according to claim 1 or claim 2. A pile that is formed in a cylindrical shape and has a metal portion on the upper surface, and is sunk in an excavation hole in which soil cement is formed, and a steel column that includes a base plate having a plurality of bolt insertion holes at the lower end. In order to join, it is a pile head joint hardware attached to the upper end of the pile before settling,
A substantially circular metal plate portion that is disposed opposite to the upper surface of the pile and covers the hollow portion of the pile in the axial direction,
One end is connected to the surface of the plate portion on the pile side, and is disposed apart from each other along the periphery of the plate portion, and the other end is attached to the upper end of the pile. A pile head joint hardware comprising: a plurality of leg portions that form openings that communicate the hollow portion of the pile and the upper outside of the pile between two adjacent ones along the periphery of the pile.   The pile head joint hardware according to claim 4, further comprising a metal ring-shaped plate portion connected to the other end side of the plurality of leg portions and connecting the plurality of leg portions.

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