JP2014020027A - Pile foundation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile foundation structure which: can reliably maintain a distance between neighboring piles; is hardly affected by deformation of the ground generated when an earthquake occurs; and can reduce a construction cost.SOLUTION: A pile foundation structure 1 which supports a support object above the same with pile head sections 3 of piles 2 has an inter-pile connection section 10 which connects the pile head sections 3 of the neighboring piles 2. The inter-pile connection section 10 is held in a manner that keeps a distance from or contact with a floor mold slab 130. Because the inter-pile connection section 10 of the pile foundation structure 1 can reliably maintain the distance between the piles 2 and the inter-pile connection section 10 is held in a manner that keeps the distance from or contact with the floor mold slab 130, the pile foundation structure 1 is hardly affected by deformation of the ground when an earthquake occurs and can reduce a construction cost.

Description

  The present invention relates to a pile foundation structure for supporting an object to be supported by a pile.

  A support object such as a building is supported on the ground using a pile foundation structure. When a large-scale logistics facility is described as an example of a support object, there is a high demand for seismic isolation structure not only in the case of newly building a large-scale logistics facility but also in the case of an existing large-scale logistics facility. The reason for this is that if a large-scale logistics facility is damaged by an earthquake, the distribution of goods will be stopped, interrupted, and disrupted, and the social impact will be great, so social responsibility cannot be fulfilled.

  In the pile foundation structure, in order to make the support object seismic isolation structure, a seismic isolation structure is installed in which the seismic isolation device is installed on the pile head and the support target is isolated There is. This type of seismic isolation structure absorbs the horizontal force of an earthquake and reduces the force that a large-scale logistics facility receives during an earthquake. As this type of seismic isolation structure, a pile head seismic isolation structure is proposed in Patent Document 1. In the pile head seismic isolation structure disclosed in Patent Document 1, a flat pile head capital made of reinforced concrete is provided integrally with the pile head, and the seismic isolation device is installed on this pile head capital.

  Several pile head capitals installed adjacent to each other are connected by flat reinforced beams made of reinforced concrete. This flat connecting beam is constructed by digging the ground, forming a recess, placing the concrete in this recess and placing concrete, and at the bottom of the seismic isolation pit, a number of flat connecting beams are installed on the pile heads. It is constructed in a grid as a whole across the capital. Since this grid-like flat bridging beam connects adjacent pile head capitals, the flat bridging beams bend the pile head bending moment transmitted from the pile head of each pile to each pile head capital. By returning, the rotation of the pile head of each pile is suppressed.

JP 2007-120232 A

  By the way, a client who requests a seismic isolation structure for a large-scale logistics facility wants to shorten the construction period and reduce costs when seismically isolating the floor of a large-scale logistics facility. However, when the pile head seismic isolation structure described in Patent Document 1 described above is employed, there are the following problems.

  The width of each flat connecting beam of reinforced concrete is slightly smaller than the length of one side of the pile head capital, and the height of the flat connecting beam is smaller than the height of the pile head capital, but the upper side of the flat connecting beam. The slab that forms the bottom of the seismic isolation pit is integrated. In this way, the top of the side of many flat bridging beams adopts a structure in which the soil slabs that form the bottom of the seismic isolation pit are adjacent to each other. It is necessary to dig deeper over a long distance. For this reason, the amount of soil discharged when the ground is dug up increases, and the construction period becomes longer. For this reason, even when constructing a pile foundation structure equipped with a seismic isolation device, or constructing a pile foundation structure without a seismic isolation device, the construction of grid-like flat tethered beams is troublesome. However, there is a problem that it is difficult to shorten the construction period and the cost cannot be reduced.

  In addition, the structure with adjacent soil slabs, that is, the flat bridging beams are directly embedded in the ground at the top of the side surfaces of many flat bridging beams. It is directly affected by the deformation of the liquid, for example, by liquefaction.

  The present invention has been made in view of the above, and the object of the present invention is to be able to reliably maintain the interval between adjacent piles, to be less affected by the deformation of the ground that occurs when an earthquake occurs, and to shorten the construction period and work It is providing the pile foundation structure which can aim at cost control.

  In order to achieve the above object, the pile foundation structure according to claim 1 is a pile foundation structure that supports an upper support object on a pile head of the pile, and the pile head of the adjacent piles. The inter-pile connection part which connects a part is provided, and it makes it a summary that the said inter-pile connection part is kept away from the soil slab or on the soil slab.

  In the pile foundation structure according to claim 1, the interval between the piles can be reliably maintained, it is difficult to be affected by the deformation of the ground that occurs when an earthquake occurs, and the construction period can be shortened and the construction cost can be reduced. That is, the connection part between piles which connects the pile heads of an adjacent pile can hold | maintain the space | interval between piles reliably. The connection part between piles is kept away from the soil slab or on the soil slab. That is, the connection part between piles is hold | maintained in the state which left | separated from the soil slab or contacted the soil slab. As a result, it is not affected by ground deformation that occurs when an earthquake occurs. In addition, since the soil slab is adjacent to the upper part of the side of the flat connecting beam in the past, it has been necessary to excavate the ground widely over a long distance. Since it is held away from the ground, there is no excavation work of such ground, so that the construction is easy and the construction period can be shortened and the construction cost can be reduced.

  The gist of the pile foundation structure according to claim 2 is that the support object is seismically isolated and supported by a seismic isolation device installed on the pile head of the pile.

  In the pile foundation structure according to claim 2, it is difficult to be affected by the deformation of the ground that occurs when an earthquake occurs, and it is possible to shorten the construction period and reduce the construction cost of the seismic isolation work for the support object.

  The pile foundation structure according to claim 3, wherein a capital portion is fixed to a top portion of the pile, and the inter-pile connection portion is fixed on each of the capital portions, so that the adjacent It is summarized that the pile heads of the piles to be connected are connected.

  In the pile foundation structure according to claim 3, a capital part is fixed to the top of the pile, and the work of excavating the ground to arrange the capital part is necessary. Compared to the need to excavate the ground deeply over a long distance when the soil slab is integrated at the upper part, the excavation work of the ground is less, so the construction period and construction cost can be reduced. Can be planned.

  The gist of the pile foundation structure according to claim 4 is that the end of the inter-pile connection part is directly fixed to the outer peripheral part of the pile head of each pile.

  In the pile foundation structure according to claim 4, without fixing the capital part to the pile head of the steel pipe pile, the end of the connection part between the piles is directly to the outer peripheral part of the pile head of the pile. Since it is fixed, the work of excavating the ground to arrange the capital part is not required, so that the construction period can be further shortened and the construction cost can be reduced.

  The pile foundation structure according to claim 5, wherein the pile has a steel pipe, and the outer peripheral portion of the steel pipe is prevented from being deformed out of plane when a tensile force is applied to the connection portion between the piles. The gist is to have an out-of-plane deformation prevention part.

  In the pile foundation structure according to claim 5, even if a tensile force is applied to the connection portion between the piles, the outer peripheral portion of the steel pipe can be prevented from being deformed to the outside, so that the shape of the steel pipe can be maintained. .

  The pile foundation structure of Claim 6 makes the summary the pile head which consists of concrete which embed | buried a part of said connection part between the piles above the said pile.

  In the pile foundation structure according to the sixth aspect, since the connection portion between the piles is embedded in the concrete, the construction is easy, and the construction period can be shortened and the construction cost can be reduced.

  The gist of the pile foundation structure according to claim 7 is that the connection part between piles is a steel frame.

  In the pile foundation structure according to claim 7, when the connection portion between the piles is a steel frame, it is lighter and easier to handle at the time of construction than a reinforced concrete beam or a steel reinforced concrete beam, and costs are reduced. be able to.

  ADVANTAGE OF THE INVENTION According to this invention, the space | interval between piles can be hold | maintained reliably, it is hard to receive to the influence of the ground deformation which arises at the time of an earthquake occurrence, and a pile foundation structure which can aim at construction period reduction and construction cost control can be provided.

It is sectional drawing which shows the foundation part of the building which is a support target object provided with preferable 1st Embodiment of the pile foundation structure of this invention. It is sectional drawing which shows the pile of one place in the pile foundation structure shown in FIG. 1, and its peripheral part as a representative example. It is a top view which shows the example of a shape of the pile foundation structure in the foundation part shown in FIG. 1 and FIG. FIG. 4 (A) is a plan view showing a second embodiment of the pile foundation structure of the present invention, and FIG. 4 (B) is a plan view showing a third embodiment of the pile foundation structure of the present invention. is there. It is sectional drawing which shows 4th Embodiment of the pile foundation structure of this invention. It is a figure which shows 4th Embodiment of the pile foundation structure of this invention. It is a figure which shows 5th Embodiment of the pile foundation structure of this invention. It is a figure which shows 6th Embodiment of the pile foundation structure of this invention. 9 shows a seventh embodiment of the pile foundation structure of the present invention, FIG. 9 (A) is a plan view of the pile foundation structure, and FIG. 9 (B) is a pile foundation shown in FIG. 9 (A). It is a side view of a structure. It is a figure which shows the part M of the pile foundation structure of FIG. 9 (B) in detail.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
Drawing 1 is a sectional view showing foundation part 100 of a building which is a support subject provided with a desirable 1st embodiment of a pile foundation structure of the present invention. FIG. 2 is a cross-sectional view showing the pile foundation structure 1 according to the first embodiment of the present invention installed in the foundation portion 100 shown in FIG. 1. FIG. 3 is a plan view showing a shape example of the pile foundation structure 1 in the foundation part 100 shown in FIGS. 1 and 2.

  The pile foundation structure 1 of 1st Embodiment of this invention is a seismic isolation structure which carries out isolation support of the upper support target object as an example. This support object is, for example, a large-scale logistics facility that is an example of a building. The first floor 101 and the first floor footing 102 of the foundation 100 of the large-scale logistics facility shown in FIGS. 1 and 2 sandwich the seismic isolation device 5 such as laminated rubber against the pile foundation structure 1. Seismic isolation is supported.

  In FIG. 2, the pile 2 of one place in the pile foundation structure 1 used for the foundation part 100 shown in FIG. 1 and its peripheral part are shown as a representative example.

  The pile foundation structure 1 is installed over a plurality of piles 2 that support the foundation portion 100. This pile 2 is a cast-in-place steel pipe concrete pile, for example, and the diameter of the pile 2 is 2500 mm, for example. However, the type, material, and size of the pile 2 are not particularly limited. A plate 4 is fixed to the installation surface of the pile head 3 of the pile 2. A plate 103 is fixed to the lower surface of the footing 102 on the first floor. Between the plate 4 and the plate 103, a seismic isolation device 5 such as laminated rubber is installed. If the dimension example of the diameter of the seismic isolation apparatus 5 is given, for example, it is 1500 mm, but it is not particularly limited.

  As shown in FIG. 2, a capital portion 6 is fixed to the outer periphery 2 </ b> G near the pile head 3 of the pile 2. As shown in FIG. 2, the capital portion 6 is fixed to the outer periphery 2G in the vicinity of the pile head 3 of the pile 2 by, for example, a stud bolt or the like. In the example shown in FIG. 3, the capital portion 6 is installed so as to protrude along the X direction and the Y direction around the pile head 3 of the pile 2, and has a square shape when viewed from above. The dimension L in the direction and the dimension L in the Y direction orthogonal to the X direction are the same. Two opposing side surface portions 8 of the capital portion 6 are along the X direction, and the remaining two opposing side surface portions 9 of the capital portion 6 are along the Y direction. The capital part 6 is preferably a steel structure, a reinforced concrete structure, or a steel reinforced concrete structure, but is not limited thereto. When the capital part 6 is a steel structure, construction is particularly easy and cost reduction can be achieved.

  Returning to FIG. 2, a ground portion 111 is formed in the ground 110. The dug-down portion 111 of the ground 110 has a rectangular parallelepiped concave portion 119 formed by dug down in the Z direction by the dug down dimension S. A substantially lower half portion of the capital portion 6 is disposed in the recess 119 of the dug-down portion 111. The capital portion 6 is fixed to the concave portion 119 of the ground 110 so that the position of the capital portion 6 does not shift in the X direction or the Y direction. When the capital part 6 is installed on the pile head 3 of the pile 2, it is only necessary to dig only the dug portion 111 against the ground 110 to form the recess 119.

  Next, the pile connection part 10 will be described with reference to FIGS.

  As shown in FIG. 2 and FIG. 3, the inter-pile connecting portion 10 connects the capital portions 6 of the pile heads 3 of the adjacent piles 2 so as to reliably maintain the interval between the adjacent piles 2. It has become. The inter-pile connection portion 10 is arranged in a lattice shape along the X direction and the Y direction across the capital portion 6 of the pile heads 3 of the plurality of piles 2.

  The connection part 10 between piles is comprised from the some 1st connection member 11 arrange | positioned in parallel with a X direction, and the some 2nd connection member 12 arrange | positioned in parallel to a Y direction, as shown in FIG. The inter-pile connecting portions 10 are arranged in a lattice shape along the X direction and the Y direction. The 1st connection member 11 and the 2nd connection member 12 are connection beams, such as steel structure, for connecting the capital parts 6 of a plurality of adjacent pile heads 3 mutually.

  As shown in FIG. 2 and FIG. 3, the 1st connection member 11 and the 2nd connection member 12 are comprised as a group by the number of 1 piece or 2 or more, respectively. 2 and 3, the two first connecting members 11 and the two second connecting members 12 are arranged in pairs. As shown in FIG. 2, a soil slab 130 is provided on the ground 110, and the thickness of the soil slab 130 is indicated by t. As shown in FIG. 2, the first connecting member 11 and the second connecting member 12 are provided with spacers, plates, mortars and the like for increasing the height of arrangement on the installation surface (upper surface) 7 of each capital portion 6. The pedestal 7R is fixed. The 1st connection member 11 and the 2nd connection member 12 are arrange | positioned away from the installation surface 7 of the capital part 6 using this base part 7R, and the 1st connection member 11 and the 2nd connection member 12 are the soil slabs 130. It is spaced apart from the top surface by a gap T. The inter-pile connection part 10 can firmly connect the capital parts 6 of the pile heads 3 of the adjacent piles 2, and can reliably maintain the interval between the adjacent piles 2. Thereby, at the time of an earthquake occurrence, when the pile head 3 rotates and the bending moment is transmitted from the pile head 3 to the capital part 6, the capital part 6 is connected to this capital part 6. Since the bending moment in the reverse direction that is bent back by the connecting portion 10 between the piles is received, the rotation of the pile head 3 of each pile 2 is suppressed by the rigidity of the connecting portion 10 between the piles. Yes.

  As the 1st connection member 11 and the 2nd connection member 12 of the connection part 10 between piles, the steel frame beam of H steel is preferably employ | adopted together, and other forms, such as a reinforced concrete structure, are employ | adopted as this steel beam. Compared to the use of this beam, it is lighter and cheaper, and is a dry type that does not use ready-mixed concrete, so it is easy to handle and the construction period can be shortened, so that the cost can be reduced. In addition, although the height of the beam of the 1st connection member 11 and the 2nd connection member 12 is 400 mm, for example, the width of a beam is 200 mm, It is not limited to this. The material of the first connecting member 11 and the second connecting member 12 is not limited to steel structure, but is reinforced concrete beam, steel reinforced concrete beam, various concrete structures such as high toughness concrete structure, prestressed concrete (PC) and the like. May be.

  As shown in FIG. 2, the 1st connection member 11 and the 2nd connection member 12 are fixed with respect to the installation surface 7 of the capital part 6, for example using a volt | bolt, and as shown in FIG. The first connecting member 11 and the second connecting member 12 are in a cross beam shape. The intersecting portion G of the first connecting member 11 and the second connecting member 12 shown in FIG. 3 is fixed by, for example, abutting each other on the installation surface 7 of the capital portion 6 and welding. The intersecting portions G of the first connecting member 11 and the second connecting member 12 are fixed at the positions of the four corners of one capital portion 6, respectively.

  In FIG. 2, the soil slab 130 is concrete covering the ground 110. The 1st connection member 11 and the 2nd connection member 12 of the connection part 10 between piles shown in FIG. 2 are hold | maintained in the state separated from the upper surface 112 of the soil slab 130 only by the clearance gap T in the Z direction (upward). The state where the first connecting member 11 and the second connecting member 12 are separated from the upper surface 112 of the soil slab 130 by a gap T by being fixed on the installation surface 7 of the capital portion 6 with the pedestal portion 7R interposed therebetween. Is held securely.

  For this reason, as shown in FIG. 2, the first connecting member 11 and the second connecting member 12 are not embedded in the ground 110 of the seismic isolation pit 120, and the soil slab 130 is in contact with the gap T. Absent. In other words, the first connecting member 11 and the second connecting member 12 are connecting beams that connect the capital portions 6 of the pile heads 3 of the adjacent piles 2. The member 12 is located away from the upper surface 112 of the dirt slab 130. Therefore, in the embodiment of the present invention, unlike the conventional case, the first connecting member 11 and the second connecting member 12 are arranged in a lattice shape along the X direction and the Y direction in the seismic isolation pit 120. Regardless, it is not necessary to excavate the ground 110 over a long distance in order to fill the ground 110 with the first connecting member 11 and the second connecting member 12.

  Moreover, since the 1st connection member 11 and the 2nd connection member 12 exist in the position away from the upper surface 112 of the soil slab 130, the 1st connection member 11 and the 2nd connection member 12 of the connection part 10 between piles are caused by an earthquake. Even if the ground vibrates and there is ground deformation such as liquefaction, it is not affected by the ground deformation. Furthermore, since the 1st connection member 11 and the 2nd connection member 12 are in the position away from the upper surface 112 of the soil slab 130, the 1st connection member 11 and the 2nd connection member 12 of the connection part 10 between piles spring water. There is no clogging. Since the seismic isolation pit 120 does not collect water, the accumulated water does not cause rusting of the iron part or sanitary problems. In addition, in the pile foundation structure 1 shown in FIG. 2 and FIG. 3, since there is a gap T below the first connecting member 11 and the second connecting member 12, spring water is not shown in the figure but can flow to the lower berth side. it can.

  As shown in FIGS. 2 and 3, two first connecting members 11 and two second connecting members 12 are fixed to the installation surface 7 of each capital section 6 as a pair. However, the present invention is not limited to this, and each of the first connecting member 11 and the second connecting member 12 may be configured by one, or may be configured by three or more.

  Moreover, although the 1st connection member 11 and the 2nd connection member 12 have connected the pile head 3 of the adjacent pile 2 mutually, many flat connecting beams are adjacent to the ground like before without performing ground improvement. Compared to the structure that is used, it is less susceptible to ground deformation. Therefore, when inspecting the seismic isolation device 5 shown in FIG. easy.

  As already explained, the conventional flat bridge beam with a pile-head isolation structure is a reinforced concrete structure, and the ground is adjacent to the upper side of the flat link beam. Excavation work is required, the amount of soil is increased, the construction period is long, and the cost cannot be reduced in the construction. Since the soil slabs are adjacent to the upper side of many flat connecting beams of the conventional pile head isolation structure, they are directly affected by the deformation of the ground when an earthquake occurs. Moreover, if the level of the grid-like flat connecting beam is raised to make it a reverse beam, water will be blocked. In addition, in the case of a forward beam, the distance between the beams is long, so that water accumulates in a portion where the center of the beam is lowered. For this reason, conventionally, water is accumulated in the seismic isolation pit, and the accumulated water may cause rusting of the iron part and sanitary problems.

  By the way, in 1st Embodiment of this invention shown in FIGS. 1-3 mentioned above, the 1st connection member 11 and the 2nd connection member 12 of the connection part 10 between piles are Z direction (upward) from the upper surface 112 of the soil slab 130. ) Are held apart by a gap T. However, the present invention is not limited to this, and the first connecting member 11 and the second connecting member 12 of the inter-pile connecting portion 10 may be on the soil slab 130. That is, the 1st connection member 11 and the 2nd connection member 12 of the connection part 10 between piles may be in contact with the soil slab 130. FIG.

  Moreover, the form which the capital part protrudes from the circumference | surroundings of a pile not only the form extended from the circumference | surroundings of a pile may be sufficient.

(Second embodiment)
FIG. 4A is a plan view showing a second embodiment of the pile foundation structure of the present invention.

  In the pile foundation structure 1 </ b> A shown in FIG. 4A, the capital portion 6 is arranged so as to protrude along the X direction and the Y direction around the pile head 3 of the pile 2. The two opposing side surface portions 8 are along the X direction, and the remaining two opposing side surface portions 9 of the capital portion 6 are along the Y direction. This is the same as the case of the pile foundation structure 1 of the first embodiment of the present invention shown in FIGS. 2 and 3. When the elements of the pile foundation structure 1A shown in FIG. 4 (A) are the same as the elements of the pile foundation structure 1 shown in FIGS. 2 and 3, the same reference numerals are given and the description thereof is omitted.

  The pile foundation structure 1A shown in FIG. 4 (A) is different from the pile foundation structure 1 shown in FIGS. 2 and 3 in that the end of the first connecting member 11A of the inter-pile connecting portion 10A and the second connecting member. That is, the end portion of 12A is directly fixed to the installation surface 7 of each capital portion 6. The first connecting member 11A and the second connecting member 12A are spaced apart from the soil slab, or are on the soil slab, that is, separated from or in contact with the soil slab, according to the first embodiment. Same as the case.

  Thereby, the intersection part G can be omitted in the installation surface 7 of each capital part 6 shown in FIG. 3, and the cost can be further reduced. The first connecting member 11A and the second connecting member 12A of the inter-pile connecting portion 10A can reliably hold the interval between the adjacent piles 2, and the ground vibrates due to an earthquake, and there is deformation of the ground such as liquefaction. Even so, it is not affected by ground deformation. In addition, the first connecting member 11A and the second connecting member 12A of the connecting portion 10A between the piles are lighter and cheaper than adopting other types of beams such as reinforced concrete structures by adopting steel beams. In addition, since it is a dry type that does not use ready-mixed concrete, construction can be speeded up, so that costs can be reduced. The number of the first connecting member 11A and the second connecting member 12A of the inter-pile connecting portion 10A may be one, or may be three or more.

(Third embodiment)
FIG.4 (B) is a top view which shows 3rd Embodiment of the pile foundation structure of this invention.

  The pile foundation structure 1B shown in FIG. 4 (B) is different from the pile foundation structure 1 shown in FIGS. 2 and 3 in the following points. That is, two opposing side surface portions 8B and two opposing side surface portions 9B of the capital portion 6 are disposed with an inclination of 45 degrees with respect to the X direction and the Y direction. And the edge part of the 1st connection member 11B and the edge part of the 2nd connection member 12B of the connection part 10B between piles are being fixed to the four corner | angular parts of the installation surface 7 of the capital part 6. FIG.

  The first connecting member 11B and the second connecting member 12B of the inter-pile connecting portion 10B in FIG. 4B are spaced apart from the soil slab or on the soil slab, that is, away from the soil slab. The presence or contact is the same as in the first embodiment. Thereby, the crossing part G can be omitted in the installation surface 7 of each capital part 6 shown in FIG. 3, and the cost can be further reduced. The first connecting member 11B and the second connecting member 12B of the inter-pile connecting portion 10B can reliably hold the interval between the adjacent piles 2, and the ground vibrates due to an earthquake, causing liquefaction and other ground deformation. Even so, it is not affected by ground deformation. Moreover, the 1st connection member 11B and the 2nd connection member 12B of the connection part 10B between piles are cheap compared with employ | adopting other types of beams, such as a reinforced concrete structure, by adopting a steel beam etc., Because construction can be done quickly, costs can be reduced. The number of the first connecting members 11B and the second connecting members 12B of the inter-pile connecting portion 10B may be one, or may be three or more.

(Fourth embodiment)
FIG. 5: is sectional drawing which shows 4th Embodiment of the pile foundation structure of this invention.

  When the element of the pile foundation structure 1C shown in FIG. 5 is the same as the element of the pile foundation structure 1 shown in FIG. 2, the same code | symbol is described and the description is abbreviate | omitted. The structure of the pile foundation structure 1C shown in FIG. 5 is different from the structure of the pile foundation structure 1 shown in FIG. 2 in the following points.

  In the pile foundation structure 1C shown in FIG. 5, it is omitted to fix the capital part 6 shown in FIG. 2 in the vicinity of the pile head 3 of the pile 2, and the first connecting member 11 </ b> C and the second connecting member 11 </ b> C of the inter-pile connecting part 10 </ b> C. The connecting member 12C is directly fixed to the gusset plate 2P of the outer peripheral portion 2G of the pile 2 using bolts and nuts. The pile 2 is a cast-in-place steel pipe concrete pile, for example. The gusset plate 2P is not fixed to the outer peripheral portion 2G of the pile 2 in advance.

  By adopting this structure, it is possible to omit the installation of the capital part 6 with respect to the pile head 3 of the pile 2, the structure is simplified, and the cost can be reduced. The number of the first connection members 11C and the second connection members 12C of the inter-pile connection portion 10C connected between the pile heads 3 of the plurality of adjacent piles 2 may be one, or 2 as shown in FIG. It may be more than a book.

(Fifth embodiment)
FIG. 7 shows a fifth embodiment of the pile foundation structure of the present invention, and FIG. 7 (A) shows a state in which a detachable attachment plate 40 is attached to the outer peripheral portion 2G of the pile 2. . FIG. 7B is a plan view of the outer peripheral portion 2G of the pile 2 and the detachable mounting plate 40 as seen from the line FF in FIG. 7A.

  The mounting plate 40 shown in FIG. 7 has a groove portion 41, and the outer peripheral portion 2 </ b> G of the pile 2 is fitted into the groove portion 41, so that the mounting plate 40 is fixed to the outer peripheral portion 2 </ b> G of the pile 2. The inner portion 43 of the mounting plate 40 has a plurality of long nuts 42, and the long nuts 42 are directed in the X direction (or Y direction). The outer portion 44 of the mounting plate 40 is connected to the end of the first connecting member 11C or the end of the second connecting member 12C of the inter-pile connecting portion 10C by a bolt and nut. The fixing plate 45 is fixed to the inside of the pile 2. For example, one end portion side of a long screw bolt (or threaded different diameter reinforcing bar) 47 is attached to the fixing plate 45 using a nut 46. The other end of the long screw bolt (or threaded different diameter reinforcing bar) 47 is screwed into the long nut 42, so that the fixing plate 45 and the mounting plate 40 are connected in tension by the long screw 47. The mounting plate 40, the fixing plate 45, the long nut 42, the nut 46, and the long screw 47 constitute an out-of-plane deformation preventing unit 70. The out-of-plane deformation preventing portion 70 has a function of preventing the outer peripheral portion 2G of the pile 2 that is a steel pipe pile from swelling out of plane when a tensile force SS is applied in the arrow direction in the inter-pile connecting portion 10C.

  Thereby, the 1st connection member 11C or the 2nd connection member 12C of the connection part 10C between piles is directly fixed to the outer peripheral part 2G of the pile 2 using the attachment board 40. As shown in FIG. And even if the 1st connection member 11C or the 2nd connection member 12C of the connection part 10C between piles receives the pulling force SS toward the outer side, the outer peripheral part 2G of the pile 2 faces the outer side. It can prevent that it deforms out of the plane, and while maintaining the shape of the pile head 3 of the pile 2, the distance between adjacent piles can be maintained. Concrete is added and placed in the steel pipe of the pile 2.

(Sixth embodiment)
FIG. 8 shows a sixth embodiment of the pile foundation structure of the present invention.

  In FIG. 8, the through hole 50 is provided in the outer peripheral portion 2 </ b> G of the pile 2 at an opposing position. A rod-like body 51 for applying tension is passed through the through hole 50. This rod-shaped body 51 is, for example, a (PC) steel rod, and screws 52 are formed at both ends. The screw 52 of the rod-shaped body 51 protrudes to the outside of the outer peripheral portion 2G through the through hole 50 of the pile 2, and the hole of the first connecting member 11C or the hole of the second connecting member 12C of the inter-pile connecting portion 10C has a rod shape. The screw 52 of the body 51 is passed. The first connecting member 11C or the second connecting member 12C is directly fixed to the outer peripheral portion 2G of the pile 2 by attaching and tightening the nut 55 to the screw 52. The rod-shaped body 51 and the nut 55 constitute an out-of-plane deformation preventing portion 170. The rod 51 is coated with an insulating material such as asphalt or resin, or is passed through a separately provided sleeve material so that it can be insulated from concrete to be placed later. In the steel pipe of the pile 2, after adding concrete and placing it, tension is given.

  Thereby, even if the 1st connection member 11C or the 2nd connection member 12C receives the tensile force SS toward the outer side, the out-of-plane deformation preventing portion 170 causes the rod-shaped body 51 to compress the tensile force SS against the tensile force SS. By exhibiting RS, the outer peripheral portion 2G of the pile 2 can be prevented from being deformed out of plane toward the outside, and the shape of the pile head of the pile 2 is maintained and the distance between adjacent piles is maintained. can do.

(Seventh embodiment)
9 and 10 show a seventh embodiment of the pile foundation structure of the present invention, FIG. 9 (A) is a plan view of the pile foundation structure 1D, and FIG. 9 (B) is a diagram of FIG. It is a side view of pile foundation structure 1D shown to 9 (A). FIG. 10 shows a portion M of the pile foundation structure 1D of FIG. 9B as a representative example.

  In FIG. 9, the pile foundation structure 1 </ b> D is a seismic isolation structure that supports the upper support object as a seismic isolation as an example. This support object is, for example, a large-scale logistics facility that is an example of a building. The floor 101D on the first floor and the footing 102D on the first floor of the foundation 100D of the large-scale logistics facility shown in FIG. 9 sandwich the seismic isolation device 105 with a sliding support with a rotating mechanism with respect to the pile foundation structure 1D. Seismic isolation is supported.

  As shown in FIG. 9, the plurality of piles 2 of the pile foundation structure 1 </ b> D are, for example, cast-in-place steel pipe concrete piles, and the pile head 3 of the pile 2 is provided with a capital portion 106. Between the capital part 106 and the footing 102D on the first floor, a seismic isolation device 105 for a sliding support with a rotation mechanism is installed. The capital part 106 can also be called a pile head capital or a pile cap part.

  As illustrated in FIG. 10, the seismic isolation device 105 of the sliding support with a rotation mechanism includes, for example, a concave member 105R, a convex member 105S fitted into the concave member 105R, and a clearance between the concave member 105R and the convex member 105S. It has a foam material 105T to be filled, a slip receiving material 105F, and the like. The slip receiving material 105F is fixed to the lower surface of the footing 102D. The concave member 105R, the convex member 105S, and the foam material 105T serve as a slider with respect to the slip receiving material 105F. Compared with the laminated rubber seismic isolation device 5 shown in FIG. 2, the sliding bearing with a rotating mechanism 105 can be reduced in height and is inexpensive.

  As shown in FIG. 9A, the capital portion 106 is arranged so as to project along the X direction and the Y direction around the pile head 3 of the pile 2, and has a square shape when viewed from above. The dimension in the X direction and the dimension in the Y direction orthogonal to the X direction are the same. Two opposing side surface portions 8D of the capital portion 106 are along the X direction, and the remaining two opposing side surface portions 9D of the capital portion 106 are along the Y direction. The capital part 106 is, for example, a reinforced concrete structure.

  Next, with reference to FIG. 9B and FIG. 10, the inter-pile connection portion 10 </ b> D will be described.

  9 is arranged in a grid pattern along the X direction and the Y direction by connecting the capital portions 106 of the pile heads 3 of the adjacent piles 2. This inter-pile connection portion 10 is composed of a plurality of first connection members 11D arranged in parallel to the X direction and a plurality of second connection members 12D arranged in parallel to the Y direction. As 1st connection member 11D and 2nd connection member 12D, the capital parts 106 of several adjacent pile heads 3 are connected. The first connecting member 11 </ b> D and the second connecting member 12 </ b> D are each fixed to each capital portion 106 as a pair. The two first connecting members 11D are connected to each other by a connecting auxiliary material in order to increase rigidity, and the two second connecting members 12D are connected to each other by a connecting auxiliary material to increase rigidity.

  As illustrated in FIG. 9A, a portion 11M of the first connecting member 11D and a portion 12M of the second connecting member 12D are integrally formed in advance with respect to the capital portion 106, so that the cross-beam-shaped unit 200 is formed. Can be formed and prepared. As shown in FIG. 10, a portion 11 </ b> M of the first connecting member 11 </ b> D and a portion 12 </ b> M of the second connecting member 12 </ b> D are fixed to the capital portion 105 using a connecting reinforcing bar 150. The cross-girder-shaped unit 200 is prepared in advance, and the cross-girder-shaped unit 200 can be installed on the pile head 3 of the pile 2 at the site of the seismic isolation work. The cross-girder-shaped unit 200 has margins in the X and Y directions. When the pile core is eccentric with respect to the column center of the building, the installation position of the seismic isolation device can be adjusted within the range of the cross-girder unit 200.

  The end of the first connecting member 11D is connected to the part 11M of the first connecting member 11D, and the end of the second connecting member 12D is connected to the part 12M of the second connecting member 12D. The 1st connection member 11D and the 2nd connection member 12D can connect the capital part 106 of the pile head 3 of the some pile 2 which adjoins each other.

  Thus, since the connection part 10D between piles has connected the capital parts 106 of the pile head 3 of the pile 2 which adjoins, the space | interval between the adjacent piles 2 can be hold | maintained reliably. As a result, when an earthquake occurs, the pile head 3 of the pile 2 is rotated and the bending moment is transmitted from the pile head 3 to the capital portion 106, the capital portion 106 is connected to the capital portion 106. Since the bending moment in the reverse direction that is bent back by the inter-pile connection portion 10D is received, the rotation of the pile head 3 of each pile 2 is suppressed by the rigidity of the inter-pile connection portion 10D. Both the first connecting member 11D and the second connecting member 12D preferably employ steel steel beams of H steel. By adopting this steel beam, compared to adopting other types of materials, Since the construction time can be shortened and the construction is easy, the cost can be reduced.

  As shown in FIGS. 9B and 10, the first connecting member 11D and the second connecting member 12D of the inter-pile connecting portion 10D are spaced apart from the upper surface 112D of the soil slab 110D or the soil slab 110D. The upper surface 112D of the soil slab 110D is held away from or in contact with the upper surface 112D of the soil slab 110D in the Z direction (upward). For this reason, the first connecting member 11D and the second connecting member 12D are not embedded in the ground 110 of the seismic isolation pit 120D. That is, the first connecting member 11D and the second connecting member 12D are connecting beams that connect the capital portions 106 of the adjacent pile heads 3 to each other.

  Above the pile 2, there is a pile head 3 made of concrete in which a part of the inter-pile connection portion 10 </ b> D is embedded. In other words, the pile connecting portion 10D is integrated with the cast-in-place concrete. Thereby, since the connection part 10D between piles is embed | buried in concrete, construction is easy, and a construction period shortening and construction cost control can be aimed at.

  Therefore, unlike the conventional case, the first connecting member 11D and the second connecting member 12D are arranged on the ground 110 in the seismic isolation pit 120D in spite of being arranged in a lattice shape along the X direction and the Y direction. In order to fill the first connecting member 11D and the second connecting member 12D, it is not necessary to excavate the ground 110 over a long distance.

  In the example shown in FIG. 10, the first connecting member 11D and the second connecting member 12D are located away from the top surface 112D of the soil slab 110D of the seismic isolation pit 120D or on the soil slab, that is, away from the soil slab. Since the first connection member 11D and the second connection member 12D of the inter-pile connection portion 10D can reliably hold the interval between the adjacent piles 2 because the ground is vibrated by an earthquake, Even if there is a change in the ground, such as liquefaction, it is not affected by the change in the ground. Also, the first connecting member 11D and the second connecting member 12D are located away from the top surface 112D of the soil slab 110D of the seismic isolation pit 120D or on the soil slab, that is, at a position away from the soil slab, or Since the first connecting member 11D and the second connecting member 12D of the inter-pile connecting portion 10D do not block water, the seismic isolation pit 120D does not collect water, and the accumulated water There is no risk of adverse effects such as rusting on the piles 2 and the like, and no sanitary problems occur.

  As illustrated in FIG. 10, when constructing the pile foundation structure 1 </ b> D, for example, after placing the on-site pile 2 </ b> W, the concrete including the cross-shaped unit 200 is placed on the on-site pile 2 </ b> W. Concrete is placed so that the unit 2V is integrated. As shown in FIGS. 2 and 3, the first connecting member 11 </ b> D and the second connecting member 12 </ b> D of the inter-pile connecting portion 10 </ b> D each form a pair. However, the present invention is not limited to this, and each of the first connecting member 11D and the second connecting member 12D may be configured by one, or may be configured by three or more.

  In addition, the first connecting member 11D and the second connecting member 12D connect the pile heads 3 of the adjacent piles 2 to each other. However, when the ground improvement is not performed, a number of flat connecting beams are provided in the ground as in the past. 2 is less susceptible to ground deformation when the seismic isolation device 105 shown in FIG. 2 is inspected, so that the inspection operator can be located near the seismic isolation device 105. Close and easy to check.

  The pile foundation structure of the embodiment of the present invention described above is a pile foundation structure that supports an upper support object on the pile head of the pile, and the inter-pile connection that connects the pile heads of adjacent piles. The inter-pile connecting portion is held away from the soil slab or on the soil slab.

  Thereby, in the pile foundation structure, the connection part between piles is kept away from the soil slab or on the soil slab. That is, the connection part between piles is hold | maintained in the state which left | separated from the soil slab or contacted the soil slab. In the pile foundation structure, the interval between the piles can be reliably maintained, it is difficult to be affected by the deformation of the ground that occurs when an earthquake occurs, and the construction period can be shortened and the construction cost can be reduced. That is, the connection part between piles which connects the pile heads of an adjacent pile can hold | maintain the space | interval between piles reliably. The joint between piles is affected by the deformation of the ground caused by the occurrence of an earthquake by being held away from the soil slab or on the soil slab, i.e., separated from the soil slab or in contact with the soil slab. Absent.

  Moreover, conventionally, since the soil slab is adjacent to the upper side of the flat connecting beam, it has been necessary to excavate the ground deeply over a long distance. However, since the inter-pile connecting portion of the embodiment of the present invention is held away from the soil slab or on the soil slab, there is no excavation work of such ground, so the construction is easy and the construction period is shortened. And can reduce construction costs. In the embodiment of the present invention, since the conventionally used flat bridging beam is unnecessary, water is not blocked by the flat bridging and the water does not accumulate, and the water has an adverse effect such as rusting on the iron part of the foundation part. And no hygiene problems.

  In the pile foundation structure of the present invention, the object to be supported is preferably a structure of ground deformation caused by the occurrence of an earthquake by adopting a structure that is seismically isolated and supported by a seismic isolation device installed at the pile head of the pile. It is less affected and can reduce the cost of seismic isolation work for supporting objects.

  Moreover, in the pile foundation structure, the capital part is preferably fixed to the pile head of the pile, the capital part is arranged in the concave portion of the ground, and the connection part between the piles is fixed on each capital part. As a result, the pile heads of adjacent piles are connected. Thereby, a capital part is fixed to the pile head part of a pile, and the operation | work which excavates the recessed part of a ground is needed in order to arrange | position this capital part. However, in the past, since the soil slab is integrated with the upper part of the side of the flat connecting beam, it is necessary to excavate the ground deeply over a long distance. Since less excavation work is required, the construction period can be shortened, the construction can be facilitated, and the construction cost can be reduced.

  In the pile foundation structure, preferably, the pile is a steel pipe pile, and an end portion of the connection portion between the piles is directly fixed to an outer peripheral portion of a pile head portion of each pile. Thereby, without fixing a capital part with respect to the pile head of a cast-in-place steel pipe concrete pile, the edge part of a connection part between piles is directly fixed with respect to the outer peripheral part of the pile head of a pile. For this reason, the work of excavating the ground to dispose the capital portion is not necessary, so that the construction cost can be further reduced.

  In the pile foundation structure, the pile includes a steel pipe, and the outer peripheral portion of the steel pipe has an out-of-plane deformation preventing portion on the outside when a tensile force is applied to the connecting portion between the piles. Thereby, even if tensile force is added to the connection part between piles, since it can prevent that the outer peripheral part of a steel pipe swells outside, while maintaining the shape of a steel pipe, the distance between adjacent piles can be hold | maintained.

  In the pile foundation structure, since the connecting part between the piles is preferably a steel frame, compared to using a reinforced concrete beam or a steel reinforced concrete beam, the handling at the time of construction is easy, the construction period can be shortened, and the cost can be reduced. .

  By using the pile foundation structure of the embodiment of the present invention, ground improvement for preventing liquefaction can be eliminated, for example, in the ground for connecting pile heads of piles directly under the seismic isolation device Reinforced concrete flat connecting beams can be eliminated, so the construction period can be shortened and costs can be reduced.

  The capital part of the pile may be precast, and even if a long steel beam straddling the capital part is fixed to the capital part, a short steel beam connecting between the capital parts is connected and fixed to the capital part. Also good.

  In the pile foundation structure of the embodiment of the present invention, when the seismic isolation structure is provided with a seismic isolation device, even if this seismic isolation structure is applied to all the piles of the foundation supporting the building, Or you may apply only to the one part selected pile of foundation piles.

  The steel beams that make up the connecting part between piles are separated (floating) or in contact with the soil slab as already explained, so water does not hinder the movement of water, so water accumulates at the foundation of the building Because there is no, there is no problem of rusting and hygiene of the iron part. Even if liquefaction occurs in the ground due to an earthquake, the steel beams that make up the connection part between piles are generally healthy, so that seismic isolation devices can be inspected, and the pile foundation structure including the pile and the upper part The soundness of the structural main frame can be secured.

  The pile foundation structure according to the embodiment of the present invention can be applied even when the seismic isolation device is not installed or when it is installed. A form in which the building foundation is fixed to the pile head, a form in which the building foundation is semi-fixed to the pile head, or a form in which the building foundation is connected to the pile head with a pin However, they can be mixed in the building foundation. For this reason, in the case of new construction of buildings or improvement of existing buildings, the fixing form of these three pile heads can be changed as appropriate, and the design of the foundation adjusted for the degree of fixation is the object to be supported. It is possible depending on the situation.

  Although the steel pipe pile is mentioned as an example of a pile, it is not restricted to this, A spot cast concrete pile, a cast-in-place steel pipe concrete pile, an iron pipe pile, a ready-made pile, etc. can also be employ | adopted.

  The present invention has been described with reference to the embodiments. However, each embodiment of the present invention is an example, and the scope of the invention described in the claims of the present invention is within the scope not departing from the gist of the invention. Various changes can be made.

  The illustrated pile foundation structure of each embodiment of the present invention is a seismic isolation structure in which a seismic isolation device is installed between the pile head of the pile and the foundation portion of the upper support object. However, the pile foundation structure of the present invention is not limited to this seismic isolation structure, and is a structure that directly fixes the pile head of the pile and the foundation portion of the upper support object without installing a seismic isolation device. There may be.

  For example, in the pile foundation structure 1 according to the first embodiment of the present invention shown in FIG. 3, a part of the first connecting member 11, a part of the second connecting member 12, and the crossed portion G in the cross-beam shape are It can be prepared in advance by fixing the crossing portion G and the capital portion 6 in a cross-beam shape in advance. Thereby, with respect to the crossed portion G of the cross section G of the capital portion 6 of the pile head 3 of the pile 2, the end of the first connecting member 11 and the end of the second connecting member 12 are bolted at the construction site. By connecting with a nut or the like, the construction can be performed more easily, the construction period is short, and the construction cost can be reduced.

  By adopting the pile foundation structure of the embodiment of the present invention, it is not necessary to place a flat connecting beam, so the amount of concrete can be reduced, and since no flat connecting beam is required, the amount of ground excavation can be reduced. Since the cost can be reduced, the construction cost can be reduced and the construction period can be shortened, so that the cost can be reduced.

  As a building which is a support object to which the pile foundation structure of the embodiment of the present invention is applied, a large-scale logistics facility has been described as an example. However, this large-scale logistics facility is constructed on soft ground, for example. For example, it is a high-rise article such as a high-rise logistics center having two or more layers, and the height and scale are not limited. However, the present invention is not limited to this, and the support object to which the pile foundation structure of the embodiment of the present invention is applied may be, for example, a factory, an office building, a house, etc. in addition to a large-scale logistics facility. As a support object, it can select from arbitrary things, such as a reinforced concrete structure, a steel frame structure, and a steel frame reinforced concrete structure. The pile foundation structure according to the embodiment of the present invention is not limited to the case of a newly-supported support object, and can be applied to an existing support object. The steel pipe pile includes an object in which hollow or concrete is even cast, and further includes an object obtained by adding a steel pipe to the completed pile.

DESCRIPTION OF SYMBOLS 1 Pile foundation structure 2 Pile 3 Pile head 5 Seismic isolation device 6 Capital part 10 Pile connection part 70 Out-of-plane deformation prevention part 110 Ground 130 Soil slab 170 Out-of-plane deformation prevention part

Claims (7)

A pile foundation structure that supports the upper support object on the pile head of the pile,
It comprises an inter-pile connection part that connects the pile heads of the adjacent piles,
The said pile connection part is separated from the soil slab, or is hold | maintained on the soil slab, The pile foundation structure characterized by the above-mentioned.   The pile foundation structure according to claim 1, wherein the support object is seismically isolated and supported by a seismic isolation device installed at the pile head of the pile.   The capital part is fixed to the top part of the pile, and the connecting part between the piles is fixed on each of the capital parts, thereby connecting the pile heads of the adjacent piles. The pile foundation structure according to claim 1 or 2, wherein the pile foundation structure is provided.   The pile foundation structure according to claim 1 or 2, wherein an end of the connection part between piles is directly fixed to an outer peripheral part of the pile head of each pile.   The pile has a steel pipe, and has an out-of-plane deformation preventing portion that prevents the outer peripheral portion of the steel pipe from being deformed out of plane when a tensile force is applied to the connecting portion between the piles. The pile foundation structure according to claim 4.   The pile foundation structure according to claim 1 or 2, wherein a pile head is made of concrete in which a part of the inter-pile connection portion is embedded above the pile.   The pile foundation structure according to any one of claims 1 to 6, wherein the connection part between piles is a steel frame.

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