JP5280799B2 - Pile foundation for buildings and buildings - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pile foundation having a foundation body stably supported by piles. <P>SOLUTION: A pile 24 is disposed on the lower side of the footing 22B of the foundation body 22. Since the axis of a column 12, the lateral center line of the footing 22B, and the axis of the pile 24 are aligned with one another, the vertical load of a prefabricated building 10 which is transmitted from the column 12 in the lateral direction of the footing 22B can act uniformly on the pile. Since the axis of the footing is aligned with the axis of the pile 24, a uniform vertical load acts on the axis of the pile 24 on both sides of the footing 22B in the lateral direction. Therefore, the pile 24 can stably support the foundation body 22 disposed on the upper side thereof, a moment is prevented from being produced on the foundation body 22 by the vertical load of the prefabricated building 10, and the foundation body 22 is stably formed. Since the torsional deformation of the foundation body 2 is suppressed, the durability of the foundation body 22 is also improved. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a pile foundation for a building and a building.

When building a house on soft ground, a pile may be struck to reinforce the ground (see, for example, Patent Documents 1 and 2).
JP-A-11-093273. Japanese Patent Laid-Open No. 2006-127186.

  The ground can be reinforced by driving the pile into the ground. However, if the position of the pile and the position of the foundation body placed on it are not appropriate, the pile cannot reliably support the foundation body, the foundation body may be distorted, or the durability of the foundation body There is a concern that this may cause problems such as lowering.

  This invention considers the said fact and aims at provision of the pile foundation by which a foundation main body is stably supported by a pile.

A pile foundation for a building according to claim 1, comprising a footing and a rising part integrally standing at an upper end of the footing, and supporting a vertical load of the building, and disposed below the footing A pile foundation for a building having a pile to be constructed, wherein the building is formed by connecting a plurality of adjacently arranged building units, and the center of gravity coincides with the width center line of the footing A plurality of the piles are arranged along the beam of the building, and a column of one of the building units and a column of the other building unit are arranged adjacent to each other to form a plurality of columns. The common piles are arranged below the plurality of pillars , and the pillars are mounted and fixed on the upper surface of the foundation body, and the beams of the building are Located apart from the upper surface of the base body To have.

Next, the effect | action of the pile foundation for buildings of Claim 1 is demonstrated.
By arranging the pile below the footing, the vertical load of the building is transmitted to the pile through the foundation body.
Furthermore, since the individual building units are stably and reliably supported by the pile foundation, it is possible to prevent problems such as the building units being shifted from each other.
In addition, when a pillar of one building unit and a pillar of the other building unit are arranged adjacent to each other and a plurality of pillars are combined, a pile is placed below the combined pillars. It is preferable to arrange them, whereby vertical loads from a plurality of columns can be supported by a common pile.
When the pile foundation is viewed in plan, the vertical load of the building can be applied evenly across the width direction of the footing by matching the width center line of the footing and the center of gravity of the pile. A moment (when viewed in a cross section in the longitudinal direction of the foundation) is prevented from occurring in the main body, and the basic main body can be stabilized. In addition, since the torsional deformation of the basic body is suppressed, the durability of the basic body is also improved.
Moreover, when the vertical load of a building acts along a beam and a foundation main body supports this vertical load, it is preferable to arrange | position the pile which receives this vertical load along a beam. As a result, the vertical load acting along the beam, that is, the vertical load acting along the longitudinal direction of the foundation is supported by the plurality of piles, and the longitudinal deflection of the foundation body due to the vertical load is prevented. Can do.

The invention according to claim 2 is the pile foundation according to claim 1, wherein the common pile is one, and the center of gravity of the plurality of columns and the center of gravity of the one pile coincide with each other. Yes.

  According to a third aspect of the present invention, in the pile foundation for a building according to the first or second aspect, when viewed in plan, the axis of the pile and the vertical load of the building act on the foundation main body. The point matches.

Next, the effect | action of the pile foundation for buildings of Claim 3 is demonstrated.
By matching the axial center of the pile when viewed in plan with the point at which the vertical load of the building acts on the foundation body, the building's vertical load acts on the pile directly below the foundation body. Thereby, the pile can receive the vertical load of a building reliably and stably, and the force of the direction which falls a pile is not applied to a pile, and it becomes a preferable aspect also on the durability of a pile.

  According to a fourth aspect of the present invention, in the pile foundation for a building according to the third aspect, the point is a position where a pillar constituting the building is erected.

Next, the effect | action of the pile foundation for buildings of Claim 4 is demonstrated.
Since the vertical load of the building acts on the lower ends of the pillars constituting the building, the point where the vertical load of the building acts on the foundation body is specifically the position where the pillars constituting the building are erected. .

Therefore, in this case, the pile is arranged directly under the pillar.
Thereby, the vertical load transmitted from the column can be applied to the pile arranged immediately below the column via the foundation body.

Invention of Claim 5 is the pile foundation for buildings of Claim 3, The said point is arrange | positioned between the pillars of the said building unit, and the said building which connects the said pillars The load transmitting member is disposed between the beam and the foundation main body and transmits the vertical load of the building to the foundation main body, and the pile is disposed immediately below the load transmitting member. ing.

Next, the effect | action of the pile foundation for buildings of Claim 5 is demonstrated.
The vertical load of the building acts on the lower ends of the columns that make up the building. For example, the vertical load of the building is applied from the beam to the foundation between the foundation body and the beam placed between the columns. When the load transmission member to be transmitted to the main body is arranged, the vertical load of the building is transmitted to the foundation main body also from the portion where the load transmission member is arranged.

Therefore, in this case, the pile is disposed directly below the load transmission member.
Thereby, the vertical load transmitted from the load transmitting member can be applied to the pile disposed directly below the column via the foundation body.

  A sixth aspect of the present invention is the building pile foundation according to any one of the first to fifth aspects, wherein the footing has a constant width.

Next, the effect | action of the pile foundation for buildings of Claim 6 is demonstrated.
By forming the footing width constant, the vertical load can be stably supported along the longitudinal direction of the pile foundation. In addition, by forming the footing width constant, it is easy to construct a foundation body that integrally includes the footing.

  The invention according to claim 7 is the pile foundation for a building according to any one of claims 1 to 6, wherein the axis of the column arranged along the outer periphery of the building is The said pile is arrange | positioned under the outer peripheral part of the said base main body so that the axial center of a pile may correspond.

Next, the effect | action of the pile foundation for buildings of Claim 7 is demonstrated.
In a building such as a house, the load support performance particularly in the outer peripheral portion of the building is important from the viewpoint of load support of the building and the viewpoint of external force due to an earthquake or the like. For this reason, it is preferable to arrange the pile below the outer peripheral portion of the foundation main body so that the axis of the pile coincides with the axial center of the column arranged along the outer peripheral portion of the building when viewed in plan. Thereby, a building can be supported stably and reliably.

Building according to claim 8, comprising the pile foundation according to any one of claims 1 to 7, having a pillar which is arranged on the axis of the pile.

Next, the operation of the building according to claim 8 will be described.
The building of claim 8 includes the pile foundation according to any one of claims 1 to 7 , and the pillar is disposed on the axis of the pile, so even if the ground is soft, It is supported stably and securely on the ground.

  As described above, according to the pile foundation for buildings of the present invention, the foundation body is stably supported by the pile even when the ground is soft.

  Moreover, according to the building of this invention, even if the ground is soft, it is stably supported by the pile foundation.

  As shown in FIG. 1, the unit building 10 of the present embodiment includes a plurality of building units 18 in which frames are arranged in a box shape with a plurality of columns 12, a ceiling beam 14, and a floor beam 16. It arrange | positions adjacent to a direction and is comprised by installing on the pile foundation 20 one by one. Although only the first floor is shown in the unit building 10 in FIG. 1, the building unit 18 may be arranged on the first floor building unit 18 to have two or more floors. The unit configuration is not limited to the above configuration, and may be another box-shaped frame structure.

  As shown in FIGS. 1 and 2, the ground 26 is provided with a pile foundation 20 for supporting the unit building 10. The pile foundation 20 of the present embodiment is composed of a concrete foundation main body 22 and a pile 24 that is arranged below the foundation main body 22 and extends in the vertical direction.

  As shown in FIG. 2, the basic body 22 of the present embodiment includes a rising portion 22A that extends in the vertical direction with a constant width, and a footing 22B that is integrally formed at the lower end of the rising portion 22A and extends in the width direction. The cross-sectional shape is an inverted T shape. In the basic body 22 of the present embodiment, the center line in the width direction of the rising portion 22A and the center line in the width direction of the footing 22B are coincident, and the cross-sectional shape is a symmetrical shape.

The pillar 12 of each building unit 18 is mounted and fixed on the upper surface of the foundation body 22 so that the vertical load of the building unit 18 is transmitted to the foundation body 22 through the pillar 12. In building unit 18 of the present embodiment, that the floor girders 16 are slightly spaced from the upper surface of the basic body 22.
In the present embodiment, when the foundation is viewed in plan, the relative positions of the pile 24 and the footing 22B are determined so that the width center line of the footing 22B matches the axis of the pile 24.

  Moreover, as shown in FIG. 2 (B), when the pile foundation 20 is viewed in plan, the part where the vertical load of the building unit 18 acts on the foundation body 22, for example, the part where the pillar 12 is arranged and the pile 24 It is preferable to determine the relative positions of the pile 24 and the column 12 so as to match the arranged portion, and it is more preferable to match the axis of the pile 24 and the axis of the column 12.

As shown in FIG. 3, a plurality of (in this case, two) piles 24 adjacent to each other may be arranged in pairs below the foundation body 22. In such a case, it is preferable to match the width center line of the footing 22B with the centers of gravity of the plurality of piles 24 adjacent to each other, and the axis of the column 12 and the plurality of piles It is preferable to match the center of gravity of 24 .

Furthermore, when a plurality of (four in this embodiment) pillars 12 adjacent to each other, such as on the center side of the unit building 10, are arranged in pairs, as shown in FIG. It is preferable to make the center of gravity G of the pillar 12 and the center of gravity of the pile 24 coincide.
In addition, although illustration is abbreviate | omitted, the pile 24 can arrange | position multiple pieces along the floor girder 16.

  As shown in FIG. 5, when a load transmission member 28 that transmits the vertical load of the building unit 18 to the foundation main body 22 is disposed between the floor beam 16 and the foundation main body 22, It is preferable to arrange the piles 24 directly below.

The footing 22B can be formed with a constant width along the longitudinal direction.
In addition, the cross-sectional shape perpendicular to the axial direction of the pile 24 is generally circular, but may be another conventionally known shape. Moreover, as a pile construction method, conventionally well-known various pile construction methods, such as a dry column improvement pile method, a wet column improvement pile method, a SMD construction method, and a duck pile construction method, can be used.

[Pile foundation design method]
Next, an example of an efficient design method for a pile foundation will be described with reference to the drawings.

  FIG. 6 shows a schematic configuration of a computer system 30 for performing pile foundation design. In FIG. 6, reference numeral 32 denotes a computer. The computer 32 includes a RAM 34, a CPU 36, a ROM 38, a hard disk drive 40 for storing programs and various data, an I / O 42, and the like. 46, a monitor 48, etc. are connected.

Below, the pile foundation design procedure of a unit house is demonstrated as an example.
(Advance preparation)
First, preparations are made before designing the pile foundation of the building.
As a preliminary preparation, as shown in FIG. 7, first, a pile method, a pile diameter, a pile strength, etc. are determined in advance (step (1) in FIG. 7), and the above contents are used for each pile. The pile foundation shape is determined in advance (step (2) in FIG. 7). Then, a structure calculation sheet is created in advance for each pile foundation shape with the above contents (step (3) in FIG. 7).

  As a pile method, multiple types of pile methods (for example, dry column improved pile method, wet column improved pile method, SMD method, duct pile method column shape improvement, etc.) may be used, or only a specific pile method may be used. good. And the pile yield strength of the pile to be used is determined in advance. Moreover, you may use several types of piles from which a diameter differs also with the same construction method, ie, a pile yield strength differs. In this case, the pile strength is determined in advance for each pile having a different diameter.

  As an example, in the columnar improvement method, for example, the pile strength is determined and prepared in advance for four types of piles having a diameter of 400 mm, 500 mm, 600 mm, and 800 mm. In the steel pipe pile method, for example, the diameter is 114.3 mm, 139 The pile strength is determined in advance and prepared for three types of piles such as .8mm and 165.2mm.

  As described above, in this embodiment, a plurality of pile foundation shapes are determined and prepared in advance for each pile number, and a calculation document for each pile foundation shape is prepared and prepared in advance.

Specifically, for example, as shown in FIGS. 8 and 9, a pile foundation shape in which a plurality of types of foundation main bodies 22 and piles 24 having different shapes such as the number of piles and linear shapes, L shapes, and cross shapes are paired. 50 is prepared in advance and stored in the computer 32, and a calculation document for each pile foundation shape is stored in the computer 32 so that it can be output at any time.
In the pile foundation shape 50 shown in FIGS. 8 and 9, the axes of all the piles 24 coincide with the width center line of the footing 22B.

  In the present embodiment, a plurality of pile foundation shapes 50 having different shapes in plan view of the foundation body 22 used for the beam receiving portion, the protruding corner portion, the entering corner portion, etc. are prepared in the computer 32 in advance, and the same shape Also in the pile foundation shape 50, those having different pile strength are prepared in advance in the computer.

  For example, as shown in FIG. 8, the pile foundation shape 50 having one pile, the pile foundation shape 50 having two piles, and the L-shaped pile foundation shape 50 in a plan view used for the protruding corners, and A pile foundation shape 50 with three piles is prepared in advance (difference in pile number = difference in pile strength). That is, in the computer 32 of this embodiment, the pile foundation shape 50, the pile strength of the pile foundation shape 50, and the calculation document of the pile foundation shape 50 are stored correspondingly.

(Individual design)
Next, the procedure for actually designing the pile foundation will be described.
First, after the customer's building shape, specifications, plane, etc. are determined, the axial force (vertical load) at each column position is calculated (step (4) in FIG. 7). This calculation can be performed by a computer as usual based on the building shape, specifications, plane, and the like. This calculation is the same for the conventional technique and this embodiment.

  On the other hand, for the site, as in the past, for example, a ground survey is performed by a SWS (Swedish Sounding) test or the like to obtain ground survey data. As the ground data, for example, the site is partitioned in a matrix, the ground strength of each partitioned region is obtained, and data regarding the site such as the site shape and ground survey data is input to the computer 32 and stored.

  And on the computer, the floor plan of the shed is superimposed on the site where the ground strength is known. For example, the site shape input to the computer 32 is displayed on the monitor 48, and a plan view of the roof in which the positions of columns and beams are described is superimposed on the site shape.

  The computer 32 compares the axial force at the column position with the ground strength in the area immediately below the column position based on the ground survey data and the axial force at the column position, and the pile having a pile strength greater than the ground strength. Select the foundation shape for each column position.

  FIG. 10 (A) is a plan view showing a schematic shape of a foundation main body configured by combining the pile foundation shapes described later, and (B) is a plan view of a roof in which columns and lower beams are described. It is an example of the top view of the protrusion corner part which piled up and the pile foundation shape.

  In FIG. 10A, a numerical value such as 35.0 indicates a vertical downward axial force (unit: KN) at a column position, and alphabets (A to D) indicate a pile foundation having a pile strength shown in Table 1 below. The shape is shown. For example, since the axial force at the column position of the upper left protruding corner portion in FIG. 10 (A) is 35.0 KN, the pile foundation shape B having a pile strength exceeding 35.0 KN is selected at the upper left protruding corner portion. ing. In addition, the code | symbol E has shown the pile foundation shape which is not provided with the pile here, and the pile foundation shape E has connected the pile foundation shapes AD which are mutually spaced apart.

なお、この選択の方法は、例えば、先ず最初に杭本数が１本の杭基礎形状（即ち、一番杭耐力の小さい杭基礎形状）を選択し、杭１本の杭耐力と、柱位置での軸力とを比較して、杭耐力が柱位置に作用する軸力よりも大きいことが確認できれば、ここで選択された杭基礎形状を採用することを決定する（図７の（５）のステップ）。

In addition, this selection method is, for example, firstly selecting a pile foundation shape having one pile (ie, a pile foundation shape having the smallest pile strength), and selecting the pile strength of one pile and the column position. If it is confirmed that the pile bearing strength is greater than the axial force acting on the column position, it is decided to adopt the pile foundation shape selected here ((5) in FIG. 7). Step).

However, if the pile yield strength of one pile is less than the axial force acting on the column position, is the number of piles increased by one and is the pile yield strength of the two piles greater than the axial force acting on the column position? If it can be confirmed and it can be confirmed that the pile strength is greater than the axial force acting on the column position, it is decided to adopt the pile foundation shape of two piles. If the pile strength does not become larger than the axial force acting on the column position even if the number of piles is increased, the number of piles is increased sequentially until the pile strength becomes larger than the axial force, and the pile strength acts on the column position. It decides to adopt the pile foundation shape which becomes larger than the axial force to do.
In this way, the pile foundation shape is determined for all column positions.

  The computer 32 has a planar shape of the basic body 22 as shown in FIGS. 8 and 9, for example, a straight shape, an L shape, or a cross shape, based on the position of the column, the shape and position of the beam. Can also be selected at the same time.

  Thus, after determining the pile foundation shape for every column position, the computer 32 arrange | positions the pile foundation shape 50 according to the pillar position of a roof, a beam, etc., and the some pile foundation shape 50 arrange | positioned. The pile foundation design that matches the building is completed (step (6) in FIG. 7).

  As described above, according to this pile foundation design method, since a plurality of types of pile foundation shapes having different pile strengths are prepared in advance, individual designs are shown in (4), (5) of FIG. The pile foundation can be designed more quickly and easily than in the past only through the three steps (6).

  After completing the pile foundation design, the foundation plan can be displayed on the monitor 48 connected to the computer 32, or the foundation plan can be printed out from the printer 46.

  In addition, a list in which the axial force for each column position is associated with the pile strength can be displayed on the monitor 48 or printed out from the printer 46.

  The hard disk drive 40 of the computer 32 stores a program for executing the steps of FIG. Further, this program may be recorded on a known recording medium such as a CD-ROM or a semiconductor memory.

(Function)

  Like this embodiment, the vertical load of the unit building 10 can be supported by the foundation main body 22 and the pile 24 by arranging the pile 24 below the footing 22B of the foundation main body 22, and the ground is soft. Even if it exists, the unit building 10 which consists of the some building unit 18 can be supported reliably.

  In this embodiment, when the pile foundation 20 is viewed in plan, the axis of the pillar 12, the width center line of the footing 22B, and the axis of the pile 24 are matched, so that the width of the footing 22B extends. The vertical load of the unit building 10 transmitted from the pillar 12 can be applied equally.

  In addition, since the axis of the footing 22B is aligned with the axis of the pile 24, an equal vertical load is applied to the axis of the pile 24 on both sides in the width direction of the footing 22B. However, the foundation main body 22 arrange | positioned at the upper side can be supported in the stable state.

  For this reason, it is suppressed that the moment M (refer FIG. 3 (A)) arises in the base main body 22 by the vertical load of the unit building 10, and it becomes the aspect which the base main body 22 becomes stable. Further, since the torsional deformation of the base body 2 is suppressed, the durability of the base body 22 is also improved.

  Furthermore, since the vertical load of the unit building 10 is applied in the vertical direction toward the axial center of the pile 24 extending in the vertical direction, the force in the direction of tilting the pile 24 against the pile 24 is not applied. This is a preferable aspect in terms of durability of 24.

  Note that the vertical load can be stably supported along the longitudinal direction by forming the footing 22B with a constant width. In addition, it is easy to construct the base body 22 integrally including the footing 22B.

[Other Embodiments]

  In the above embodiment, the piles 24 are arranged only directly below the pillars 12. However, for example, the foundation body 22 may receive a vertical load of the building from the floor beams 16. In such a case, it is preferable to arrange the piles 24 along the floor beams 16. As a result, the vertical load acting along the floor beam 16, that is, the vertical load acting along the longitudinal direction of the foundation is supported by the plurality of piles 24, and the longitudinal deflection of the foundation body 22 due to the vertical load. Can be prevented.

  In the above pile foundation design method, the number of piles is changed for each pile foundation shape, but the pile diameter may be changed, and the pile construction method may be changed.

  The shape of the foundation main body 22 is not limited to that shown in FIG. 2, and various conventionally known ones such as a solid foundation and a deep foundation may be adopted in addition to the cloth foundation.

  For example, when the pile is a steel pipe pile, the footing width can be set to the maximum width for each construction method for each pile diameter, and in the case of a non-certified general construction method, it can be adjusted to the above maximum width by 2.5d. . In the case of columnar improvement, the footing width can be set to a pile diameter +100 mm.

  In addition, in the case of pile-shaped reinforcement specifications, the footing width may be set to be the same for each door, and when two types of pile diameters are used in combination, the footing width may be set to be the same with a thick pile diameter. In addition, the rising width can be, for example, a width of 170 mm for the outer peripheral portion and a width of 400 mm for the inner connecting beam portion, as in the case of the direct foundation.

It is a perspective view of a pile foundation and a unit building. (A) is sectional drawing orthogonal to the longitudinal direction of the pile foundation which shows a part of pile foundation and a unit building, (B) is a top view of the pile foundation of the part in which the pillar has stood up. It is sectional drawing perpendicular to the longitudinal direction of the pile foundation which shows a part of pile foundation and unit building which concern on other embodiment. It is a top view of the pile foundation of the part in which the pillar which concerns on other embodiment is standing. It is a side view of the pile foundation of the part by which the load transmission member is arrange | positioned. It is a schematic block diagram of the computer system for performing pile foundation design. It is a flow which shows the procedure at the time of designing a pile foundation. It is a top view which shows an example of a pile foundation shape. It is a top view which shows an example of a pile foundation shape. (A) is a top view of a pile foundation which arranged and constituted a plurality of pile foundation shapes, and (B) is a figure which piled up a top view and pile foundation shape of a unit building.

Explanation of symbols

10 unit building 12 pillar 16 floor girder 18 building unit 20 pile foundation 22 foundation body 22B footing 24 pile 26 ground 28 load transmission member 50 pile foundation shape

Claims (8)

It is a pile foundation for a building comprising a footing and a rising part integrally standing on the upper end of the footing and supporting a vertical load of the building, and a pile disposed below the footing. And
The building is constructed by connecting a plurality of adjacent building units,
Comprising a pile whose center of gravity coincides with the width centerline of the footing;
A plurality of the piles are arranged along the beam of the building,
When the pillar of one said building unit and the pillar of the other said building unit are arrange | positioned adjacently and several pillars are set, the said common pile is arrange | positioned under the said several pillars Has been
Furthermore, the said pillar is mounted and fixed on the upper surface of the said foundation main body, and the beam of the said building is spaced apart from the upper surface of the said foundation main body, The pile foundation for buildings. The common pile is one,
The pile foundation for buildings according to claim 1, wherein the center of gravity of the plurality of columns and the center of gravity of the one pile coincide with each other.   The pile foundation for buildings according to claim 1 or 2, wherein when viewed in plan, the axis of the pile coincides with a point at which a vertical load of the building acts on the foundation body.   The said point is the pile foundation for buildings of Claim 3 which is the position where the pillar which comprises the said building is erected. The point is arranged between the pillars of the building unit and between the pillars of the building and the foundation main body that connect the pillars to each other. The pile foundation for buildings according to claim 3, wherein the pile is disposed at a position where a load transmission member to be transmitted to is disposed, and immediately below the load transmission member .   The pile foundation for buildings according to any one of claims 1 to 5, wherein the footing has a constant width.   The said pile is arrange | positioned under the outer peripheral part of the said base main body so that the axial center of the said pile may correspond with respect to the axial center of the pillar arrange | positioned along the outer peripheral part of a building. The pile foundation for buildings according to any one of items 6.   A building comprising the pile foundation according to any one of claims 1 to 7, and having a pillar arranged on an axis of the pile.

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