JP2000178981A - Pile foundation structure - Google Patents

Pile foundation structure

Info

Publication number
JP2000178981A
JP2000178981A JP10355534A JP35553498A JP2000178981A JP 2000178981 A JP2000178981 A JP 2000178981A JP 10355534 A JP10355534 A JP 10355534A JP 35553498 A JP35553498 A JP 35553498A JP 2000178981 A JP2000178981 A JP 2000178981A
Authority
JP
Japan
Prior art keywords
foundation
pile
head
frame
pile head
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10355534A
Other languages
Japanese (ja)
Inventor
Eiji Wakita
英治 脇田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shimizu Construction Co Ltd
Shimizu Corp
Original Assignee
Shimizu Construction Co Ltd
Shimizu Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shimizu Construction Co Ltd, Shimizu Corp filed Critical Shimizu Construction Co Ltd
Priority to JP10355534A priority Critical patent/JP2000178981A/en
Publication of JP2000178981A publication Critical patent/JP2000178981A/en
Pending legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide a pile foundation structure obtained by combining a foundation skeleton and a foundation pile, which can prevent damage of the foundation pile without fail at the time of a large earthquake, and can achieve reduction of costs, based on the specifications of the piles and by decreasing the number of piles. SOLUTION: A pile foundation structure 1 is made up of a foundation skeleton 2 and a foundation pile 3 with an elastoplastic material 4 interposed at a coupling portion therebetween. The elastoplasic material 4 is provided at the coupling portion between the foundation skeleton 2 and a foundation pile head portion 7, or between the skeleton 2 and a head peripheral wall 9 of the base pile, and the coupling portion between the base body and the base pile head portion is formed into a coupling hole 5. Further, a steel member is arranged on a wall of the hole, or alternatively, a sliding plate is provided on the bottom surface of the coupling hole, and a steel plate which is in contact with the sliding plate, is arranged on the center of the foundation pile head portion. Thus, even at the time of a large or small earthquake, only a small horizontal displacement is caused in the pile foundation structure, which can prevent damage of the foundation pile without fail. Further, the specifications of the piles and decrease in the number of the piles can lead to reduction of costs.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、大地震時において
も基礎杭に所定値以上の応力を発生させずに、杭の破損
を防止した杭基礎構造に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile foundation structure in which a pile is prevented from being damaged without generating a stress exceeding a predetermined value even in a large earthquake.

【0002】[0002]

【従来の技術】建築・土木における構造物の基礎杭頭部
における結合構造は、従来から剛結を中心に計画されて
きた。そのため、大部分のものが建築物の基礎杭頭部を
基礎に剛結している杭基礎構造が用いられてきた。そし
て、杭基礎構造の一部には、完全な剛結構造でなく半剛
結と見られるものも存在していたが、半剛結の状態を合
理的に評価できないために、設計上は剛結として扱わざ
るを得ないのが実態であった。基礎杭の頭部が剛結の場
合には、大地震時に杭頭部分に発生する大きな曲げ応力
が杭基礎の杭頭部分を破損することになり大きな災害を
引き起こしている例が数多く報告されている。
2. Description of the Related Art Conventionally, a connection structure of a foundation in a building or civil engineering at the head of a foundation pile has been planned mainly on rigid connection. For this reason, a pile foundation structure in which most are rigidly connected to the foundation pile head of the building has been used. Some of the pile foundations were not completely rigid, but seemed to be semi-rigid. In fact, it had to be treated as a conclusion. When the head of the foundation pile is rigidly connected, a large number of cases have been reported in which a large bending stress generated at the pile head during a large earthquake may damage the pile head of the pile foundation and cause a major disaster. I have.

【0003】どんな大地震に対しても破損することのな
い程の強度を有する基礎杭を用いると杭頭破損の回避は
可能であるが、コストや効率の観点から現実的でない。
そこで、杭頭部分の破損を避けるために、杭基礎構造5
0をピン結合にする例が提案されてきた。杭基礎構造5
0をピン結合にすると、図8に示すように、基礎躯体5
1と杭頭部52とは互いに拘束されていないので、地震
時に建物に対して加えられる水平力が基礎躯体51を図
示のように移動させても、ピン結合装置53の働きによ
って杭頭部52に発生する水平力は杭頭部を押圧するの
みであるから、杭頭部52における曲げ応力はゼロにな
って杭頭部部分の破損は防止できる。しかし、図8で明
らかなように、杭頭部52が水平方向に曲げられるため
に、杭頭部53よりも下方にある杭体部54に曲げ応力
を発生させることになり、杭頭剛結時の曲げ応力に対し
て70〜90%の曲げ応力とはいえ、大規模な地震に対
しては杭全体の破損を完全には防止できない。さらに、
杭頭部のピン結合は、地震時の水平変位が杭頭剛結の場
合に比較して倍程度に大きくなる点も問題であった。
[0003] If a foundation pile having such strength that it is not damaged by any large earthquake can be used, it is possible to avoid pile head damage, but it is not realistic in terms of cost and efficiency.
Therefore, in order to avoid damage to the pile head,
Examples have been proposed in which 0 is pinned. Pile foundation structure 5
When pin 0 is a pin connection, as shown in FIG.
1 and the pile head 52 are not constrained to each other, so that even if the horizontal force applied to the building during an earthquake causes the foundation frame 51 to move as shown in the drawing, the Since the horizontal force generated only at the pile head presses the pile head, the bending stress at the pile head 52 becomes zero and the pile head can be prevented from being damaged. However, as is apparent from FIG. 8, since the pile head 52 is bent in the horizontal direction, a bending stress is generated in the pile body portion 54 below the pile head 53, and the pile head is rigidly connected. Although the bending stress is 70 to 90% of the bending stress at the time, the damage of the entire pile cannot be completely prevented by a large-scale earthquake. further,
The problem with the pin connection at the pile head was that the horizontal displacement during the earthquake was about twice as large as that of the rigid connection at the pile head.

【0004】従って、ピン結合のように、基礎躯体に基
礎杭頭部を結合した杭基礎構造において、地震時におけ
る杭頭部の発生応力を低減して、杭の仕様や本数の低減
によるコストダウンを図りながら、大地震時における基
礎杭の破損を防止できるような杭基礎構造の改善が期待
されていた。
Accordingly, in a pile foundation structure in which a foundation pile head is joined to a foundation frame, such as a pin joint, the stress generated at the pile head during an earthquake is reduced, and the cost and cost are reduced by reducing the specifications and the number of piles. The improvement of the pile foundation structure that could prevent the foundation pile from being damaged in the event of a large earthquake was expected.

【0005】[0005]

【発明が解決しようとする課題】本発明は、上記の問題
点に鑑みて杭基礎構造の改善を図ったものであり、基礎
躯体と基礎杭を結合して成る杭基礎構造において、大地
震時における基礎杭の破損を確実に防止すると共に杭の
仕様や本数の低減によるコストダウンを図ることができ
る杭基礎構造の提供を目的にしている。
SUMMARY OF THE INVENTION The present invention has been made to improve a pile foundation structure in view of the above-mentioned problems, and is intended to improve a pile foundation structure composed of a foundation frame and a foundation pile during a large earthquake. It is an object of the present invention to provide a pile foundation structure capable of reliably preventing damage to a foundation pile and reducing costs by reducing the specification and number of piles.

【0006】[0006]

【課題を解決するための手段】本発明による杭基礎構造
は、基本的に、基礎躯体と基礎杭を結合して成る杭基礎
構造において、基礎躯体と基礎杭との結合部に弾塑性体
状材料を介在させることを特徴としており、具体的に
は、基礎躯体と基礎杭頭部もしくは基礎躯体と基礎杭の
頭部周壁との結合部に弾塑性体状材料を介在させること
を特徴とし、基礎躯体と基礎杭頭部との結合部を結合孔
にしてその孔壁に鋼材を配置したり、結合孔の底部表面
に滑り板を設けて、基礎杭頭部の中央に滑り板と当接す
る鋼板を設けることを特徴にしている。
A pile foundation structure according to the present invention basically comprises an elasto-plastic body at a joint between a foundation frame and a foundation pile in a pile foundation structure composed of a foundation frame and a foundation pile. It is characterized by interposing a material, specifically, characterized by interposing an elasto-plastic material at the joint between the foundation frame and the foundation pile head or the foundation frame and the peripheral wall of the foundation pile head, The joint between the foundation frame and the foundation pile head is used as a connection hole, steel is placed on the hole wall, or a slide plate is provided on the bottom surface of the connection hole, and the slide plate contacts the center of the foundation pile head. It is characterized by providing a steel plate.

【0007】[0007]

【作用】基礎躯体と基礎杭の結合部に介在させてある弾
塑性体状材料は、基礎躯体の水平力が所定値(降伏応力)
に達するまでは、その応力を増大させるが、所定値を超
えた段階からは応力の増大がほとんど無い特性を有して
いるので、常時及び小規模の地震に対しては弾塑性体状
材料が歪に対応した応力の増大と伝達を行うことで、杭
基礎構造は結果的に剛結として機能し、基礎躯体の水平
変位が少ない状態では杭基礎構造の破壊を防止する。こ
れに対して、大規模な地震では弾塑性体状材料の歪が上
記所定値を超えることから、弾塑性体状材料は応力の飽
和状態を形成して伝達する応力の増大を無くし、所定値
を超越した余分の応力を基礎杭に発生させない。このた
め、基礎杭頭部は前記余分の応力に対してピン結合とし
て機能し、基礎杭の頭部及び杭体部の曲げ応力を完全な
剛結よりも小さくして杭基礎構造の破壊を防止する。
[Function] The elastic-plastic body material interposed at the joint between the foundation frame and the foundation pile has a predetermined horizontal force of the foundation frame (yield stress).
Until the stress reaches the threshold, the stress is increased, but since the stress exceeds the specified value, the stress is hardly increased. By increasing and transmitting the stress corresponding to the strain, the pile foundation structure eventually functions as a rigid connection, and prevents the failure of the pile foundation structure when the horizontal displacement of the foundation frame is small. On the other hand, in the case of a large-scale earthquake, the strain of the elasto-plastic material exceeds the above-mentioned predetermined value. No extra stress is generated in the foundation pile beyond For this reason, the foundation pile head functions as a pin connection for the extra stress, and the bending stress of the foundation pile head and the pile body is made smaller than perfect rigid connection to prevent the fracture of the pile foundation structure. I do.

【0008】[0008]

【発明の実施の形態】本発明による杭基礎構造は、基礎
躯体と基礎杭とが結合して成り、基礎躯体と基礎杭頭部
との結合部に弾塑性体状材料を介在させることで、地震
時における杭頭応力を低減するものであり、以下に図面
に基づいて説明する。図1は、本発明による杭基礎構造
の実施の形態を示す立断面図である。図において、杭基
礎構造1は、基礎躯体2と基礎躯体に結合している基礎
杭3及び基礎躯体2と基礎杭3との間に介在する弾塑性
体状材料4から構成されている。基礎躯体2には、基礎
杭3を受け入れるための結合孔5を設けており、結合孔
5の底面には弾塑性体状材料4を装着するための穴6を
設けてあり、基礎杭の杭頭部7にも同様の穴8を形成し
ている。
BEST MODE FOR CARRYING OUT THE INVENTION A pile foundation structure according to the present invention comprises a foundation frame and a foundation pile joined together, and an elastic-plastic body material is interposed at the joint between the foundation frame and the foundation pile head. The purpose of the present invention is to reduce the pile head stress during an earthquake, and will be described below with reference to drawings. FIG. 1 is an elevational sectional view showing an embodiment of a pile foundation structure according to the present invention. In the figure, a pile foundation structure 1 is composed of a foundation frame 2, a foundation pile 3 connected to the foundation frame, and an elastic-plastic material 4 interposed between the foundation frame 2 and the foundation pile 3. The base frame 2 is provided with a connection hole 5 for receiving the foundation pile 3, and the bottom of the connection hole 5 is provided with a hole 6 for mounting the elasto-plastic material 4. A similar hole 8 is formed in the head 7.

【0009】本実施の形態では、基礎杭3は基礎躯体2
の結合孔5に遊嵌して結合しているが、基礎躯体2と基
礎杭3との結合は、上記弾塑性体状材料4のみで実施さ
れており、基礎杭3の周壁9と結合孔5とは接触するこ
となく、間隙10を形成し、杭頭部7と結合孔5の底面
との間には空隙11を設けているので、基礎杭3と基礎
躯体2との結合は、弾塑性体状材料4を介在させた弾塑
性型の接合状態を形成している。以上のように、本発明
による杭基礎構造では、基礎杭を結合孔に遊嵌させるこ
とは必ずしも必要でなく、基礎躯体の底面平版に直接、
弾塑性体状材料4を配置して結合することも可能であ
り、杭頭部に配置する弾塑性体状材料4の形状について
も、図示の円柱形状に限らず、中空円筒形もしくは円柱
の中心に棒状の鋼製の芯材を設けた形状のものであって
も採用可能である。このことは以下に述べる他の実施の
形態でも同様である。
In the present embodiment, the foundation pile 3 is
Is loosely fitted into the connection hole 5 of the base pile 2, but the connection between the foundation frame 2 and the foundation pile 3 is performed only by the elasto-plastic material 4, and the peripheral wall 9 of the foundation pile 3 is connected to the connection hole. Since the gap 10 is formed without contact with the base 5 and the gap 11 is provided between the pile head 7 and the bottom surface of the coupling hole 5, the connection between the foundation pile 3 and the foundation frame 2 is not An elasto-plastic joining state with the plastic material 4 interposed is formed. As described above, in the pile foundation structure according to the present invention, it is not always necessary to loosely fit the foundation pile into the connection hole, and directly on the bottom planographic plate of the foundation frame,
It is also possible to arrange the elasto-plastic material 4 and combine it. The shape of the elasto-plastic material 4 disposed on the pile head is not limited to the columnar shape shown in FIG. It is also possible to adopt a configuration in which a bar-shaped steel core is provided. This is the same in other embodiments described below.

【0010】図2、3は、本発明による杭基礎構造を他
の実施の形態で示す立断面図である。図において、杭基
礎構造20は、基礎躯体21と基礎躯体に結合している
基礎杭22及び基礎躯体21と基礎杭22との間に介在
する弾塑性体状材料23、24から構成されている。本
実施の形態では、上記実施の形態と同様に、基礎杭22
は基礎躯体21の結合孔25に遊嵌して結合している
が、基礎躯体21と基礎杭22との結合は、基礎杭22
の杭頭部26に配置された弾塑性体状材料23と、杭頭
部の周壁27に円筒状に貼り付けた弾塑性体状材料24
とで実施されている。なお、基礎躯体21の結合孔25
の孔壁28には、鋼管29を全周に配置して基礎躯体2
1の補強を図っている。従って、基礎杭22と基礎躯体
21との結合は、弾塑性体状材料23、24を介在させ
た剛結状態を形成している。
FIGS. 2 and 3 are vertical sectional views showing another embodiment of the pile foundation structure according to the present invention. In the figure, a pile foundation structure 20 is composed of a foundation frame 21 and a foundation pile 22 connected to the foundation frame, and elasto-plastic materials 23 and 24 interposed between the foundation frame 21 and the foundation pile 22. . In the present embodiment, similarly to the above embodiment, the foundation pile 22
Is loosely fitted into the connection hole 25 of the base frame 21 and is connected thereto. However, the connection between the base frame 21 and the base pile 22 is
Elasto-plastic material 23 disposed on the pile head 26 and an elasto-plastic material 24 cylindrically attached to the peripheral wall 27 of the pile head.
And has been implemented. In addition, the connection hole 25 of the
The steel pipe 29 is arranged all around the hole wall 28 of
1 is reinforced. Therefore, the connection between the foundation pile 22 and the foundation frame 21 forms a rigidly connected state with the elastic-plastic body materials 23 and 24 interposed therebetween.

【0011】図3は、図2で示した実施の形態における
A−A矢視図である。図示のように、基礎躯体21と基
礎杭22との間に介在させる弾塑性体状材料23、24
は、本実施の形態の場合は、基礎杭22の杭頭部の周壁
27と結合孔25の孔壁28との間に配置している。弾
塑性体状材料24の形状は、図示のように杭頭部の周壁
27の全面に円筒状に貼り付けしているが、状況によっ
ては複数に分割して所定の間隔で放射状に配置してもよ
い。
FIG. 3 is a view taken in the direction of arrows AA in the embodiment shown in FIG. As shown in the drawing, elasto-plastic materials 23 and 24 interposed between the foundation frame 21 and the foundation pile 22 are shown.
In the present embodiment, is disposed between the peripheral wall 27 of the pile head of the foundation pile 22 and the hole wall 28 of the coupling hole 25. The shape of the elasto-plastic material 24 is attached to the entire surface of the peripheral wall 27 of the pile head in a cylindrical shape as shown in the figure, but depending on the situation, it may be divided into a plurality and radially arranged at predetermined intervals. Is also good.

【0012】図4、5は、本発明による杭基礎構造を、
さらに他の実施の形態で示す立断面図である。図におい
て、杭基礎構造30は、基礎躯体31と基礎躯体にピン
結合している基礎杭32及び基礎躯体31と基礎杭32
との間に介在する弾塑性体状材料33から構成されてい
る。基礎躯体31には基礎杭32を受け入れるための結
合孔34を設けており、結合孔34の底面には滑り板3
5を貼り付けてあり、孔壁42には鋼管36を全周に配
置している。基礎杭32は、杭体部37と杭頭部38か
ら構成されている。杭頭部38の中央部にはコーティン
グ処理を施した鋼板39を敷設し、杭頭部38の周壁4
0には上記弾塑性体状材料33を円筒状に張り付けてい
る。上記鋼板39のコーティング加工は、テフロンや合
成樹脂等の摩擦係数の小さい材料を使用しており、基礎
躯体31に形成した結合孔34の底面に設けた上記滑り
板35と小さい力で容易に摺動できるようにしている。
4 and 5 show a pile foundation structure according to the present invention.
It is a sectional elevational view shown in another embodiment. In the drawing, a pile foundation structure 30 includes a foundation frame 31 and a foundation pile 32 pin-connected to the foundation frame, and a foundation frame 31 and a foundation pile 32.
And an elastic-plastic body material 33 interposed therebetween. The base frame 31 is provided with a coupling hole 34 for receiving the foundation pile 32, and the bottom of the coupling hole 34 has a sliding plate 3.
5 is adhered, and the steel pipe 36 is arranged on the hole wall 42 all around. The foundation pile 32 includes a pile body 37 and a pile head 38. At the center of the pile head 38, a coated steel plate 39 is laid, and the peripheral wall 4 of the pile head 38 is laid.
At 0, the elastic-plastic body material 33 is attached in a cylindrical shape. The steel plate 39 is coated with a material having a small coefficient of friction, such as Teflon or a synthetic resin, and is easily slid with a small force with the slide plate 35 provided on the bottom surface of the coupling hole 34 formed in the base frame 31. I can move.

【0013】以上のように、基礎杭32は基礎躯体31
の結合孔34に遊嵌して結合しているが、杭頭部38と
結合孔34の底面との間には空隙41を設けている。従
って、基礎杭32と基礎躯体31との結合は、結合孔3
4の底面に設けた滑り板35と基礎杭32の杭頭部38
に敷設した鋼板39とが接触するもので、上述のように
摩擦を低減する処理を施された状態で水平移動に従順な
構造を形成している。
As described above, the foundation pile 32 is used as the foundation frame 31.
The hole 41 is provided between the pile head 38 and the bottom surface of the coupling hole 34. Therefore, the connection between the foundation pile 32 and the foundation frame 31 is made by the connection hole 3
The slide plate 35 provided on the bottom surface of 4 and the pile head 38 of the foundation pile 32
And a steel plate 39 laid in the contact area, and forms a structure that is compliant with horizontal movement in a state where the processing for reducing friction has been performed as described above.

【0014】図5は、図4で示した実施の形態における
A−A矢視図である。図示のように、基礎躯体31と基
礎杭32との間に介在させる弾塑性体状材料33は、本
実施の形態の場合は、基礎杭32の杭頭部の周壁40と
結合孔34の孔壁31との間に配置している。弾塑性体
状材料33の形状は、図示のように杭頭部の周壁40の
全面に円筒状に貼り付けしているが、状況によっては複
数に分割して所定の間隔で放射状に配置してもよい。
FIG. 5 is a view taken in the direction of arrows AA in the embodiment shown in FIG. As shown in the figure, the elastic-plastic body material 33 interposed between the foundation frame 31 and the foundation pile 32 is, in the case of the present embodiment, a peripheral wall 40 of the pile head of the foundation pile 32 and a hole of the coupling hole 34. It is located between the wall 31. The shape of the elasto-plastic material 33 is attached to the entire surface of the peripheral wall 40 of the pile head in a cylindrical shape as shown in the figure, but depending on the situation, it may be divided into a plurality and radially arranged at predetermined intervals. Is also good.

【0015】次に、弾塑性体状材料について図6及び図
7に基づいて説明する。本発明で用いる弾塑性体状材料
は、「完全弾塑性体に近い特性を備えた」材料を称して
いる。このような材料としては、極低降伏点鋼材等が該
当しているので、極低降伏点鋼材の性質を示して弾塑性
体状材料4の性質を説明する。図6は、極低降伏点鋼材
の「応力―歪関係」の特性を普通鋼との比較において示
している。図示のように、極低降伏点鋼材の降伏応力
は、σmax =2,400kgf/cm2程度であり、普
通鋼より小さい。そして、図示のように歪1%程度まで
は歪の増加に比例して応力が増大し、地震時に発生する
歪1%付近で上記の降伏応力に到達し、それ以上は普通
鋼が応力を増加させて行くのと異なって、応力の飽和状
態が発生して歪が4%に増加するまではその値を持続す
る特徴を持っている。即ち、歪が4%以下の範囲でこの
鋼材を使用すれば、「完全弾塑性体に近い特性を備え
た」材料である。
Next, the elasto-plastic material will be described with reference to FIGS. 6 and 7. FIG. The elasto-plastic material used in the present invention refers to a material “having characteristics close to a perfect elasto-plastic body”. As such a material, an extremely low yield point steel material or the like is applicable. Therefore, the properties of the extremely low yield point steel material will be described, and the properties of the elasto-plastic material 4 will be described. FIG. 6 shows the characteristics of “stress-strain relationship” of the extremely low yield point steel material in comparison with ordinary steel. As shown in the drawing, the yield stress of the extremely low yield point steel is about σ max = 2,400 kgf / cm 2, which is smaller than ordinary steel. As shown in the figure, the stress increases in proportion to the increase in strain up to about 1% strain, reaches the above-mentioned yield stress near 1% strain generated during an earthquake, and beyond that, ordinary steel increases the stress. Unlike the case where the stress is increased, the stress is maintained until the stress is saturated and the strain increases to 4%. That is, if this steel material is used within a strain range of 4% or less, it is a material “having characteristics close to a perfect elastoplastic body”.

【0016】本発明に用いる弾塑性体状材料の応力ー歪
関係は、図7に示すような理想的構造モデルによる「完
全弾塑性体型の応力―歪関係」を指向している。同応力
―歪関係は、図示のようにわずかな歪で応力が所定値に
到達しながら、歪がそれ以上に増加して大きな値に至っ
ても、応力が所定値付近に留まったまま推移する性質を
示している。「完全弾塑性体に近い特性を備えた」材料
としては、極低降伏点鋼の他に、低降伏点鋼や極軟鋼等
も同様の特性を有している。
The stress-strain relationship of the elasto-plastic material used in the present invention is directed to the "stress-strain relationship of a perfect elasto-plastic body" based on an ideal structure model as shown in FIG. The stress-strain relationship is such that, as shown in the figure, the stress reaches a predetermined value with a slight strain, and even if the strain increases further and reaches a large value, the stress remains around the specified value. Is shown. As a material "having characteristics close to that of a perfect elasto-plastic body", in addition to extremely low yield point steel, low yield point steel, extremely mild steel, and the like also have similar characteristics.

【0017】上述のように、弾塑性体状材料は、応力―
歪関係において所定の歪までは応力度が比例して増加し
て行くが、一定の歪以上では応力度が飽和状態になる特
性を有しているから、本発明による杭基礎構造は、従来
の単純なピン結合でない作用効果を発揮している。即
ち、通常や小地震のレベルでは、基礎躯体の水平移動に
よって弾塑性体状材料に生じる歪は上述の所定値1%に
達しないので、応力―歪特性は比例関係にあり、歪の増
加に従って応力の増大が行われて基礎躯体に加えられる
水平力はそのまま基礎杭に伝達される。従って、杭基礎
構造は、杭頭部にピン結合があってもその機能は弾塑性
体状材料によって制限された状態の下に、水平力が基礎
躯体―弾塑性体状材料―基礎杭のように伝達されて実質
的に剛結としての機能を発揮することになり、小地震に
対しては破壊することなく小さい水平変位で対処するこ
とを可能にしている。
As described above, the elasto-plastic material has a stress-
In the strain relation, the stress level increases in proportion to a predetermined strain, but has a characteristic that the stress level becomes a saturated state at a certain strain or more, the pile foundation structure according to the present invention is a conventional pile foundation structure. The effect is not a simple pin connection. That is, at the level of a normal or small earthquake, the strain generated in the elasto-plastic material by the horizontal movement of the foundation does not reach the above-mentioned predetermined value of 1%, so that the stress-strain characteristics are in a proportional relationship, and as the strain increases, The horizontal force applied to the foundation frame due to the increase in stress is transmitted to the foundation pile as it is. Therefore, even if there is a pin connection at the pile head, the function of the pile foundation structure is limited by the elasto-plastic body material, and the horizontal force is similar to that of the foundation frame-elasto-plastic body material-foundation pile. It is effectively transmitted to the shore and functions as a rigid connection, making it possible to cope with small earthquakes with small horizontal displacement without breaking.

【0018】一方、大地震のレベルになり、歪が大きく
なって1%を超える場合には、上述したように弾塑性体
状材料4に応力の飽和状態が形成されるので、基礎躯体
に加えられる、それ以上の押圧力は基礎杭に伝達されな
くなる。従って、歪が1%を超える範囲では、所定応力
の超過分に対して弾塑性体状材料等が実質的に存在しな
い状態を形成して、杭頭の移動や回転を自由にしたり、
ピン結合の機能を明確に発揮させたりするものであるか
ら、基礎杭の杭頭部に完全剛結時のような曲げ応力が加
えられる状態を回避して、杭頭の破損を確実に防止する
と共に、杭体部の部分でも破壊しないように機能してい
る。
On the other hand, when the level of a large earthquake is reached and the strain increases and exceeds 1%, a saturated state of stress is formed in the elasto-plastic material 4 as described above. No further pressing force is transmitted to the foundation pile. Therefore, in the range where the strain exceeds 1%, a state in which the elasto-plastic material is substantially absent for the excess of the predetermined stress is formed, and the movement and rotation of the pile head are made free,
Since it clearly demonstrates the function of the pin connection, it avoids the state where bending stress is applied to the pile head of the foundation pile as in the case of full rigid connection, and reliably prevents the breakage of the pile head At the same time, it functions so as not to break even the pile part.

【0019】以上、本発明について実施の形態に基づい
て詳細に説明してきたが、本発明による杭基礎構造は、
基礎と基礎杭との結合状態がピン結合である杭基礎構造
において、基礎と基礎杭の頭部周壁との間に弾塑性体状
材料を介在させることで、地震時における杭頭応力を低
減させながら基礎杭の破損を確実に防止するものであ
り、本発明の趣旨を逸脱しない範囲において上述した実
施の形態に何ら限定されるものでなく、種々の変更が可
能であることは当然のことである。
As described above, the present invention has been described in detail based on the embodiments.
In a pile foundation structure in which the connection between the foundation and the foundation pile is a pin connection, an elasto-plastic material is interposed between the foundation and the peripheral wall of the head of the foundation pile to reduce the pile head stress during an earthquake. However, it is intended to surely prevent damage to the foundation pile, and is not limited to the above-described embodiment without departing from the spirit of the present invention, and various modifications are naturally possible. is there.

【0020】[0020]

【発明の効果】本発明による杭基礎構造は、基本的に、
基礎躯体と基礎杭を結合して成る杭基礎構造において、
基礎躯体と基礎杭との結合部に弾塑性体状材料を介在さ
せることを特徴としており、具体的には、基礎躯体と基
礎杭頭部もしくは基礎躯体と基礎杭の頭部周壁との結合
部に弾塑性体状材料を介在させることを特徴とし、基礎
躯体と基礎杭頭部との結合部を結合孔にしてその孔壁に
鋼材を配置したり、結合孔の底部表面に滑り板を設け
て、基礎杭頭部の中央に滑り板と当接する鋼板を設ける
ことを特徴にしているから、大小いずれの地震時に対し
ても小さい水平変位で基礎杭の破損を確実に防止すると
共に、杭の仕様や本数の低減によるコストダウンを図る
ことができる効果を発揮している。
The pile foundation structure according to the present invention basically includes:
In a pile foundation structure consisting of a foundation frame and a foundation pile,
It is characterized in that an elastic-plastic body material is interposed at the joint between the foundation frame and the foundation pile, and specifically, the joint between the foundation frame and the foundation pile head or the peripheral wall of the foundation frame and the foundation pile head The joint between the foundation frame and the foundation pile head is a connection hole, steel is placed on the hole wall, and a sliding plate is provided on the bottom surface of the connection hole. Therefore, a steel plate that comes into contact with the sliding plate is provided at the center of the foundation pile head. This has the effect of reducing costs by reducing specifications and the number of units.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明による杭基礎構造を示す実施の形態図FIG. 1 is an embodiment view showing a pile foundation structure according to the present invention.

【図2】本発明による杭基礎構造を示す他の実施の形態
FIG. 2 is a view showing another embodiment of the pile foundation structure according to the present invention.

【図3】図2で示した杭基礎構造の実施の形態における
A−A矢視図
3 is an AA arrow view of the embodiment of the pile foundation structure shown in FIG. 2;

【図4】本発明による杭基礎構造を示す他の実施の形態
FIG. 4 is another embodiment showing a pile foundation structure according to the present invention.

【図5】図4で示した杭基礎構造の実施の形態における
A−A矢視図
FIG. 5 is a view on arrow AA in the embodiment of the pile foundation structure shown in FIG. 4;

【図6】極低降伏点鋼材の「応力―歪関係」図Fig. 6 "Stress-strain relationship" diagram of ultra low yield point steel

【図7】理想的構造モデルによる「完全弾塑性体型の応
力―歪関係」図
FIG. 7: "Stress-strain relationship of perfect elasto-plastic body" by ideal structure model

【図8】ピン結合した杭基礎構造における変形状態の立
断面図
FIG. 8 is an elevational sectional view of a deformed state in a pile-bonded pile foundation structure.

【符号の説明】[Explanation of symbols]

1、20、30 杭基礎構造 2、21、31 基礎躯体 3、22,32 基礎杭 4、23、24、33 弾塑性体状材料 5、25、34 結合孔 6 結合孔の穴 7 基礎杭の杭頭部 8 杭頭部の穴 9 杭頭部の周壁 10 杭頭部と結合孔との間隙 11 杭頭部と結合孔底面との間隙 26 基礎杭の杭頭部 27 杭頭部の周壁 28 結合孔の孔壁 29 鋼管 35 滑り板 36 鋼管 37 基礎杭の杭体部 38 基礎杭の杭頭部 39 鋼板 40 杭頭部の周壁 41 杭頭部と結合孔底面との間隙 42 結合孔の孔壁 50 杭基礎構造 51 基礎躯体 52 杭頭部 53 ピン結合装置 54 基礎杭 1, 20, 30 Pile foundation structure 2, 21, 31 Foundation frame 3, 22, 32 Foundation pile 4, 23, 24, 33 Elasto-plastic material 5, 25, 34 Connection hole 6 Hole of connection hole 7 Pile head 8 Hole in pile head 9 Perimeter wall of pile head 10 Gap between pile head and connection hole 11 Gap between pile head and bottom of connection hole 26 Pile head of foundation pile 27 Perimeter wall of pile head 28 Hole wall of connection hole 29 Steel pipe 35 Slide plate 36 Steel pipe 37 Pile body part of foundation pile 38 Pile head of foundation pile 39 Steel plate 40 Perimeter wall of pile head 41 Gap between pile head and bottom of coupling hole 42 Hole of coupling hole Wall 50 Pile foundation structure 51 Foundation frame 52 Pile head 53 Pin connection device 54 Foundation pile

Claims (5)

【特許請求の範囲】[Claims] 【請求項1】 基礎躯体と基礎杭とを結合して成る杭基
礎構造において、基礎躯体と基礎杭との結合部に弾塑性
体状材料を介在させることを特徴とする杭基礎構造。
1. A pile foundation structure comprising a foundation frame and a foundation pile joined together, wherein an elastic-plastic material is interposed at a joint between the foundation frame and the foundation pile.
【請求項2】 基礎躯体と基礎杭頭部との結合部に弾塑
性体状材料を介在させることを特徴とする請求項1に記
載の杭基礎構造。
2. The pile foundation structure according to claim 1, wherein an elastic-plastic material is interposed at a joint between the foundation frame and the foundation pile head.
【請求項3】 基礎躯体と基礎杭の頭部周壁との結合部
に弾塑性体状材料を介在させることを特徴とする請求項
1に記載の杭基礎構造。
3. The pile foundation structure according to claim 1, wherein an elastic-plastic material is interposed at a joint between the foundation frame and the peripheral wall of the head of the foundation pile.
【請求項4】 基礎躯体に基礎杭頭部を遊嵌する結合孔
を設け、該結合孔の孔壁に鋼材を配置することを特徴と
する請求項3に記載の杭基礎構造。
4. The pile foundation structure according to claim 3, wherein a coupling hole for loosely fitting the foundation pile head is provided in the foundation frame, and a steel material is disposed on a hole wall of the coupling hole.
【請求項5】 基礎躯体に基礎杭頭部を遊嵌する結合孔
を設け、該結合孔の底部表面に滑り板を設け、該基礎杭
頭部の中央に滑り板と当接する鋼板を設けることを特徴
とする請求項3、4に記載の杭基礎構造。
5. A joint hole for loosely fitting a foundation pile head in a foundation frame, a slide plate provided on a bottom surface of the joint hole, and a steel plate contacting the slide plate at the center of the foundation pile head. The pile foundation structure according to claim 3, characterized in that:
JP10355534A 1998-12-15 1998-12-15 Pile foundation structure Pending JP2000178981A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10355534A JP2000178981A (en) 1998-12-15 1998-12-15 Pile foundation structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10355534A JP2000178981A (en) 1998-12-15 1998-12-15 Pile foundation structure

Publications (1)

Publication Number Publication Date
JP2000178981A true JP2000178981A (en) 2000-06-27

Family

ID=18444498

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10355534A Pending JP2000178981A (en) 1998-12-15 1998-12-15 Pile foundation structure

Country Status (1)

Country Link
JP (1) JP2000178981A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008231916A (en) * 2008-07-02 2008-10-02 Jfe Steel Kk Pile head connection structure
CN102022994A (en) * 2010-11-03 2011-04-20 河南省电力公司洛阳供电公司 Pit separation method of two-to-one branching tower and two single-circuit angle towers
CN102021915A (en) * 2010-11-02 2011-04-20 河南省电力公司洛阳供电公司 Method for constructing large plate type foundation of line
JP2013249709A (en) * 2012-06-04 2013-12-12 Taisei Corp Pile reinforcing structure for existing building, and constructing method thereof
CN105507342A (en) * 2015-11-25 2016-04-20 国家电网公司 Pit dividing method for rectangular foundation of power transmission tower

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008231916A (en) * 2008-07-02 2008-10-02 Jfe Steel Kk Pile head connection structure
CN102021915A (en) * 2010-11-02 2011-04-20 河南省电力公司洛阳供电公司 Method for constructing large plate type foundation of line
CN102021915B (en) * 2010-11-02 2017-02-08 河南省电力公司洛阳供电公司 Method for constructing large plate type foundation of line
CN102022994A (en) * 2010-11-03 2011-04-20 河南省电力公司洛阳供电公司 Pit separation method of two-to-one branching tower and two single-circuit angle towers
JP2013249709A (en) * 2012-06-04 2013-12-12 Taisei Corp Pile reinforcing structure for existing building, and constructing method thereof
CN105507342A (en) * 2015-11-25 2016-04-20 国家电网公司 Pit dividing method for rectangular foundation of power transmission tower

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