JPH09302621A - Low noise type base isolation stacked rubber bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flange for a bridge beam, which can withstand a direct onslaught of a disastrous earthquake and which can reduce vibration and noise during passing of a vehicle or the like. SOLUTION: Rubber boards 3 and metal boards 4 are alternately stacked one upon another between upper and lower flanges 1, 2, and PC steel wires 5 are extended through the entire stack of the boards and are fixed to the upper and lower flanges 1, 2, the positions and the sizes of the wires 5 being calculated so as to withstand a vertical load caused by a disastrous earthquake. Further, a tension of 50 to 80% of a load exerted by a passing vehicle is initially applied to the PC wires 5. The tension is relieved so that the displacement of the rubber boards is restrained only when an active load is applied, and as a result no height difference occurs between bridge beams so that no noise is caused. The tension of the PC steel wires 5 which is extremely strong against vertical wave motion copes with the earthquake. The upper and lower flanges 1, 2 cannot be separated from the stacked robber boards 3, thereby it is possible to inhibit the bridge beam from being broken.

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】本発明は橋梁構造物を支える
支承、特に最大級の地震の直撃にも耐え得る免震機能と
共に車両通過などでに発生する振動、騒音を低レベルに
抑制する積層ゴム支承の新規な構造に係る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support for supporting a bridge structure, and in particular, a laminated rubber that suppresses vibration and noise generated when a vehicle passes, etc. to a low level with a seismic isolation function capable of withstanding a direct impact of the largest earthquake. The new structure of the bearing.

【０００２】[0002]

【従来の技術】橋梁構造物の両端部ににそれぞれ配置す
る支承は、気温の変化に伴う構造物の伸縮を可能とする
ように支持し、自動車などの重量物が通過するときの一
過性の活荷重にも耐え、さらに地震が発生した場合に橋
梁本体がこれを支える基礎床から離脱しないように確実
に連結することも求められるなど、種々の機能を満足し
なければならない。これらの要請に対して応える最も一
般的な形態として近年は積層ゴム支承が広く慣用化され
ている。2. Description of the Related Art Bearings arranged at both ends of a bridge structure are supported so that the structure can be expanded and contracted in accordance with changes in temperature, and are temporarily used when heavy objects such as automobiles pass through. It must withstand various live loads, and must be securely connected so that the bridge body does not separate from the foundation floor that supports it in the event of an earthquake. In recent years, laminated rubber bearings have been widely used as the most general form to meet these demands.

【０００３】積層ゴム支承は基礎床（橋脚構造物いわゆ
る下部工）へアンカーボルトと共に埋め込まれた下沓
と、橋梁構造物（橋桁構造物いわゆる上部工）の下フラ
ンジに取り付けた上沓との間に、ネオプレンゴムなどの
弾性体の複数の平板を重ねて積層し、かつ、補強と摺動
性を向上するために各層間に金属平板を交互に挾在した
積層体を一体的に成型した形態を指す。また、積層ゴム
支承の該基本形態に対し、さらに改良を加えて必要とす
る種々の機能の何れかを重点的に強化した従来技術もか
なり多数の提示が認められる。The laminated rubber bearing is between a lower shoe which is embedded in the foundation floor (bridge pier structure, so-called substructure) together with anchor bolts, and an upper shoe which is attached to the lower flange of the bridge structure (bridge girder structure, so-called superstructure). In addition, multiple flat plates of elastic material such as neoprene rubber are stacked and laminated, and a laminated body in which metal flat plates are alternately sandwiched between the layers to improve reinforcement and slidability is integrally molded. Refers to. In addition, a considerable number of prior arts in which any of various required functions are strengthened by further improving the basic form of the laminated rubber bearing can be recognized.

【０００４】実公平３−５２８０９号公報では、上沓１
ａ、下沓２ａの間に重ねて取り付けるゴムの積層板を、
従来のような１枚物で形成せず図５で示すように３個１
組のゴム沓１０１、１０２、１０３で形成し、中央のゴ
ム沓１０２の上面に摩擦板１０４を組み込んだ構成を特
徴とする。この構成によって積層ゴム支承のうち、左右
に位置するゴム沓１０１，１０３は在来のゴム沓と同様
に緩衝機能を有し、中央部に位置するゴム沓１０２は、
上面に摩擦板１０４を有するために減衰機能を具えるの
で、桁の伸縮時の抵抗力を少なくし、また、地震時にお
ける減衰機能を発揮することができると謳っている。In Japanese Utility Model Publication No. 3-52809, Kamitsuku 1
a, a rubber laminated plate to be attached between the lower shoe 2a,
3 pieces 1 as shown in FIG.
It is characterized in that it is formed of a pair of rubber grits 101, 102, 103, and a friction plate 104 is incorporated on the upper surface of the central rubber grove 102. With this structure, the rubber crates 101 and 103 located on the left and right sides of the laminated rubber bearing have a cushioning function similarly to the conventional rubber crates, and the rubber crud 102 located at the center is
Since the friction plate 104 is provided on the upper surface of the girder, it has a damping function, so that it is possible to reduce the resistance force when the girder expands and contracts, and to exert the damping function at the time of an earthquake.

【０００５】実開平２−１０９８１７号公報で開示され
た従来技術では、図６で示すように上沓１ｂ，下沓２ｂ
の間に挟持する積層ゴム支承が、横移動防止板１０５を
挟んで上下にゴム支承１０６，１０７で一体的に形成さ
れ、金属ベースプレート１０８の橋桁長手方向の両端部
に近接するように配置された橋桁長手方向移動防止用ス
トッパー１０９を立設したことを構成上の特徴とする。
この構成により橋桁長手方向の大きな水平地震力が作用
したとき、横移動防止板１０５が橋桁長手方向移動防止
ストッパー１０９に突き当って下部のゴム支承１０７の
剪断変形を防止すると共に、上部のゴム支承１０６のみ
が剪断変形するので、簡単な手段によって橋桁長手方向
の橋桁の安定性を向上できると謳っている。According to the prior art disclosed in Japanese Utility Model Laid-Open No. 2-109817, as shown in FIG. 6, an upper shoe 1b and a lower shoe 2b.
The laminated rubber bearing sandwiched between the two is integrally formed by the rubber bearings 106 and 107 with the lateral movement prevention plate 105 sandwiched therebetween, and is arranged so as to be close to both ends of the metal base plate 108 in the longitudinal direction of the bridge girder. The structural feature is that a stopper 109 for preventing movement of the bridge girder in the longitudinal direction is provided upright.
With this configuration, when a large horizontal seismic force in the longitudinal direction of the bridge girder is applied, the lateral movement prevention plate 105 abuts on the bridge girder longitudinal movement prevention stopper 109 to prevent shear deformation of the lower rubber bearing 107, and at the same time, the upper rubber bearing is supported. Since only 106 is sheared and deformed, it is stated that the stability of the bridge girder in the longitudinal direction of the bridge can be improved by a simple means.

【０００６】しかし、これらの従来技術は阪神大震災発
生前の改良に係り、橋梁構造物と基礎床との連結が分断
され、大きな被害を蒙った今回のような最大級の地震が
直撃したとき、果たして完全に耐えられるか否か改めて
問い直す必要性が強調されるようになった。（財）土木
研究センターで進められている「建設省・道路橋の免震
設計法マニュアル（案）」によれば、下記の表１のよう
に作動原理別に分類した対策案が提示され、各々の具体
的な構成も例示されているが、表からも窺えるように、
積層ゴム支承をベースとしてさらに他の要件を附加した
強化策が主体を占める。However, these prior arts are related to the improvement before the Great Hanshin Earthquake, and when the connection between the bridge structure and the foundation floor was cut off and the largest earthquake such as this time, which suffered a great deal of damage, was hit directly, The necessity of re-questioning whether or not it could be completely tolerated came to be emphasized. According to the “Ministry of Construction / Seismic Isolation Design Method Manual for Road Bridges (Draft)” being promoted by the Civil Engineering Research Center, the measures proposed by the operating principle are presented as shown in Table 1 below. The specific configuration of is also illustrated, but as you can see from the table,
Mainly reinforced measures are based on laminated rubber bearings and added other requirements.

【０００７】[0007]

【表１】 [Table 1]

【０００８】たとえば鉛プラグ入り免震積層ゴム支承
は、図７に示すようにアンカーバーを立設した上プレー
ト１ｃ、アンカーボルトを垂設した下プレート２ｃの間
に金属補強板１１０と積層ゴム板１１１とを交互に積み
重ね、一体的に加硫接着した積層構造に、嵌入孔を穿孔
して円柱状の鉛プラグ１１２を内嵌した構成である。ま
た、橋軸と直角方向にはサイドブロック１１３を立設し
て横方向の移動を防止する機能も具え、 積層ゴムは垂直方向に対する剛性が高く水平方向の剛
性が小さいため、大きな垂直荷重を支え、構造物の周期
を長周期化する。すなわち、緩衝と減衰の機能が高い。 積層ゴムの変形に伴って鉛プラグが塑性変形を起こし
地震エネルギーを吸収する。 風荷重や制動荷重などの日常の低レベルの水平力に対
しては、鉛プラグの剛性によって抵抗し揺動を防止す
る。 特徴によって従来技術の積層ゴム支承に比べると、さら
に免震機能が強化すると期待されている。For example, as shown in FIG. 7, a seismically isolated laminated rubber bearing containing a lead plug has a metal reinforcing plate 110 and a laminated rubber plate between an upper plate 1c on which an anchor bar is erected and a lower plate 2c on which anchor bolts are vertically installed. This is a structure in which a lead plug 112 having a cylindrical shape is internally fitted by forming insertion holes in a laminated structure in which 111 and 111 are alternately stacked and integrally vulcanized and bonded. It also has a function to prevent lateral movement by standing side blocks 113 in the direction perpendicular to the bridge axis. The laminated rubber has a high rigidity in the vertical direction and a small rigidity in the horizontal direction, so it supports a large vertical load. , Make the cycle of the structure longer. That is, the functions of buffering and damping are high. The lead plug undergoes plastic deformation as the laminated rubber deforms, and seismic energy is absorbed. Rigidity of the lead plugs resists daily low level horizontal forces such as wind loads and braking loads, and prevents swinging. Due to its characteristics, it is expected that the seismic isolation function will be further strengthened compared to the conventional laminated rubber bearing.

【０００９】[0009]

【発明が解決しようとする課題】ここで例示した代表的
な従来技術は、日常の温度変化をはじめ地震などの緊急
時においても橋梁と橋脚の相対的な横方向の位置変動が
両者の連結を断ち切って離脱、さらに脱落の可能性を最
大の課題として捉え、積層ゴム支承の横方向への移動防
止に焦点を当てた解決手段を提起した点で共通する。も
ちろん、図５の従来技術でも従来の緩衝機能に摩擦力に
よる減衰機能を加えたことによって、垂直荷重は各ゴム
支承が分担するため剪断抵抗力を小さくできると説き、
図７の従来技術でも鉛プラグの挿入が垂直方向の強化に
全く無関係ではないと評価はできるが、直接、垂直方向
の激しい上下運動に抵抗する能力向上を目指した構成と
は言えず、垂直方向の震動に対しては、なお、強化の必
要性が残っていると判断せざるを得ない。The typical prior art illustrated here is such that the relative lateral positional fluctuations of the bridge and the bridge pier can connect the two even in an emergency such as an earthquake such as daily temperature change. It is common to point out the possibility of disconnection and disconnection as well as the possibility of falling off, and to propose a solution that focuses on preventing lateral movement of the laminated rubber bearing. Of course, even in the conventional technique of FIG. 5, it is explained that the vertical load is shared by each rubber bearing by adding the damping function by the friction force to the conventional cushioning function, so that the shear resistance can be reduced.
Although it can be evaluated that the insertion of the lead plug has nothing to do with the vertical strengthening even in the conventional technique of FIG. 7, it cannot be said that the configuration is aimed directly at improving the ability to resist the severe vertical movement in the vertical direction. With respect to the earthquake, there is no choice but to judge that the need for strengthening remains.

【００１０】一方、橋梁における別の課題として車両な
どの通過時に発生する振動や騒音の抑制が挙げられる。
図９に概念的に示したように、連結された長大な橋梁の
橋桁Ｋ1，Ｋ2の継合部が橋脚Ｂで支えられ、その支持部
において橋脚の両側にそれぞれ積層ゴム支承が介装され
て橋脚と橋梁構造とを連結しているとき、隣接する橋桁
間にはその伸縮量を吸収するゴム伸縮継手Ｃが介在する
のが通常の方式である。この構造において、たとえば重
車両が左側の橋桁Ｋ1上から図の右方へ向って高速で進
行してきた瞬間を想定すれば、当然、その重量に伴う活
荷重が一方の橋桁Ｋ1にだけ負荷して支承の積層ゴム板
を圧縮変形させ、ゴム伸縮継手を境として両橋桁Ｋ1〜
Ｋ2の水平レベル間に段差Ｄが生じ、車両が段差Ｄを通
過するときに振動と騒音を発生する原因となる。On the other hand, another problem in bridges is suppression of vibration and noise generated when a vehicle or the like passes by.
As conceptually shown in FIG. 9, the joint portion of the bridge girders K1 and K2 of the connected long bridge is supported by the pier B, and the laminated rubber bearings are interposed on both sides of the pier at the support portion. When connecting a pier and a bridge structure, it is a usual method that a rubber expansion joint C for absorbing the expansion amount is interposed between adjacent bridge girders. In this structure, for example, assuming the moment when a heavy vehicle is moving from the left bridge girder K1 toward the right side of the figure at a high speed, naturally, the live load due to its weight is applied to only one bridge girder K1. The laminated rubber plates of the bearing are compressed and deformed, and both bridge girders K1 ~
A step D occurs between the horizontal levels of K2, which causes vibration and noise when the vehicle passes through the step D.

【００１１】従来技術の積層ゴム支承の構造では、この
段差が０．２ｍｍ以上に達すると大型車が６０ｋｍ／ｈ
以上の速度で通過した場合に橋脚の振動と騒音を避けら
れないことが経験的に認められており、この速度以下に
制限することは特に高速道路では機能を無視する結果に
繋がるから、速度制限の強制を前提とする対策は最早利
用者の受忍できる限度を超える。他方、特に都市部の高
速道路などを中心に車両走行の高速化に伴う振動や騒音
は道路周辺の住民に対する公害であると明確に認識さ
れ、訴訟の対象ともなる今日であるから、地震などの天
災時の安全性と共に日常のニーズとして深刻な課題とな
っている。In the structure of the laminated rubber bearing according to the prior art, when the step reaches 0.2 mm or more, a large vehicle is 60 km / h.
It has been empirically recognized that vibration and noise of piers cannot be avoided when passing at the above speeds, and limiting speeds below this speed leads to the result of ignoring the function, especially on expressways. Measures that are subject to mandatory enforcement are no longer acceptable to users. On the other hand, vibrations and noise associated with the speeding up of vehicles, especially in highways in urban areas, are clearly recognized as pollution to residents around the road and are subject to lawsuits today. It has become a serious issue as a daily need along with safety in the event of a natural disaster.

【００１２】阪神大震災後の河川や高速道路などの被害
の実態を精緻に調査した結果、最大級の地震による上下
方向への波動は予想以上に激しく、従来技術が特に水平
方向の揺動に重点をおいて強化を図ってきた定説に一石
を投じる一方、高速道路の公害訴訟の多発によって排気
ガスの問題と共に騒音、振動の抑制が強く望まれる背景
を受けて、本発明は直接的な強化手段によって災害や公
害から公共の財産と住民の健康を守る新たな低騒音タイ
プの免震積層ゴム支承の提供を目的とするものである。As a result of a detailed investigation of the actual conditions of damage to rivers and highways after the Great Hanshin Earthquake, the vertical vibration due to the largest earthquake was more severe than expected, and the prior art focused on horizontal rocking. However, the present invention provides a direct strengthening means in light of the background of the desire to suppress noise and vibration as well as exhaust gas problems due to the frequent occurrence of highway pollution lawsuits. The purpose is to provide a new low-noise type seismic isolation laminated rubber bearing that protects public property and residents' health from disasters and pollution.

【００１３】[0013]

【課題を解決するための手段】本発明に係る低騒音の免
震積層ゴム支承は、橋梁構造物と基礎床との間に介装し
上沓１と下沓２間に複数のゴム平板３と金属平板４を交
互に重ね合わせた積層ゴム支承を基本とし、最大級の地
震に伴う垂直荷重に耐え得るように位置とサイズを計算
したＰＣ鋼線５を、全てのゴム板３を貫通して上沓、下
沓にそれぞれ固着し、車両通過に伴う活荷重の５０〜８
０％に相当する引張り荷重を初めから負荷したことを構
成上の特徴とする。なお、本発明でいうＰＣ鋼線とは、
鋼線を撚って形成した撚り線だけでなく、単独の引き抜
き加工を受けて成形したより大径のＰＣ鋼棒も含むもの
とする。A low noise seismic isolation laminated rubber bearing according to the present invention is interposed between a bridge structure and a foundation floor, and a plurality of rubber flat plates 3 are provided between an upper shoe 1 and a lower shoe 2. Based on a laminated rubber bearing in which metal plates and metal flat plates 4 are alternately stacked, the PC steel wire 5 whose position and size are calculated to withstand the vertical load associated with the largest earthquake penetrates all the rubber plates 3. It adheres to the upper shoe and lower shoe respectively, and it has a live load of 50 to 8 as the vehicle passes.
The structural feature is that a tensile load corresponding to 0% was applied from the beginning. The PC steel wire referred to in the present invention means
Not only a stranded wire formed by twisting a steel wire, but also a larger-diameter PC steel rod formed by a single drawing process is included.

【００１４】日常、橋梁上を重車両などの重量物が通過
するとき、隣接する橋桁の一方にだけ不均等な活荷重が
負荷した瞬間、ＰＣ鋼線に初めから掛かっている張力が
変動活荷重に置換されて相殺され、初めから張力によっ
て弾性変形していた積層ゴム平板の垂直方向に対する圧
縮力の絶対値はほとんど変らない。積層ゴム平板に加わ
る圧縮量が変らなければゴムの変位量もほとんど変らな
いから、車両重量の掛かった橋桁頂面とまだ通過前の隣
接する橋桁頂面との段差が現われず、両橋桁頂面のレベ
ルはほぼ同一に保たれて発生する筈の振動や騒音が大幅
に軽減される。一方、水平方向の荷重に対しては、積層
ゴムの剪断変形とＰＣ鋼線を引き伸ばそうとする力が発
生するので２つの曲げ剛性によって対抗し、結局活荷重
に対する積層ゴムの変位はほぼ０に抑えられる。When a heavy load such as a heavy vehicle passes on a bridge on a daily basis, the tension applied to the PC steel wire from the beginning fluctuates when an uneven live load is applied to only one of the adjacent bridge girders. The absolute value of the compressive force with respect to the vertical direction of the laminated rubber flat plate which has been elastically deformed by the tension from the beginning is hardly changed. If the amount of compression applied to the laminated rubber flat plate does not change, the amount of displacement of the rubber does not change much.Therefore, there is no step between the bridge girder top surface where the vehicle weight is applied and the adjacent bridge girder top surface before passing, and both bridge girder top surfaces. The level of will be kept almost the same and the vibration and noise that should occur will be greatly reduced. On the other hand, with respect to a load in the horizontal direction, shear deformation of the laminated rubber and a force for stretching the PC steel wire are generated, so two bending rigidity opposes each other, and the displacement of the laminated rubber with respect to the live load is almost zero. It can be suppressed.

【００１５】初めからＰＣ鋼線に負荷する張力を想定さ
れる活荷重の５０〜８０％に限定した理由を述べると、
言うまでもなく活荷重は定常的に掛かる負荷ではなく重
車両などの通過によって一時的に発生する非定常的な荷
重のうち、想定される最大限の車両重量から算出した負
荷に、さらに安全率を掛けて万全を期した数値であり、
大荷重が常に積層ゴム平板を圧縮することは、ＰＣ鋼線
材、ゴム材の何れにも材質的な疲労を誘発する可能性が
否定できないから、最大限活荷重の８０％に留めた。し
かし、一方で重車両の通過が頻発する中で目的とする積
層ゴム平板を初めから定常的に圧縮し、通過時と非通過
時とのゴム剪断変位量を常にほぼ一定に維持するために
は、少なくとも活荷重の５０％に相当する張力が必要で
あり、この上限と下限の設定が課題を解決する上で必須
の要件として特定された。The reason why the tension applied to the PC steel wire is limited to 50 to 80% of the assumed live load from the beginning is as follows.
Needless to say, the live load is not a load that is steadily applied, but a non-steady load that is temporarily generated when a heavy vehicle passes, and the load calculated from the maximum possible vehicle weight is multiplied by a safety factor. It is a numerical value that
Since it is undeniable that a large load constantly compresses the laminated rubber flat plate may induce material fatigue in both the PC steel wire rod and the rubber material, the maximum live load was limited to 80%. However, on the other hand, in order to keep the target rubber laminated flat plate steady from the beginning in order to keep the amount of rubber shear displacement between passing and non-passing almost constant, the passing of heavy vehicles occurs frequently. The tension corresponding to at least 50% of the live load is required, and the setting of the upper limit and the lower limit is specified as an essential requirement for solving the problem.

【００１６】活荷重とＰＣ鋼線に最初から与える初期の
張力の設定を図２（Ａ）（Ｂ）に基づいて説明すると、
図（Ａ）のように積層ゴム支承に最初から死荷重として
負荷する初期荷重をＷ、図（Ｂ）のように車両などの通
過によって非定常的に負荷する活荷重をＷaとし、積層
ゴム支承の支持力をＦ、ゴム支承の鉛直方向の単位面積
当りの支持力をｆ′とし、ＰＣ鋼線の初期張力をＰ、活
荷重が作用したときの張力をＰaとすると、初期（車両
などの非通過時）の図（Ａ）の時点では、Ｗ＋Ｐ＝Ｆ…
…（１）変動荷重（車両通過時など）の図（Ｂ）の時点
では、Ｗ＋Ｗa+Ｐa≒Ｆ……（２）の両式が成立するよ
うにあらかじめ設計基準によりＰa が決まると、ＰＣ鋼
線で上下沓を固定する際に適当な初期張力を掛けておけ
ば目的が達成される。The setting of the live load and the initial tension applied to the PC steel wire from the beginning will be described with reference to FIGS. 2 (A) and 2 (B).
As shown in Fig. (A), the initial load that is applied to the laminated rubber bearing as a dead load from the beginning is W, and as shown in Fig. (B), the live load that is unsteadily applied by passage of a vehicle is Wa and the laminated rubber bearing is Let F be the bearing force of the rubber bearing, f ′ be the bearing force per unit area in the vertical direction of the rubber bearing, P be the initial tension of the PC steel wire, and Pa be the tension when a live load is applied. At the time of the figure (A) (when not passing), W + P = F ...
(1) At the time of the variable load (when passing a vehicle, etc.) in the figure (B), if Pa is determined in advance by the design criteria so that both expressions of W + Wa + Pa≈F (2) are established, PC steel The purpose is achieved by applying an appropriate initial tension when fixing the upper and lower shoes with a wire.

【００１７】前記の２数式において、活荷重Ｗaが働け
ばゴム支承は圧縮変形しようとするからＰＣ鋼線に加え
られていた張力が活荷重Ｗa分減少してＰからＰaとな
る。ＰＣ鋼線の弾性係数はゴムに比べると格段に大きい
から、ＰＣ鋼線のＰからＰa の変化による変位量はほぼ
０である。すなわち、恰も活荷重ＷaがＰＣ鋼線の張力
の現象に置き換えられたような現象を示す。このように
ゴム支承の変化量が常にほぼ一定に保たれれば、日常の
使用時に発生する騒音、振動の防止に有効に機能する。In the above two equations, if the live load Wa works, the rubber bearing tends to be compressed and deformed, so that the tension applied to the PC steel wire is reduced by the live load Wa to change from P to Pa. Since the elastic modulus of PC steel wire is much larger than that of rubber, the amount of displacement of PC steel wire due to the change from P to Pa is almost zero. That is, it shows a phenomenon in which the live load Wa is replaced by the tension phenomenon of the PC steel wire. In this way, if the amount of change in the rubber bearing is always kept substantially constant, it effectively functions to prevent noise and vibration generated during daily use.

【００１８】つぎに予期されなかった地震が突然直撃す
るという非常事態が発生した場合の挙動を見れば、垂直
方向の波動に対しては予め計算した通りにきわめて強大
なＰＣ鋼線の抗張力で対抗するから、最大級の地震に遭
遇しても十分耐えて上沓と積層ゴム支承間、および積層
ゴム支承と下沓間の離脱を許さず、確実に積層ゴム支承
の一体的な集合行動を守り抜く。また、地震時の水平方
向の震動に対しては横方向への引張り力の分力が加わる
ために、ＰＣ鋼線には垂直力以外に水平力の合成した張
力が働くが、ＰＣ鋼線の最高水準の強度がこの合成した
外力に対抗して積層ゴム支承を一体的に拘束し、両者の
分断を防止して橋梁・橋脚間の離脱を許容しない作用が
現われる。Next, looking at the behavior in the event of an emergency in which an unexpected earthquake suddenly hits directly, the wave motion in the vertical direction is counteracted by the extremely strong tensile strength of the PC steel wire as calculated in advance. Therefore, even if it encounters the largest earthquake, it does not allow separation between the upper shoe and the laminated rubber bearing, and between the laminated rubber bearing and the lower shoe, and securely protects the integrated behavior of the laminated rubber bearing. . In addition, since a tensile force component in the lateral direction is applied to the horizontal vibration during an earthquake, the combined tension of horizontal force acts on the PC steel wire in addition to the vertical force. The strength of the highest level counteracts this combined external force, integrally restrains the laminated rubber bearing, prevents the separation of both, and does not allow separation between the bridge and pier.

【００１９】また、前記構成を基本とし、上沓１、下沓
２内に固着したＰＣ鋼線５を内嵌するために上下沓に穿
孔した嵌入孔１１，２１の開口端を垂直方向に対して、
ｔａｎα＝１／５〜１／１０ の範囲に含まれる傾斜角
αで拡径する円錐面１２，２２で形成する要件を附加す
れば理想的な実施の形態となる。すなわち、前記のよう
にＰＣ鋼線には地震などの異常な震動時には垂直方向の
引張り力と水平方向の横揺れの合成した斜めの曲げ応力
が加わる。ＰＣ鋼線の端部は上下沓の内部に固着して拘
束され、端部から上下沓内に穿孔されたほぼ同径の嵌入
孔を通って最上層または最下層の積層ゴム板内へ嵌入し
ているから、剛性の高い上下沓表面と剛性の低いゴム平
板表面が接する境界面では、ＰＣ鋼線に最大の曲げ応力
が集中し、ＰＣ鋼線の外周が鋭く折り曲げられこの位置
で切断する可能性も否定できない。そのために上下沓の
表面近くの嵌入孔内周面を開口部に向って拡径した円錐
面で形成し、ＰＣ鋼線の変形を緩やかな屈曲に変えるこ
とによって鋭角的な曲げに基づく破断作用を緩和するこ
とができる。傾斜角αは前記のような限定を加えるが、
ｔａｎαが１／５よりも大きいと、ＰＣ鋼線による積層
ゴム支承の固定拘束作用が過小に失してその免震作用が
最大級の地震に対抗できなくなるし、ｔａｎαが１／１
０よりも小さいと嵌入孔の側面に突き当って曲げ応力の
集中作用を受け、切断する懸念が現われるので、前記の
ようにαの範囲を限定した。On the basis of the above construction, the opening ends of the fitting holes 11 and 21 drilled in the upper and lower gears for fitting the PC steel wire 5 fixed in the upper gear 1 and the lower gear 2 in the vertical direction. hand,
An ideal embodiment can be obtained by adding the requirement of forming the conical surfaces 12 and 22 whose diameter is expanded at the inclination angle α included in the range of tan α = 1/5 to 1/10. That is, as described above, the PC steel wire is subjected to an oblique bending stress, which is a combination of a tensile force in the vertical direction and a horizontal roll, during an abnormal vibration such as an earthquake. The end of the PC steel wire is fixedly fixed inside the upper and lower troughs and fitted into the laminated rubber plate of the uppermost layer or the lowermost layer through the fitting holes formed in the upper and lower troughs from the ends. Therefore, the maximum bending stress concentrates on the PC steel wire at the boundary surface where the upper and lower rake surfaces with high rigidity and the rubber flat plate surface with low rigidity are in contact, and the outer circumference of the PC steel wire is sharply bent and can be cut at this position. Sex cannot be denied. For this reason, the inner peripheral surface of the insertion hole near the surface of the upper and lower shoes is formed by a conical surface whose diameter is expanded toward the opening, and the deformation of the PC steel wire is changed to a gentle bending, so that the breaking action based on an acute angle bending is performed. Can be relaxed. The inclination angle α is limited as described above,
If tan α is larger than ⅕, the fixed restraint action of the laminated rubber bearing by the PC steel wire will be too small and its seismic isolation will not be able to counter the largest earthquake, and tan α will be 1/1
If it is less than 0, there is a concern that it may hit the side surface of the fitting hole and be subjected to a concentration action of bending stress, resulting in cutting. Therefore, the range of α is limited as described above.

【００２０】[0020]

【発明の実施の形態】図１は本発明の実施の形態を示す
縦断正面図であり、図（Ａ）が全体図、図（Ｂ）が上沓
内のＰＣ鋼線端部を拡大して示す部分図である。上沓１
と下沓２との間にはネオプレーンゴムなどのゴム平板３
とステンレス製の金属平板４とが交互に累積を繰り返し
積層ゴム支承を形成している。金属平板４が剛性の補強
と水平方向への摺動性を向上させる目的で挾在している
ことは言うまでもない。この図の実施形態では４層のゴ
ム平板を示しているが、橋梁の規模、サイズ、荷重量の
多寡によって２〜２０層程度の広い範囲からの選定が行
なわれる。1 is a vertical sectional front view showing an embodiment of the present invention, FIG. 1 (A) is an overall view, and FIG. 1 (B) is an enlarged view of an end of a PC steel wire in an upper shoe. FIG. Upper shoe 1
A rubber flat plate 3 such as neoprene rubber between the lower shoe 2 and the lower shoe 2.
And the metal flat plate 4 made of stainless steel are alternately accumulated repeatedly to form a laminated rubber bearing. It goes without saying that the metal flat plate 4 is present for the purpose of reinforcing rigidity and improving slidability in the horizontal direction. In the embodiment shown in this figure, a four-layer rubber flat plate is shown, but selection is made from a wide range of about 2 to 20 layers depending on the scale, size and load amount of the bridge.

【００２１】すべてのゴム平板３と金属平板４を共通し
て貫通し、上端が上沓１内に、下端が下沓２内にそれぞ
れ固着されるＰＣ鋼線５を必要な本数と配置を選択して
取り付ける。必要な本数とは最大級の地震の直撃があっ
たとき、積層ゴム支承の断面積全体に想定される垂直方
向の引張り力の総絶対量に対し、十分に耐えられる対抗
力をＰＣ鋼線材（高抗張力鋼）の単位断面積当りの抗張
力から算出し、市販のＰＣ鋼線単品の断面積から割り出
せばよく、その本数を積層ゴム支承の断面に均等に配分
して位置を設定することによって特定される。Select the required number and arrangement of PC steel wires 5 that pass through all the rubber flat plates 3 and the metal flat plates 4 in common and the upper end is fixed in the upper gear 1 and the lower end is fixed in the lower gear 2. Then install. What is the required number? When a direct earthquake hits one of the largest, the opposing force that can withstand the total absolute tensile force in the vertical direction that is assumed for the entire cross-sectional area of the laminated rubber bearing is PC steel wire ( It can be calculated from the tensile strength per unit cross-sectional area of (high tensile strength steel) and can be calculated from the cross-sectional area of a commercially available PC steel wire single item, and the number is specified by evenly distributing it to the cross section of the laminated rubber bearing and setting the position. To be done.

【００２２】ＰＣ鋼線５が挿通するための嵌入孔１１，
２１が上沓１、下沓２内に穿孔されるが、その内周面の
開口端近くには外開きの拡径した円錐面１２，２２が形
成される。拡径する傾斜角αは、ｔａｎα＝１／５〜１
／１０ の範囲が妥当であり、とくに１／８が最適の傾
斜角である。この円錐面が端部に形成されているから、
ＰＣ鋼線に曲げ変形が強いられたときでも鋭角的な屈折
が起こらず、緩やかな屈曲線を描く変形に置換されて外
力の集中がなく、ＰＣ鋼線の破断を防止できる。この図
の場合はＰＣ鋼線はＰＣ鋼棒と呼ばれる種類に属し、上
下両端部に雄ネジを螺刻しワッシャ１４，２４と硬質ゴ
ム環１５，２５を介して締結ナット１３および２３によ
って締結し、上沓または下沓へ強固に固着される。A fitting hole 11 for inserting the PC steel wire 5,
21 is bored in the upper shoe 1 and the lower shoe 2, and conical surfaces 12 and 22 having an outward opening and having an enlarged diameter are formed near the open end of the inner circumferential surface thereof. The inclination angle α for expanding the diameter is tan α = 1/5 to 1
A range of / 10 is appropriate, and 1/8 is the optimum tilt angle. Since this conical surface is formed at the end,
Even when bending deformation is forced on the PC steel wire, sharp refraction does not occur, it is replaced by deformation that draws a gentle bending line, concentration of external force does not occur, and breakage of the PC steel wire can be prevented. In the case of this figure, the PC steel wire belongs to a type called a PC steel rod, and male and female screws are threaded on both upper and lower ends and fastened with fastening nuts 13 and 23 via washers 14 and 24 and hard rubber rings 15 and 25. , It is firmly fixed to the upper or lower shoe.

【００２３】ＰＣ鋼線が撚り鋼線で形成しているとき
は、前例のように両端に雄ネジを螺刻してナットで締結
することができないから、図３（Ａ）（Ｂ）（Ｃ）のよ
うな公知技術を適用して上沓、下沓に固着する。すなわ
ち、下沓２Ａへ固着するＰＣ鋼線５Ａの下端に対して
は、専用機（ヘッディングマシン）によって図（Ｃ）の
ように球状にヘッド５１を成形して、アンカーヘッド２
６の凹部内へ嵌入係止し、ＰＣ鋼線５Ａの上端は図
（Ｂ）のように適宜必要な長さに切断して上沓１Ａ内を
挿通し、アンカーヘッド１６内でウェッジ１７を打ち込
んで傾斜面の楔作用によってＰＣ鋼線の端部を係止する
構成を採っている。When the PC steel wire is formed of twisted steel wire, it is not possible to thread male screws on both ends and fasten it with nuts as in the previous example, and therefore, as shown in FIGS. 3 (A) (B) (C). ) Is applied to fix the upper and lower shoes. That is, for the lower end of the PC steel wire 5A fixed to the lower shoe 2A, a dedicated machine (heading machine) is used to form a spherical head 51 as shown in FIG.
(6) The upper end of the PC steel wire 5A is cut to an appropriate length as shown in FIG. (B) and inserted through the upper shoe 1A, and the wedge 17 is driven in the anchor head 16 Thus, the end portion of the PC steel wire is locked by the wedge action of the inclined surface.

【００２４】[0024]

【実施例】図４は本発明の具体的な実施例を想定した縦
断正面図（Ａ）と平面図（Ｂ）である。上沓１、下沓２
はそれぞれ７５０ｍｍ×７５０ｍｍ×３８ｍｍのＳＳ４
００の鋼板で形成し、上沓１は桁下フランジＫに溶接
し、下沓２は橋脚のベースプレートＰに溶接固定してい
る。上沓と下沓の間には４枚の厚さ２２ｍｍのネオプレ
ーンゴムで製作したゴム平板３と厚さ２ｍｍのステンレ
ス平板４を交互に累積して積層ゴム支承を形成してい
る。設計条件としては、 橋長×巾員＝50ｍ×18ｍ（主桁６本） 主桁一本当りの反力：15tonf×50ｍ×1/2×1/6＝62.5
tonf→100tonf沓を使用 ＰＣ鋼線の降伏点応力：δa＝78.5kgf/mm² 最大級の地震の垂直震度係数：0.4（現在確定してい
ないが旧基準１の４倍として考える） 地震の垂直荷重Ｆv＝62.5×0.4＝25tonf ＰＣ鋼線の引張力ｆ＝78.5×(π/4)×9.2²＝78.5×6
6.43＝5214kgf ６本使用するとＦ₆＝5.214×6＝31.284tonf Ｆv＝25tonf＜Ｆ₆＝31.284tonf として計算すると、図（Ｂ）に示す６箇所の位置に外径
９．２ｍｍのＰＣ鋼線を６本上下に貫通強化することに
よって最大級の地震の直撃に遭っても積層ゴム支承内で
の分断が起こらない確証が得られた。FIG. 4 is a vertical sectional front view (A) and a plan view (B) assuming a specific embodiment of the present invention. Upper shoe 1, lower shoe 2
Are SS4 of 750mm x 750mm x 38mm respectively
No. 00 steel plate, the upper shoe 1 is welded to the girder lower flange K, and the lower shoe 2 is welded and fixed to the base plate P of the pier. Between the upper shoe and the lower shoe, four rubber flat plates 3 made of neoprene rubber having a thickness of 22 mm and a stainless flat plate 4 having a thickness of 2 mm are alternately accumulated to form a laminated rubber bearing. The design conditions are: bridge length x width = 50m x 18m (6 main girders) Reaction force per main girder: 15tonf x 50m x 1/2 x 1/6 = 62.5
tonf → 100 tonf shavings used Stress at yield point of PC steel wire: δa ＝ 78.5kgf / mm ² Vertical seismic coefficient of the largest earthquake: 0.4 (not confirmed at present, but considered as 4 times of old standard 1) Earthquake vertical Load Fv = 62.5 × 0.4 = 25tonf Tensile force of PC steel wire f = 78.5 × (π / 4) × 9.2 ² ＝ 78.5 × 6
6.43 = 5214kgf 6 present Use is calculated as _{F 6 = 5.214 × 6 = 31.284tonf} Fv = 25tonf <F 6 = 31.284tonf, the PC steel wire having an outer diameter of 9.2mm at the position of the six shown in FIG. (B) It was confirmed that by strengthening the six vertical penetrations, no division occurs in the laminated rubber bearing even if the largest earthquake hits directly.

【００２５】別の実施例として図５に示すように日常の
温度変化に伴う発生応力とＰＣ鋼線の材力との検討を計
算した結果を示す。図５は変形図であってＰＣ鋼線の変
形前の位置５′（点線）が発生応力によって５（実戦）
の位置まで変形したことを示している。設計条件は、 桁長：Ｌ＝４０ｍ 鋼の線膨張係数：α＝１２×１０^-6 温度変化：Δｔ＝±２５℃ 支承高：Ｉ＝２００ｍｍ ＰＣ鋼線のヤング係数：Ｅ＝２×１０⁶Kgf/mm² として外気の温度変化とＰＣ鋼線の材力を計算する。As another example, as shown in FIG. 5, the calculation results of the examination of the stress generated due to the daily temperature change and the strength of the PC steel wire are shown. FIG. 5 is a deformation diagram, in which the position 5 '(dotted line) before deformation of the PC steel wire is 5 due to the generated stress (actual battle).
It has been transformed to the position of. Design conditions are: Girder length: L = 40 m Steel linear expansion coefficient: α = 12 × 10 ⁻⁶ Temperature change: Δt = ± 25 ° C. Bearing height: I = 200 mm Young's modulus of PC steel wire: E = 2 × 10 ⁶ The temperature change of the outside air and the strength of the PC steel wire are calculated as Kgf / mm ² .

【００２６】 温度変化による桁の移動量ΔＬは、 ΔＬ＝Ｌ×α×Δｔ＝４０×１０³×１２×１０^-6×２
５＝１２ｍｍ ＰＣ鋼線の伸びΔＩは、 ΔＩ＝（Ｉ²＋ΔＬ²）^1/2−Ｉ＝（２００²＋１２²）^1/2
−２００＝０．３６ｍｍ 作用応力σは、 σ＝Ｅ×ΔＩ／Ｉ＝２．０×１０⁶×０．３６／２００
＝３６Kgf/mm²であり、ＰＣ鋼線の安全率として規格さ
れている７８．５Kgf/mm²よりも遥かに低いから余裕を
以てクリアできる。The shift amount ΔL of the digit due to the temperature change is ΔL = L × α × Δt = 40 × 10 ³ × 12 × 10 ⁻⁶ × 2
5 = 12 mm The elongation ΔI of the PC steel wire is ΔI = (I ² + ΔL ² ) ^1/2 −I = (200 ² +12 ² ) ^1/2
-200 = 0.36 mm Working stress σ is σ = E × ΔI / I = 2.0 × 10 ⁶ × 0.36 / 200
= A 36 Kgf / mm ^2, can be cleared with a margin because much lower than 78.5Kgf / mm ² which is standardized as a safety factor of PC steel wire.

【００２７】さらに本発明特有の機能である騒音、振動
抑制のためにＰＣ鋼線を上沓、下沓へそれぞれ固定する
初期取り付けの段階において、それぞれ１５０Kgf/m
m²、本実施例の場合ではＰＣ鋼線１本当り１０トンの活
荷重分に相当する張力を与えておくことが必要である。Further, in order to suppress noise and vibration, which are features peculiar to the present invention, 150 Kgf / m each at the initial stage of fixing the PC steel wire to the upper and lower gears respectively.
In the case of the present embodiment, it is necessary to apply a tension corresponding to a live load of 10 tons per m ² of PC steel wire.

【００２８】[0028]

【発明の効果】本発明は以上に述べた通り日常の使用状
態において定常的に負荷する水平、垂直方向への外力、
特に重車両などの通過によって瞬間的に負荷する変動荷
重が誘発するゴム材の変位と、変位に基づく段差の発生
を阻止し通過時の騒音や振動の総量を大幅に軽減して、
大きな社会的課題を解決する効果がある。その上、最大
級の地震が直撃した場合には、水平方向だけでの抵抗力
だけでなく、今回の災害調査の結果、改めて強く指摘を
受けた垂直方向の激しい震動に対しても十分耐え得る新
たな機能が加わり、万全の態勢を都市機能に具える効果
が得られ、その意味で最新の従来技術に比べても明らか
に凌駕する。また、本発明は実施形態として図示した２
〜３の形態に留まらず、従来技術の全ての形態にＰＣ鋼
線を挿通し直すという比較的簡単な補強工事によって飛
躍的な能力向上に結び付けることができるから、たとえ
ば図５、図６、図７などの既設の構造に、新たな本発明
の要件を追加することによって、公害防止と天災防止の
両機能を格段に向上できるという実施の容易さも看過し
難い効果の一つである。INDUSTRIAL APPLICABILITY As described above, the present invention constantly applies an external force in the horizontal and vertical directions in daily use,
In particular, the displacement of the rubber material, which is caused by the fluctuating load that is momentarily applied by the passage of heavy vehicles, and the generation of steps due to the displacement are prevented, and the total amount of noise and vibration during passage is significantly reduced.
It has the effect of solving major social issues. In addition, when the largest earthquake hits directly, it can withstand not only horizontal resistance, but also the strong vertical tremor that was strongly pointed out again as a result of this disaster investigation. With the addition of new functions, the city's functions are fully prepared, and in that sense, it is clearly superior to the latest conventional technology. In addition, the present invention is illustrated in FIG.
Not only the configurations of 3 to 3, but also the comparatively simple reinforcement work of reinserting the PC steel wire into all the configurations of the prior art can lead to a dramatic improvement in performance. One of the effects that is easy to implement is that both the pollution prevention and natural disaster prevention functions can be markedly improved by adding new requirements of the present invention to the existing structure such as 7.

【００２９】請求項２に係る発明独自の効果は桁長の大
きい橋梁の適用に対してきわめて信頼性を高める点にあ
る。ＰＣ鋼線自体は既述のようにきわめて強靭であり引
張り強度が高いが、曲げ応力が局部的に集中するとその
鋭角的に屈折した部分が耐え切れずに切断する可能性も
なくはない。したがって桁長が大きく水平方向への移動
量の大きい長大な連結桁の橋梁については、過大な張力
を分散吸収するために曲げ方向を緩やかな屈曲に置換す
る構成がきわめて効果的であり、橋梁構造全体の非常時
における耐性の信頼性を大幅に昂進する効果が顕著であ
る。The effect peculiar to the invention according to claim 2 resides in that the reliability is extremely improved for the application of a bridge having a large girder length. As described above, the PC steel wire itself is extremely tough and has a high tensile strength. However, if the bending stress is locally concentrated, there is a possibility that the sharply bent portion will not endure and will be cut. Therefore, for bridges with long girders that have a large girder length and large horizontal movement, it is extremely effective to replace the bending direction with a gentle bend in order to disperse and absorb excessive tension. The effect of significantly improving the reliability of resistance in an overall emergency is remarkable.

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

【図１】本発明の実施の形態を示す縦断正面図（Ａ）と
要部の拡大図（Ｂ）である。FIG. 1 is a vertical front view (A) showing an embodiment of the present invention and an enlarged view (B) of a main part.

【図２】本発明の死荷重だけの負荷時（Ａ）と活荷重も
同時に負荷した時（Ｂ）の作用の変化を説明する作用図
である。FIG. 2 is an action diagram for explaining a change in action of the present invention when a dead load alone is applied (A) and when a live load is also applied simultaneously (B).

【図３】本発明の別の実施形態を示す縦断正面図
（Ａ）、上沓とＰＣ鋼線の固定部の拡大図（Ｂ）、およ
び下沓とＰＣ鋼線の固定部の拡大図（Ｃ）である。FIG. 3 is a vertical sectional front view showing another embodiment of the present invention (A), an enlarged view of a fixed portion of an upper shoe and a PC steel wire (B), and an enlarged view of a fixed portion of a lower shoe and a PC steel wire ( C).

【図４】本発明実施例の縦断正面図（Ａ）と平面図
（Ｂ）である。FIG. 4 is a vertical sectional front view (A) and a plan view (B) of an embodiment of the present invention.

【図５】別の実施例の計算手順を説明する縦断正面図で
ある。FIG. 5 is a vertical sectional front view illustrating a calculation procedure of another embodiment.

【図６】従来技術の縦断正面図である。FIG. 6 is a vertical sectional front view of a conventional technique.

【図７】別の従来技術の縦断正面図である。FIG. 7 is a vertical sectional front view of another prior art.

【図８】さらに別の従来技術の斜視図である。FIG. 8 is a perspective view of yet another prior art.

【図９】従来技術の課題の一つを示す概略の正面図であ
る。FIG. 9 is a schematic front view showing one of the problems of the prior art.

【符号の説明】[Explanation of symbols]

１ 上沓 ２ 下沓 ３ ゴム平板 ４ 金属平板 ５ ＰＣ鋼線 21 嵌入孔 22 円錐面 α 傾斜角 1 Upper shoe 2 Lower shoe 3 Rubber flat plate 4 Metal flat plate 5 PC steel wire 21 Fitting hole 22 Conical surface α Inclination angle

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 橋梁構造物と基礎床との間に介装し上沓
１と下沓２間に複数のゴム平板３と金属平板４を交互に
重ね合わせた積層ゴム支承において、最大級の地震に伴
う垂直荷重に耐え得るように位置とサイズを計算したＰ
Ｃ鋼線５を、全てのゴム板３を貫通して上沓、下沓にそ
れぞれ固着し、車両通過などに伴う活荷重の５０〜８０
％に相当する引張り荷重を負荷したことを特徴とする低
騒音の免震積層ゴム支承。1. A laminated rubber bearing in which a plurality of rubber flat plates 3 and metal flat plates 4 are alternately stacked between an upper shoe 1 and a lower shoe 2 and interposed between a bridge structure and a foundation floor. Position and size are calculated to withstand vertical load caused by earthquake P
The C steel wire 5 penetrates through all the rubber plates 3 and is fixed to the upper and lower shoes, respectively, and has a live load of 50 to 80 accompanying vehicle passage.
%, A low-noise seismic isolation laminated rubber bearing characterized by being loaded with a tensile load equivalent to%. 【請求項２】 請求項１において上沓１、下沓２内に固
着したＰＣ鋼線５を内嵌するために該上下沓に穿孔した
嵌入孔１１，２１の内周面開口端を垂直方向に対して、
ｔａｎα＝１／５〜１／１０ の範囲に含まれる傾斜角
αで拡径する円錐面１２，２２で形成することを特徴と
する低騒音の免震積層ゴム支承。2. The inner peripheral surface open ends of the fitting holes 11 and 21 formed in the upper and lower shoes in order to fit the PC steel wire 5 fixed in the upper and lower shoes 1 and 2 in the vertical direction. Against
A low noise seismic isolation laminated rubber bearing characterized in that it is formed of conical surfaces 12 and 22 that expand in diameter at an inclination angle α included in the range of tan α = 1/5 to 1/10.