JP4665320B2 - Membrane roof of storage tank - Google Patents

Description

【０００１】
【発明の属する技術分野】
この発明は、潅漑用水や上水道水等の液体、或いは穀物や石炭等の粉粒体、若しくは廃棄物やごみ等の固体などの貯蔵物を常圧下で貯蔵する貯槽に設ける膜屋根に関するものである。
【０００２】
【従来の技術】
潅漑用水や上水道水等の液体、或いは粉粒体や固体などの貯蔵物を常圧下で貯蔵する貯槽の上部に設ける屋根は、一般にコンクリート製、或いは金属製で剛構造に形成されている。このコンクリート製や金属製の屋根は、重量及び荷重が大きくなるため堅牢な構造にしなければならず、この屋根を支える貯槽本体も堅牢な構造に構築しなければならなかった。
そこで、上記のような堅牢な構造の屋根に替えて、軽量で簡易な膜構造の屋根を貯槽本体上部に設けることが考えられている。そして、より軽量かつ簡単な構造で経済的な膜屋根として、複雑な屋根骨やフレームを用いることなく、センター支柱及び索条によって支える吊膜屋根構造、つまりサスペンション膜構造の膜屋根が知られている。
【０００３】
【発明が解決しようとする課題】
上記軽量で簡易な吊膜屋根、つまりサスペンション膜構造の膜屋根を、貯槽の上部を被覆するように設ける場合には、膜屋根上部に雨水が滞留することなく、また夾雑物が堆積することなく、さらにまた強風によってばたつくことがないようにすることが求められていた。つまり、可撓膜体が垂れ下がることなく、たるみ部を生じないように、膜体全体を緊張状態に保持しながら、かつ周縁取付部を気密な状態に取付けることは難しいものであった。
そして、可撓膜体を貯槽の側壁上端部に取付ける展設作業は、膜体に張力を加えながらその周縁部を気密に固着するという同時作業を要するため扱いが難しく、さらに可撓膜体の周縁部を貯槽上端部のアンカーボルトなどへ固着する位置合わせは、可撓膜体に片寄りや変形、皺などが生じ易いため難しく、可撓膜体の展開作業及び取付作業に労力と手間を要するものであった。
【０００４】
また、膜屋根天頂部の構築は、可撓膜体を吊り上げてセンター支柱上端部上方へ移動した後に膜体中央部の位置合わせをする際の作業が不安定で難しく、さらに、膜体中央部をセンター支柱上端部に固着する作業も皺伸ばしや纏めなどが雑然として処理がし難く、労力と手間を要するものであった。このような膜体をセンター支柱の上部に取付ける作業は、膜体上部に乗って不安定な位置で行わなければならない場合もあって、足場や架台などを必要としその際の作業性も良くなかった。
【０００５】
この発明は、上述の課題に鑑みてなされたもので、緊張状態及び気密状態を確保し、展設の作業性が良く、耐久性と経済性に優れた貯槽の膜屋根を提供するものである。
【０００６】
【課題を解決するための手段】
この発明に係る貯槽の膜屋根は、底版と、該底版外周縁に立設した側壁とから貯槽本体を形成し、該貯槽本体の底版中央にセンター支柱を立設し、該センター支柱に支えられて貯槽本体上方を被覆する可撓膜体を設けた膜屋根であって、該可撓膜体は、裾部の周縁近傍を上下に分岐する下側膜体と上側膜体の二重膜構造に形成し、下側膜体は、膜体下部周縁を側壁上端部に緊張状態に取付け、上側膜体は、膜体下部周縁を側壁上端部に気密状態に取付けたものである。
【０００７】
また、上記センター支柱の上端部と側壁上端部との間に、上記可撓膜体に押圧接触して下から支える下側索条と、上記可撓膜体に係合して上から押える上側索条とを設けたものである。
【０００８】
また、上記センター支柱の上端部に下側筒体を設け、該下側筒体と、該下側筒体に嵌合する上側筒体とをフランジ接続し、上記下側筒体のフランジには上記下側索条を取付け、上記上側筒体のフランジには可撓膜体の中央部を固着するとともに、該上側筒体には上記上側索条を取付けて形成したものである。
【０００９】
【発明の実施の形態】
図１乃至図４に基づき、この発明に係る貯槽の膜屋根の実施の形態について説明する。図１は、潅漑用水を貯蔵するファームポンド、上水道水を貯蔵する配水池などのコンクリート製大形貯槽に、膜屋根を設けた事例であり、図２は側壁上端部の近傍を示し、図３は屋根天頂部の近傍を示す。また、図４（ａ），（ｂ）は、膜屋根を構築する手順の一例を示す。
なお、この実施形態例はコンクリート製貯槽に膜屋根を適用した場合について説明するが、底版及び側壁が金属製等の大形貯槽その他の貯槽の場合であっても、この発明に係る膜屋根を適用することができることは言うまでもない。
【００１０】
図１に示すように、コンクリート構造の貯槽本体１は、円形平盤状の底版２と、この底版２の外周縁近傍に垂直に立設した円形筒体状の側壁３とから形成されている。この貯槽本体１の上部に設ける膜屋根４は、大きな断面性能を備え肉厚な形状の側壁上端部９から、貯槽中央に向かって上りの急勾配で屋根天頂部１０に至るように、側壁３より屋根天頂部１０が高い略円錐形状に被覆する可撓膜体７にて形成するものである。
この略円錐形状の可撓膜体７は、上記底版２の底版中央部１１から屋根天頂部１０に至る間に、例えば金属製の大口径パイプ材、形鋼材、コンクリート製パイル材などを用いて垂直に立設したセンター支柱５によって支えられている。
【００１１】
この可撓膜体７は、可撓性と気密性を有する材料、例えば繊維織物に合成樹脂材をコーティングした材料などを用いて、上記センター支柱上端部８と側壁上端部９との間に緊張状態を保持しかつ周縁部を気密状態に展設するもので、この可撓膜体７の裾部の周縁近傍は、上下に分岐する下側膜体７Ａと上側膜体７Ｂの二重膜構造に形成し、下側膜体７Ａは可撓膜体７から延出してその下部周縁を側壁上端部９へ緊張状態に取付け、上側膜体７Ｂは下側膜体７Ａの外周縁取付部の上方を被覆しその下部周縁を側壁上端部９へ気密状態に取付ける。
【００１２】
また、上記センター支柱５のセンター支柱上端部８と側壁上端部９との間に、例えば鋼線を撚り合わせたワイヤロープなどの索条６を放射状に張設する。この索条６は、上記可撓膜体７を接触による押圧力でもって下から支える下側索条６Ａと、上記可撓膜体７と係合させこの係合による動きの抑制によって浮き上がりや移動を上から押える上側索条６Ｂとで形成することによって、可撓膜体７を下側索条６Ａと上側索条６Ｂの間に挟み込むように配設する。
【００１３】
可撓膜体７の裾部の周縁部の二重膜構造、及びその取付構造の一例について、図２に基づいて詳細に説明する。図２に示すように、上下に分岐させて二重膜構造に形成した下側の膜体７Ａは、可撓膜体７から連続して延出させ、その外周縁を先方位置の側壁上端部９へ緊張状態に取付ける。この緊張状態に取付ける構造は、例えば、下側膜体７Ａの周縁部位置を、側壁上端部９の取付部へ届く位置よりも短く形成し、この下側膜体７Ａの周縁部にハトメ部１７を設け、このハトメ部１７を緊締する構造とする。つまり、ハトメ部１７に、ワイヤ、ロープなどの締結部材１８を挿通し、側壁上端部９の周方向に沿って環状に配設した棒状部材１６にからめ付け、順々に絞り上げて張り具合を調整して緊張させ、バックルなど逆止構造の緊締具１８Ａによって緊締する。なお、棒状部材１６は、側壁上端部９の周方向に沿って所定間隔をおいて固定金具１５を埋設固定し、この固定金具１５に鋼棒などを挿通して環状に形成した場合を示している。
このように、下側膜体７Ａは、順次緊締によって調整して取付け、例えば所定範囲に区分し緊張状態の均衡を調整しながら作業性良く施工し、可撓膜体７の全体を均一に張設することが可能となる。
【００１４】
また、図２に示すように、上下に分岐させて二重膜構造に形成した上側の膜体７Ｂは、上記下側膜体７Ａの外周縁取付部上方の所定範囲にわたって、然程張力を与えることなくなだらかに傾斜させて被覆し気密状態に取付ける。この上側膜体７Ｂは、例えば、所定幅の略矩形膜体を用いて、その内周縁１９を周方向に沿って下側膜体７Ａ上面に溶着や接着或いは縫合などによって接合し、外周縁２０を側壁上端部９に膜保護材、押えプレート、アンカーボルト・ナットなどからなる着脱自在な面接合部材によって気密状態に固着し、両側縁２１，２１は着脱自在な面状ファスナーや両面接合テープなどの面接合部材によって固着する。
このように、上側膜体７Ｂは、張力を余り与えることなく被覆するので、片寄りや変形などが生じ難く無理のない面接合で気密に取付けることができ、また下側膜体７Ａの外周縁取付部の上方開口部をなだらかに傾斜させて被覆しているので、膜屋根にかかる雨やゴミなどを外周側へ円滑に滑り落として貯槽内へ侵入するのを防止することができる。また、外周縁２０は着脱可能な構造で、両側縁２１，２１も着脱自在な簡単な取付構造に形成したので、この上側膜体７Ｂを開けて、下側索条６Ａ及び下側膜体７Ａの緊張力の付加調整、及び取付金具などの点検やメンテナンスを行うことができる。
【００１５】
図２に基づいて、上記可撓膜体７の上下にそれぞれ複数本放射状に張設する下側索条６Ａ及び上側索条６Ｂの取付構造の一例について説明する。
下側索条６Ａは、コンクリート製の側壁上端部９の最内側に周方向に沿って所定間隔をおいて埋設固定した取付金具１２Ａに端縁を係合し、ターンバックル、、レバーブロックなどの締付具１３Ａを用いて取付ける。また、上側索条６Ｂは、コンクリート製の側壁上端部９の最外側に周方向に沿って所定間隔をおいて埋設固定した取付金具１２Ｂに端縁を係合し、ターンバックル、レバーブロックなどの締付具１３Ｂを用いて取付ける。
【００１６】
上記説明したように、可撓膜体７は緊張状態に展設され、さらに放射状に張設した複数本の下側索条６Ａに押圧力をもって接触し平均に下から支えられているので、落葉や土砂などの夾雑物、雨や雪による荷重に対して一層耐久性を向上することができる。また、可撓膜体７は、外周縁取付部の上方を被覆し周囲を確りと気密に固着され、さらに、可撓膜体７上面に複数隔離して設けた係合部材１４によって、放射状に張設した複数本の上側索条６Ｂと係合して動きを抑制するように、バランス良く上から押えられているので、強風や気圧の変化などによる浮上がりやばたつきに対して一層耐久性を向上することができる。
このように形成した膜屋根４を、屋外のファームポンド、配水池などの貯水槽等に設けた場合には、落葉や土砂等の塵芥などは可撓膜体７の上面に堆積させることなく、傾斜した上面に沿って重力で円滑に、貯槽の周囲に落とすことができ、雨水や雪も、可撓膜体７の上面に溜めることなく周囲に流し落とすことができる。なお、既設の屋根なしファームポンドなどの貯槽に、このような膜屋根４を適用すると、より軽量かつ構築が容易で経済的な簡易屋根となる。
【００１７】
可撓膜体７は、例えばポリエステル繊維、ポリアミド繊維、炭素繊維などの織物に、ポリウレタン、塩化ビニール系樹脂、フッ素ゴムなどの合成樹脂材料をコーティングした膜材を用いて、太陽光の紫外線、大気や雨などに含まれる腐食性ガスなどに対して耐候性及び耐食性を有するようにして、恒久的な屋外膜屋根構造物のように長期間にわたって使用することができる。
また、例えば黒色の繊維や樹脂、不透光性材料など太陽光を遮断する材料を用いた場合には、貯槽本体１の内部に太陽光が入ることなく、ファームポンドや配水池などの貯水槽において、太陽光によって繁茂する藻などの発生を防止することができる。
【００１８】
図３に基づいて、屋根天頂部１０近傍の構造の一例について説明する。センター支柱上端部８に、内径が上方に向かって拡大する漏斗状の下側筒体２３を接続し、この下側筒体２３の上端縁に、水平リング状に張出した下側フランジ２２を設ける。この下側フランジ２２と面接触するように、水平リング状に張出した上側フランジ２４を設け、この上側フランジ２４には、上記下側筒体２３内に下部を遊嵌状に挿し込んだ後に、図３に示すような嵌合状態で収容するように、外径が下方に向かって縮小する案内部材２５を有する上側筒体２６を設ける。そして、下側フランジ２２と上側フランジ２４をボルト・ナットなどの固着部材２７を用いて接続する。
上側フランジ２４には、ボルト・ナットなどの固着部材２７を取付け、このボルトに可撓膜体７の膜体中央部２８の端縁を挿通し、面接触する当て板やワッシャーなどを用いて挟み込んでナットを締め付けて気密状態に固着する。
また、下側フランジ２２には、下側索条６Ａの端縁を取付ける固着部２９を設け、上側筒体２６には、上側索条６Ｂの端縁を取付ける固着部３０を設ける。
【００１９】
このように、センター支柱上端部８に設けた下側筒体２３と、この下側筒体２３に嵌合する上側筒体２６とをフランジ２２，２４で接続するように形成したので、上記案内部材２５を介しての位置合わせと接続作業がやり易くなる。また、下側索条６Ａ及び上側索条６Ｂの固着作業、並びに可撓膜体７端縁の膜体中央部２８の固着作業もやり易くなり、そして、放射状に張設した下側索条６Ａに支えられた状態で、可撓膜体７を沿わせ移動し展開して取付けるという一連の展設作業を行うことにより、可撓膜体７の展開作業及び取付作業を作業性良く行うことができる。
また、上側フランジ２４には、可撓膜体７の膜体中央部２８を、予め地上の低所で作業性良く安全作業にて固着することができる。そして、下側フランジ２２に上側フランジ２４を固着する作業は、上記案内部材２５を沿わせて位置決めができるため、膜体中央部２８の上に乗って位置決め作業を行う必要がなくセンター支柱上端部８の下側から安全作業で簡単容易に取付作業ができるとともに、膜体中央部２８が固定され安定しているので、可撓膜体７を周囲に向かって展開する作業、及び側壁上端部９へ接続する作業も一層やり易くなる。
【００２０】
図４（ａ），（ｂ）に基づいて、貯槽の膜屋根を構築する手順の一例についてさらに詳述する。
図４（ａ）に示すように、側壁３に囲まれた底版２の中央部１１上に、センター支柱５を立設し、センター支柱上端部８と側壁上端部９との間に下側索条６Ａを架け渡し緊張状態に固定する。
次いで、予め地上の低所にて可撓膜体７及び上側索条６Ｂを固着した天頂部１０を、矢印▲１▼及び矢印▲２▼に示すように、吊り上げてセンター支柱上端部８へ移動する。
そして、図４（ｂ）の矢印▲３▼に示すように、上記吊り上げて移動した天頂部１０を吊り込んで位置合わせしてセンター支柱上端部８へ接続する。
次いで、矢印▲４▼のように、下側索条６Ａを支え架台にして、可撓膜体７を展開して側壁上端部９に固着し、その上に上側索条６Ｂを張設する。
【００２１】
上記のようにして膜屋根を構築するので、可撓膜体７及び上側索条６Ｂは、地上の低い場所で天頂部１０に作業性良く安全作業で固着することができ、次いで、この天頂部１０を吊り込んでセンター支柱上端部８へ固着する作業もやり易くなり、さらに、予め張設されている下側索条６Ａに支えられた状態で、安定性良くかつ作業性良く可撓膜体７を展設しその上の上側索条６Ｂを張ることができるため、構築時の一連の作業性に優れた膜屋根となる。
【００２２】
【発明の効果】
叙述の説明で明らかなように、この発明に係る貯槽の膜屋根は、膜屋根を構成する可撓膜体の裾部の周縁近傍を上下に分岐する下側膜体と上側膜体の二重膜構造に形成し、下側膜体は、膜体下部周縁を側壁上端部に緊張状態に取付け、上側膜体は、膜体下部周縁を側壁上端部に気密状態に取付けているので、予め下側膜体に所定の緊張力を付加して張ってから、次に上側膜体を被覆し気密状態を得るようにすることができ、下側膜体による緊張付加と上側膜体による気密被覆とで役割分担して、可撓膜体を作業性良く安全確実に取付けることが可能となる。
そして、可撓膜体を所定の緊張状態に維持しかつ気密状態を保持し、膜屋根にかかる雨やゴミなどを周囲に円滑に落とし貯槽内へ侵入するのを防止することができるため、雨や雪、塵芥、風などに対して耐用性を有し、簡単な構造で軽量かつ高強度で耐久性を有し、経済性に優れた貯槽の膜屋根とすることができる。
なお、必要に応じて上側膜体を開けて、下側膜体に緊張力を付加することも可能となるので、取付部や取付金具などの点検やメンテナンスを適宜行うこともできるため、長期間の耐用性を配慮した経済的な膜屋根となる。
【００２３】
また、上記センター支柱の上端部と側壁上端部との間に、上記可撓膜体に押圧接触して下から支える下側索条と、上記可撓膜体に係合して上から押える上側索条とを設けた膜屋根にあっては、上記下側索条による押圧支えによって雨や雪や塵芥などの荷重に対する垂れ下がりが一層抑制され、また、上記上側索条との係合による動きの抑制によって強風や気圧の変化などに対する浮き上がりやばたつきが生じ難く、膜屋根全体の安定性と強靭性が増加し、大きな負荷変動に対する信頼性もより一層向上する。
【００２４】
また、上記センター支柱の上端部に下側筒体を設け、該下側筒体と、該下側筒体に嵌合する上側筒体とをフランジ接続し、上記下側筒体のフランジには上記下側索条を取付け、上記上側筒体のフランジには可撓膜体の中央部を固着するとともに、該上側筒体には上記上側索条を取付けて形成した膜屋根にあっては、膜屋根中央部を吊り込んで案内し嵌合する位置合わせと接続が容易にでき、この膜屋根中央部の膜体及び索条の固着形成も安定状態で能率良く行うことができる。
そして、上側筒体に可撓膜体の中央部を固着する作業及び上側索条を取付ける作業は、予め地上の低い場所にて作業性良く安全作業で行うことができるとともに、次いで、上記のように下側筒体に嵌合してフランジ接続した後に、上記下側索条を膜体展設時の支え架台として使用することにより、可撓膜体を天頂部から周囲に向け沿わせて移動し展開する作業、及び側壁上端部へ取付ける作業もやり易くなるため、構築時の作業性に優れた膜屋根となる。
【００２５】
【図面の簡単な説明】
【図１】 この発明に係る貯槽の膜屋根の実施形態例の概略を示す一部を欠除し断面とした側面説明図である。
【図２】 側壁上端部近傍の概略を示す一部を欠除し断面とした斜視説明図である。
【図３】 屋根天頂部近傍の概略を示す一部を欠除し断面とした側面説明図である。
【図４】 （ａ），（ｂ）は、貯槽の膜屋根を構築する手順の一例を説明する一部を欠除し断面とした側面説明図である。
【符号の説明】
１ 貯槽本体 ２ 底版
３ 側壁 ４ 膜屋根
５ センター支柱
６ 索条
６Ａ 下側索条 ６Ｂ 上側索条
７ 可撓膜体
７Ａ 下側膜体 ７Ｂ 上側膜体
８ センター支柱上端部 ９ 側壁上端部
１０ 屋根天頂部 １１ 底版中央部
１２Ａ 取付金具 １２Ｂ 取付金具
１３Ａ 締付具 １３Ｂ 締付具
１４ 係合部材
１５ 固定金具 １６ 棒状部材
１７ 周縁ハトメ部 １８ 締結部材
１８Ａ 緊締具
１９ 内周縁 ２０ 外周縁
２１ 両側縁 ２２ 下側フランジ
２３ 下側筒体 ２４ 上側フランジ
２５ 案内部材 ２６ 上側筒体
２７ 固着部材 ２８ 膜体中央部
２９ 固着部 ３０ 固着部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a membrane roof provided in a storage tank for storing a liquid such as irrigation water or tap water, a granular material such as grain or coal, or a solid such as waste or garbage under normal pressure. .
[0002]
[Prior art]
The roof provided on the upper part of the storage tank which stores liquids, such as irrigation water and tap water, or storage things, such as a granular material and a solid, under normal pressure is generally made of concrete or metal and has a rigid structure. The concrete or metal roof has to be made strong because of its heavy weight and load, and the storage tank body that supports this roof has to be constructed in a strong structure.
In view of this, it has been considered that a roof having a light and simple membrane structure is provided on the upper portion of the storage tank body instead of the roof having a robust structure as described above. And, as a membrane roof that is lighter and simpler and more economical, a suspended membrane roof structure that is supported by center struts and ropes without using complex roof bones and frames, that is, a membrane roof with a suspension membrane structure is known. Yes.
[0003]
[Problems to be solved by the invention]
When the above-mentioned lightweight and simple suspended membrane roof, that is, a membrane roof with a suspension membrane structure, is provided so as to cover the upper part of the storage tank, rainwater does not stay on the membrane roof, and impurities do not accumulate. In addition, there was a demand to prevent flapping by strong winds. That is, it is difficult to attach the peripheral attachment portion in an airtight state while holding the entire membrane body in a tensioned state so that the flexible film body does not sag and a slack portion is not generated.
The installation work for attaching the flexible film body to the upper end of the side wall of the storage tank is difficult to handle because it requires simultaneous work of airtightly fixing the peripheral edge while applying tension to the film body. It is difficult to align the peripheral edge to the anchor bolt at the upper end of the storage tank because the flexible membrane tends to be displaced, deformed, wrinkled, etc., and labor and effort are required for the deployment and installation of the flexible membrane. It was necessary.
[0004]
In addition, the construction of the top of the membrane roof is unstable and difficult to align the center of the membrane after the flexible membrane is lifted and moved above the upper end of the center column. The work for fixing the upper end of the center strut to the center strut is difficult to process due to cluttering and gathering, and requires labor and labor. The work of attaching such a membrane body to the upper part of the center column may be performed at an unstable position on the top of the membrane body, and requires a scaffold or a base, and the workability at that time is not good. It was.
[0005]
The present invention has been made in view of the above-described problems, and provides a membrane roof of a storage tank that secures a tensioned state and an airtight state, has excellent workability for installation, and is excellent in durability and economy. .
[0006]
[Means for Solving the Problems]
The membrane roof of the storage tank according to the present invention forms a storage tank body from a bottom plate and a side wall erected on the outer periphery of the bottom plate, a center column is erected at the center of the bottom plate of the storage tank body, and is supported by the center column. A membrane roof provided with a flexible membrane body covering the upper part of the storage tank body, the flexible membrane body having a double membrane structure of a lower membrane body and an upper membrane body that vertically branches near the periphery of the skirt The lower film body is attached with the lower periphery of the film body in a tensioned state at the upper end of the side wall, and the upper film body is attached with the lower periphery of the film body in an airtight state at the upper end of the side wall.
[0007]
Moreover, between the upper end part of the said center support | pillar, and the upper end part of a side wall, the upper side which presses and contacts the said flexible membrane body and supports from the bottom, and engages with the said flexible membrane body, and is pressed from the top A rope is provided.
[0008]
In addition, a lower cylinder is provided at the upper end of the center column, the lower cylinder and the upper cylinder fitted to the lower cylinder are flange-connected, and the flange of the lower cylinder is connected to the flange of the lower cylinder The lower cable is attached, and the central part of the flexible membrane is fixed to the flange of the upper cylinder, and the upper cable is attached to the upper cylinder.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a membrane roof of a storage tank according to the present invention will be described based on FIGS. FIG. 1 is an example in which a membrane roof is provided in a large concrete tank such as a farm pond for storing irrigation water and a distribution reservoir for storing tap water, and FIG. 2 shows the vicinity of the upper end of the side wall. Indicates the vicinity of the top of the roof. 4 (a) and 4 (b) show an example of a procedure for constructing a membrane roof.
In addition, although this embodiment demonstrates the case where a membrane roof is applied to a concrete storage tank, even if the bottom plate and the side wall are large storage tanks or other storage tanks made of metal or the like, the membrane roof according to the present invention is used. It goes without saying that it can be applied.
[0010]
As shown in FIG. 1, the storage tank body 1 having a concrete structure is formed of a circular flat plate-like bottom plate 2 and a circular cylindrical side wall 3 erected vertically in the vicinity of the outer peripheral edge of the bottom plate 2. . The membrane roof 4 provided on the upper part of the storage tank main body 1 has the side wall 3 so as to reach the roof top 10 with a steep upward slope from the thick side wall upper end part 9 having a large cross-sectional performance toward the center of the storage tank. The roof top 10 is formed of a flexible membrane 7 that covers a substantially conical shape.
The flexible film body 7 having a substantially conical shape is formed using, for example, a metal large-diameter pipe material, a shape steel material, a concrete pile material, or the like between the bottom plate center portion 11 and the roof top portion 10 of the bottom plate 2. It is supported by a center column 5 that is erected vertically.
[0011]
The flexible film body 7 is made of a material having flexibility and airtightness, for example, a material in which a fiber woven fabric is coated with a synthetic resin material, and is tensioned between the center column upper end 8 and the side wall upper end 9. The peripheral portion of the flexible film body 7 is held in the airtight state while maintaining the state, and the vicinity of the peripheral edge of the flexible film body 7 has a double film structure of the lower film body 7A and the upper film body 7B that branches up and down. The lower film body 7A extends from the flexible film body 7 and the lower peripheral edge thereof is attached to the side wall upper end portion 9 in a tension state, and the upper film body 7B is located above the outer peripheral edge attaching portion of the lower film body 7A. And the lower peripheral edge thereof is attached to the side wall upper end portion 9 in an airtight state.
[0012]
Further, between the center column upper end portion 8 and the side wall upper end portion 9 of the center column 5, for example, a rope 6 such as a wire rope formed by twisting steel wires is stretched radially. The cord 6 is lifted or moved by engaging the flexible membrane body 7 with the lower cord 6A that supports the flexible membrane body 7 from below with a pressing force by contact, and suppressing the movement by this engagement. The flexible membrane 7 is disposed so as to be sandwiched between the lower cable 6A and the upper cable 6B.
[0013]
An example of the double membrane structure at the peripheral edge of the skirt portion of the flexible membrane body 7 and an example of its mounting structure will be described in detail with reference to FIG. As shown in FIG. 2, the lower film body 7 </ b> A branched up and down to form a double film structure is continuously extended from the flexible film body 7, and the outer peripheral edge thereof is the upper end of the side wall at the front position. Attach to 9 in tension. In the structure attached in this tension state, for example, the peripheral portion of the lower film body 7A is formed to be shorter than the position reaching the attachment portion of the upper end portion 9 of the side wall, and the eyelet portion 17 is formed on the peripheral portion of the lower film body 7A. And a structure for tightening the eyelet portion 17. That is, a fastening member 18 such as a wire or a rope is inserted into the eyelet part 17, is entangled with a rod-like member 16 that is annularly arranged along the circumferential direction of the side wall upper end part 9, and is squeezed up in order to increase the tension. The tension is adjusted and tightened by a tightening tool 18A having a check structure such as a buckle. The rod-shaped member 16 shows a case in which a fixing bracket 15 is embedded and fixed at a predetermined interval along the circumferential direction of the side wall upper end portion 9, and a steel rod or the like is inserted into the fixing bracket 15 to form an annular shape. Yes.
Thus, the lower film body 7A is adjusted and attached by tightening one after another. For example, the lower film body 7A is divided into a predetermined range and applied with good workability while adjusting the balance of the tension state, and the entire flexible film body 7 is stretched uniformly. Can be installed.
[0014]
Further, as shown in FIG. 2, the upper film body 7B branched up and down to form a double film structure gives a certain tension over a predetermined range above the outer peripheral edge mounting portion of the lower film body 7A. Install it in an airtight state by gently inclining without covering. The upper film body 7B is, for example, a substantially rectangular film body having a predetermined width, and its inner peripheral edge 19 is joined to the upper surface of the lower film body 7A along the circumferential direction by welding, bonding, stitching, or the like. Is fixed to the side wall upper end 9 in an airtight state by a detachable surface joining member made of a membrane protective material, a presser plate, anchor bolts and nuts, and both side edges 21 and 21 are detachable surface fasteners, double-sided joining tapes and the like. It is fixed by the surface bonding member.
In this way, the upper film body 7B covers the film without giving too much tension, so that it can be attached airtight with a reasonable surface bonding that is unlikely to be displaced or deformed, and the outer periphery of the lower film body 7A. Since the upper opening of the mounting portion is gently inclined and covered, it is possible to prevent rain or dirt on the membrane roof from slipping smoothly to the outer peripheral side and entering the storage tank. Further, since the outer peripheral edge 20 has a detachable structure and the side edges 21 and 21 are also formed in a simple attachment structure that is detachable, the upper film body 7B is opened, and the lower cord 6A and the lower film body 7A are opened. It is possible to perform additional adjustment of the tension force and inspection and maintenance of the mounting bracket.
[0015]
Based on FIG. 2, an example of the attachment structure of the lower cable 6A and the upper cable 6B, which is radially laid on the upper and lower sides of the flexible film body 7, respectively, will be described.
The lower rope 6A engages an end edge with a mounting bracket 12A embedded and fixed at a predetermined interval along the circumferential direction on the innermost side of the upper end 9 of the concrete side wall, such as a turnbuckle, a lever block, etc. It is attached using a fastener 13A. Further, the upper ridge 6B engages an end edge with a mounting bracket 12B embedded and fixed at a predetermined interval along the circumferential direction on the outermost side of the upper end portion 9 made of concrete, such as a turnbuckle or a lever block. It attaches using the fastener 13B.
[0016]
As described above, the flexible membrane body 7 is stretched in a tension state, and is in contact with a plurality of lower ropes 6A that are radially stretched with a pressing force and is supported from the bottom on average. It is possible to further improve durability against loads such as sand and sand, rain, and snow. In addition, the flexible membrane body 7 covers the upper part of the outer peripheral edge mounting portion and is firmly fixed in an airtight manner. Further, the flexible membrane body 7 is radially provided by a plurality of engagement members 14 provided separately on the upper surface of the flexible membrane body 7. Since it is pressed from the top in a balanced manner so as to restrain the movement by engaging with the multiple upper ropes 6B, it is more durable against lifting and fluttering due to strong winds and changes in atmospheric pressure. Can be improved.
When the membrane roof 4 formed in this way is provided in a storage tank or the like such as an outdoor farm pond or a distribution reservoir, dust such as fallen leaves and earth and sand is not deposited on the upper surface of the flexible membrane body 7, Gravity along the inclined upper surface can be smoothly dropped around the storage tank, and rainwater and snow can also be washed away without accumulating on the upper surface of the flexible film body 7. In addition, when such a membrane roof 4 is applied to an existing storage tank such as a farm pound without a roof, a simple roof that is lighter, easier to construct, and economical.
[0017]
The flexible film body 7 is formed by using a film material obtained by coating a woven fabric such as polyester fiber, polyamide fiber, or carbon fiber with a synthetic resin material such as polyurethane, vinyl chloride resin, or fluorine rubber. It can be used over a long period of time like a permanent outdoor membrane roof structure by having weather resistance and corrosion resistance against corrosive gas contained in rain or the like.
In addition, when a material that blocks sunlight, such as black fibers, resin, or a light-impermeable material, is used, a storage tank such as a farm pond or a distribution pond without sunlight entering the storage tank body 1. , It is possible to prevent the generation of algae and the like that proliferate by sunlight.
[0018]
An example of the structure in the vicinity of the roof top 10 will be described with reference to FIG. A funnel-shaped lower cylindrical body 23 whose inner diameter expands upward is connected to the upper end 8 of the center column, and a lower flange 22 protruding in a horizontal ring shape is provided at the upper end edge of the lower cylindrical body 23. . An upper flange 24 projecting in a horizontal ring shape is provided so as to be in surface contact with the lower flange 22, and after inserting the lower portion into the lower cylinder 23 in a loose fit, the upper flange 24, An upper cylindrical body 26 having a guide member 25 whose outer diameter decreases downward is provided so as to be accommodated in a fitted state as shown in FIG. Then, the lower flange 22 and the upper flange 24 are connected by using fixing members 27 such as bolts and nuts.
A fixing member 27 such as a bolt and a nut is attached to the upper flange 24, the edge of the film body central portion 28 of the flexible film body 7 is inserted into this bolt, and is sandwiched by using a contact plate or a washer that makes surface contact. Tighten the nut to secure it in an airtight state.
The lower flange 22 is provided with a fixing portion 29 for attaching the edge of the lower strand 6A, and the upper cylindrical body 26 is provided with a fixing portion 30 for attaching the edge of the upper strand 6B.
[0019]
Thus, the lower cylinder 23 provided at the upper end 8 of the center column and the upper cylinder 26 fitted to the lower cylinder 23 are formed to be connected by the flanges 22 and 24. Positioning and connecting work via the member 25 is facilitated. In addition, the fixing operation of the lower ridge 6A and the upper ridge 6B and the fixing operation of the film body central portion 28 at the edge of the flexible film body 7 can be easily performed, and the lower ridge 6A stretched radially. The flexible film body 7 can be unfolded and attached with good workability by performing a series of expanding operations in which the flexible film body 7 is moved along with being supported, and deployed and mounted. it can.
Further, the film body central portion 28 of the flexible film body 7 can be fixed to the upper flange 24 in advance by a safe work with good workability in a low place on the ground. The work of fixing the upper flange 24 to the lower flange 22 can be performed along the guide member 25, so that it is not necessary to perform the positioning work on the film body central portion 28 and the upper end portion of the center column. 8 can be easily and easily attached from the lower side of the body 8, and the center part 28 of the film body is fixed and stable. Therefore, the work of expanding the flexible film body 7 toward the periphery, and the side wall upper end part 9 It becomes easier to connect to the device.
[0020]
Based on FIG. 4 (a), (b), an example of the procedure which constructs | assembles the membrane roof of a storage tank is further explained in full detail.
As shown in FIG. 4 (a), a center column 5 is erected on the central part 11 of the bottom plate 2 surrounded by the side wall 3, and the lower cable is placed between the center column upper end 8 and the side wall upper end 9. Cross over 6A and fix in tension.
Next, the zenith portion 10 to which the flexible membrane body 7 and the upper cord 6B are fixed in advance at a low place on the ground is lifted and moved to the upper end portion 8 of the center column as indicated by the arrows (1) and (2). To do.
Then, as indicated by an arrow (3) in FIG. 4B, the zenith portion 10 that has been lifted and moved is suspended, aligned, and connected to the upper end portion 8 of the center column.
Next, as shown by the arrow (4), the lower rope 6A is used as a support frame, the flexible film body 7 is developed and fixed to the side wall upper end portion 9, and the upper rope 6B is stretched thereon.
[0021]
Since the membrane roof is constructed as described above, the flexible membrane body 7 and the upper ridge 6B can be secured to the zenith portion 10 at a low location on the ground with good workability and with a safe operation, and then the zenith portion. It is also easy to do the work of hanging 10 and fixing to the upper end 8 of the center column. Further, the flexible membrane body is stable and has good workability while being supported by the lower rope 6A stretched in advance. 7 can be extended and the upper rope 6B can be stretched thereon, so that a membrane roof excellent in a series of workability at the time of construction is obtained.
[0022]
【The invention's effect】
As is clear from the description, the membrane roof of the storage tank according to the present invention is a double membrane of a lower membrane and an upper membrane that branches up and down in the vicinity of the periphery of the hem of the flexible membrane constituting the membrane roof. Since the lower film body is attached to the upper end of the side wall in a tension state while the lower film body is attached to the upper end of the side wall in an airtight state, After applying a predetermined tension force to the side membrane body and stretching it, it is possible to cover the upper membrane body to obtain an airtight state, and apply tension by the lower membrane body and airtight coating by the upper membrane body. Thus, the flexible film body can be securely and securely attached with good workability.
Since the flexible membrane body can be maintained in a predetermined tension state and kept airtight, it is possible to prevent rain or dirt on the membrane roof from dropping smoothly around and entering the storage tank. It has durability against snow, snow, dust, wind, etc., can be made into a membrane roof of a storage tank having a simple structure, light weight, high strength and durability, and excellent in economic efficiency.
In addition, since it becomes possible to open the upper film body and apply tension to the lower film body as necessary, inspection and maintenance of the mounting part and the mounting bracket can be performed as appropriate, so that it can be used for a long time. It becomes an economical membrane roof considering the durability of the.
[0023]
Moreover, between the upper end part of the said center support | pillar, and the upper end part of a side wall, the upper side which presses and contacts the said flexible membrane body and supports from the bottom, and engages with the said flexible membrane body, and is pressed from the top In a membrane roof provided with a rope, the pressure support by the lower rope further suppresses the drooping against a load such as rain, snow and dust, and the movement due to the engagement with the upper rope is further suppressed. Suppression makes it difficult for floating and flapping to occur due to changes in strong winds and atmospheric pressure, etc., increasing the stability and toughness of the entire membrane roof, and further improving the reliability against large load fluctuations.
[0024]
In addition, a lower cylinder is provided at the upper end of the center column, the lower cylinder and the upper cylinder fitted to the lower cylinder are flange-connected, and the flange of the lower cylinder is connected to the flange of the lower cylinder Attaching the lower line, and fixing the central portion of the flexible film body to the flange of the upper cylinder, and in the membrane roof formed by attaching the upper line to the upper cylinder, Positioning and connection of the membrane roof central part suspended and guided and fitted can be facilitated, and the film body and the striated formation of the membrane roof central part can be performed efficiently in a stable state.
Then, the work of fixing the central portion of the flexible membrane body to the upper cylinder and the work of attaching the upper cable can be performed in advance in a safe work with good workability in a low place on the ground, and then as described above. After fitting the lower cylinder to the flange and connecting the flange, the flexible membrane can be moved from the zenith part to the surroundings by using the lower cable as a support frame when the film body is deployed. Then, since the work of expanding and attaching to the upper end of the side wall becomes easy, a membrane roof excellent in workability at the time of construction is obtained.
[0025]
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory side view of a section of a membrane roof of a storage tank according to the present invention, with a part thereof removed and schematically showing a cross section.
FIG. 2 is a perspective explanatory view in which a part of an outline of the vicinity of the upper end of the side wall is omitted and a cross section is removed.
FIG. 3 is an explanatory side view in which a part of the roof zenith in the vicinity of the top of the roof is cut away and a cross section is removed.
FIGS. 4A and 4B are side explanatory views showing a cross-section with a part omitted for explaining an example of a procedure for constructing a membrane roof of a storage tank. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Storage tank main body 2 Bottom plate 3 Side wall 4 Membrane roof 5 Center support | pillar 6 Line 6A Lower cable 6B Upper cable 7 Flexible film body 7A Lower film body 7B Upper film body 8 Center support | pillar upper end part 9 Side wall upper end part 10 Roof Zenith part 11 Bottom plate center part 12A Mounting bracket 12B Mounting bracket 13A Fastening tool 13B Fastening tool 14 Engaging member 15 Fixing bracket 16 Bar-shaped member 17 Peripheral eyelet part 18 Fastening member 18A Fastening tool 19 Inner peripheral edge 20 Outer peripheral edge 21 Both side edges 22 Lower flange 23 Lower cylinder 24 Upper flange 25 Guide member 26 Upper cylinder 27 Adhering member 28 Film body central portion 29 Adhering portion 30 Adhering portion

Claims (3)

底版と、該底版外周縁に立設した側壁とから貯槽本体を形成し、該貯槽本体の底版中央にセンター支柱を立設し、該センター支柱に支えられて貯槽本体上方を被覆する可撓膜体を設けた膜屋根であって、該可撓膜体は、裾部の周縁近傍を上下に分岐する下側膜体と上側膜体の二重膜構造に形成し、下側膜体は、膜体下部周縁を側壁上端部に緊張状態に取付け、上側膜体は、膜体下部周縁を側壁上端部に気密状態に取付けたことを特徴とする貯槽の膜屋根。A storage tank main body is formed from a bottom plate and a side wall standing on the outer periphery of the bottom plate, a center column is erected at the center of the bottom plate of the storage tank body, and a flexible membrane is supported by the center column and covers the upper side of the storage tank body A flexible membrane body is formed in a double membrane structure of a lower membrane body and an upper membrane body branching up and down in the vicinity of the periphery of the skirt, A membrane roof of a storage tank, wherein the lower periphery of the membrane body is attached to the upper end of the side wall in a tension state, and the upper membrane body is attached to the upper end of the membrane in an airtight state. 上記センター支柱の上端部と側壁上端部との間に、上記可撓膜体に押圧接触して下から支える下側索条と、上記可撓膜体に係合して上から押える上側索条とを設けたことを特徴とする請求項１記載の貯槽の膜屋根。Between the upper end portion of the center column and the upper end portion of the side wall, a lower strip that presses against and supports the flexible membrane body from below, and an upper strand that engages with the flexible membrane body and presses from above The membrane roof of the storage tank according to claim 1, wherein: 上記センター支柱の上端部に下側筒体を設け、該下側筒体と、該下側筒体に嵌合する上側筒体とをフランジ接続し、上記下側筒体のフランジには上記下側索条を取付け、上記上側筒体のフランジには可撓膜体の中央部を固着するとともに、該上側筒体には上記上側索条を取付けて形成したことを特徴とする請求項２記載の貯槽の膜屋根。A lower cylinder is provided at the upper end of the center column, the lower cylinder and the upper cylinder fitted to the lower cylinder are flange-connected, and the lower cylinder is flanged to the lower cylinder 3. A side rope is attached, and the central portion of the flexible membrane is fixed to the flange of the upper cylinder, and the upper rope is attached to the upper cylinder. Storage tank membrane roof.

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