2002年--橋梁工程外文翻譯--空間懸索橋斜吊桿安裝索纜試驗（譯文）

1、<p>　　中文5000漢字，3400單詞，1.7萬英文字符</p><p>　　出處：Gil H, Choi Y. Cable Erection Test at Splay Band for Spatial Suspension Bridge[J]. Journal of Bridge Engineering, 2002, 7(5):300-307.</p><p>　　空間懸

2、索橋斜吊桿安裝索纜試驗</p><p>　　Heungbae Gil , MASCE, AND Youngjae Choi</p><p>　　摘要：永江大橋中包含一段有斜纜索的自錨式懸索橋。該橋采用錨固在剛架末端的斜索 面支撐主纜。在主纜的架設(shè)過程中，人們預(yù)計斜面索會因為相對較大的張角產(chǎn)生側(cè)向位移或 提升現(xiàn)象。人們用相同比例的實物模型試驗來測量纜索的位移值，以決定采取相應(yīng)的措施來 解決這

3、一問題。通過這些試驗安排架設(shè)斜面上繩索的方案被修正，在嘗試。最后的方案在實</p><p>　　橋中得到成功的應(yīng)用。</p><p>　　DOI：10.1061/（ASCE）1084-0702（2002）7：5（300）</p><p>　　數(shù)據(jù)庫:關(guān)鍵詞：橋，懸索，朝鮮；索纜。 簡介：永江大橋包含一跨鋼箱梁，一跨剛桁架，一跨懸索橋。懸索橋跨度 550m，采取&l

4、t;/p><p>　　斜索面自錨體系。（如圖 1）自錨式橋主纜錨固在剛桁架上，只有一小部分已經(jīng)完工。由于 纜索的空間布置形式。在紡絲架纜過程中，主跨的主纜保持豎直。但是在吊桿與主纜相連后 纜索平面會發(fā)生傾斜。在成橋狀態(tài)主跨，邊跨的索面都是斜的。懸索橋主纜由 14 股鋼絞線 絞合而成。每股包含 480 根直徑 5.1mm 的鍍鋅鋼絲。為架設(shè)主纜人們采用了可以比平行索 法架設(shè)更多股鋼絲的空氣離心技術(shù)。</p>

5、<p>　　懸索橋在錨固區(qū)附近通常采用索鞍來支撐主纜。各股索纜在索鞍處分散開來，延伸出去。 由錨固腳或錨槽錨固。同時把索力傳到錨固塊上。一般來說，索鞍布置在股腳上部以把各索 向下分散開來。為了像圖 2 那樣把各索合理的分散開來，大橋的懸索跨與其說采用索鞍還不</p><p>　　如說用了傾斜的索箍，與個索連在一起，在水平和豎直方向?qū)⒗|索對稱的分散開來。圖 3</p><p>

6、　　所示斜索箍以 16.314°安裝。以同主纜軸線張角相適應(yīng)。為了安放放射鋼線，水平和豎直的 定位塊布置在各股鋼索之間，斜吊桿外側(cè).斜吊桿由兩份構(gòu)成：頂部和底部。在紡索過程中 索面下部臨時固結(jié)在剛架上，然后在其上架設(shè)鋼絲。吊桿的下部有可嵌入鋼絲的索槽。索纜 架設(shè)完畢后斜吊桿上下部都用螺栓錨固，然后在其自身平衡下，放松剛架的臨時固結(jié)。</p><p>　　懸索橋段的獨特之處在于：自錨式體系和其索的空間布置

7、形式，帶來一系列的架設(shè)問題， 在索塔，索鞍處更加突出。為了解決這些問題人們許多按實物尺寸的模型演示試驗，試驗和 鞍塔處的試驗結(jié)果，另有文章論述。本文只論述斜索面的試驗結(jié)果。為了解決架設(shè)問題，人 們 提 出 了 好 多 可 替 代 的 架 設(shè) 方 案 ， 選 出 最 好 的 用 于 大 橋 住 纜 架 設(shè) 。</p><p><b>　　圖 1懸索橋總覽</b></p><

8、;p>　　圖 3 錨定處張拉鋼絲</p><p><b>　　問題的提出：</b></p><p>　　錨固區(qū)是指從斜索面底到半圓形套管的整個區(qū)域。如圖 5 所示，套管沿主籃軸線對稱</p><p>　　布置。由于主纜錨固在剛架上，斜索面到套管的距離相當(dāng)?shù)男。挥?13 米，而且主索的水 平傾角 16.650º大于豎向 8.76

9、º的傾角。一些套管，例如 8，10，14 號只好安裝在主纜軸線 的上側(cè)或偏左偏右。連接套管的索在成橋狀態(tài)下是彎曲的。而在架設(shè)過程中表現(xiàn)出提升和側(cè) 移現(xiàn)象。下面對架設(shè)過程中出現(xiàn)的問題進(jìn)行了細(xì)致的描述。</p><p><b>　　鋼絲的側(cè)向位移：</b></p><p>　　在典型的地錨式懸索橋中，索鞍放置在套管之上水平-位移非常小在大橋中 14 股纜索<

10、;/p><p>　　（包含主纜）像扇子一樣在斜索面上展開。與各自的套管相連。對于這些有水平張角的鋼索， 斜索面上索的水平彎曲力比豎向彎曲力還大。這就導(dǎo)致了斜索槽側(cè)面鋼絲卷起。如圖 6 所示</p><p><b>　　鋼絲的提升現(xiàn)象：</b></p><p>　　在成橋狀態(tài)下，如圖 2 所示，各股鋼索從斜索面處向外延伸，在豎直和水平兩個面內(nèi)都 是對

11、稱的。為了與主纜延伸相適應(yīng)，面的入口一側(cè)（塔架一側(cè)）是直的，而在出口一側(cè)（套</p><p>　　管一側(cè)）是豎向彎曲的。上面一排的 5 個套管布置在主纜軸線的上方，與這些套管相連的索 在斜索成型后以 4.3811º上揚(yáng)。</p><p>　　在纜索的紡線過程中 斜索底部要與剛架臨時固結(jié)，然后在其上架索，與套管相連的索 有向上移動的趨勢。由于索的抬升趨勢，如圖 7 所示，朝向索塔一

12、側(cè)的索可以布置在索槽根 部。但是朝向套管一側(cè)的索并不與索鞍底部接觸。因此始終得不到支撐，這就要在架設(shè)過程 中約束主纜。</p><p>　　圖 4 豎直和水平方向上的墊片</p><p>　　試驗安裝與安裝次序：</p><p>　　14 根主纜的布置形式如圖 3 所示，在這些實物比例的模擬試驗中，人們對 4，10 號兩 根索進(jìn)行了試驗。在紡索過程中人們預(yù)計 4 號

13、索鋼絞線在斜索面上會出現(xiàn)側(cè)向位移。10 號 索回同時發(fā)生側(cè)向位移和提升現(xiàn)象。</p><p>　　如圖 8 所示，在框架上設(shè)置等比例的套管和索槽。套管設(shè)置在左側(cè)，人們設(shè)計從不同的 方位安裝，以演示不同的套管試驗。同時用以鑄鐵制造的中心框架將索槽封閉起來。索槽內(nèi) 部寬度為 105 ㎜。斜索面處主纜的傾角及各索的張角與成橋狀態(tài)保持一致，鋼絞線纏繞在套 管上，錨固在用楔子在右側(cè)框架上安裝的錨固塊上。人們用 343n 的

14、反力張拉纜索，以同紡 索施工中對索的張拉力相同。</p><p>　　實橋中每根主纜都有 480 根鋼絞線（24 層，每層 20 根），人們對每根索配的鋼絞線只</p><p>　　有 100 根，（5 層，每層 20 根）。先對側(cè)向位移試驗然后再對抬升現(xiàn)象試驗》</p><p>　　本試驗以 4 號索進(jìn)行演示，該索與主纜軸線左側(cè)的套管相連，如圖 5 所示，人們估計

15、在</p><p>　　紡索過程中該索會發(fā)生側(cè)向位移，以斜索面上的槽來模擬實橋中的索槽。如圖 9 所示。在出 口一側(cè)，索槽水平豎直方向都有彎曲。以與兩個面內(nèi)索的彎曲相適應(yīng)。人們對 幾種安裝索 的方案進(jìn)行修正，試驗。如有必要，在試驗過程中人們對索槽也要修改。</p><p><b>　　圖 5馬蹄裝置</b></p><p><b>

16、　　圖 6</b></p><p>　　方案一：采用索纜成型器。</p><p>　　大家一致認(rèn)為，索纜成型器是塔鞍處安裝索纜的有效工具。它看起來像個梳子，是一根 內(nèi)部塞有琴弦一樣鋼絞線的鋼桿。如圖 10 所示，將 21 根高強(qiáng)鋼絲嵌入 20 根鋼絞線中，這 樣就與每層上線的數(shù)目相同。在纜索架設(shè)過程中，索布置在鋼絲的接縫之間。本試驗中鋼索 成型器在斜索面兩側(cè)都有布置。試驗結(jié)果表

17、明，成型器使人們有能力在槽兩側(cè)都安裝。索槽 內(nèi)側(cè)的水平彎曲和鋼絞線的側(cè)向彎曲卻造成了，索槽內(nèi)部的安裝障礙，而且鋼索偏向一側(cè)。 同時人們發(fā)現(xiàn)用手工對張拉過的索重新定位幾乎是不可能的。</p><p>　　方案二：改變索的安裝次序。 以空氣絞線法架設(shè)纜索。索，以其位置被分為：固定索于活動索兩種。為了減少索在</p><p>　　錨固段的交叉數(shù)量，（從索箍到套管）固定索從 槽中心開始安裝，活動索

18、從兩邊開始。因此 斜索面上槽的安裝以活動-固定-活動的模式，如圖 11（a）所示。圖 11 所示的數(shù)字代表槽 內(nèi)索的架設(shè)順序。</p><p>　　圖7斜吊桿鋼筋拉伸</p><p>　　圖8建立實驗 正如前面解釋的那樣，鋼絞線偏向一側(cè)，（如圖 11，偏向左側(cè)），這就造成了架設(shè)主纜安</p><p>　　裝不到位。大家認(rèn)為通過改變索纜的安裝次序可以解決這一問

19、題。各索簡單的從左向右架固 定索和活動索之間不留空隙。因此像圖 11b 那樣，兩條活動索緊跟著固定索架設(shè)。（紡車每 次可以紡兩條索），而不是采用活動-固定-活動的安裝模式。</p><p>　　但是人們?nèi)匀话l(fā)現(xiàn)槽左側(cè)纜索的偏移，抬升現(xiàn)象。工程師設(shè)計了一個特制的導(dǎo)索來阻止 纜索的抬升，以保證各索始終在其設(shè)計位置。這個裝置是一根 95 ㎜長的鐵桿，安裝在一個</p><p>　　與纜索直徑 5

20、.1 ㎜相適應(yīng)的高度。在導(dǎo)索的幫助下，第一層索可以很輕松的安裝好。但隨后</p><p>　　工程師們又發(fā)現(xiàn)，在用導(dǎo)索安裝第二層索時，第一層索卻礙手礙腳。更糟糕的是由于固定和 活 動 索 的 混 合 使 用 ， 人 們 發(fā) 現(xiàn) 許 多 索 在 錨 固 區(qū) 交 叉 。</p><p><b>　　圖9</b></p><p&g

21、t;　　圖10成絲機(jī) 方案三：用松弛裝置降低預(yù)應(yīng)力索的預(yù)應(yīng)力。 除了鋼絲索平彎之外，人們發(fā)現(xiàn)鋼索的預(yù)加應(yīng)力會盡量使鋼索保持水平，同樣造成鋼索</p><p>　　布置的紊亂。工程師們認(rèn)為當(dāng)索的預(yù)加力足夠小時人們可以輕易的用手工對其進(jìn)行控制，安 裝。為 降低索面的 內(nèi)部應(yīng)力， 人們設(shè)計了 一個降低索 力的松弛裝 置，如圖 12 所示。</p><p><b>　　圖12拉伸

22、裝置</b></p><p><b>　　圖13定型裝置</b></p><p>　　人們引入了一個每層可以容納 20 根索的扣件，作為松弛裝置的一部分。一個安置在出 口（套管一側(cè)），另一個安置在槽入口（塔架一側(cè)）與緊線器相連。架設(shè)完一層后，槽兩側(cè) 的索也架設(shè)好了。并由這個緊線器來支撐。這樣就可以通過調(diào)整 緊線器來調(diào)整降低索的預(yù)</p>

23、<p><b>　　加應(yīng)力 。</b></p><p>　　試驗結(jié)果顯示，人們可以通過縮短緊線器間的距離來降低索力。但是索槽內(nèi)部 索的長 度并沒有減少，它們很自然的開始下催。結(jié)果是安裝索草幾乎是不可能的。盡管第一層索可 以安裝得很合適，為安裝第二層索移動緊線器時，安裝工作很容易受阻。</p><p>　　圖14布置鋼絲的夾具</p><

24、;p><b>　　圖15鋼絲布置</b></p><p>　　方案四：形狀保持裝置。 到目前為止，人們發(fā)現(xiàn)的架設(shè)問題的一個是，怎樣在架設(shè)新一層索纜時保持以架設(shè)索纜</p><p>　　不發(fā)生位置變化。在方案四中，人們采用如圖 13 所示的，綁扎用鐵絲，熱處理的鋼條（3</p><p>　　㎜厚，25 ㎜寬），還有索夾來布置纜索，以保證

25、隨后架設(shè)過程中先前架設(shè)的不發(fā)生位置改變。 有必要的話，人們可以切斷斜纜索槽的側(cè)壁來安放這些設(shè)備。為錨固鋼桿和夾子人們把螺紋 鋼筋也焊到了槽底和側(cè)壁上。</p><p>　　在紡纜過程中以架設(shè)的索被綁扎鋼絲臨時連成一列，該施工階段不但用到了綁扎鋼絲， 還用到了索夾，來保持索始終在其設(shè)計位置（如圖 14 所示）。新的纜索紡?fù)旰螅瑠A子繞著螺 紋錨具旋轉(zhuǎn)，打開然后將個股鋼絲放置進(jìn)去。第一層索安裝完畢后，人們便將綁扎鋼絲移

26、走， 靠手工和木錘布置纜索。同時另添加兩個裝在側(cè)壁的夾子來壓緊第一層索（Ⅱ型索夾），安 裝完畢后，側(cè)壁開口處的鋼桿被錨固到斜索底部，同時將Ⅱ型夾子移走。</p><p>　　在假設(shè)第二層索的過程中人們用鋼桿來維持個索的布置。第二層索被架設(shè)在鋼桿上，鋼 束像第一層索一樣被紡起來，然后固定在Ⅱ型索夾下面。架設(shè)完畢后兩層間的鋼桿被抽出來。 重新安在第二層上，此工藝流程循環(huán)進(jìn)行，直到架設(shè)完畢。</p>&l

27、t;p>　　索槽內(nèi)部通道寬 105 ㎜比索層厚度（5.1 ㎜×20=102 ㎜）要大。奇數(shù)層的纜索從索槽的 右側(cè)壁開始安裝。偶數(shù)層的索從左側(cè)開始安裝。因此，新一層的纜索被安放在以架設(shè)好的鋼 絞線之間形成的凹槽處。如圖 15 所示。人們發(fā)現(xiàn)由于索的平彎，偶數(shù)層索傾向于滑向左側(cè)， 從而到了以架設(shè)好索的頂部而不是在凹槽之中。為了阻止這種現(xiàn)象發(fā)生，人們在索槽側(cè)壁和 左彎較多的索之間安了一塊 3 ㎜厚的墊板。</p>

28、<p><b>　　圖17</b></p><p>　　試驗結(jié)果： 經(jīng)過這一系列的試驗，人們發(fā)現(xiàn)方案四是解決安裝纜索過程中發(fā)生側(cè)向位移的理想體</p><p>　　系。安裝完每一層后工程師都要測量其高度與理論高度值相比較。從表 1 的比較中我們可以 發(fā)現(xiàn)隨著層數(shù)的增加實際與理論高差越來越小，而且左側(cè)發(fā)生偏移的一邊反而比右冊側(cè)還高 些。</p>

29、<p>　　試驗的另一個重要因數(shù)是安裝個索所需要的時間。人們用紡車把攬索從一個錨固區(qū)牽引 到另一個錨固區(qū)所需要的時間大約是 15 分 20 秒。為了不影響紡線，各層必須在這段時間內(nèi)</p><p>　　完成。這一點人們還是很自信的，因為從表 1 得到的試驗數(shù)據(jù)，時間為從 14 分 23 秒到 12</p><p>　　分 40 秒，小于紡絲所需要的時間。</p>

30、<p>　　圖18出口處鋼筋布置裝置</p><p><b>　　抬升試驗：</b></p><p>　　工程師取預(yù)計會發(fā)生抬升現(xiàn)象并伴隨側(cè)向位移的 10 號索作為試驗對象。容納 10 號索的 索槽采用鑄鐵作成，安裝是采用與主纜相適應(yīng) 16.2414°。如圖 16 所示，為與主纜的張角相 適應(yīng)，10 號索槽在水平和豎直面內(nèi)都有彎曲。而且人們專

31、門設(shè)計了一個架設(shè)在地面上 450</p><p>　　㎜的水平纜索定位架，人們用它在斜纜索內(nèi)部將個條索分隔開來。在試驗中人們先預(yù)計一個 量值然后與分析后的實際數(shù)值想比較再設(shè)計控制抬升與布索方案。</p><p>　　試驗程序與結(jié)論； 最初設(shè)計用來阻止先前試驗纜索側(cè)向位移的鋼桿和夾子同索槽連在一起，兩者都是通過</p><p>　　將纜索壓向索槽底部來保持以架設(shè)纜索的

32、位置。如有必要可以切斷斜索面槽的側(cè)壁來安放鋼 桿，夾子。</p><p>　　正如預(yù)計的那樣，由于斜索面的豎向彎曲和抬升，鋼索只與底部部分相接觸，如圖 7 所示，盡管用鋼桿，夾子可以向下壓人們?nèi)匀话l(fā)現(xiàn)第一層和與底版之間有一條很大的縫隙。 在水平索纜定位器末端附近。由于縫隙的存在在加上索纜的縱向向上移動，鋼桿甲子并不能 將索纜有效的壓回底部，這樣鋼索變得紊亂而無法安裝。</p><p>　　

33、人們吊桿內(nèi)部引入了一個木制的墊板，索槽外側(cè)布置一對鋼桿來幫助鋼索安裝。如圖</p><p>　　17 所示，木制的墊板被安裝在水平索纜定位器末端來填充索纜與槽底的空間。它支撐著架</p><p>　　設(shè)好的索纜，被工程師用做抵抗鋼桿傳來力的平面。在實吊桿中水平墊板被延伸到 815 ㎜長。</p><p>　　如圖 18 所示，安裝在吊桿外側(cè)的鋼桿，索夾同樣阻止索纜變

34、得紊亂。在成橋狀態(tài)下，低一 些支架的架設(shè)高度要與第一層索纜的布置高度相適應(yīng)，索架在支撐桿頂部，而且每一層架設(shè) 完畢后，纜索保持在上下兩桿之間的設(shè)設(shè)計位置。</p><p>　　控制抬升的鋼桿與索夾的施工工序與控制側(cè)向位移的極為相似。索同樣架在鋼桿頂部， 夾限制纜索位移。每層架完后人們將鋼桿抽出，在架在剛安好的纜上。放松索夾，架好，如 此重復(fù)施工直到完畢。</p><p>　　為測試體系的有

35、效性，工程師測量架好索的高度，與理論值比較，結(jié)果總結(jié)在表 2 中。</p><p>　　同樣的測試架設(shè)索纜所需要的時間，表 2 中的結(jié)果顯示，實際層高與理論層高從第二層開始</p><p>　　不同，而且隨層高加大。架完第十層，偏差以達(dá) 4 ㎜，但偏差并不顯著增加。</p><p>　　表 1 所示 10 號索實際與理論偏差略大于 4 號索。由于 10 號索

36、還發(fā)生抬升，4 號索只有 側(cè)向位移。</p><p>　　如前所示，紡車從一個錨固區(qū)移到另一個大約要 15 分 20 秒，隨層數(shù)增加架索時間減少，</p><p>　　到第十層時只要 13 分鐘左右，因此不會影響防線作業(yè)。 結(jié)論：</p><p>　　工程師們估計，懸索橋架設(shè)過程中會發(fā)生吊桿側(cè)向移動，垂直移動，與設(shè)計位置偏離。 通過一系列的試驗，修正，嘗試。工程師發(fā)

37、現(xiàn)鋼桿與索箍組合體系最為有效。一些細(xì)節(jié)問題 如墊板長度等也得到檢驗。該體系在實際橋中得到成功應(yīng)用。</p><p><b>　　Abstract:</b></p><p>　　Cable Eraction Test at Splay Band for Spatial Suspension Bridge Heungbae Gil , MASCE, AND Youngja

38、e Choi</p><p>　　The Youngjong Grand Bridge include a self-anchored suspension bridge with inclined cable planes.The bridge use splay band (cable collars) to flare the main cable at anchorage, which is locate

39、d at the end of a stiffing truss. During the cable erection,some of the wires at the splay band were expected to experience lateral displacement and/or lift phenomena because of the large flare angles at the splay b

40、and .mockup cable erection test at the anchorage were carried out to find the degree of d</p><p>　　DOI:10,1061/(ASCE)1084-0702(2002)7:5(300)</p><p>　　CE Database keywords: Bridges, suspension ;

41、Korea; Cables Introduction</p><p>　　The young jiong Grand bridge consists of a steel box girder span, a truss span ,and a suspension span(Gil and cho1998).The suspension span (550m) is a self-anchored suspen

42、sion bridge with inclined main planes(Fig.1).Self-anchored suspension bridge have the main cable anchorage at the Stiffing truss ,and only a limited number of them have been built (ochsendorf and biillington 1999).Due to

43、 the spatial layout of the cable ,the main cable plane of the main span is vertical during the cable spinn</p><p>　　,which can have more wires per strands than the parallel wire strand method ,is used to

44、erect main cables.</p><p>　　The typical suspension bridge use splay saddles to splay the main cable near the anchorage .The strands diverging from the splay saddles are flared and anchored to strand shoes or

45、 sockets and transmit the cable forces to anchor block ,In general ,the splay saddle is placed above the strand shoes or socket and spreads the cable downward .To flare the main cable as shown in Fig2 ,the suspension spa

46、n of the Grand Bridge has a splay band (cable collar )rather than a splay saddle .The sp</p><p>　　horizontal plane .The splay band shown in Fig3 is installed with an angle of 16.314 °

47、,which</p><p>　　correspond to the angle of the main cable centerline .To accommodate the flare ,vertical and horizontal spacers ,shown in Fig4 ,are placed between the strands at the exit side of the spla

48、y band ,the splay band composed of two parts ,the top and the bottom .during the cable spinning ,the bottom of the splay band is temporarily fixed to the stiffing truss and wires are erected on it.the bottom has rectangl

49、e grooves to house the strands. after completion of the cable erection ,the top and botto</p><p>　　The unique features of the suspension span –the self-anchored and spatial cable layout –pose cable erection

50、problems ,which are most prominent in the tower saddles and at the splay band .Mockup erection test were performed to deal with these problems ;The problems of and the results of the mockup tests at the tower saddle are

51、dealt with in an other paper (gil and choi2002) .this paper presents the results of mockup tests at the splay band .A few alternative proposals were</p><p>　　suggested to deal with the ere

52、ction problems, and the optimal alternative was selected and used for erection of the main cables of the Grand Bridge.</p><p>　　Problem statements</p><p>　　The anchorage zone refers to the zone

53、 from the splay bands to the semicircular strand shoes .as shown in Fig 5 ,the strands shoes are symmetrically distributed around the main cable centerline .since the main cable anchorage is located at the stiffin

54、g truss ,The distance between the splay band and the strand shoes is rather short (13.0m).Furthermore ,the horizontal flare angle of</p><p>　　the cable ,16.65 ° ,is larger than the vertical flar

55、e angle 8.76 ° .Some strand shoes –for</p><p>　　example ,Nos,8,10,and 14-are located above and/or the left(right)of the centerline .The strands linked to these strands bend at the complete state a

56、nd showed lift and/or lateral displacement phenomena during cable erection .A detailed description of the cable erection problem is given below :</p><p>　　Lateral displacement of wires</p><p>　　

57、In a typical earth-anchored suspension bridge, the splay saddle is placed above the strand and the horizontal flare is rather small .Therefore ,the wires at splay saddle bend downward and there is little horizontal movem

58、ent of the wires .In the Grand Bridge ,14 strands composing a main cable fan out from the splay band and linked to the respective strand shoes .for the strand that have horizontal flare angles ,the horizontal bending fo

59、rce of the wires at the splay band is higher than the vert</p><p><b>　　WIRE LIFT</b></p><p>　　In the complete state ,the strands as shown in Fig2 ,are symmetrical flare out from t

60、he splay band in vertical as well as in horizontal plane . To accommodate the flare of the main cable ,the band at the entrances (pylon sides) is straight but has vertical curvatures at the exit (strand

61、 shoe</p><p>　　side) .The five strand shoes of the upper row (Fig5) are placed above the main cable centerline ,and the strands linked to these shoes bend upward with the angle of 4.338 

62、6; after</p><p>　　leaving the splay band at the complete state.</p><p>　　During cable spinning ,the bottom of the splay band is temporarily attached to the stiffing truss and the wires are e

63、rected on it .strands linked to the upper strand shoes tend to move upward .Because of this phenomena (wire lift), shown in Fig7 ,the wire toward the main pylon can be laid on the base of the band channel ,but

64、the wire toward the strand shoes do not contract the base of the sadldle and therefore remain unsupported .this requires restraining of the wires during erecti</p><p>　　Test setup and procedure</p>&l

65、t;p>　　The arrangement of 14 strands at the splay band is shown in Fig 3. In the mockup test ,the wire arrangement of two strands ,Nos .4and 10 ,were tested . During cable spinning ,the wires of the strand NO4 are expe

66、cted to be displaced laterally at the splay band ,and those of NO.10 are expected to show both lateral displacement and lift.</p><p>　　A mockup strand shoe and splay band channels are placed on the frames ,a

67、s shown in Fig8, and the mockup strand shoe was placed on the left ;it was designed to be fixed at different position to model different strand shoes to be tested. The center frame housed the full scale splay band chan

68、nels ,which are made of cast iron. The interior width of the channel is 105mm .the main cable angles at the splay band and flare angles of the strands were kept the same as those of the real bridge ,and the w</p>

69、<p>　　frame using wedges. The wires were tensioned using a 343N countering weight ,which corresponded to the cable tension during cable spinning.</p><p>　　Each strand in the real bridge has 480 wires (2

70、0 wires per x24 layers ).In the mockup test, the fewer than 100 wires (20 wires per layerx5layers) were erected for each strand .the lateral displacement of wires at the splay band was investigated first,after which the

71、 lift was performed.</p><p>　　Lateral displacement</p><p>　　The test was performed using strand NO14,which was linked to the strand shoe located to the left of the centerline (Fig5).Its wires we

72、re expected to be displaced laterally during cable spinning.The splay band channel that stimulated the groove of the splay band is shown in Fig 9.The channel has horizontal and vertical curvatures at the exit side to acc

73、ommodate flaring of the strand in both planes . several schemes to arrange the wires were devised and tried .The modification to splay band channe</p><p>　　PROPOSAL 1 Wire Former use</p><p>　　A

74、“wire former” proved to be an effective tool for the arrangement of the wires at the pylon saddle of the Grand Bridge (Gil and Choi2001).The wire former ,which look like somewhat a comb, is a steel bar with inserted pian

75、o wires were inserted to house 20 wires ,which is equal to the number of the wires to each layer .During cable erection ,the cable wires were placed in the slots between piano wires.</p><p>　　Wires formers w

76、ere placed at both ends of the splay band channel in this test the test results showed that the wire former enable the arrangement at both end of the channel .At the inside of the channel ,however ,the arrangement was

77、disturbed and the wires shifted to one side of due to the horizontal curvature of the channel and the lateral bending of the wires .it was also found that realigning the shifted wires by hand was almost impossible due to

78、 the wire tension.</p><p>　　PROPOSAL2 Change of Wires layout order</p><p>　　In air spinning method of cable erection,The wires are classified into “dead wire”and “l(fā)ive wire”,depending on the pos

79、ition of the wires.To minimize the number of wire crossings (tangling )at the anchor span (from the splay band to the strand shoes), the dead wires are laid from the sides .therefore the wires at the splay band are

80、 arranged in the live wire-dead wire –live wire pattern shown in Fig11(a).The number in Fig11 represent the erection order of the wires inside the channel.</p><p>　　As explainearlier, the wires moved to one

81、side (The left side in Fig 11), which caused disarrangement of the erected wires . It was thought that these problems could be dealt with by changing the layout order of the wires . the wires were simply placed from left

82、 to right without distinction between dead wires or live wires. Thus, as shown in Fig11(b),two live wires were followed by two dead wires(the spinning wheel carried two wires at a time )rather than the live wire-dead wir

83、e –live wire patte</p><p>　　However, it was observed that the wires still shifted and piled up at the left side of the channel .A special wire guide was devised to prevent wire piling and keep the wires at t

84、he desired position. This device is a 95mm long metal bar, which is fixed at a height corresponding to the diameter of one wire(5.1mm).With the help of this guide ,the arrangement of the first layer wire can be eas

85、ily finished. However, it was found that the arrangement of the first layer was easily disturbed when</p><p>　　PROPOSAL3.Tension reduction by Slacking Device</p><p>　　In addition to horizontal b

86、ending of the strand ,wire tension was observed to cause the wire disarrangement as it tried to straighten the wires . It was thought that the wires could be easily managed and arranged by hand if the wire tension at the

87、 splay band is low enough .to reduce the wire tension inside the splay band, a tension-reduction” slacking device” was devised, as shown in Fig12.</p><p>　　As a part of the slacking device, a special fastene

88、r that can hold one layer of 20wires was introduced. One fastener was fixed at the exit side (strand shoe side)of the channel and the other was placed at the entrance side(pylon side)and connected to a turnbuckle. After

89、a layer was erected, wires at both ends of the channel were arranged and held by the fasteners. Wire tension inside the band could be reduced by adjusting the turnbuckle.</p><p>　　Test resuts showed that th

90、e tension of the wire inside the splay band could be reduced by decreasing the distance between the fastener .However, the length of wires inside the channel was not reduced and the wires simply started to sag.As a resul

91、t, arranging the wires was almost impossible .Even f the wires of the first layer was properly arranged ,The arrangement was easily disturbed when the fastener were removed for the erection of the second layer.</p&

92、gt;<p>　　PROPOSA.Shape-preserving Device</p><p>　　One of the erection problem observed so far was how to maintain the arrangement of the previously erected layer during erection of a new layer.In Pro

93、posal 4 tie wires ,heat treated steel bars(thickness :3mm;width 25mm)and clamps ,as shown in Fig13,were employed to arrange the wires and to maintain the arrangement of the erected layers during the erection of a new lay

94、er.When necessary ,the sidewalls of the mockup splay band channel were cut out to install the device.To anchor thje bars and the c</p><p>　　During cable spinning, the erected wires were temporarily bound in

95、order by tie wires.In addition to tie wires ,two clamps (Clamp1),shown in Fig14,were also installed to keep the wires temporarily in position during spinning. When new wires were spun,these clamps,which rotated arou

96、nd the threaded anchor,were opened and the wires were placed .Once all the wires of the first layer were laid ,the tie wires were removed and the wires were arranged by hand and by wood hammers , while two additio</p&

97、gt;<p>　　The steel bars maintained the arrangement of the wires during erection of the second layer. The second layer was erected on the top of the steel bars.The wires were spun and arranged as in the first and k

98、ept under clamp2 .After that ,the steel bars placed between the first and the second layers were pulled out and resinstalled at the top of the second layer.this procedure was repeated and enabled the arrangement of the w

99、ires at the splay band.</p><p>　　The interior width of the channel is 105mm and is larger than the width of the wire layer (5.1mmx20=102mm).the odd-numbered layers were placed from the right side wall of the

100、 channel and the even numbered layers were placed from the left side of the wall so that the wires of the new layer were placed on the groove-formed between the wires of an erected layer as shown inFig15.It was observed

101、that due to horizontal bending ,the wires of the even-numbered layers tended to slide to the left side and</p><p>　　Test Results</p><p>　　After a few trials,Proposal4 turned out to be the most s

102、atisfactory system to facilitated the arrangement of the wire with the lateral displacement phenomena .After the arrangement of each layer ,The height was measured to compare the theoretical height.The comparison in Ta