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,并具有用料省、自重輕的特點(diǎn),因此懸索橋在各種體系橋梁中的跨越能力最大,跨徑可以達(dá)到 1000 米以上。但從發(fā)展趨勢(shì)上看,斜拉橋具有明顯優(yōu)勢(shì)。由于斜拉橋良好的力學(xué)性能、建造相對(duì)經(jīng)濟(jì)、景觀優(yōu)美,已成為大跨徑橋梁建設(shè)中最有競(jìng)爭(zhēng)力的橋型。 Leonhardt 認(rèn)為,即使跨徑 14o0m 的斜拉橋也比同等跨徑懸索 橋的高強(qiáng)鋼絲節(jié)省二分之一,其造價(jià)低30%左右。 施工方法:混凝土斜拉橋主要采用懸臂澆筑和預(yù)制拼裝;鋼箱和混合梁斜位橋的鋼箱采用正交異性板,工廠焊接成段,現(xiàn)場(chǎng)吊裝架設(shè)。在跨度大或索力變化幅度大時(shí)影響較大,須用精密的計(jì)算方法和電子計(jì)算 機(jī)分析結(jié)構(gòu)受力。在多塔斜拉橋中,如采用預(yù)應(yīng)力混凝土連續(xù)梁結(jié)構(gòu),因混凝土徐變收縮,則在主梁的無(wú)索區(qū)要產(chǎn)生拉力與彎矩,須采取措施克服。鋼絞線斜拉索目前在汕頭宕石大橋采用。 現(xiàn)在已建成的斜拉橋有獨(dú)塔、雙塔和三塔式。 我國(guó) 70 年代中期開(kāi)始修建混凝土斜拉橋,改革開(kāi)放后,我國(guó)修建斜拉橋的勢(shì)頭一直呈上升趨勢(shì)。 值得提醒注意的是,大跨徑拱橋施工階段及使用階段的橫向穩(wěn)定性,據(jù)統(tǒng)計(jì)國(guó)內(nèi)、外拱橋垮塌事故,多發(fā)生在施工階段。例如,貴州省跨烏江的江界河橋,地處 深山、峽谷,拱橋跨徑 330m,橋面離谷底 263m,令人嘆服橋梁設(shè)計(jì)者和建設(shè)者的匠心和偉大。根據(jù)近年的實(shí)踐,常用的拱橋施工方法有:( 1)主支架現(xiàn)澆;( 2)預(yù)制梁段纜索吊裝;( 3)預(yù)制塊件懸臂安裝;( 4)半拱轉(zhuǎn)體法;( 5)剛性或半剛性骨架法。山區(qū)道路上的中、小橋涵,因地制宜,采用石拱橋(涵)還是合適的。 其建筑歷史悠久外形優(yōu)美,古今中外名橋遍布各地,在橋梁建筑中占有重要文華學(xué)院 20xx 屆畢業(yè)設(shè)計(jì)(論文) 地位。其缺點(diǎn)是,當(dāng)?shù)鼗l(fā)生差異沉降時(shí),梁內(nèi)要產(chǎn)生額外的附加內(nèi)力,為此在設(shè)計(jì)中必須考慮在支座處設(shè)置頂梁與調(diào)節(jié)支座標(biāo)高的裝置。為此,現(xiàn)在公路橋多采用橋面連續(xù)的簡(jiǎn)支梁橋來(lái)改善。 按上部結(jié)構(gòu)靜力體系分:主要有簡(jiǎn)支梁橋、連續(xù)梁橋和懸臂梁橋 。隨著我國(guó)國(guó)民經(jīng)濟(jì)的迅速發(fā)展和經(jīng)濟(jì)的 全球化,大力發(fā)展交通運(yùn)輸事業(yè),建立四通八達(dá)的現(xiàn)代交通網(wǎng)已成必需,而交通網(wǎng)的建立離不開(kāi)橋梁建設(shè)。 在有了鐵路之后,木橋、石橋、鐵橋和原來(lái)的橋梁基礎(chǔ)施工技術(shù)就難以適應(yīng)需求。 在 19 世紀(jì) 20 年代鐵路出現(xiàn)以前,造橋所用的材料是以石材和木材為主,鐵只是偶爾使用。 關(guān)鍵詞:預(yù)應(yīng)力空心板,雙柱式橋墩,施工組織 abricated simply supported prestressed concrete slab bridge ABSTRACT The design of the bridge crossing T River includes putation and drawings. Computational part is divided into alternative program selection, the calculation of the superstructure, the calculation of substructure and a part of construction management plan. Drawing part consist of three views of alternative program selection, the superstructure ’s structural map, the substructure’ s structural map and the overall layout of the bridge. The length of T River Bridge is 140m, with 7span of 20m standardspan prestressed hollow slab. The superstructure is a form of continuous deck but simply supported system with prestressed fabricated hollow slab. The layout of crosssectional of the bridge across the board is separated standard twoway fourlane highway. This article will just design half frame of it. Its width is , and consists of two sides board and six internal board, the width sides board is m, and the width of internal board is . The substructure selects twocolumn pier and the rigid spreaded foundation. Keywords: prestressed hollow slab, twocolumn pier, the construction management plan文華學(xué)院 20xx 屆畢業(yè)設(shè)計(jì)(論文) 第一章、文 獻(xiàn) 綜 述 ...................................................................................................... 4 、引言 .................................................................................................................. 4 、 橋梁類(lèi)型及發(fā)展趨勢(shì) ......................................................................................... 5 梁式橋 ....................................................................................................... 5 鋼筋混凝土拱橋 ......................................................................................... 5 斜拉橋 ....................................................................................................... 6 懸索橋 ....................................................................................................... 8 、結(jié)論 .................................................................................................................. 9 第二章、方案的比選 .......................................................................................................10 .比選方案的主要標(biāo)準(zhǔn): .....................................................................................10 .方案類(lèi)別 .......................................................................................................... 11 .方案比選 ..........................................................................................................12 第三章 預(yù)應(yīng)力空心板上部結(jié)構(gòu)計(jì)算 ................................................................................12 、 設(shè)計(jì)資料 ........................................................................................................12 、設(shè)計(jì)標(biāo)準(zhǔn) ................................................................................................12 、主要材料 ................................................................................................13 、 構(gòu)造形式及尺寸選定 ......................................................................................13 、 空心中板毛截面幾何特性計(jì)算 .......................................................................14 、毛截面面積 A .........................................................................................14 、 作用效應(yīng)計(jì)算 ...............................................................................................16 永久作用效應(yīng)計(jì)算 ..................................................................................16 可變作用效應(yīng)計(jì)算 ................................................................................17 作用效應(yīng)組合 .........................................................................................24 預(yù)應(yīng)力鋼筋數(shù)量計(jì)算及布置 ..............................................................................26 預(yù)應(yīng)力鋼筋數(shù)量的估算 ...........................................................................26 預(yù)應(yīng)力鋼筋的布置 ..................................................................................28 普通鋼筋 數(shù)量的估算及布置 ....................................................................28 換算截面幾何特性計(jì)算 .....................................................................................30 承載能力極限狀態(tài)計(jì)算 ....................................................................................32 跨中截面正截面抗彎承載力計(jì)算 .............................................................32 斜截面抗彎承載力計(jì)算 ...........................................................................33 預(yù)應(yīng)力損失計(jì)算 ...............................................................................................37 正常使用極限狀態(tài)計(jì)算 .....................................................................................42 正截面抗裂性驗(yàn)算 ..................................................................................42 斜截面抗裂性驗(yàn)算 ......................................................