【正文】 ................................. 30 6. 換算截面幾何特性計(jì)算 ................................................................... 33 換算截面面積 A0 ........................................................................ 34 換算截面重心位置 ..................................................................... 34 換算截面慣性矩 ......................................................................... 35 換算截面彈性抵抗矩 ................................................................. 35 7. 承載能力極限狀態(tài)計(jì)算 ................................................................... 36 跨中截面正截面抗彎承載力計(jì)算 .............................................. 36 斜截面抗剪承載力計(jì)算 ............................................................. 37 8. 預(yù)應(yīng)力損失計(jì)算 ............................................................................... 41 錨具變形、回縮引起的預(yù)應(yīng)力損失σ l2 .................................... 41 預(yù)應(yīng)力鋼筋與臺(tái)座之間的溫差引起的預(yù)應(yīng)力損失σ l3 ............. 41 預(yù)應(yīng)力鋼絞線由于鋼筋松弛引起的預(yù)應(yīng)力損失σ l5 ................. 42 混凝土彈性壓縮引起的預(yù)應(yīng)力損失σ l4 .................................... 42 混凝土收縮和徐變引起的預(yù)應(yīng)力損失σ l6 ................................ 44 預(yù)應(yīng)力損失組合計(jì)算 ................................................................. 47 9. 正常使用極限狀態(tài)計(jì)算 ................................................................... 48 正截面抗裂性計(jì)算 ..................................................................... 48 斜截面抗裂性驗(yàn)算 ..................................................................... 52 10. 主梁變形驗(yàn)算 ................................................................................. 59 正常使用階段的撓度計(jì)算 ........................................................ 59 預(yù)加力引起的反拱度計(jì)算及預(yù)拱度的設(shè)置 ............................ 60 11. 持久 狀況應(yīng)力驗(yàn)算 ......................................................................... 63 跨中截面混凝土正壓應(yīng)力σ kc 的驗(yàn)算 ..................................... 63 跨中截面預(yù)應(yīng)力鋼絞線拉應(yīng)力σ p 的驗(yàn)算 ............................... 64 斜截面主應(yīng)力驗(yàn)算 ................................................................... 64 12. 短暫狀況應(yīng)力驗(yàn)算 ......................................................................... 70 跨中截面 ................................................................................... 71 l/4 處截面 ................................................................................... 73 支點(diǎn)截面 ................................................................................... 74 13. 最小配筋率復(fù)核 ............................................................................. 77 14. 鉸縫計(jì)算 ......................................................................................... 79 鉸縫剪力計(jì)算 ........................................................................... 79 鉸縫抗剪強(qiáng) 度計(jì)算 ................................................................... 82 第二部分：橋梁重要部位施工說明 15. 施工方案說明簡(jiǎn)述 ........................................................................... 84 16. 橋梁基礎(chǔ)施工 ................................................................................... 85 17. 鉆孔灌注樁施工 ............................................................................... 88 18. 承臺(tái)施工 ........................................................................................... 90 19. 墩臺(tái)施工 ........................................................................................... 92 20. 先張法預(yù)應(yīng)力混凝土空心板施工 .................................................... 95 準(zhǔn)備工作 ................................................................................... 95 預(yù)應(yīng)力鋼絞線施工 ................................................................... 96 混凝土的澆筑及養(yǎng)護(hù) ............................................................... 98 鋼絞線放張 ............................................................................... 98 板的起吊、存放、養(yǎng)護(hù) ......................................................... 100 參考文獻(xiàn) ............................................................................................... 101 附錄 ....................................................................................................... 102 8 第一部分：先張法預(yù)應(yīng)力混凝土空心板設(shè)計(jì) 1. 設(shè)計(jì)資料 工程概況 X 市 P 市高速公路跨京廣鐵路立交橋，位于京廣線 許昌至石橋區(qū)間，與京廣上下行線正交，鐵路里程為 K769+373，公路里程為 K4+，設(shè)計(jì)公路北側(cè)緊鄰劉王村，鐵路兩側(cè)地形平坦開闊，大多為農(nóng)田，鐵路西側(cè)約 500 米有南北方向縣鄉(xiāng)公路一條，交通狀況一般。在第二部分中，設(shè)計(jì)僅對(duì)基礎(chǔ)、承臺(tái)、墩臺(tái)、預(yù)應(yīng)力空心板等的施工方法進(jìn)行了簡(jiǎn)單說明，由于存在一定限制，僅供參考之用。設(shè)計(jì)采用先張法預(yù)應(yīng)力混凝土空心 板結(jié)構(gòu)，橋梁全長(zhǎng) 159m，除主跨外，其余部分單跨 17m，共計(jì) 8 跨，橋?qū)?14m，板寬 ，共計(jì) 11塊。 全文為 X 市至 P 市高速公路 K4+ 處的跨京廣鐵路立交板式橋設(shè)計(jì)方案，共分兩個(gè)部分，第一部分為預(yù)應(yīng)力混凝土板橋設(shè)計(jì)，第二部分為板橋重要部位施工方案說明。 板式橋是公路橋梁中量大 、面廣的常用橋型，構(gòu)造簡(jiǎn)單、受力明確的特點(diǎn)使其成為中、小跨徑橋梁的首選方案。 Construction 前言 公路橋梁是國(guó)民經(jīng)濟(jì)發(fā)展、人民生活水平提高的重要基礎(chǔ)性公共設(shè)施，也是衡量一個(gè)國(guó)家現(xiàn)代化水平的重要指標(biāo)。 Pretensioning method。 關(guān)鍵詞 空心板；預(yù)應(yīng)力；先張法；結(jié)構(gòu)計(jì)算；施工 Abstract Prestressed concrete hollow slab bridge has a most important position in the bridge architecture of China. At the moment, for small and mediumsized span of the permanent bridge, even the Highway Bridge or city Bridges, prestressed concrete hollow slab bridge are wanted as far as possible. The design basis for the design of information and the “Code for Design of Highway Reiforce Concrete and Prestressed Concrete Briges and Culverts”(JTGD62—2020)， the “General Code for Highway Bridages and Culver”(JTGD60—2020) and so on conducted design and the calculation of the upper structure,which contains load internal force of main girder, the layout of prestressed reinforcement and the prestressing loss calculation, main girder cross section strength and stress calculation, total lenth is 159m and the width is 13+2,design load lever for road —Ⅰ .The bridge length is 417+23+417m. The bridge belongs to the prestressed concreted structure which is a simple slab bridge which the standard span of main span is 23m and the calculation of span of main pain is and the standard span of others are