【正文】 ...................................................................................................... 7 拱式橋 .......................................................................................................... 8 方案比選 ......................................................................................................... 8 3 主梁的設(shè)計 ...................................................................................................... 10 主梁截面尺寸擬定 ....................................................................................... 10 橫截面布置 ................................................................................................ 10 橋梁橫斷面圖 .............................................................................................11 縱斷面的布置 .............................................................................................11 毛截面幾何特性 ............................................................................................11 4 主梁內(nèi)力計算 .................................................................................................. 15 橫向分布系數(shù) m ............................................................................................ 15 支點截面的橫向分布系數(shù)求法：杠桿法 ................................................. 16 跨中截面橫向分布系數(shù)的求法：偏心受壓法 ......................................... 17 荷載橫向分布系數(shù)匯總 ............................................................................ 22 荷載內(nèi)力計算 ............................................................................................... 22 荷載集度 .................................................................................................... 22 恒載內(nèi)力 .................................................................................................... 24 活載內(nèi)力計算 ............................................................................................ 26 主梁內(nèi)力組合 ............................................................................................ 40 5 預(yù)應(yīng)力鋼筋面積的估算及預(yù)應(yīng)力筋布置 ....................................................... 43 預(yù)應(yīng)力鋼筋截面積估算 ................................................................................ 43 預(yù)應(yīng)力鋼筋布置 ........................................................................................... 44 跨中截面預(yù)應(yīng)力鋼筋的布置 ..................................................................... 44 錨固面鋼束布置 ........................................................................................ 44 其他截面鋼束位置及傾角計算 ................................................................. 45 鋼束平彎段的位置及平彎角 ..................................................................... 49 非預(yù)應(yīng)力鋼筋截面估計及布置 .................................................................... 49 6 主梁截面幾何特性計算 .................................................................................. 52 第一階段：主梁預(yù)制并張拉預(yù)應(yīng)力鋼筋 .................................................... 53 跨中截面 .................................................................................................... 53 四分之一跨截面 ........................................................................................ 58 變化點截面 ................................................................................................ 60 支點截面 .................................................................................................... 62 第二階段：灌漿封錨，主梁吊裝就位并現(xiàn)澆 200mm 濕接縫 ...................... 64 跨中截面 .................................................................................................... 64 四分之一跨截面 ........................................................................................ 66 變化點截面 ................................................................................................ 68 支點截面 .................................................................................................... 70 第三階段：橋面、欄桿及人行道施工和運營階段 ..................................... 72 跨中截面 .................................................................................................... 72 四分之一跨截面 ........................................................................................ 74 變化點截面 ................................................................................................ 76 支點截面 .................................................................................................... 78 7 持久狀況截面承載能力極限狀態(tài)計算 ........................................................... 81 正截面承載力計算 ....................................................................................... 81 斜截面承載力計算 ....................................................................................... 82 斜截面抗剪承載力 .................................................................................... 82 斜截面抗彎承載力 .................................................................................... 83 8 鋼束預(yù)應(yīng)力損失估算 ...................................................................................... 84 預(yù)應(yīng)力鋼筋張拉（錨下）控制應(yīng)力計算 .................................................... 84 鋼束 應(yīng)力損失 ............................................................................................... 84 預(yù)應(yīng)力鋼筋與管道間摩擦引起的預(yù)應(yīng)力損失 1l? ..................................... 84 錨具變形、鋼絲回縮引起的預(yù)應(yīng)力損失 2l? ............................................ 88 預(yù)應(yīng)力鋼筋分批張拉時混凝土彈性壓縮引起的應(yīng)力損失 4l? ................. 89 鋼筋松弛引起的預(yù)應(yīng)力損失 5l? ................................................................ 90 混凝土收縮、徐變引起的損失 6l? ............................................................ 91 9 應(yīng)力驗算 ......................................................................................................... 94 短暫狀況下的正應(yīng)力驗算 ............................................................................ 94 持久狀況下的正應(yīng)力驗算 ............................................................................ 95 截面混凝土的正應(yīng)力驗算 ........................................................................ 95 持久狀況下預(yù)應(yīng)力鋼筋的應(yīng)力驗算 ..........................