【正文】 板厚度取用 10cm，翼板根部加厚到 22cm以抵抗翼緣根部較大的彎矩。 ．主梁跨中截面主要尺寸的擬定 （ 1）主梁高度 預(yù)應(yīng)力混凝土簡(jiǎn)支橋橋梁的主梁高度與其跨徑之比通常在 1/15~1/25，標(biāo)準(zhǔn)設(shè)計(jì)中高跨比約在 1/13~1/19。 （ 4）基本計(jì)算數(shù)據(jù) 表 1 基本計(jì)算數(shù)據(jù)表 名 稱 項(xiàng) 目 符 合 單位 數(shù)據(jù) 混 凝 立方強(qiáng)度 R MPa 40 彈性模量 Eh MPa 104 軸心抗壓標(biāo)準(zhǔn)強(qiáng)度 baR MPa 抗拉標(biāo)準(zhǔn)強(qiáng)度 blR MPa 軸心抗壓設(shè)計(jì)強(qiáng)度 Ra MPa 抗拉設(shè)計(jì)強(qiáng)度 Rl MPa 預(yù)施應(yīng)力階段 極限壓應(yīng)力 0． 70 1baR * MPa 極限拉應(yīng)力 0． 70 1blR * MPa 大學(xué)畢業(yè)設(shè)計(jì) 2 土 使用荷載 作用階段 荷載組合Ⅰ： 極限壓應(yīng)力 baR MPa 極限主拉應(yīng)力 blR MPa 極限主壓應(yīng)力 baR MPa 荷載組合Ⅱ或組合Ⅲ： MPa 極限壓應(yīng)力 baR MPa 極限主拉應(yīng)力 blR MPa 極限主壓應(yīng)力 baR MPa s? 5 碳 素 鋼 絲 標(biāo)準(zhǔn)強(qiáng)度 byR MPa 1600 彈性模量 Ey MPa 103 抗拉設(shè)計(jì)強(qiáng)度 Ry MPa 1280 最大控制應(yīng)力 σ k byR MPa 1200 使用荷載作用階段極限應(yīng)力： 荷載組合Ⅰ byR MPa 1040 荷載組合Ⅱ或組合Ⅲ byR MPa 1120 材料 容重 鋼筋混凝土 r1 KN/m3 混凝土 r2 KN/m3 鋼絲束 R3 KN/m3 鋼束與混凝土的彈性模量比值 ny 無量鋼 *注：本設(shè)計(jì)考慮主梁混凝土達(dá) 90%標(biāo)準(zhǔn)強(qiáng)度時(shí)，開始張拉預(yù)應(yīng)力鋼束。 預(yù)應(yīng)力鋼筋束：采用 64YB255 標(biāo)準(zhǔn)的 ? 碳素鋼絲，每束由 24 絲組成。行車道板設(shè)計(jì)：本設(shè)計(jì)中行車道板的受力圖示為單向板。根據(jù)計(jì)算得出的各種內(nèi)力組合確定設(shè)計(jì)控制內(nèi)力進(jìn)而對(duì)預(yù)應(yīng) 力鋼束數(shù)進(jìn)行估算。 本設(shè)計(jì)的主要內(nèi)容包括：縱橫斷面布置，主梁設(shè)計(jì)，橫隔梁設(shè)計(jì)，還有行車道板設(shè)計(jì)?？v橫斷面布置：根據(jù)規(guī)范要求和工程實(shí)踐經(jīng)驗(yàn)確定主梁間距與主梁片數(shù)和主梁高度及各截面主要尺寸。按后張法制作主梁，采用錐型錨具和直徑 50mm的抽拔橡膠管，計(jì)算各種預(yù)應(yīng)力損失得出有效預(yù)應(yīng)力，對(duì)主梁進(jìn)行強(qiáng)度、應(yīng)力和變形驗(yàn)算。 關(guān)鍵詞 ： T形梁；預(yù)應(yīng)力；混凝土橋 大學(xué)畢業(yè)設(shè)計(jì) II ABSTRACT This design begins with basic method and gives most content to the design of main beams. When the method of main beams designing is mastered, we can go on the designing of other parts. The main content of this design is as followings: The arrange of longitudinal section and lateral section, Main beams design, Crossing beam designing and Driveway plank arrange of longitudinal section and lateral section:According to the specification and the experience of practical engineering, we can decide the distance of girders, the number of the girders, the height of the main beams and the main size of each beams design: Internal forces include invariable force and variable force. We can use the method of the structural mechanics. To calculate the variable internal force, we calculate the lateral direction coefficient of the load with the method of corrected eccentricity the result of the calculation, we can obtain the control internal force, and we can approximately decide the number of the prestressed concrete the main beams with posttensioning method, selecting preburry corrected tube anchoring. Then calculate the loss of the prestress and obtain the valid prestress and examine the strength, stress, and transform of the main beam designing:To make sure that all main beams rear the load together and to enhance the globality of the construction, this design goes on the crossing beam calculation with the method of corrected eccentricity pressures. We only calculate the internal force of the middle crossing beam because of the maximum force is in the place of the middle of the span. Driveway plank designing:In this design, the force diagram of the driveway plank is single direction plank. Key words: Tbeam； prestress； concrete bridge. 大學(xué)畢業(yè)設(shè)計(jì) III 目 錄 摘 要 .............................................................................................................................. I ABSTRACT .................................................................................................................II 第 1 章 縱橫截面布置 .............................................................................................. 1 設(shè)計(jì)目的 ............................................................................................................ 1 基本資料 ............................................................................................................ 1 主梁間距與主梁片數(shù) ........................................................................................ 2 主梁跨中界面尺寸擬定 .................................................................................... 4 橫截面沿跨長(zhǎng)的變化 ........................................................................................ 5 橫隔梁的設(shè)置 .................................................................................................... 5 第 2 章 主梁計(jì)算 ...................................................................................................... 6 恒載內(nèi)力計(jì)算 .................................................................................................... 6 恒載集度 ..................................................................................................... 6 恒載內(nèi)力 ..................................................................................................... 7 活載內(nèi)力計(jì)算（修正剛性橫梁法） ................................................................ 7 沖擊系數(shù)和車道折減系數(shù) ......................................................................... 7 計(jì)算主梁的荷載橫向分部系數(shù) ................................................................. 8 車道荷載的取值 ....................................................................................... 12 主梁內(nèi)力組合 .................................................................................................. 15 預(yù)應(yīng)力鋼束的估算及其布置 .......................................................................... 15 跨中截面鋼束的估算和確定 ................................................................... 15 預(yù)應(yīng)力鋼束布置 ....................................................................................... 17 計(jì)算主梁截面幾何特性 .................................................................................. 22 凈截面幾何特 性計(jì)算 ............................................................................... 22 換算截面幾何特性計(jì)算 ........................................................................... 22 有效分布寬度內(nèi)截面幾何特性計(jì)算 ....................................................... 23 各階段截面對(duì)形心軸的靜矩 計(jì)算 ........................................................... 24 鋼束預(yù)應(yīng)力損失計(jì)算 ...................................................................................... 26 預(yù)應(yīng)力鋼束與管道壁之間的摩擦損失 ...............