【正文】 s heavy traffic, the bridge has bee designed to have a 3 percent maximum slope.To ensure bridge longevity and facilitate deck, replacement operations, engineers will use reinforcing bars instead of post tensioning tendons in the deck slab. Reinforcing bars will also be used as ties in the footings to resist lateral thrust between the inclined tower legs. Builtup Ishaped steel beams spaced 4 m apart will form the floor beams and will match the m height of the connecting edge girders. The top flanges of the floor beams will follow the cross, slope of the deck. Three longitudinal beams will provide temporary lateral support for the floor beam top flanges before the CIP concrete strips reach sufficient strength. The top flanges of the longitudinal beams will be wide enough to serve as forms for the CIP concrete strips between precast deck panels.The bridge is designed so that the superstructure of the main span can be erected by delivering the major structural ponents to the deck from the towers. The boxshaped steel edge girders have high tensional strength and are designed to cantilever during floor beam erection. With an inclined outside web and a vertical inside web, this m high, boxshaped steel edge girders will deepen to m as they approach the ends to match the depth of the concrete box girders in the approaches. The top flange will be m wide and the bottom flange will be m wide. To make the concrete deck and steel edge girder posite, shear studs will be welded to the flange. Four rubber bumpers at the deck level of each tower are designed to transfer horizontal wind loads from the superstructure. Bumpers eliminate the use of bearings, which require costly, laborintensive inspections and replacements. The bumpers XX 大學(xué)畢業(yè)設(shè)計（論文）40are easily accessible for inspection and can be replaced by a single person. Cable anchors are located inside the edge girder, which protects the cabletogirder anchors from the elements. A circular access hole ii1 the inside web and a platform will be constructed at every cable connection between the floor beams to provide easy access to the cable anchors for inspection and main tenancy purposes. For aesthetic reasons, the bottoms of the girders have smooth stay cables consisting of 24 to 77 lowrelaxation, sevenwire welds less strands will support the bridge’s superstructure. The strands are 15 mm in diameter and conform to ASTM International39。 and Parsons Brinckerhoff (PB), of New York City. Once the joint venture was formed, designers began a feasibility study of the Chao Phraya River crossing and set about determining the most suitable type of crossing. Tunnels and cablestayed bridges were developed and evaluated. Eventually, however, it became clear that a bridge would be more economical, would not interrupt marine traffic, and would best lend itself to the highway interchange.In 1999 engineers began to design the SOBRR. The Chao Phraya River Bridge design was led by PB and supported by AEC and TEC. Conceptual and preliminary designs were prepared by PB39。s notoriously heavy traffic but also contribute a new architectural symbol to the capital city. By Ruchu Hsu, RE.The bridge will carry four lanes of traffic in each direction. The upper portion of each tower will have an enclosed chamber for cable anchors, a m square opening at the bottom providing easy access for maintenance and inspection.For the past 20 years, Thailand39。經(jīng)過四年美好的大學(xué)生活，我對交大的感情與日俱增，在即將畢業(yè)離校之際，深感留戀，忠心感謝學(xué)校領(lǐng)導(dǎo)和老師的悉心培育，使我不斷成長、成熟?？梢哉f老師和同學(xué)的幫助是我們設(shè)計得以順利完成的有力保障。在這兩個多月設(shè)計期間，學(xué)校領(lǐng)導(dǎo)密切關(guān)注我們的畢業(yè)設(shè)計的進度與質(zhì)量，許多老師花費了大量的時間及精力，親歷監(jiān)督和指導(dǎo)。欣喜之余,各種困難歷歷在目,遇到困難時的沮喪,解決后的狂喜,挫敗感、成就感交織交替,在此過程中煅煉了處理事物的能力，受益頗多。接下來的日子基本上都是在設(shè)計中度過的，遇到的困難可謂空前，首先，有限元法我們只知道皮毛，而我們的設(shè)計起步就要用到有限元法進行單元的劃分來計算各個截面的幾何特征，同樣的工作重復(fù)了幾次下來給人的感覺用大學(xué)里最時髦的話來說就是郁悶的不得了，最終理智還是戰(zhàn)勝了一切；，這也是我們的設(shè)計能最終完成的關(guān)鍵一步。xma m/15/ NIV ???＝??因此梁的剪應(yīng)力檢算合格。腹板計算高度邊緣處同時受到較大的正應(yīng)力和剪應(yīng)力時，鋼材處于復(fù)雜受力狀態(tài)，故取腹板邊緣為檢算點。1 /15m/?????中支點處壓應(yīng)力： 22/.63N＝＝支2．抗拉應(yīng)力檢算第一體系：（跨中）263max1 m/.????（支點）2 263ax / N第二體系：XX 大學(xué)畢業(yè)設(shè)計（論文）32239。m)合計(kN圖 58 求 時的荷載位置01QxlPFm?? 0 0 0支點 m 0′ 1′ 2′ 3′ 4′ 5′ 6′ 7′1 2 3 4 5 0 0 0 0 0Fm/P小計 ? ? 0 0XX 大學(xué)畢業(yè)設(shè)計（論文）30 2g=, g=, e= x=, b=25m∴ ?????? ?????? bdbdbdbegQx 65432101 sinisinisinicossin8 ????? = 縱肋跨間的彎矩修正值(2)M0= ???lPFQalmx?011 =2 =539。039。M0=（2）縱肋的活載支點彎矩 M0 計算計算作用于寬度 2c 的后輪荷載所產(chǎn)生的彎矩： 2max,.????????????????lcplk ... 2,0 ?k N?28因為其他幾個輪的集中荷載對 0 點彎矩影響很小，故近似取M0=539。039。車輪與橋面板的接觸面積： A＝b 1a1=9252＝4784cm 2＝㎡重車的軸重為 200KN,輪重為 100KN輪壓:P= =.㎡ （包括 30％的沖擊）03.?板的局部應(yīng)力可以將板看作支承在一系列剛性支點上的彈性板進行分析確定，如圖 5－3 所示。 213.I 39?！渌勺兒奢d中溫度影響和基礎(chǔ)變位影響的一種或幾種產(chǎn)生的效應(yīng)；2S對于本橋而言采用荷載組合Ⅰ進行計算。對于預(yù)應(yīng)力混凝土連續(xù)梁橋，同一截面因不同荷載作用所產(chǎn)生的內(nèi)力可能同號，也可能異號，所以要考慮不同的荷載安全系數(shù)進行內(nèi)力組合。上部結(jié)構(gòu)可變作用效應(yīng)組合的計算：均布荷載：q＝4m cξηq ＝4110 ＝集中荷載：P=4mcξηp =41300 = kN/m主梁內(nèi)力影響線及加載如下圖所示（圖 4－5）：（a）主梁布置圖 單位（m） Mmaxin（b）B 截面彎矩最不利位置影響線加載圖 maxin（c）C 截面彎矩最不利位置影響線加載圖XX 大學(xué)畢業(yè)設(shè)計（論文）15Mmaxin（d）D 截面彎矩最不利位置影響加載圖 QA右min右ax（e）A 截面剪力最不利位置影響線加載 C右minQ右ax（f）C 截面剪力最不利位置影響線加載 B右min右ax（g）B 左截面剪力最不利位置影響線加載XX 大學(xué)畢業(yè)設(shè)計（論文）16QB右min右ax（h）B 右截面剪力最不利位置影響線加載 D右minQ右ax（i ）D 截面剪力最不利位置影響線加載圖 4－5 彎矩、剪力最不利位置影響線加載彎矩包絡(luò)圖計算如下圖所示（圖 4－6）：（a ）梁的受力類型、位置（b）恒載彎矩圖XX 大學(xué)畢業(yè)設(shè)計（論文）17（c）集中荷載作用在左邊跨夸中時梁彎矩圖（d）集中荷載作用在中跨夸中時梁彎矩圖（e）集中荷載作用在右邊跨夸中時梁彎矩圖（f）均布荷載作用在左邊跨時梁彎矩圖（g）均布荷載作用在中跨時梁彎矩圖XX 大學(xué)畢業(yè)設(shè)計（論文）18（h）均布荷載作用在右邊跨時梁彎矩圖（i） 彎矩包絡(luò)圖圖 4－6 彎矩包絡(luò)圖 單位（kN也可用結(jié)構(gòu)矩陣程序進行計算繪制。 橫向分布系數(shù)的計算本梁為單箱三室，有四片腹板組成，可劃分為四個單元，每片腹板作為一個主梁，求主梁①的橫向分布系數(shù) m。在使用階段，結(jié)構(gòu)以成為最終體系，其縱向的力學(xué)計算圖式是明確的。m ）圖 41 一期荷載內(nèi)力圖 二期恒載內(nèi)力二期恒載集度計算： =橋面鋪裝集度+防撞護欄集度2q =（21+23）25+425 = （kN/m）式中，A——截面面積； 分別為鋪裝瀝青混凝土厚度和鋼筋混凝土面板鋪裝厚度； 表示護欄按每 10m 為 混凝土計。隨著預(yù)應(yīng)力工藝、懸臂施工方法等的發(fā)展，預(yù)應(yīng)力混凝土兩瞧的施工方法得到不斷創(chuàng)新和發(fā)展。XX