【正文】 游艇船塢等建筑，是為了給公寓和服務(wù)樓騰出空間。新的口岸或小游艇船塢的建筑包含一條運(yùn)河，它將跨過(guò)一條大約350 。這條運(yùn)河可作為小船的停船塢。 為了建造這條新的水路和穿越現(xiàn)有的鐵路線，有必要修建一座新的橋梁 (參見(jiàn)圖1)。 在本文中，這座橋梁的構(gòu)想過(guò)程將被描述為都市發(fā)展的標(biāo)志。 該橋主要須滿(mǎn)足的條件有以下內(nèi)容：橋梁寬度必須符合鐵路線的橫向和縱向有關(guān)條件。橋梁建筑高度，需要非常嚴(yán)格的要求。橫向通道寬度，必須至少有45米，雖然這取的是運(yùn)河無(wú)任何支持的情況。最后的結(jié)論是，一個(gè)主跨至少72米。橋梁，也必須在道路兩邊留出地方讓運(yùn)河的港口運(yùn)作，還要留出一個(gè)回旋距離給當(dāng)?shù)氐慕煌?。既然它是一座鐵路橋，它不可能是一個(gè)很輕的結(jié)構(gòu)。它需要有適當(dāng)?shù)膭偠群统休d能力。 最后一點(diǎn)，大橋被看作是城市發(fā)展的一個(gè)象征，因此，美學(xué)的要求是非常重要的。 最后這點(diǎn)不能不考慮問(wèn)題：有一個(gè)非常昂貴的結(jié)構(gòu)，但事實(shí)上，財(cái)政預(yù)算案是非常有限，而且這是該項(xiàng)目的一個(gè)重大的問(wèn)題。結(jié)構(gòu)成本必須牢記，還有維護(hù)的問(wèn)題，特別是在位于海岸線旁邊的結(jié)構(gòu)。FHECOR咨詢(xún)工程設(shè)計(jì)室參加了這個(gè)競(jìng)賽，用所謂的瑪麗娜德巴達(dá)洛納計(jì)劃贏得了合同，該計(jì)劃描述了一座簡(jiǎn)單，優(yōu)雅，結(jié)構(gòu)經(jīng)濟(jì)和有效新的橋梁方案。3. 對(duì)方案的說(shuō)明， ， ， 。橫斷面由高度可改變的二個(gè)網(wǎng)形成( m主墩高度)。 因此橋面板撓度符合彎曲力矩定律(參見(jiàn)圖3)。采用裝配式預(yù)應(yīng)力梁。梁的肋狀部分可以發(fā)光。這是橋梁的一個(gè)重要特點(diǎn)，這樣一來(lái)，照亮了人行道和抵消橋梁寬度占橋梁高度的比例。有鑒于此，這些光也提供了一個(gè)間斷的鐵路形象。圖4顯示二個(gè)主要的橋梁橫斷面(主墩和中跨的橋墩)。 圖5顯示橋肋中央發(fā)出的光線。橋梁設(shè)計(jì)的另一個(gè)重要特點(diǎn)是外面懸臂式平板的位置。這些平板使用作為壓縮平板作用在重要橫斷面。因?yàn)閴嚎s位于橫剖面的底部在支持(彎曲的陰性的)，并且在中跨的橫剖面頂部間距(彎曲的正面)壓縮平板沿橋梁軸移動(dòng)是使它每個(gè)部分更加發(fā)揮出最大承載能力，這一個(gè)老想法在科教文組織巴黎大廈使用過(guò)。這一特點(diǎn)也產(chǎn)生了一個(gè)有吸引力的設(shè)計(jì)，提供了高效的結(jié)構(gòu)和極具審美價(jià)值的結(jié)構(gòu)。基礎(chǔ)，雖然從美觀角度進(jìn)行設(shè)計(jì)進(jìn)行優(yōu)選，但事實(shí)上他們的高度不可能小的，并提供足夠的空間來(lái)找到的橋梁奇摩一鍋軸承。垂直渠道的橫截面減少了，這將使引進(jìn)照明的架構(gòu)下的特殊設(shè)計(jì)有待關(guān)注。圖6顯示了基礎(chǔ)所采用的主要幾何形狀。 大橋錨定在臺(tái)座1，以便吸收列車(chē)駛過(guò)時(shí)的產(chǎn)生的高強(qiáng)沖擊荷載，這是相當(dāng)于25％的列車(chē)重量的力。另一扶垛提供聯(lián)接以及平板支持在墻壁，被設(shè)計(jì)運(yùn)載被認(rèn)為的鐵路擴(kuò)展用具允許橋梁運(yùn)動(dòng)，無(wú)需影響鐵路操作性能適應(yīng)。增大空間而引起的在可能在將來(lái)使用作為儲(chǔ)蓄空間的扶垛2。圖7顯示扶垛的主要設(shè)計(jì)形式。4. 最后結(jié)論 所提出的橋梁結(jié)構(gòu)方案包括了所有巴達(dá)洛納運(yùn)河未來(lái)的體育和漁業(yè)項(xiàng)目的所有設(shè)施。強(qiáng)度高的橋梁才有可能適應(yīng)鐵路線的荷載條件，同時(shí)擁有著來(lái)自于其自身結(jié)構(gòu)的合理性、穩(wěn)定性。整個(gè)方案將會(huì)導(dǎo)致一座很經(jīng)濟(jì)的橋梁，它將作為巴達(dá)羅那港的一個(gè)非高成本的象征。The New Badalona Railway Bridge – A Structure for the CitySummary The design of structures in metropolitan habitats is always a challenge due to the important number of requirements to fulfil. Design especially when it deals with railways or roads has to bine the needs of those infrastructures with the human environment, which is the case of the railway bridge in the city of Badalona. Nowadays the city area that faces the sea is occupied by contaminating industries. The council is trying to open the city to the Mediterranean Sea, demolishing unsightly and useless buildings and changing the use of the ones with architectural or technical value. Now a beach and a yachting harbour are being built. A railway line runs parallel to the coast dividing the centre of the city from the shore area. There are no funds to construct a tunnel for the railway line, consequently a bridge has to be built to increase the connection between the centre of the city and the new coast facilities. A design petition was carried out for a railway bridge, which will cross a new pedestrian area, a part of the new harbour and two streets. The contract for the bridge design was awarded to FHECOR Consulting Engineers on the basis of a preliminary design. The idea of the proposal was to bine functionality, structural rationality, aesthetics and low construction and maintenance costs. Also the client has the intention to construct the bridge as a landmark that will be the image of the new urban development. Keywords: Urban Bridge, Railway, Prestressed, Structural shape. 1. Introduction Badalona is a major satellite city of Barcelona on the Mediterranean coast. The nucleus of the city is cut off from the shoreline by the railway line which connects the different suburban centres of Barcelona located along the Mediterranean coast. The railway line is currently one of the Spanish Railway Consortium’s (RENFE) most profitable passenger lines. Along the railway line industrial buildings have sprung up over the years forming a once important industrial centre but at the same time furthering the alienation of the people of Badalona from the sea. In order to try to regenerate the coast and improve its connection with the urban centre, the City of Badalona together with the Comarcal Council of Barcelona have created Marina de Badalona . whose main purpose is to regenerate the urban landscape by carrying out a major urban development project which includes a port for sport boats and fishing, the reconditioning of existing interesting industrial buildings for other use and the demolishing of more mon warehouses and other constructions in order to make room for apartment and service buildings. The construction of the new port or marina involves the building of a new canal which will cross the existing railway line extending into the land about 350 m. This canal will serve as parking docks for the boats. In order to create this new waterway and allow the crossing of the existing railway line, a new bridge is needed (see fig 1). In this paper the conception process of this bridge, which will bee a symbol of the urban development is described.2. Main condition to be fulfilled by the bridge The main conditions to be fulfilled by the bridge are the following: The bridge width must fulfil the horizontal and vertical clearance conditions of the railway line.The depth of the deck needs to be small due to the very strict vertical clearance.The horizontal channel clearance needs to be at least 45 meters, although it is desirable not to locate any supports within the canal. This last condition results in a main span of at least 72 m.The bridge must also leave clearance for port operation roads on both sides of the canal and cross over a roundabout carrying local traffic.Since it is a railway bridge it cannot be a very light structure. It requires appropriate stiffness and bearing capacity.In spite of the last point, the bridge is conceived as a symbol of the urban development and therefore aesthetical conditions are of great importance. This last point cannot however result in a very expensive structure due to the fact that the budget is very limited and this is a major condition of the project. The cost of the structure must also bear in mind maintenance issues especially in a structure located next to the shoreline. FHECOR consulting engineers participated in a contest called by Marina de Badalona . and was awarded the contract of the design of the new bridge with a simple, elegant, economic and structurally e