梁橋外文翻譯

1、<p><b>　　附錄Ⅱ</b></p><p><b>　　英文翻譯:</b></p><p>　　BEAM BRIDGE</p><p>　　In designing a bridge, preference is often given to beam structure, unless it has

2、a very long span. Simple in structure, convenient to fabricate and erect, easy to maintain, and with less construction time and low cost, beam structure has found wide application in bridgework. In 1937, over the Qiantan

3、g River, in the city of Hangzhou, was erected a railway-highway bi-purpose bridge, with a total length of 1453m, the longest span being 67m. When completed, it was a remarkable milestone of the beam</p><p>　

4、　Pre-stressed concrete girder bridges cover a wide range of spans and types. In the short span range, pre-cast AASHTO beams with a composite cast-in-place non pre-stressed concrete slab are frequently used for simple spa

5、ns. A similar form of construction is used for partially continuous spans using I-girders and box girder in the medium span range .In the medium to long span range, continuous pre-cast segmental box girders are common, w

6、hile the longest spans are generally cast-in-place segmental </p><p>　　For cost-in-place construction, the girders and slab are generally formed together and both cast before formwork and supports are remove

7、d. This construction is fully composite for dead load and live load. The usual cross sections are T-beams and box girders. Spans are usually continuous, and transverse post-tensioning of the slab is frequently prescribed

8、 to allow the use of thinner slabs or a reduced number of longitudinal girders at a larger spacing. Since longitudinal post-tensioning is requir</p><p>　　The design and analysis items given for reinforced co

9、ncrete girder bridges also apply to pre-stressed girder bridges. For the box girder section, a detailed transverse live load analysis of the section should be carried out. Temperature effects are important for box girder

10、, due to the possibility of large differential temperatures between the top and bottom slabs.</p><p>　　For cast-in-place segmental construction built by the balanced cantilever method, a knowledge of the exa

11、ct construction loads is necessary, in order to calculate stresses and deformations at each stage. A knowledge of the creep characteristics of the concrete is essential for calculating deformations after the addition of

12、each segment, and also to calculate the redistribution of moments after completion and final stressing.</p><p>　　Standard pre-cast, pre-stressed beams cover spans up to the 140ft (43m) range. After the beams

13、 are erected, forms for the slabs are placed between the beams and a reinforced concrete slab cast in place. The slab and beams act compositely for superimposed dead load and live load. Intermediate diaphragms are not no

14、rmally used , and the design and analysis items given for reinforced concrete girder bridges, also apply to pre-stressed multi-beam type bridges. </p><p>　　Pre-cast pre-stressed beams can be made partially

15、continuous for multi-span bridges. This system is not only structurally efficient, but has the advantage of reducing the number of deck joints. Support moments are developed due to superimposed dead load, live load, diff

16、erential temperature, shrinkage and creep. Continuity for superimposed dead load and for live load can be achieved by casting diaphragms at the time the deck concrete is placed. Reinforced steel placed longitudinally in

17、the deck s</p><p>　　Pre-cast segmental construction employs single or multiple cell boxes with transverse segments post-tensioned together longitudinally. For medium sans, the segments may be erected for the

18、 full span on falsework before post-tensioning. Longer spans are usually erected by the balanced cantilever method, where each segment is successively stressed after erection. The design and analysis considerations given

19、 for cast-in-place segmental construction also apply to pre-cast segmental construction. The </p><p>　　Pre-stressed concrete beam bridge is a new type of structure. China began to make researches and develop

20、 its construction in the fifties. In early 1956, a simply-supported prestressed concrete beam bridge with a main span of 23.9m -a railway bridge -was erected over the Xinyi River along the Longhai Railway line. Completed

21、 at the same time, the first P.C. highway bridge was the Jingzhou Highway Bridge. The longest simply-supported P.C. beam which reaches 62m belongs to the Feiyun River Bridge in</p><p>　　Elastic analysis and

22、beam theory are usually used in the design of segmental box girder structures. For box girders of unusual proportion, other methods of analysis which consider shear lag should be used to determine the portion of the cros

23、s section effective in resisting longitudinal bending. Possible reserve shearing stress in the shear keys should be investigated, particularly in segments near a pier. At time of erection, the shear stress carried by the

24、 key should not exceed . The </p><p><b>　　梁橋</b></p><p>　　梁橋構(gòu)造簡單、施工方便、工期短、造價低、且維修容易，除特大跨度橋梁外，是設(shè)計中優(yōu)先考慮的結(jié)構(gòu)體系，應(yīng)用甚廣。1949年前由國人設(shè)計監(jiān)造的梁橋，以總長1453m，最大跨度67m的杭州錢塘江公路鐵路兩用橋（1937年建成）為一里程碑

25、，1949年后這種梁橋已有長足的發(fā)展。</p><p>　　鋼筋混凝土梁橋是一種常用的中小跨度橋梁，以廣西壯族自治區(qū)的南寧邕江橋（1964年）為代表，主跨醉大55m，系中國最早按閉口薄壁構(gòu)件設(shè)計的一座箱形懸臂梁橋。</p><p>　　預(yù)應(yīng)力混凝土梁橋在本世紀50年代中國即已開始研制，1956年初首先在隴海線新沂河鐵路橋上建成了跨度23.9m的簡支梁?？缍?0m的京周公路橋也于同期建成。這

26、種橋型的最大跨度為浙江省瑞安飛云江橋（跨度為62m，1988年）；1989年建成的開封黃河大橋總長4475.09m，其中有77孔50m簡支梁采用連續(xù)長度達450m，并按部分預(yù)應(yīng)力混凝土結(jié)構(gòu)設(shè)計。</p><p>　　預(yù)應(yīng)力混凝土梁橋跨度范圍廣，形式多樣。預(yù)制的AASHTO梁和組合的現(xiàn)澆非預(yù)應(yīng)力混凝土板常用于小跨徑的簡支跨。上述結(jié)構(gòu)性失業(yè)可用于使用了工字梁和箱形梁的中等跨徑的部分連續(xù)梁。而連續(xù)的預(yù)制分段裝配式箱梁則

27、普遍地使用與中等跨徑及大跨徑的橋梁，而最長的跨一般采用分段現(xiàn)澆箱梁。</p><p>　　現(xiàn)澆的施工方法一般是將梁和板組合在一起，并在移去模板和支承之前對其進行現(xiàn)澆。這種結(jié)構(gòu)作為一個整體來承擔靜載和活載。一般來說梁的橫截面一般呈T型和箱形。通常橋跨為連續(xù)跨。將板進行橫向后張拉時，允許使用較薄的板或者減少縱梁數(shù)目來擴大空間?？v向后張拉要求在現(xiàn)場進行；而橫向后張拉更經(jīng)濟，因而運用更廣泛。</p><

28、;p>　　對鋼筋混凝土梁橋的設(shè)計和分析同樣也適用于預(yù)應(yīng)力橋梁。對于箱梁截面，其橫向活載應(yīng)進行詳細分析。由于頂板和底板之間的溫度可能存在較大的差異，所以溫度效應(yīng)對箱梁來說很重要。</p><p>　　應(yīng)用平衡懸臂梁施工法進行現(xiàn)澆分段施工時，為了計算各個階段的應(yīng)力和變形，有必要知道準確的施工荷載?；炷恋男熳兲匦圆粌H對每增加一段后得變形的計算很重要，而且對竣工和最后加壓后彎矩重新分布的計算也很重要。</p

29、><p>　　標準的預(yù)制預(yù)應(yīng)力梁最大跨徑可達140ft(43)m。梁安裝之后，板模就放置在梁和現(xiàn)澆的鋼筋混凝土板之間以澆筑混凝土加勁板。板與梁共同承受疊加的靜載和活載。一般不使用中橫隔板，對鋼筋混凝土梁橋的設(shè)計和分析同樣適用于預(yù)應(yīng)力多梁橋。</p><p>　　預(yù)制的預(yù)應(yīng)力梁可以做成部分連續(xù)形成多跨橋。這種體系不僅在結(jié)構(gòu)上有效，而且可減少橋面結(jié)點數(shù)。由于疊加的靜載和活載、溫度差異，以及收縮和徐

30、變作用，支承彎矩就產(chǎn)生了。澆筑橋面混凝土的同時澆筑橫隔板就可得到連續(xù)的疊加靜載和連續(xù)的疊加活載。在橋面板里縱向放置的、與中間橋墩垂直的加強鋼筋承受支點處負彎矩產(chǎn)生的拉應(yīng)力。橫隔板處。相鄰梁的底翼緣應(yīng)連在一起抵制由于溫差、收縮和徐變產(chǎn)生的正彎矩而形成的拉應(yīng)力。一般可使用分段式先張法預(yù)制的梁來做成邊跨，但這已超出了預(yù)制梁的范圍。橋面板放置之后，對暫時支撐在彎曲處的兩端和最小力矩點附近的節(jié)點連續(xù)進行后張法。梁段的最大長度通常受裝運距離和運重量

31、的限制。</p><p>　　預(yù)制的分段式施工法運用單個或多個孔型箱梁，將橫向梁段縱向用后張法連在一起。若跨徑中等，在后張法進行前用腳手架就可將所有梁段裝配成一個整跨。大跨兩一般用平衡法安裝起來，每段在依次放置之后可陸續(xù)受壓。對現(xiàn)澆分段結(jié)構(gòu)的設(shè)計和分析同樣適用于預(yù)制的分段結(jié)構(gòu)。裝配懸臂時結(jié)構(gòu)的變形取決于梁段的預(yù)制和安裝之間的時間差。如果施工進度不同于設(shè)計進度，應(yīng)重復(fù)進行設(shè)計計算。</p><p

32、>　　設(shè)計分段式箱梁結(jié)構(gòu)是運用彈性理論和梁理論。對于比例特殊的箱梁，應(yīng)運用考慮了剪力滯后情況的分析方法來計算抵抗縱向彎矩時的有效橫截面面積。對剪力鍵的反向剪應(yīng)力應(yīng)進行研究，特別是對橋墩周圍的梁段。安裝時由剪力鍵承受的剪應(yīng)力不超過。</p><p>　　預(yù)應(yīng)力混凝土T型剛構(gòu)橋以其最適宜采用平衡懸臂拼裝或澆筑法施工，在中國60年代首先受到重視和發(fā)展。懸臂拼裝T型剛構(gòu)橋以河南五陵衛(wèi)河橋（1964年）為首創(chuàng)；懸臂澆

33、筑T型剛構(gòu)橋則以廣西柳州柳江大橋（1967年）為先導(dǎo)。重慶長江大橋（1980年）是這種體系目前的最大者，主跨達174m.</p><p>　　在預(yù)應(yīng)力混凝土T型剛構(gòu)橋的設(shè)計與施工經(jīng)驗的基礎(chǔ)上，有發(fā)展了跨度更大、運營條件更好的多聯(lián)預(yù)應(yīng)力混凝土連續(xù)梁橋和連續(xù)-剛構(gòu)橋，其中廣東省廣州洛溪大橋（1988年）跨度達到180m；正在施工中的湖北省黃石長江大橋，跨度已增至245m。鐵路預(yù)應(yīng)力混凝土連續(xù)梁橋中的杭州錢塘江二橋（1

34、991年），跨度聯(lián)長（主跨80m，聯(lián)長18孔），且在罕有的施工涌潮高度1.96m和潮壓強度32kPa下建成。連續(xù)梁橋的廣泛采用，又促進了頂推法（在直橋與彎橋上）、大噸位（500t浮吊安裝和移動式，模架逐孔澆筑等施工方法的發(fā)展。</p><p>　　V型墩或Y型墩預(yù)應(yīng)力混凝土連續(xù)梁橋或懸臂梁橋，可以優(yōu)化造型，削減支點彎矩，降低橋梁建筑高度。臺灣忠孝橋（1981年）、桂林雉山漓江橋（1987年）都是其中的佼佼者。&l

35、t;/p><p>　　鋼橋在中國主要用于鐵路橋或公路鐵路兩用橋。公路鋼橋以山東省北鎮(zhèn)黃河公路橋（1972年）為最大，最大跨度112m，是一座鉚接連續(xù)鋼桁梁，基礎(chǔ)采用φ1.5m鉆孔灌注樁，最長入土深度達107m，為目前國內(nèi)之最。1980年建成的廣東省馬房北江公路橋，已采用先進的栓焊箱梁和正交異性鋼橋面板設(shè)計。公路鐵路兩用的武漢長江大橋（1957年）采用主跨128m的鋼連續(xù)桁架梁，3號鋼鉚接連接，首創(chuàng)了新型的直徑φ1.5

36、5m管柱基礎(chǔ)（以后在江西省南昌贛江南橋中發(fā)展到φ5.8m,1962年），是中國橋梁建設(shè)的又一里程碑。南京長江大橋（1968年）采用了較好的16Mnq鋼材，主跨增大為160m的鉚接連續(xù)鋼桁架梁，從材料、設(shè)計到施工均依靠本國力量建成，并且發(fā)展了深水基礎(chǔ)，其中重型混凝土沉井，穿越深度達54.87m；首次采用了φ3.6m先張法預(yù)應(yīng)力混凝土管柱；并且創(chuàng)造了新穎的復(fù)合基礎(chǔ)；清基潛水作業(yè)水深達65m。九江長江大橋（1992年）采用了更好的國產(chǎn)15Mn