外文翻譯----橋梁走向未來

1、<p><b>　　附錄A</b></p><p>　　Bridge to the Future</p><p>　　The Chao Phraya River Bridge is designed to accommodate marine traffic. The 500 m main span will provid

2、 50.5 m of vertical clearance, and the two towers will be situated away from the main navigation channel.</p><p>　　The final component of Thailand's new Outer Bangkok Ring R

3、oad, the eight-lane cable-stayed Chao Phraya River Bridge, will not only alleviate Bangkok's notoriously heavy traffic but also contribute a new architectural symbol to the capital city. By Ruchu Hsu, RE.</p>

4、<p>　　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 1.5 m square opening at the bottom providing easy access for ma

5、intenance and inspection.</p><p>　　For the past 20 years, Thailand's capital, Bangkok, has been constructing expressways to lleviate traffic congestion. Among the major expressway projects in the capital

6、 is the Outer Bangkok Ring Road, a 170 km long highway encircling the city. The road is nearly complete; only the eastern half of the southern leg--the Southern Outer Bangkok Ring Road, or S-OBRR--remains to be construct

7、ed. Scheduled for completion in 2007, the 21 km elevated viaduct will incorporate four major interchanges and a </p><p>　　In 1996 the Department of Highways retained a joint venture team of consultants to de

8、sign the S-OBRR. The design team included Asian Engineering Consultants (AEC), Thai Engineering Consultants (TEC), and Siam General Engineering Consultants, all of Bangkok; Oriental Consultants, of Tokyo; and Parsons Bri

9、nckerhoff (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 cros</p><p>　　In

10、 1999 engineers began to design the S-OBRR. The Chao Phraya River Bridge design was led by PB and supported by AEC and TEC. Conceptual and preliminary designs were pre-pared by PB'S New York staff, and Thai engineers

11、 working in Bangkok with the author completed the subsequent final design. The engineers established four design goals. They wanted a bridge that would (1) be long lasting and easily maintained, (2) enhance the city arch

12、itecturally, (3) be economical and incorporate the maximum amo</p><p>　　material, and (4) not disrupt marine traffic the</p><p>　　Chao Phraya River during construction. Superstructure true that

13、will carry four traffic lanes in each direction and provide 50.5 m of vertical clearance for marine traffic. The bridge's two A-shaped towers will straddle the 500 m main span and will stand as stylized representatio

14、ns of the traditional Thai greeting, the hands steep led together. The superstructure is a steel frame composite with a concrete deck. Stay cables spaced at 12 m intervals along the edge girders are designed to carry the

15、</p><p>　　The hollow legs of the two 187 m high towers are made of reinforced concrete. A horizontal strut just below deck level provides lateral support for the slender legs and reduces deflection. The legs

16、, each supported by two 24 by 24 by 4 m footings, join at the top to form a chamber for cable anchors. Decorative spheres 3 m in diameter and spires 8 m tall at the top of the towers will be gilded in traditional Thai st

17、yle. The two towers--one located in shallow water on the east bank, the other behin</p><p>　　The three anchor piers will be situated behind each tower on the bridge's back spans. The piers will maximize

18、the vertical and lateral stiffness of the bridge superstructure and the tensional stiffness of the main-span superstructure and will stabilize the bridge during strong winds. The A-shaped towers will also contribute to t

19、he tensional stiffness of the superstructure. Moment connections between the superstructure and the anchor piers eliminate the need for wind locks, which attach the deck </p><p>　　The composite superstructur

20、e includes a rein-forced-concrete deck, steel floor beams, and two teel edge girders. A deck slab that varies in thickness from 260 to directly supports vehicle loads310 mm. The thicker slab segments will extend98.5 m fr

21、om each tower in both directions. Recast deck panels will span between the floor beams but will not fully cover the top flanges of the beams. Cast-in-place (CIP) concrete will be placed on top of the floor beams and the

22、exposed portions of the, flanges </p><p>　　To ensure bridge longevity and facilitate deck, replacement operations, engineers will use reinforcing bars instead of post tensioning tendons in the deck slab. Rei

23、nforcing bars will also be used as ties in the footings to resist lateral thrust between the inclined tower legs. Built-up I-shaped steel beams spaced 4 m apart will form the floor beams and will match the 1.625 m height

24、 of the connecting edge girders. The top flanges of the floor beams will follow the cross, slope of the deck. Three </p><p>　　The bridge is designed so that the superstructure of the main span can be erected

25、 by delivering the major structural components to the deck from the towers. The box-shaped steel edge girders have high tensional strength and are designed to cantilever during floor beam erection. With an inclined outsi

26、de web and a vertical inside web, this 1.625 m high, box-shaped steel edge girders will deepen to 2.2 m as they approach the ends to match the depth of the concrete box girders in the approaches. The</p><p>

27、　　white, will reduce heat absorption. Welded beads will be placed in a spiral pattern along the exterior surface of the HDPE pipes to control cable vibrations caused by wind and rain.. Since the long cables (up to 260 m)

28、 are prone to large-amplitude vibrations, crossties-an effective and economical method of controlling cable vibration-will be installed. The wind ties suppress individual cable resonance by forcing cables with</p>

29、<p>　　different mode frequencies to vibrate together.</p><p>　　The Post Tensioning Institute, based in Phoenix, requires that stay cables be replaceable. The engineers have designed the Chao Phraya Riv

30、er Bridge so that one stay cable can be replaced while traffic continues on two lanes in each direction. The bridge has also been designed to allow for the accidental loss of any one cable without bridge failure.</p&g

31、t;<p>　　The bridge design includes a large chamber on each tower to house cable anchors. The chamber is 8.8 by 3.4 m at the top and 23 by 5 m at the bottom and will provide sufficient space for ladders and platfor

32、ms to directly access all of the cable anchors. A 1.5 by 1.5 m opening in the bottom slab will allow for the lifting of heavy equipment or materials directly from the deck to the chamber. This opening will ease construct

33、ion, inspection, maintenance, and future cable replacement. Each anchor pie</p><p>　　The bridge, like much of Bangkok, is located in a floodplain, and there is a 15 m layer of soft clay near the site's s

34、urface. To properly support the towers and anchor piers, engineers will drill shafts 2 m in diameter to a depth of 50 m. The engineers chose 2 m shafts because they possess the lateral bending capacity required for large

35、 foundations in soft soils. To facilitate inspection and maintenance, the designers provided easy access to all of the major structural components. No special equ</p><p>　　Because cable-stayed bridges tend t

36、o be highly redundant, the engineers found it necessary to use computers to calculate the multitude of member forces under various loading conditions. EARS& a structural analysis program developed by Larsa, Inc., of

37、Melville, New York, were used in the design. Linear analyses were performed for live loads, wind loads, and temperature loads; nonlinear analyses were performed for dead loads, cable replacements, and cable loss; dynamic

38、 analyses were performed for </p><p>　　The bridge deck can experience vortex-shedding vibrations at 25 m/s. The peak deck acceleration was found to be lower than the allowable specifications set forth in 198

39、0 by ASCE'S Committee on Loads and Forces on Bridges. The bridge can withstand buffeting--a random vibration caused by unsteady wind loading arising from turbulence. In particular, the test showed that the bridge is

40、able to withstand wind load distributions having a 100-year return period.</p><p>　　The concrete, reinforcing steel, steel shapes, gratings, and HDPE pipes necessary for the S-OBRR'S Chao Phraya River Br

41、idge will be produced locally. Only such specialty items as cable anchorages will be imported. Construction of the bridge began in August and is expected to be completed in early 2007, providing a badly needed solution t

42、o traffic problems and a structure that promises to add to the beauty of this bustling Asian metropolis. </p><p>　　The piles. 40 in long and 3 m in diameter, arc driven into the sandy river bottom from a

43、bove the water level. This foundation system was considered to be more effective than concrete piling because of the steel piles’ lateral stiffness and strength. Research was conducted into the possibility of improving t

44、he axial stiffness by means of pressure grout injection at the pile bottom. However, because this method had not before been applied in similar situations and because the operational risks wer</p><p>　　On to

45、p of each casing a hollow rectangular vertical shaft of varying cross section was cast in site. The shafts vary in height by as much as 7 m from the middle of the bridge to the ends. The shaft heads include anchors for t

46、he bridge supports, so the shafts had to be positioned within tolerances as small as 10 mm. The top plane of each shaft, measuring just 5 by 6 m, included space for the vertical supports at the edges, jacks for bridge li

47、fting, horizontal supports, and a central lower-level i</p><p>　　The acceptable vertical tolerance of the deck was set at ±15 mm, or 1/7000 of the span. Considering the length of the spans, the fact tha

48、t the girder was continuous over multiple spans, and the composite nature of the structure, however, and this standard proved difficult to meet. In consultation with the rail authorities the acceptable tolerance was incr

49、eased to ±40 mm.</p><p>　　The hammer sections, identical except for small details, also were reassembled, but here six subsections were involved. These parts were manufactured to within a tolerance of &

50、#177;5 mm. Since the bridge site is between two existing bridges, the height of the parts to be transported was limited to the vertical clearance of the existing structures. Thus the 10.5 m high hammer sections were tran

51、sported not in their upright position but on their sides. On the hammer sections, therefore, the concrete dec</p><p>　　The project also included the design and construction of approach structures on both end

52、s of the crossing, because the trains may reach speeds of more than 300 km/h, the approaches must provide a smooth track to enable trains to come from 20 m below mean sea level in the tunnel north of the bridge to 20 m a

53、bove mean sea level at the summit of the bridge, in the middle of the river. The alignment has a maximum slope of 2.5 percent and has a horizontal radius of curvature of 15 km. At the south en</p><p>　　Ruchu

54、 Hsu, P.E., M.ASCE, is a supervising structural engineer for Parsons Brinckerhoff, Inc., in New York City. This paper was presented at the 21st Annual International Bridge Conference, which took place in Pittsburgh June

55、12-I6, 2004.</p><p><b>　　橋梁走向未來</b></p><p>　　過去 20 年里，泰國的首都曼谷,已經(jīng)修筑高速道路以減輕交通擁擠。在這些主要的高速道路之中，位于首都的是曼谷外部的環(huán)形路，一條170千米長環(huán)繞這個(gè)城市的公路。這條路就快完全修完，只剩南邊的東邊一半，即：曼谷南面外部的環(huán)形路還沒有竣工,或者說是東南線OBRR還需要修建。 預(yù)計(jì)

56、在2007年完成,抬高的21千米陸橋?qū)退膫€(gè)主要的立交橋和一個(gè)斜拉橋位于 Chao Phraya 河川之上，由一個(gè)220.5米的主跨和二個(gè)500米的邊跨組成,那Chao Phraya 河川橋?qū)翘﹪淖铋L的橋梁。</p><p>　　1996年，公路部共同投資隊(duì)聘請顧問來設(shè)計(jì) S-N線路OBRR 。設(shè)計(jì)隊(duì)伍中有亞洲的工程顧問 (AEC) ，泰國工程顧問 (TEC),還有來自暹羅的指揮工程顧問，所有的、東方各國

57、、東京、邊區(qū)牧師(PB)和紐約的顧問共同組成了一支探險(xiǎn)隊(duì)伍，設(shè)計(jì)師們開始對橫跨Chao Phraya 河川的可行性研究以及有關(guān)決定最適當(dāng)類型進(jìn)行研究。 隧道和斜拉橋被提出而且評估。然而最后，越來越清楚地認(rèn)識到橋是最經(jīng)濟(jì)的,不會打擾航道交通, 并且最好是把他發(fā)展成為公路立交橋。</p><p>　　1999年，工程師們開始設(shè)計(jì)S-N線路OBRR 。Chao Phraya 河川橋的設(shè)計(jì)以 PB為主導(dǎo)了而且得到AEC

58、和TEC的支持。 初期的理論設(shè)計(jì)是由PB的紐約職工完成的，然而后來的結(jié)局設(shè)計(jì)是由在曼谷的泰國工程師完成的。工程師設(shè)立了四個(gè)設(shè)計(jì)目標(biāo)。他們希望這座橋?qū)?(1) 耐久性好而且維護(hù)容易 (2)增加都市建筑場地 (3)節(jié)約并且盡可能地使用當(dāng)?shù)夭牧?(4) 在構(gòu)造期間不打斷Chao Phraya 河上航道的交通。</p><p>　　因此而產(chǎn)生的設(shè)計(jì)是 一個(gè)有每個(gè)方向的四個(gè)車道而且能夠提供50.5米垂直凈空給船用的行車的

59、36.7米寬的上部結(jié)構(gòu)。橋的雙面塔將會跨越 500 米 主跨并且將會立如傳統(tǒng)的泰國人問候時(shí)的姿態(tài)那樣兩臂結(jié)合在一起呈尖塔狀。上部結(jié)構(gòu)是一個(gè)由混凝土平臺和一個(gè)鋼架組成的集成物。 斜拉鋼絲繩被設(shè)計(jì)為沿著邊梁以12米為間距作等間隔排列用來承受上部結(jié)構(gòu)的負(fù)荷。 在每個(gè)邊沿上的三個(gè)錨墩將會提供穩(wěn)定性。 橋以一個(gè)對稱的縱斷面為特征并且斜坡只達(dá)3%. 該橋被設(shè)計(jì)來承受來自卡車的208千牛的荷載—比以前1996年美國公路橋公會和官方運(yùn)輸?shù)臉?biāo)準(zhǔn)規(guī)范第 1

60、6 版中的荷載高30%. </p><p>　　這兩個(gè)187米高的塔的空心腳是用鋼筋混凝土做成的。在裝飾水平儀下面的一個(gè)水平的橫撐可以給細(xì)的腳提供側(cè)面支撐并且減少撓度。每個(gè)塔肢被間隔24米的4米高的塔腳支撐，在頂部結(jié)合在一起形成一個(gè)擱置鋼絲繩錨造形池。有直徑為3米球體和8米高尖頂?shù)乃攲髠鹘y(tǒng)的泰國式樣裝飾，鍍金。</p><p>　　這二個(gè)塔，一個(gè)位于約旦河?xùn)|岸的淺水中；另一個(gè)在西部的

61、一個(gè)碼頭將會被位于遠(yuǎn)離主要的航道以便除去和可能橋沖突的可能性并且確保航道的交通不會受到妨礙。三個(gè)錨墩將會位于每個(gè)塔之后的橋的頂面跨上。 橋墩的勁度將取上部結(jié)構(gòu)和主跨上部結(jié)構(gòu)的垂直和側(cè)面勁度的最大值以保證在強(qiáng)烈的風(fēng)荷載作用下使橋穩(wěn)定。A字形的塔也將會對上部結(jié)構(gòu)的勁度非常有利。上部結(jié)構(gòu)和錨墩之間的活動(dòng)連結(jié)能夠抵消風(fēng)荷載作用下所產(chǎn)生的位移, 這樣的活動(dòng)連結(jié)能把平臺附在錨墩上并且需要特別的檢驗(yàn)和養(yǎng)護(hù)。和錨墩的這種直接聯(lián)接將會實(shí)質(zhì)性地減少鋼絲繩的

62、壓應(yīng)力而且可以降低鋼絲繩疲勞的可能性。鋼絲繩而不是那更普遍使用過的承座,將會支撐塔的上部結(jié)構(gòu)而且減少塔的邊梁在某種活載作用下的屈曲彎曲位移。</p><p>　　組合結(jié)構(gòu)的上部結(jié)構(gòu)包括預(yù)應(yīng)力混凝土、鋼板梁、兩個(gè)鋼邊梁。車輛荷載由一塊從260毫米漸變到300毫米的厚鋼板直接承受。較厚的弓形版將會向每個(gè)塔的兩個(gè)方向擴(kuò)充98.5米。 預(yù)制節(jié)板將會跨越在樓板梁之間但是不完全覆蓋上梁的上凸椽?，F(xiàn)澆混凝土將會放置在樓板梁之上

63、并且暴露出部分凸緣使混凝土平臺與鋼支承架成為集成物。40毫米厚的高強(qiáng)混凝土鋪在上面來保護(hù)使之不被腐蝕。為減少曼谷擁擠交通車輛所引起的巨大應(yīng)力,該橋設(shè)計(jì)有一個(gè)最大坡度為3%的斜坡。為確保橋有足夠的耐久性并且便于維修時(shí)施工,工程師將會在厚板中使用高強(qiáng)鋼筋而不用早強(qiáng)鋼筋。 高強(qiáng)桿也將會被當(dāng)作基腳的連接來使用以抵抗側(cè)推力作用下塔肢之間的傾斜。</p><p>　　間隔4米分布的組合工字形鋼梁將會組成板梁并且將會與1.62

64、5米高的邊梁的相連接。板梁的上凸椽將會沿著十字接合器平臺的斜坡。 三個(gè)縱梁將會在CIP混凝土達(dá)到足夠的強(qiáng)度之前為板梁在前的翼緣提供暫時(shí)的橫支承?？v梁的上凸椽將會足夠?qū)挒轭A(yù)制CIP混凝土的脫模提供足夠的建筑平臺。</p><p>　　橋的設(shè)計(jì)有利于通過傳遞從塔對主要建筑部分到板梁的荷載使上部結(jié)構(gòu)的主跨能夠直立。箱形的鋼邊梁有較強(qiáng)的抗扭強(qiáng)度能夠在樓板梁架設(shè)期間被設(shè)計(jì)用作懸臂。 有一個(gè)向外面傾斜的腹板和內(nèi)部垂直的腹板,

65、 當(dāng)他們接近端部時(shí)候這些1.625米高的箱形鋼梁將會加深到2.2米和箱形混凝土梁所在的深度匹配。頂翼緣將會是1.5 米寬的和底凸緣將會是1.9米寬。為了使混凝土板和鋼梁共同工作,剪板墻筋將會被焊接到翼緣。</p><p>　　每個(gè)塔的在板梁水平處的四個(gè)橡皮緩沖器被設(shè)計(jì)用于緩解來自上部結(jié)構(gòu)的水平的風(fēng)負(fù)荷載。這些緩沖器除去應(yīng)該忍性高外,并且造價(jià)比較昂貴,便于人工檢驗(yàn)和替換。這些 緩沖器容易被檢驗(yàn)并且在其損壞需要替換的

66、時(shí)候替換工作可以由單個(gè)人來完成。</p><p>　　鋼絲繩錨位于邊梁之內(nèi),保護(hù)鋼絲繩到梁的錨免于自然的侵害。一個(gè)圓形的在腹板內(nèi)部的出入口孔和一個(gè)月臺將會在每個(gè)鋼絲繩之間的連結(jié)板處被修建為對鋼絲繩錨為檢驗(yàn)和養(yǎng)護(hù)提供便利的出入口。因?yàn)槊缹W(xué)的理由,大梁的底有光滑的棱。</p><p>　　橋的上部結(jié)構(gòu)將會被168跟斜拉鋼絲繩其中有24到77跟比較松弛, 沒有焊接的七跟為一股來支持。每股的直徑為

67、15毫米并且遵照美國材料試驗(yàn)學(xué)會國際的關(guān)于270 級股的規(guī)范A412-90。橋的設(shè)計(jì)中運(yùn)用了最新的防止鋼絲繩腐蝕的工藝,包括鍍鋅和和臘或滑脂的護(hù)膜然后把他們套在一層聚乙烯中。被保護(hù)的股將會被放在白色的高密度的聚乙烯 (HDPE) 管中,這樣將會減少熱量的吸收。焊頭將會被放在一個(gè)螺線型之中沿著對由風(fēng)和雨所引起的控制索振動(dòng)的 HDPE 管的外面。由于長鋼絲繩(長達(dá)260米)以后是上下的大振幅振動(dòng), 枕木一一種控制鋼絲繩振動(dòng)的效果并且節(jié)儉方法

68、將會被安裝。 風(fēng)通過強(qiáng)迫鋼絲繩以不同的頻率共振來強(qiáng)迫單跟鋼絲繩震動(dòng)。</p><p>　　學(xué)院協(xié)會,位于鳳凰城,指出需要的那一跟斜拉鋼絲繩是可替換的。工程師們已經(jīng)開始當(dāng)車輛在二個(gè)巷的每個(gè)方向繼續(xù)行車的時(shí)候設(shè)計(jì) Chao Phraya 河川橋,這座橋的設(shè)計(jì)已經(jīng)被設(shè)計(jì)的可以允許單跟鋼絲繩突然斷裂而不至使橋整體破壞。</p><p>　　橋的設(shè)計(jì)中也包括在每個(gè)塔中都有一個(gè)用于收容鋼絲繩錨的空間。

69、這個(gè)空間在頂部的面積是8.8米*3.4米在底部的面積是23米*5米而且將會提供梯和月臺的充份空間直接地放置所有的鋼絲繩錨。在底板上有一個(gè)1.5米*1.5米的開孔，用于使比較重的設(shè)備和原材料可以直接地從平臺升高到放置所有的鋼絲繩錨的這個(gè)空間。這個(gè)開孔將會方便建造、檢驗(yàn)、養(yǎng)護(hù)和未來換鋼絲繩。</p><p>　　每個(gè)錨墩將會由雙面的柱所組成。這些4米*4米的空心鋼筋混凝土結(jié)構(gòu)有0.6米厚的墻壁方便建造而且確保一個(gè)較長

70、的使用壽命。這兩個(gè)柱在頂部結(jié)合在一起來保證塔的側(cè)面穩(wěn)定性。 懸臂雙臂將會從頂部并且沿著每個(gè)柱的頂延伸, 這兩個(gè)懸臂雙臂將會在錨鋼絲繩被安裝之前平衡混凝土的重量。 懸臂雙臂也將會增加上部結(jié)構(gòu)剛度并且減少邊梁的彎曲力矩。 混凝土自重在錨墩處將會大大減少, 與如此普遍使用過的系條- 向下的方法相反如鋼的桿，鋼絲繩和測釬,需要只有最小的檢驗(yàn)和沒有養(yǎng)護(hù)。</p><p>　　這座橋 ,就像曼谷許多橋一樣,位于一個(gè)河漫灘上,

71、 而且在基地的表面附近有一個(gè)15米厚的軟黏土層。為了適當(dāng)?shù)刂С炙湾^墩,工程師們將會鉆一個(gè)深度為50 米直徑為2米的直井。因?yàn)樗麄兂钟袑浤嗟氐拇蠡A(chǔ)是必需的橫支撐彎曲容量 , 所以工程師選擇2個(gè)米直井。</p><p>　　為了便于檢測和養(yǎng)護(hù),設(shè)計(jì)師為所有的主要結(jié)構(gòu)部分提供容易的出入口。 不需要任何特別的設(shè)備或腳手架就可以到上部結(jié)構(gòu)的出入口，連接到塔的鋼絲繩或連接到梁的鋼絲繩。一個(gè)狹小甬道在提供到達(dá)平臺底部的通

72、道，并且邊梁的底部經(jīng)由到處窺視將會是可接近的-一個(gè)被特殊化的為養(yǎng)護(hù)和檢測在橋之下擴(kuò)充的升降運(yùn)送車。</p><p>　　因?yàn)樾崩瓨虻母叨热菀走^分的大,工程師發(fā)現(xiàn)使用計(jì)算機(jī)來計(jì)算在各種不同的荷載狀態(tài)下構(gòu)件的力學(xué)狀態(tài)非常是必需的。Larsa,由Larsa公司發(fā)展的結(jié)構(gòu)分析程序，在梅爾維爾、紐約被用于設(shè)計(jì)。線性分析可以完成對活載、風(fēng)荷載和溫度荷載的分析；非線性分析可以完成對靜載、鋼絲繩替換和鋼絲繩損失的分析; 電動(dòng)的分

73、析可以用于地震載荷被的分析和為各種形狀的特征值的以及對風(fēng)荷載頻率的計(jì)算;和一個(gè)有限之物- 原赤分析為樓板梁應(yīng)力分布被運(yùn)行。PIGLET---由澳大利亞西方大學(xué)發(fā)展用于處理三個(gè)尺度的土壤結(jié)構(gòu)互相作用--用來計(jì)算彎曲力矩和橋的力在那鉆軸。在結(jié)構(gòu)分析中除了用計(jì)算機(jī)工具外,工程師對工程還對工程假定的告知設(shè)計(jì)給予重視。他們也訓(xùn)練了在開始線進(jìn)量數(shù)據(jù)的精度上的一個(gè)鋒利的眼神,盡可能簡單的保存計(jì)算者模型減輕數(shù)據(jù)確認(rèn)方法。</p><

74、p>　　因?yàn)榇罂缍鹊臍怏w力學(xué)的穩(wěn)度橋總是需要特別的關(guān)心,所以工程師設(shè)計(jì)了A字形塔和錨墩組合達(dá)成最好的剛度當(dāng)與一個(gè)活動(dòng)的上部結(jié)構(gòu)連接時(shí),因此而逐漸增加氣體力學(xué)的穩(wěn)定性。使用比例為1:60斷面的模型, Rowan Williams Davies &Irwin, Inc. 一個(gè)在Guelph安大略省的工程商議公司,在一個(gè)風(fēng)道測試了橋的氣體力學(xué)的穩(wěn)定性。 這個(gè)試驗(yàn)測量了靜止的風(fēng)力和力矩系數(shù)。 其結(jié)果依下列各項(xiàng)為:</p>

75、;<p>　　1. 設(shè)計(jì)的風(fēng)速實(shí)質(zhì)上低于被測試的顫振速率, 這意味著該橋被設(shè)計(jì)能抵抗較高風(fēng)速的風(fēng)力(顫振是一個(gè)自動(dòng)的意義興奮氣體力學(xué)的不穩(wěn)定性能增加到非常大的振幅由于扭轉(zhuǎn)的或垂直的動(dòng)態(tài).) 橋已經(jīng)被設(shè)計(jì)到抵抗 56 米每秒的風(fēng)速, 一個(gè)平均每10000年才會出現(xiàn)一次的風(fēng)力。</p><p>　　2. 橋的平臺能承受以 25 m/s流出的旋渦的振動(dòng)。 尖峰平臺加速度被發(fā)現(xiàn)比在 1980年往前被 ASC

76、E'S 的委員會比準(zhǔn)許規(guī)范《橋上的負(fù)荷和力》凝結(jié)更低。</p><p>　　3. 橋能抵抗沖擊--一個(gè)亂砌由不穩(wěn)定風(fēng)所引起載入從亂流出現(xiàn)的振動(dòng)。特別地,試驗(yàn)顯示橋能夠抵抗一個(gè)以100年為重現(xiàn)期間風(fēng)載重分。</p><p>　　對S-N線路的 Chao Phraya 河川橋所需要的混凝土，預(yù)應(yīng)力鋼筋，主料和 HDPE 管將會在當(dāng)?shù)厣a(chǎn)。只有鋼絲繩錨這種唯一特殊的材料將會從外面引進(jìn) 。

77、</p><p>　　橋的建設(shè)在八月開始并且預(yù)計(jì)在2007年初完成, 為嚴(yán)重的交通問題提供一個(gè)必須的解決途徑并且構(gòu)成熙熙攘攘的亞洲大都市的一大亮景。</p><p>　　這種樁，長40米和直徑為3米, 從在水位上面的插入砂質(zhì)河底之內(nèi)。這個(gè)基礎(chǔ)系統(tǒng)因?yàn)殇摌兜膫?cè)方勁度和強(qiáng)度被考慮所以比混凝土打樁效果更好。關(guān)于進(jìn)入在樁底經(jīng)由壓力薄漿注入改良橋的勁性可能性之內(nèi)研究被引導(dǎo)。然而, 因?yàn)檫@一個(gè)方法在相

78、似的情形中沒有被應(yīng)用而且因?yàn)椴僮鞯奈ｋU(xiǎn)被認(rèn)為嚴(yán)格的,這種方法在增加樁的深度被廣泛應(yīng)用。</p><p>　　預(yù)制混凝土沉箱為25米或者10米安裝在在每個(gè)碼頭定線之前的樁上。 樁和沉箱之間的剛接通過把投混凝土浸水面下。 樁的設(shè)計(jì)和彎曲聯(lián)接由結(jié)構(gòu)在水平面上3米的一個(gè)30 MN 船碰撞而且允許在軌道不超過80毫米一個(gè)橫的變位來控制。一旦樁被安裝而且封閉,沉箱被抽干。 因?yàn)樘讱さ捻斒窃谒幌旅?0.5 m ，所以保有踢腳

79、的暫時(shí)水被保留，而且空心的套殼然后用混凝土澆注。</p><p>　　在每個(gè)箱子的頂面處都會安裝一個(gè)空心的矩形垂直的直井。 這個(gè)直井的寬度沿著高度自橋中央7米漸變到橋尾。 該直井楣包含錨由橋支承,因此這種直井的安置需要比較準(zhǔn)確公差不超出10 毫米。 每個(gè)直井的最高平面處,測量值僅為5米或6米，其中包括在邊緣處垂直的支承空間、使橋升高的千斤頂、水平支承和中央水平較低的橋面板上的供檢測的距離。</p>

80、<p>　　平臺安裝時(shí)的所允許的垂直公差不能超過±15毫米, 大約是跨度中的 1/7000?？紤]到跨度的長度 , 該梁是的跨度上復(fù)式的連續(xù)梁，并且結(jié)構(gòu)的組成性質(zhì),雖然事實(shí)證明這個(gè)標(biāo)準(zhǔn)很難的達(dá)到。在和軌條主管當(dāng)局的請教中可接受的公差增加到±40毫米。</p><p>　　對于小村莊區(qū)間, 除了小的細(xì)節(jié)以外,也都是提前安裝,但是這里六包括六個(gè)部分。 這些零配件被制作的時(shí)候所允許的最大公差

81、是5±毫米。既然橋址是位于二個(gè)已存在的橋之間，要被傳送的零配件的高度被限制到已存在的結(jié)構(gòu)垂直的凈空之內(nèi)。 因此10.5 米高的槌打區(qū)間在他們的直立位置中不被傳送而在他們的側(cè)面。因此在小村莊區(qū)間上，混凝土板不需要提前安裝。</p><p>　　因?yàn)榱熊嚨乃俾士赡艹^ 300 km/h , 所以這個(gè)工程也含了對叉道兩端的引橋結(jié)構(gòu)的設(shè)計(jì)和建造,這種引橋在河川的中央中必須能夠?yàn)樵诹熊囋跇虻捻斣趯υ谄骄Ｆ矫嫔厦?/p>

82、的 20 m 的在橋隧道北方的平均海平面下面來自 20 m提供一個(gè)光滑軌道.準(zhǔn)線有一個(gè) 2.5% 的最大斜坡并且有 15 km 的一個(gè)水平的曲率半徑。 在橋的南端引橋用在平均海平面下面在 3 m 的一個(gè)水平儀跑過開拓地的軌道連接橋。</p><p>　　Ruchu Hsu ，P.E.M.ASCE,是紐約市的一個(gè)公司監(jiān)督結(jié)構(gòu)工程師。 這篇文章在第 21 年刊國際的橋會議上刊載, 發(fā)生在匹茲堡2004.6.12-16