土木工程橋梁外文翻譯--跨越世紀(jì)之橋

1、<p><b>　　中文4735字</b></p><p><b>　　畢業(yè)設(shè)計(jì)</b></p><p><b>　　外文翻譯</b></p><p>　　題 目 跨 越 世 紀(jì) 之 橋</p><p>　　專 業(yè) 土木工程（橋梁） </p&g

2、t;<p><b>　　2011年6月</b></p><p>　　A Bridge For All Centuries</p><p>　　An extremely long-and record setting-main span was designed for the second bridge to across the Panama Cana

3、l in order to meet the owner’s requirement that no piers be placed in the water.Because no disruption of canal traffic was permitted at any time,the cable-stayed bridge of cast-in-place cancrete was carefully constructed

4、 using the balanced-cantilever method.</p><p>　　In 1962 ,the Bridge of Americas(Puente de las America) opened to traffic,serving as the only fixed link across the Panama Canal .The bridge was designed to car

5、ry 60,000 vehicles per day on four lanes, but it has beenoperating above its capacity for many years.Toalleviate bottlenecks on the route that the bridge carries over the canal-the Pan-American Highway(Inter-American Hig

6、hway)-and promotegrowth on the western side of Panama,the country’s Ministry of Public Works(Ministerio de Obras Publicas</p><p>　　In 200 the MOP invited international bridge design firms to compete for the

7、design of the crossing, requesting a two-package proposal:one techinical, the other financial. A total of eight proposals were received by December 2000 from established bridge design firms all over the world. After shor

8、t-listing three firms on the basis of the technical merits of their proposals, the MOP selected T.Y.Lin International, of San Francisco, to prepare the bridge design and provide field construction support</p><

9、p>　　The Centennial Bridge desige process was unique and aggressive,incorporating concepts from the traditional design/build/bid method, the design/build method , and the sa-called fast-track design process.To complete

10、 the construction on time-that is ,within just 27 months-the design of the bridge was carried out to a level of 30 percent before construction bidding began, in December 2001.The selected contractor-the Wiesbaden,Germany

11、,office of Bilfinger Berger,AG-was brought on board immediately aft</p><p>　　The design selected by the client features two single-mast towers,each supporting two sets of stay cables that align in one vertic

12、al plane.Concrete was used to construct both the towers and the box girder deck,as well as the approach structures.</p><p>　　The MOP , in conjunction with the Panama Canal Authority,established the following

13、 requirements for the bridge design :</p><p>　　A 420m,the minimum length for the main span to accommodate the recently widened Gaillard Cut,a narrow portion of the canal crossing the Continental Divide that

14、was straightened and widened to 275m in 2002;</p><p>　　A navigational envelope consisting of 80m of vertical clearance and 70m of horizontal clearance to accommodate the safe passage of a crane of World War

15、11 vintage-a gift from the U.S.government that is used by the Panama Canal Authority to maintain the canal gates and facilities;</p><p>　　A roadway wide enough to carry six lanes of traffic, three in each di

16、rection;</p><p>　　A deck able to accommodate a 1.5m wide pedestrian walkway;</p><p>　　A design that would adhere to the American Association of State Highway and Transportation Official standar

17、d for a 100-year service life and offer HS-25 truck loading;</p><p>　　A structure that could carry two 0.6m dianeter water lines;</p><p>　　A construction method that would not cross the canal at

18、 any time or interrupt canal operationa in any way.</p><p>　　Because of the bridge’s long main span and the potential for strong seismic activity in the area,no single building code covered all aspects of th

19、e project.Therefore the team from T.Y. Lin International determinded which portions of several standard bridge specifications were applicable and which were not.The following design codes were used in developing the desi

20、gn criteria for the bridge，it is standard specifications for highway bridge ,16th ed,1996</p><p>　　It was paramount that the towers of the cable-stayed structucture be erected on land to avoid potential ship

21、 collision and the need to construct expensive deep foundation in water. However, geological maps and boring logs produced during the preliminary design phrase revealed that the east and west banks of the canal, where th

22、e towers were to be located, featured vastly different geologicaland soil conditions. On the east side of the canal, beneath shallow layers of overburden that rangs in cons</p><p>　　Before a detailed design

23、of the foundationa could be developed,a thorough analysis of the seismic hazards at the site was required,The design seismic load for the project was developed on the basis of a probabilistic seismic hazard assessment th

24、at considered the conditions at the site.Such an assessment establishes the return period for a given earthquake and the corresponding intensity of ground shaking in the horizontal directtion in terms of an acceleration

25、response spectrum.The PSHA determin</p><p>　　The 7.7MW NPDB event was used as the safety evluation earthquake,that is,the maximum earthquake that could strike without putting the bridge out of service.The da

26、mage to the bridge would be minor but would require some closures of the bridge.The 6.5MWRio Gatun Fault event was used as the foundational evaluation earthquake,a lower-level temblor that would cause minimal damage to t

27、he bridge and would not require closures.For the FEE load case,the SEE loading was scaled back by two-thirds.The FEE i</p><p>　　Because of uncertainty about the direction from which the seismic waves would a

28、pproach the site, a single response spectrum-a curve showing the mathematically computed maximum response of a set of simple damped harmonic oscillators of different natural frequencies to a particular earthquake ground

29、acceleration-was used to characterize mitions in two mutually orthogonal directions in the horizontal plane.To conduct a time-history analysis of the bridge’s multiple supports,a set of synthetic motio</p><p&g

30、t;　　A time delay estimate-that is,an estimate of the time it would take for the motions generated by the SEEand FEE earthquakes to travel from one point to the next-was create using the assumed seismic wave velocity and

31、the distance between the piers of the bridge.Using an assumed was velocity of approximately 2.5km/s,a delay on the order of half a second to a second is appropriate for a bridge 1 to 2km long.</p><p>　　Soil-

32、foundation interaction studies were performed to determine the stiffness of the soil and foundation as well as the seismic excitation measurement that would be used in the dynamic analyses.The studieswere conducted by me

33、ans of soil-pile models using linear and nonlinear soil layera of varying depths.The equivalent pile lengths in the studies-that is, the lengths representing the portions of a given pile that would actually be affected b

34、y a given earthquake-induced ground motion-ranged from2</p><p>　　Once the above analyses were completed,the T.Y.Lin International engineers-taking into consideration the project requirements developedby the

35、owener-evaluated several different concrete cable-stayed designs.A number of structural systems were investigated,the main variables,superstructure cross sections,and the varying support conditions described above.</p

36、><p>　　The requirement that the evevation of the deck be quite high strongly influenced the tower configuration.For the proposed deck elevation of more than 80m,the most economical tower shapes included single-

37、and dual-mast towers as well as “goal post”towers-that is,a design in which the two masts would be linked to each other by crossbeams.</p><p>　　Ultimately the engineers designd the bridge to be 34.3m wide wi

38、th a 420mlong cable-stayd main span,two 200mlong side spans-one on each side of the main span-and approach structures at the ends of the side spans.On the east side there is one 46m long concrete approach structure,while

39、 on the west side there are three,measuring 60,60,and 66m,for a total bridge length of 1,052m.The side spans are supported by four piers,referred to,from west to east,as P1.P2,P3,and P4.</p><p>　　The bridge

40、deck is a continuous single-cell box girder from abutment to abutment; the expansion joints are located at the abutments only. Deck movements on the order of 400 mm are expected at these modular expansion joints Multidir

41、ectional pot bearings are used at the piers and at the abutments to accommodate these movements.</p><p>　　The deck was fixed to the two towers to facilitate the balanced-cantilever method of construction and

42、 to provide torsional rigidity and lateral restraint to the deck.. Transverse live loads, seismic loads, and wind loads are proportionally distributed to the towers and the piers by the fixity of the deck to the towers a

43、nd by reinforced-concrete shear keys located at the top of P1, P3, and P4. The deck is allowed to move longitudinally over the abutments and piers. The longitudinal, seismic, live</p><p>　　As previously ment

44、ioned, the presence of competent basalt on the east side of the site meant that shallow foundations could be used there; in particular, spread footings were designed for the east tower, the east approach structure, and t

45、he east abutment. The west tower, the west approach structure, and the western piers (P2 and P3), however, had to be founded deep within the Cucaracha Formation. A total of 48 cast-in-drilled-hole (CIDH) shafts with 2 m

46、outer diameters and lengths ranging from 2</p><p>　　A minimum amount of transverse steel had to be determined for use in the plastic regions of the shaft-that is, those at the top one-eighth of eighth of eac

47、h shaft and within the shaft caps, which would absorb the highest seismic demands. Once this amount was determined, it was used as the minimum for areas of the shafts above their points of fixity where large lateral disp

48、lacements were expected to occur. The locations of the transverse steel were then established by following code requirements </p><p>　　Even though thief foundation designs differed, the towers themselves wer

49、e designed to be identical. Each measures 185.5 m from the top of its pile cap and is designed as a hollow reinforced-concrete shaft with a truncated elliptical cross section (see figure opposite). Each tower’s width in

50、plan varies along its height, narrowing uniformly from 9.5 m at the base of the tower to 6 m at the top. In the longitudinal direction, each pylon tapers from 9.5 m at the base to about 8 m right below the de</p>

51、<p>　　The towers were designed in a accordance with the latest provisions of the ATC earthquake design manual mentioned previously (ATC-32). Owing to the portal frame action along the bridge’s longitudinal axis, spe

52、cial seismic detailing was implemented in regions with the potential to develop plastic hinges in the event of seismic activity-specifically, just below the deck and above the footing. Special confining forces and altern

53、ating open stirrups-with 90 and 135 degree hooks-within the perimeter o</p><p>　　In the transverse direction, the tower behaves like a cantilever, requiring concrete-confining steel at its base. Special atte

54、ntion was needed at the joint between the tower and the deck because of the central-plane stay-cable arrangement, it was necessary to provide sufficient torsional stiffness and special detailing at the pier-to-deck inter

55、section. This intersection is highly congested with vertical reinforcing steel, the closely spaced confining stirrups of the tower shaft, and the deck pre</p><p>　　The approach structures on either side of t

56、he main span are supported on hollow reinforced-concrete piers that measure 8.28 by 5 m in plan. The design and detailing of the piers are consistent with the latest versions of the ATC and AASHTO specifications for seis

57、mic design. Capacity design concepts were applied to the design of the piers. This approach required the use of seismic modeling with moment curvature elements to capture the inelastic behavior of elements during seismic

58、 excitation. Push</p><p>　　The deck of the cable-stayed main span is composed of single-cell box girders of cast-in-place concrete with internal, inclined steel struts and transverse posttensioned ribs, or s

59、tiffening beams, toward the tops. Each box girder segment is 4.5 m deep and 6 m long. To facilitate construction and enhance the bridge’s elegant design, similar sizes were used for the other bridge spans. An integral co

60、ncrete overlay with a thickness of 350 mm was installed instead of an applied concrete overlay on th</p><p>　　A total of 128 stay cables were used, the largest comprising 83 monostrands. All cables with a le

61、ngth of more than 80 m were equipped at their lower ends with internal hydraulic dampers. Corrosion protection for the monostrands involved galvanization of the wires through hot dipping, a tight high-density polyethylen

62、e (HDPE) sheath extruded onto each strand, and a special type of petroleum wax that fills all of the voids between the wires.</p><p>　　The stays are spaecd every 6 m and are arranged in a fan pattern.They ar

63、e designed to be stressed from the tower only and are anchored in line with a continuous stiffening beam at the centerline of the deck.The deck anchorage system is actually a composite steel frame that encapsulates two c

64、ontinous steel plates that anchor the stays and transfer the stay forces in a continuous and repetitive system-via shear studs-throuthout the extent of the cable-supported deck (see figure above).A steel fram</p>

65、<p>　　In addition to the geotechnical and seismic analyses,several structural analyses were performed to accurately capture the behavior of this complex bridge.</p><p>　　For the service-load analysis,wh

66、ich includes live,temperature,and wind loads,the engineers used SAP2000, a computer program created and maintained by Computers &Structrures,Inc.(CSI), of Berkeley, California.This program was selected for its abilit

67、y to easily model the service loads and to account for tridimensional effects.For correct SAP2000 modeling, it was necessary to define a set of initial stresses on the cables, deck, and tower elements to capture the stat

68、e of the structure at the end of</p><p>　　The seismic analysis of the structure was conducted using the SADSAP structural analysis program, also a CSI product, based on the differences in seismic motions tha

69、t will be experienced at the different piers based on their distance from one another.This sophisticated program has the capability to model inelastic behavior in that flexural plastic hinges can readily be simulated.Pla

70、stic hinge elements were modeled at varous locations along the structure where the results from a preliminary respo</p><p>　　As previously mentioned,the construction contractor was brought on board early in

71、the process;the company’s bid of $93 million was accepted and the project was awarded in March 2002.To guarantee unimpeded canal traffic,the bridge had to be constructed without the use of the canal waters.To accomplish

72、this, the cast-in-place main-pain superstructure was erected using the balanced-cantilever method.Form travelers were used to accomplish this, and they were designed in such a way that they could be</p><p>　

73、　To save time, the towers approach structure, and piers were built simultaneously.The approach viaducts were designed and built using the span-by-span erection method by means of an underslung suupport truss.The east via

74、duct span was built first and the support truss was then removed and transferred to the west side so that it could be used to build the three spans of the west viaduct, one span at a time.</p><p>　　The bridg

75、e construction was completeed in Auguse 2004 at a cost of approximately $2,780 per square meter.Its opening awaits the completion of the rest of the highway it serves.</p><p><b>　　跨越世紀(jì)之橋</b></

76、p><p>　　1962年，橫跨巴拿馬運(yùn)河的美國(guó)大橋作為僅有的固定連接開放交通車。當(dāng)初設(shè)計(jì)這座橋時(shí)4個(gè)車道的日交通量為60000輛，但是那么多年來(lái)他一直在“過(guò)載”中運(yùn)行。為了減輕大橋線路的平靜問(wèn)題，促進(jìn)巴拿馬西部地區(qū)的發(fā)展，國(guó)家公共工作部決定修建一個(gè)新的高速公路系統(tǒng)。用于聯(lián)系位于運(yùn)河?xùn)|部的巴拿馬城北部地區(qū)和運(yùn)河西部。百年大橋（為紀(jì)念巴拿馬人民獨(dú)立100周年而命名）已經(jīng)開始修建。等他對(duì)外開放那時(shí)將有6個(gè)車道，這種預(yù)應(yīng)力

77、混凝土斜拉橋的主跨為420m，是西半球此種類型橋梁中跨徑最大的。</p><p>　　2000年，MOP邀請(qǐng)國(guó)際橋梁設(shè)計(jì)公司競(jìng)爭(zhēng)設(shè)計(jì)此橋，有兩方面要求：一是技術(shù)，二是投資。2000年12月，MOP總共收到了來(lái)自全球各地橋梁設(shè)計(jì)公司的8個(gè)方案。在技術(shù)優(yōu)勢(shì)上列出了三個(gè)侯選公司后，MOP最終選擇了舊金山的T.Y.Lin設(shè)計(jì)橋梁，提供修建場(chǎng)地，依靠該公司的財(cái)政實(shí)力。</p><p>　　百年大橋的

78、設(shè)計(jì)是史上無(wú)前例的，是氣勢(shì)宏偉的，是傳統(tǒng)設(shè)計(jì)方法與所謂的快進(jìn)度設(shè)計(jì)方法的結(jié)合。為了能在27個(gè)月內(nèi)及時(shí)完成工程，在2001年12月施工開始前的設(shè)計(jì)工作的30%得進(jìn)展順利才行。選擇的承包商—法國(guó)的Wiesbanden在被MOP相中后立即簽訂了合同。因此，橋梁設(shè)計(jì)的完成與施工聯(lián)系在一起，整個(gè)工序類似于設(shè)計(jì)—修建。</p><p>　　被選中的設(shè)計(jì)以兩個(gè)獨(dú)立的塔柱為特色，每一個(gè)塔柱支撐著兩組輻射式的纜索。塔柱、縱梁以及一

79、些聯(lián)系結(jié)構(gòu)都由混凝土制作。</p><p>　　MOP聯(lián)同巴拿馬運(yùn)河當(dāng)局就大橋的設(shè)計(jì)提出了如下要求：</p><p>　　主跨長(zhǎng)度不得小于420m，能適應(yīng)最近加寬的Gaillard Cut—運(yùn)河的一小部分，橫跨Continental Divide，2002年被修補(bǔ)過(guò)并加寬到了275m。</p><p>　　為了容納第二次世界大戰(zhàn)汽車的一個(gè)起重機(jī)使用了一個(gè)垂直凈長(zhǎng)為8

80、0m，水平凈長(zhǎng)為70m的導(dǎo)航用支架。它是英國(guó)政府送給巴拿馬運(yùn)河當(dāng)局用來(lái)維修運(yùn)河大門及其設(shè)備的。</p><p>　　車行道要足夠?qū)挘苋菁{6個(gè)車道。每個(gè)方向3車道。</p><p>　　路緣能容納1.5m寬的人行道。</p><p>　　設(shè)計(jì)應(yīng)遵循美國(guó)各洲公路與運(yùn)輸工作者協(xié)會(huì)（ASHTO）關(guān)于公路100年工作壽命和H-25卡車荷載的標(biāo)準(zhǔn)。</p>&l

81、t;p>　　一個(gè)結(jié)構(gòu)要有2個(gè)直徑為0.6m瀉水管。</p><p>　　施工方法不能妨礙運(yùn)河的正常工作，不管何時(shí)、用什么方法。</p><p>　　由于橋跨過(guò)長(zhǎng)以及該地區(qū)較強(qiáng)的地震活動(dòng)，沒有哪部建設(shè)法則能涵蓋此項(xiàng)工程的所有方面。因此T.Y.Lin國(guó)際確定了橋梁規(guī)范標(biāo)準(zhǔn)的那些部分可用，那些不可用。下列設(shè)計(jì)標(biāo)準(zhǔn)被用來(lái)作為此橋的設(shè)計(jì)標(biāo)準(zhǔn)。</p><p>　　纜索的

82、塔柱結(jié)構(gòu)必須建在避免偶然的輪船沖擊力，還需要在水中修建深基礎(chǔ)，這兩方面是最重要的。然而，在初步設(shè)計(jì)階段進(jìn)行的地質(zhì)勘測(cè)和鉆孔取樣表明運(yùn)河?xùn)|部和西部堤岸的地質(zhì)和土壤條件很不一樣，也就是塔柱坐落處。運(yùn)河的東面，在過(guò)載的淺水區(qū)土層（堅(jiān)硬度軟到硬）下面有一大塊中硬到堅(jiān)硬連接緊密的玄武巖。工程師認(rèn)為在橋這邊的玄武巖能夠提供修建塔柱和墩臺(tái)及其他結(jié)構(gòu)的平臺(tái)。然而運(yùn)河西面地質(zhì)是臭名昭著的Cucaracha結(jié)構(gòu)，也就是頁(yè)巖粘土混雜砂巖、玄武巖和灰，很容易造

83、成崩塌、滑坡。作為地下基層Cucaracha結(jié)構(gòu)是相當(dāng)穩(wěn)定的，但是一旦暴露極易腐蝕風(fēng)化。因此工程師認(rèn)為西面踏柱、墩臺(tái)及其相關(guān)結(jié)構(gòu)應(yīng)需修建伸基礎(chǔ)。</p><p>　　在制度基礎(chǔ)的詳細(xì)設(shè)計(jì)方案之前，需要對(duì)該位置的地震危險(xiǎn)性作一個(gè)全面的分析。工程的地震荷載設(shè)計(jì)是基于考慮到該位置的可能地震危險(xiǎn)估計(jì)（PSHA）。這個(gè)估計(jì)確定了地震和對(duì)應(yīng)的地面震動(dòng)在水平方向的往返時(shí)間。PSHA總結(jié)了兩個(gè)主要震動(dòng)來(lái)說(shuō)：一個(gè)是Rio Gatu

84、n Fault，能產(chǎn)生6.5Mw的震級(jí)。</p><p>　　7.7Mw的NPDB震級(jí)被作為地震時(shí)的安全系數(shù)，也就是說(shuō)即使最大震級(jí)作用也不會(huì)對(duì)橋的運(yùn)作造成不良影響，對(duì)橋的損害很小不過(guò)會(huì)造成一些裂縫。6.5Mw的Rio Gatun Fault震級(jí)被作為地震時(shí)的，一個(gè)微小的地震運(yùn)動(dòng)只對(duì)橋造成及小的損害不會(huì)產(chǎn)生裂紋。如果FEE荷載已知，SEE荷載就是它的1/3，假設(shè)FEE有一個(gè)最大加速度，即0.21g一個(gè)循環(huán)周期（50

85、0年）。此加速度有可能被超越，50年增加10%，100年增加18%，同樣假設(shè)SEE也有一個(gè)最大加速度，即0.33g一個(gè)循環(huán)周期（2500年），它也有可能增大，50年增加2%，100年增加4%。</p><p>　　由于接近該位置的地震波來(lái)說(shuō)方向確定性，所以用單個(gè)反應(yīng)范圍（一條曲線顯示一批簡(jiǎn)易、潮濕、協(xié)調(diào)震動(dòng)器的不同固有頻率與個(gè)別地震加速度的統(tǒng)計(jì)規(guī)律）來(lái)描述水平面上兩個(gè)相互垂直的運(yùn)動(dòng)的特征。為了研究分析橋梁雙重支撐

86、的耐久性（縱向、橫向、豎向）組成的綜合運(yùn)動(dòng)，需要借助反復(fù)工藝過(guò)程。以及一系列由三方面因素延遲時(shí)間估計(jì)，即該段估計(jì)時(shí)間被認(rèn)為是由SEE和FEE地震產(chǎn)生的運(yùn)動(dòng)從一個(gè)點(diǎn)傳到下一個(gè)點(diǎn)的時(shí)間假設(shè)地震波速度和塔柱之間的距離計(jì)算得到。波速大約為2.5㎞/s，延遲時(shí)間為0.5s～s，這對(duì)1～2㎞長(zhǎng)的橋梁是最合適的。</p><p>　　土基相互作用研究用來(lái)確定土壤和基礎(chǔ)的硬度，以及地震刺激測(cè)量在動(dòng)力學(xué)分析上的應(yīng)用。這些研究通過(guò)土

87、壤不同深度的淺性堆積和非淺性堆積研究來(lái)實(shí)現(xiàn)。研究中的等植堆積長(zhǎng)度，此長(zhǎng)代表堆積層長(zhǎng)度的一部分受地震運(yùn)動(dòng)的影響，一般為2～10m。在這樣一個(gè)三畏空間模型中，土壤通過(guò)其硬度可從6個(gè)方向限制土體的運(yùn)動(dòng)（三方向的軸向力和三方向的扭轉(zhuǎn)彎距）。因?yàn)闃蛩谖恢冒S多不同土壤類型的土層，因此每一層需要用不同的硬度模量來(lái)表示然后進(jìn)行分析。</p><p>　　一旦以上的分析完成，T.Y國(guó)際公司的工程師考慮到該工程負(fù)責(zé)人的要求對(duì)幾

88、個(gè)不同的混凝土斜拉索設(shè)計(jì)進(jìn)行評(píng)估對(duì)此。很多結(jié)構(gòu)系統(tǒng)需檢查，包括主要的可變因素，如塔的結(jié)構(gòu)、斜索的構(gòu)造、橋跨的設(shè)計(jì)、上層結(jié)構(gòu)的交叉段以上述結(jié)構(gòu)的支撐情況。</p><p>　　橋面的提升對(duì)塔結(jié)構(gòu)有非常重要的影響。提案要求至少把橋面板提升80m，最經(jīng)濟(jì)的塔的構(gòu)造包括各自獨(dú)立的雙桿塔，也就是說(shuō)，兩桿將通過(guò)交叉鋼束相互連接。工程負(fù)責(zé)人后選擇了單桿塔，因?yàn)檫@樣設(shè)計(jì)施工簡(jiǎn)便，可運(yùn)作、簡(jiǎn)單又不失優(yōu)雅。</p>&

89、lt;p>　　最后工程師設(shè)計(jì)出了一座：寬34.3m，主跨420m長(zhǎng)的斜索橋，兩個(gè)200m長(zhǎng)的邊跨位于主跨的兩端，連接結(jié)構(gòu)在邊跨的末端。東端的混凝土連接構(gòu)造長(zhǎng)420m，而西端有3個(gè)，長(zhǎng)分別為60m，60m和66m,所以橋的全長(zhǎng)為1052m，橋的邊跨由4個(gè)橋墩支撐，至西向東為P1，P2，P3和P4。</p><p>　　橋的主梁從橋臺(tái)是一個(gè)連續(xù)的箱形絎架，并且只在支座處設(shè)置伸縮縫。這些標(biāo)準(zhǔn)化的伸縮縫允許橋面板有

90、400mm的伸縮風(fēng)4。多方位的弧形軸承用在墩位和支座上以適應(yīng)其運(yùn)動(dòng)。</p><p>　　把橋面板安裝在兩塔柱上以便懸臂法施工，并且提供橋面板的扭轉(zhuǎn)剛度和冊(cè)向約束。橫向的荷載和風(fēng)載通過(guò)塔柱以及位于P1，P2，P3和P4頂部的鋼筋混凝土剪力索被部分地分散。支座和塔柱處的橋面板允許在縱向活動(dòng)?？v向荷載、地震荷載、活載以及溫度荷載被稱為所熟悉的網(wǎng)絡(luò)框架結(jié)構(gòu)行為吸收、分散。通過(guò)塔柱和橋面板形成的接口，很像建筑物結(jié)構(gòu)的門，

91、它與兩塔柱的相對(duì)硬度互成比例地運(yùn)作。</p><p>　　如前面提到過(guò)的東西地區(qū)玄武的存在意味著此處需要淺層基礎(chǔ)。特別是東西塔柱、連接結(jié)構(gòu)和墩臺(tái)需要深扎于Cucaracha結(jié)構(gòu)中。這就需要一些外徑為2m，長(zhǎng)度為25～35m的鉆孔（CIDH）轉(zhuǎn)動(dòng)軸。用彎距分析來(lái)確定在不同數(shù)量的縱向增強(qiáng)鋼筋作用下動(dòng)軸的工作性能。結(jié)果不符合要求，基于這些結(jié)果工程師決定轉(zhuǎn)動(dòng)軸中的縱向鋼筋應(yīng)力混凝土數(shù)量的1%?？v向鋼筋的布置應(yīng)滿足以下規(guī)范

92、要求，考慮承包商優(yōu)先選擇的CIDH柱施工的限制。</p><p>　　傳動(dòng)軸塑性區(qū)域的最少橫向鋼筋數(shù)被確定，因?yàn)槊總€(gè)傳動(dòng)軸距頂端1/8處和所有傳動(dòng)軸頂部吸收了最強(qiáng)的地需要作用。一旦這個(gè)數(shù)目被決定，他就被用來(lái)作為滯后位移發(fā)生的最小區(qū)域。橫向鋼筋的布置遵循以下規(guī)范，并考慮CIDH柱施工的局限。橫向鋼筋呈螺旋布置。</p><p>　　然而它們被設(shè)計(jì)成不同的作用，索塔被設(shè)計(jì)成完全相同的。每個(gè)都放

93、在距墩帽185.5m的高處，被設(shè)計(jì)成中的預(yù)應(yīng)力砼結(jié)構(gòu)，一個(gè)被截去頂端的橢圓形受力面積。每個(gè)索塔的寬度從它的高度上變化很大，在底部都是9.5m，在塔頂是6m。在縱橋向上，從塔底部的9.5m到拱上建筑標(biāo)高處恰好寬度為8m，且矢高為87m。在橋面建筑標(biāo)高以上的塔部分寬度從4.6m變到塔頂?shù)?.5m。每個(gè)索塔兩側(cè)都帶有4m寬的人行道。這種設(shè)計(jì)上的挑戰(zhàn)需要細(xì)節(jié)上的小心謹(jǐn)慎。</p><p>　　索塔被設(shè)計(jì)的應(yīng)用了先進(jìn)的AT

94、C抗震技術(shù)。在沿縱向橋的方向上，特殊的細(xì)部結(jié)構(gòu)和區(qū)域被設(shè)計(jì)為塑料的，特別是橋面建筑下部和拱圈上部。特殊的鋼材被應(yīng)用到塔的拐角處，在這些地方有較高的應(yīng)力，需要90°和135°的鉤子鉤住。</p><p>　　在縱向橋上，撓的性能就像一個(gè)懸臂，需要在其下部鋼筋。特別要注意塔和橋面相接觸。因?yàn)樵谒虚g設(shè)置的懸索，它會(huì)提供足夠的抗扭鋼度和特殊的墩和橋面的連接是很有必要的。這些交叉的地方?jīng)]有豎向預(yù)應(yīng)力鋼

95、筋，并且設(shè)置在距塔的中性軸較近的地方，橋面構(gòu)造也要設(shè)置預(yù)應(yīng)力。</p><p>　　主跨兩邊的結(jié)構(gòu)是支撐在一個(gè)8.28m×5m的中空的預(yù)應(yīng)力砼的橋墩上。橋墩的設(shè)計(jì)和細(xì)部構(gòu)造是與ATC和AASHTO的具體結(jié)構(gòu)相一致的。允許承載能力應(yīng)用到設(shè)計(jì)中。這種方法需要一種模型，此模型的構(gòu)造件的性能反應(yīng)墩的性能。分析橋墩的邊縣形式來(lái)計(jì)算承載力并且與時(shí)程分析進(jìn)行比較。這樣來(lái)保證墩的承載作用（這是一種用特征分析的方法來(lái)標(biāo)承

96、載力的）。在這些地方提供鋼筋砼是有必要的，這些地方與基礎(chǔ)表現(xiàn)出所希望的形式。</p><p>　　橋面建筑的用懸索拉起的主跨是由整體澆注的單獨(dú)的箱梁組成的，包括鋼筋，肋板、梁、并向塔高的方向。每個(gè)箱梁件是4.2m高，6m長(zhǎng)。為了更易建筑和增加橋梁設(shè)計(jì)的簡(jiǎn)潔；在其它的路徑采用了相似的尺寸。橋上鋪的是整體的砼350mm，并不是直接在橋面上澆注的。與整體澆注相比，它是沿架設(shè)的箱梁澆注的，碾壓設(shè)備被應(yīng)用來(lái)獲得平整度的路面

97、。最小的碾壓厚度為5mm。</p><p>　　共用到了128根懸索，最大的一個(gè)是由83根鋼鉸線組成。所有大于80m長(zhǎng)度的索用器具設(shè)在塔頂?shù)哪┒恕?duì)鋼鉸線的保護(hù)包括對(duì)于進(jìn)行扭處理，及張拉，和一種特殊的材用充滿數(shù)根鋼鉸線之間。</p><p>　　每隔6m設(shè)置懸索并且是成對(duì)設(shè)置的。它們通過(guò)用連續(xù)梁在中性軸上錨固并在塔中間直線拉起。橋面錨固系統(tǒng)是由鋼架組成的，這個(gè)鋼架由兩個(gè)連續(xù)的橋面板組成錨固

98、懸索。鋼架被設(shè)計(jì)成通過(guò)縱向橋的橋面轉(zhuǎn)移水平力，并且通過(guò)整體的鋼結(jié)構(gòu)轉(zhuǎn)移豎向力。這種創(chuàng)新的簡(jiǎn)潔的荷載轉(zhuǎn)移系統(tǒng)使橋面建筑的恫結(jié)構(gòu)快速建筑，有可能的話，三到五天就能循環(huán)一次。</p><p>　　另外，由地質(zhì)技術(shù)的分析，一些結(jié)構(gòu)分析能精確的表現(xiàn)復(fù)雜橋梁的整體狀況。為了估計(jì)人行道和這種長(zhǎng)期效應(yīng)作用下的鋼筋松弛，一種被稱為TANGO的計(jì)算機(jī)程序被應(yīng)用，它由這篇文章的作者發(fā)展的，現(xiàn)在已被提供。這個(gè)程序被成功的應(yīng)用到40座懸索