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The Arup Journal

ISSUE 1


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2 The Arup Journal 1/2011

Arup engineered one of thelargest roofs in the worldto create column-freespaces for the platforms atBeijing South station.

Contents

3 Beijing South railway station

Tristram Carfrae, Vincent Cheng,Liu Di, Goman Ho, Eric Kwong,

Barry Lau, Eric Lau, Mingchun Luo,William Ng, Jane Nixon, Bibo Shi,Timothy Suen, Alex To, Colin Wade

30 The oceans as a driver of change

Elizabeth Jackson

42 Palmas Altas Campus, Seville, Spain

Pablo Checa, Mark Chown,Alejandro Fernndez,Ignacio Fernndez, Marta Figueruelo,Matas Garca, Enrique Gonzlez,Karsten Jurkait, Ramn Rodrguez

60 Scotstoun House redevelopment,

South Queensferry, Scotland

Douglas Wylie

66 Kurilpa Bridge, Brisbane

Ian Ainsworth, Kathy Franklin1.


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Beijing South railway station

Beijing is one of the worlds oldest cities.It was planned as a hierarchy, with theEmperors Forbidden City at the hub, and

progressive outer concentric rings basedon the cardinal points. Intersecting roadslead to a fairly rigid north-south/east-westplanning grid.

Beijing South, one of the capitals six majorrail stations (the others are Beijing Main,Beijing North, Beijing West, Hepingu, andGuangammen), lies between the second andthird ring roads in Fengtai district (Fig 2),

some 0.5km from the old station that itsupersedes. The new station is containedwithin one of these square grids on 94ha

of gazetted railway land, occupied byexisting tracks on a diagonal south-west/north-east axis, some 6km south of theForbidden City.

Beijing South station (BSS) also lies roughly3km south-west of the Temple of Heavencomplex, the proximity of which was to havea bearing on the visual appearance of themain canopy roofs.

AuthorsTristram Carfrae Vincent Cheng Liu Di Goman Ho Eric Kwong Barry Lau Eric LauMingchun Luo William Ng Jane Nixon Bibo Shi Timothy Suen Alex To Colin Wad

LocationBeijing, China

Introduction Awards

Royal Institute of British Architects (RIBA)International Award 2009

American Institute of Architects (AIA) Hong KChapter Merit Award for Architecture 2009

British Construction Industry Award (BCIA)International Finalist 2009

World Architecture News (WAN) Urban DesigAwards Finalist 2009.


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*The Hong Kong section known as the XRL (Express RailHong Kong government-funded 26km wholly undergrounproject, currently under construction with a planned compof 2015. Arup has been involved from the beginning, comfeasibility study in 2007 with further commissions won in 22009 for the preliminary and detailed design of the tunnelsstabling depot.

Side canopy roofs Central hall

Beijing National Stadium Boeing

1

2

3

Beijing South station

Hall for Prayer for a Good

Beijing National Stadium

Airport

Beijing South station

Hall for Prayer for a Good

Beijing National Stadium

Airport

1

2

3

4

1 (Previous page). Beijing Southstation complete, June 2009.

2. Location of Beijing South stationwithin the citys planning grid.

3. Overall station plan, withBeijing National Stadium forcomparison.

4. The Hall for Prayer forGood Harvest at the Temple ofHeaven complex.

2.

3.

4.

BSS is immense, one of Chinas (and Asias)largest railway stations, with a total grossoor area of 144 190m2. It caters forsuburban trains within greater Beijing,regular-speed trains to numerous mainlandcities, two underground mass transit lines(4 and 14), and high-speed trains to other

cities as far south as Guangzhou and thenceto Hong Kong*. Accommodating 450mhigh-speed and 550m suburban trains,the roof covers some 125 000m2Beijing National Stadium1would be easilycontained within the footprint (Fig 3).

An elevated road encloses the centralcheck-in and departure hall (which canaccommodate a peak of 6500 passengers)and serves as the arrivals and drop-off routefor road transport. Beneath, at street level,are 11 island and two side platforms giving24 platform edges, designed for a passengerthroughput reaching almost 105M per yearby 2030, equating to daily ows of 286 500and peak hourly ows of 33 280 passengers.Flexibility in the overall planning allows forincreased peak ows at festivals such asChinese New Year and Golden Week.

Beneath the platform zone at the rstbasement level is the interchange hall,catering for some 87 000 people per daytransferring to other transport modes suchas taxis, buses and private cars. There are52 taxi pick-up and drop-off bays with138 queuing spaces, 38 bus bays with 48queuing spaces, and a 909-space car park.

Below again are the two mass transit lines,each with a 120m long island platformarrangement skewed to the at-graderailway lines.

To provide a multi-modal transport servicein time for the 2008 Beijing Olympics,in October 2003 the Chinese GovernmentsMinistry of Railways (MoR) announced aninternational competition to redevelop thesite, an initiative aimed at bringing a modernavour to this very important addition to the

capitals railway infrastructure. Terry Farrell& Partners, now TFP Farrells (TFP), wasinvited by the Third Survey Design Institute(TSDI) from Tianjin to collaborate for athree-month competition period. TSDI/TFPsstation layout resolved the conict of thesquare/diagonal axis by covering theplatforms with a large low-rise domed roofsome 400m in diameter.

In March 2004, the TSDI/TFP team wasplaced rst out of ve international designrms and then short-listed with two otherdesign teams to advance to a second stagecompetition. This commenced in May 2004

and TSDI/TFPs roof was revised to anoverall elliptical shape, split into two halvesby a 100m wide glazed central section.Submitted in July 2004, this scheme wonrst prize but received comments andsuggested design renements from the MoR,requiring TSDI/TFP to incorporate furthertraditional Chinese architectural motifs,expressed in a contemporary manner.

The resulting roof silhouette was inspired bythe tiered roofs of the Hall for Prayer for aGood Harvest in the Temple of Heavencomplex (Fig 4), built during the reign ofEmperor Zhengtong (1436-1449). Elevated

on three white marble circular terraces, thetemple has a triple set of conical roofs over around building a form unique in Chinesearchitecture. This new roof shape for BSSgained MoR approval, and TSDI/TFP setabout the challenging task of preparing theoverall station design for rapid completion intime for the 2008 Olympics.

Background/competition


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In early 2005 TFP and Arup had initialdiscussions about collaborating on aspectsof the Beijing South station structure andinternal environment. Arups catalogue oflarge-span complex roofs, particularly forsports venues, stretches back for decades,but extremely long spans over rail stations

are relatively rare in the rms portfolio.The opportunity to collaborate on thisproject, particularly the roof, was quicklytaken up, while commercial negotiationstook place between TFP, TSDI, and Arup.

Initially, Arups remit was for the structural,mechanical, electrical, and public health(SMEP) engineering design of specicareas (track level, concourse, and roof)up to the preliminary design stage, witha design review and checking roleduring construction.

This scope of work developed to include

other disciplines and involvement onbuilding physics, re, and wind engineering,and Arup formed a multidisciplinary team ofengineers from its railway, re, buildingphysics, and MEP groups in Hong Kong.

After three months intensive designco-ordination, the international design teamproduced the initial scheme report, detailingthe consolidated architectural conceptsupported with sound engineering ideas anddetails for the specic constraints identiedfor this project.

In January 2006, with TSDI as the lead

consultant, Arup was formallycommissioned for:

preliminary and detailed design of thestructure for the canopy roofs

performance-based re engineering

special studies for various buildingphysics topics.

The rms Sydney and Beijing ofces werethen involved in rening respectively thestructural scheme and the detailed designworkload for the follow-on work period.The preliminary design was approved in

April 2006 and the detailed designdeliverables for the canopy roofs wereissued in September 2006.

Acoustic design for large-volume majorrailway transport hubs has been a challengein China, as local designers are not familiarwith it, and standards have not been fullydeveloped to cover large volume buildingssuch as BSS. As a result, Arup was furthercommissioned by TSDI in October 2006 foracoustic design input.

MoRs design and construction programmewas very aggressive, with 12 months for

the total design, site start in mid-2005,and anticipated completion originally inearly 2008.

The groundbreaking ceremony was held on8 July 2005 with piling commencingimmediately, and after only three years sitework, BSS was formally openedon 1 August 2008.

5. Architectural cross-section ofthe station design, August 2006.

6. With a metallic ribbed cladding,this shape and surface wasintended to reect the design of theroofs of the Hall for Prayer for a

Good Harvest.

5.

6.

Arups involvement


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Pullingforce

Forcediagram

Overturningmoment

Hanging ofdraped cable

Reaction

Support

Reactions

0.000

Loading

CableTension

7.

8.

a) b) c)

Canopy roofs either sid

of the central hallDevelopment of the original concepStructurally, TSDI initially conceivedcanopy roofs, which have a combineof 71 000m2, as using long-span tapetriangular trusses tilted to gain the roHowever, with long spans up to 85mneed for a tapering prole, this form structurally inefcient unless additioncolumns were introduced to reduce thspans. This was difcult due to thejuxtaposition of platforms and tracksthe roof truss orientations.

The TFP and Arup teams met in Honin April 2005 to scheme ideas for theThese ranged from more rigid and resmaller-span gridded options throughmore free-form larger-span ideas usinsupport trees and fabric. None provedparticularly satisfying and neither wecapable of realising the Temple of Hmotif as envisaged by TFP.

Extending and extrapolating the ideaothers is nothing new in the elds ofmedicine, science, industry, engineerarchitecture, even art, and so it was wcanopy roof. A chance reference at a

Arup design meeting resulted in furthinvestigation of ideas developed by ofor an exhibition hall at Hannover Facompleted in 1996 a series of drapeabove a space measuring some 220m110m. While the Hannover project wmuch smaller and covered a purelyrectangular space, the concept wasimmediately applicable here, as the droof could be varied in span to cope woval shape and the potentially irregulcolumn support grid (Fig 7).

Scheming proceeded along these linedesigns developed through spring an

summer 2005 (Fig 8). An initial schecomprised spans up to 75m parallel tplatforms, using the concept of steel at some 3m-3.5m spacing, acting as tequivalent of draped cables spanningbetween collector trusses in the sameas the roof. The collector trusses carrcable forces onto tall braced steelA-frames at 20.6m centres across the

When Arup was rst introduced to the project,

TSDI/TFP had conceptualised the roof to follow theTemple of Heaven motif. This kept the overall ovalshape, split into two halves by the separate large-spanat-topped roof over the central departure hall area,with each half reecting the Temple of Heavensilhouette by being made up of three long-spanseparate roofs with tilted planes. With a metallicribbed cladding, this shape and surface was intendedto reect the blue glazed tiled conical roofs of theHall for Prayer for a Good Harvest.

The challenge of the roofs


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between the rail tracks, with stability fromdeep trusses spanning between eachA-frame, forming a continuous portal framestructure. The A-frames comprised box

section legs fabricated from steel plate.The A-frame geometry varied dependingon the height and span each was supporting:initially the largest was 34m tall and 14mwide at its base, the smallest a mere 23mtall and 8m at its base (Fig 9).

Structural systemThe initial concept described above for theroof span was similar to a stressed ribbonstructure. Such a simple and elegantgeometry is very effective at resistingdownward loading, with the load beingresisted by tension in the catenary.However, the single curvature of the roof

means that a different philosophy isrequired to resist uplift and pattern loads.

Due to the lightweight nature of such aconcept, under upward loading the dead loadtension in the catenary member is usuallyovercome and the catenery is no longereffective in resisting the loads. On otherprojects such a problem has been overcomeby adding mass to the roof so that an overall

uplift on it is never generated, ie addingsuperimposed dead load so that the deadload is greater than any wind uplift loading.However, in this situation the catenary

member then has to be over-designed totake this additional loading, leading to aheavier solution. Also in such a system theresulting cable forces are larger and hencehave a corresponding knock-on effect to thecollector trusses, A-frames, and foundations.

To resist such uplift and pattern loads onthe BSS roof, an innovative scheme wasdeveloped whereby the draped steel plateswere replaced with draped I-beams.These have exural stiffness andconsequently are able to act as an arch andresist the upward loading in compression.During this process, spans were optimised

and rened within the elliptical roof outlineto a maximum of 65m at the centre,reducing to as little as 22m between theperimeter A-frames.

23m

7m 10m x-x 1:200 13.5m

28m 27m

34m

20m to

datum

75m57.5m

7. Simple structural modelof roof concept.

8. Initial scheme developmea) & b) TFP sketches, Marchc) Arup sketch April 2005.

9. Arup scheme design, sum2005.

10. Sketch by Tristram CarfArup from the November 20design review. The use of wto counteract uplift due to wthe draped roof shape is avoresulting in a draped roof sycomprising a series of parallI-section beams braced by inrods from the A-frames.

11. Part plan showing bracinthe roof plane.

12. Structural model of half canopy roof.

9. 12.

11.10.


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Axial Force, F

750k

650

35

0-400

-500

-650

-750

14.

13.

15.

13. Completed roof over platforms.

14. Typical section of the canopy roof,showing stabilising splaying cables.

15. Member forces and deection ofcatenary with: a) 1kPa downward roofloading, b) 1kPa upward roof loading.

c) I-beam catenary without cable stays,starting to sway buckle at a lowercompression load (approximately0.5kPa upward roof loading).As indicated, the pink dot on the archmoves laterally as the arch buckles.The cables prevent this lateralmovement, increasing the archscompression capacity.

a)

b)

c)


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The roof is formed mainly from 600mmdeep x 350mm wide I-beams with a 1:10drape (Fig 13). Over a 65m span, the exural

stiffness of such an I-beam is very small,and so under downward loading the memberacts just like a catenary cable, using itsaxial stiffness to resist the vertical load.However, the exural stiffness does allowthe catenary to act like an arch underupward loading. The arching behaviour ismaximised, with the minimum exuralstiffness of the member, by the in-planeand out-of-plane bracing.

The in-plane bracing of the I-beam archis provided by splaying cables from theA-frames to the underside of the roof

(Fig 14). They are notcable stays and do notdirectly resist the upward load, but simplyprovide increased stability for the arch.When an arch starts to buckle, it wants tomove sideways, but such cables prevent thesideways movement and prevent the archfrom buckling (Fig 15a-c). As these cablesare not being used as tie down cables,their diameter can be reduced to 22mm,minimising the visual impact and not

affecting the architectural aspiration to a clear line of ceiling/space.

Diamond-shaped elements in the plane roof provide out-of-plane bracing to theI-beam arch. This diamond-shaped bracset out so that the minor axis buckling a

major axis buckling occur at the same lThree I-beams are braced together (Figleaving every third bay clear of bracingskylights. Purlins supporting the roofsheeting and members supporting theskylight material running across thecatenary beams further brace the I-beamand ensure that the roof acts as a wholeunder lateral loads, thereby addingredundancy to the system.

The structure was analysed at scheme susing Arups GSA non-linear GsRelaxprogram so that the catenary shape andbehaviour were modelled accurately,resisting the loads efciently. The roof investigated under preliminary wind loauniform and patterned, as well as possibpatterned snow loads, and it was foundthe lightweight draped I-beams effectivresisted the various applied loads.

The weight of the roof structure in atraditional truss solution would be arou75kg/m, but with the braced catenary sto resist the upward, downward andpatterned loads, the draped I-beam soluis approximately 37kg/m for the drapebeams and roong.

The catenary beams are connected backthe A-frames by outrigger arms (Fig 17The deep, stiff A-frames resist the laterearthquake loading, while a portal framformed by the A-frames, outriggers, andconnecting horizontal beam is used to rthe lateral and earthquake load in theperpendicular direction, even though thload is in the weak direction of the A-fr

Altogether 94 A-frames support the entcanopy roof. The tallest is 31.6m with awidth of 13.1m, while the shortest is 18tall and 7.5m wide.

Because of the size and geometry of theroof, it was split into three separatestructures. The breaks in the roof are inwith movement joints in the structure bground level, allowing for independentthermal movements as well as seismicmovements (Fig 18).

16.

16. Perspective of a typical section ofthe canopy roof.

17. Outrigger at A-frame.

18. Plan view of half the canopy roof,indicating location of movement joints.

17.

Movementjoints

18.


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22.

20.

21.

19. Wind tunnel test model.

20. 3-D analytical models.

21, 22. Stability systems forA-frames supporting three catenaries.

Detailed design

Wind/snow engineeringDuring scheme design, approximate wloads were estimated using other simshapes covered in various internationcodes. However, due to the lightweig

nature and unique geometry of this roa boundary layer wind tunnel study wcarried out by Tongii University of Cassess the structural and cladding preAs wind tunnel test results are requirthe formal Expert Panel Review apprprocess in China, Arup was asked to the liaison with a wind laboratory to out the wind tunnel test (Fig 19).

The cladding pressures over the roof measured simultaneously on both theand lower surfaces, and were assessepeak differential pressures occurring simultaneously. The highest peak pre

and suctions were used in the design.Roof wind loading was derived from tunnel measurements using load effecanalysis to assess the structural wind relevant to the design of the roof stru

Due to the unusual shape it is possiblsnow could drift and build up at lowepositions, so a combined boundary lawind tunnel and numerical modellingwas also carried out to estimate the snloading relevant to the roof design.This gave an assessment of design snload distributions, accounting for balaunbalanced, drift and accumulated sn

loads and sliding snow loads for thestation roof.

AnalysisDynamic loading and response of thewere also investigated under the applloads. Because the roof is relatively lweight, the period of the structure is sensitive to the mass on the roof.Two models were therefore built so acapture the upper and lower bound vaunder seismic loading. The seismic mthe rst model was taken as the charavalue of dead and superimposed deadand the second model was assumed todead and superimposed dead load pluof the characteristic snow load. The vseismic effect of the roof and cantilevtaken as 10% of the standard gravity value in accordance with code requirThe design was also veried by consivertical seismic spectrum analysis.

19.


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24.

23.

23. Connection details.

24. Roof over the platforms unconstruction.

A 3-D model was built for the canopy roofsuperstructure, using SAP2000and MIDASfor cross-checking under all the standardChinese code load requirements (Fig 20).

Beijing is located in a high seismicity zone,with PGA equalling 0.07, 0.2g and 0.4g for

50 years, 475 years, and 2475 years returnperiod respectively. Because of thegeometry, standard response spectrumanalysis was applied to the elastic model.In addition, two sets of natural and one set ofarticial tri-directional time history recordswere computed to validate the results ofresponse spectrum analysis. As alreadydescribed, this was applied to the twoseismic dead load cases. Earthquake load inboth cases was applied in 15 increments toreview the structural performance and coverthe worst case. The analysis results indicatedthat the structure is controlled by wind load.

The light and slender roof structure wassusceptible to buckling, and so the globalstability was checked, taking intoconsideration geometric non-linearity, toobtain the relationship between load factorand displacement as required by the Chinesetechnical specication for latticed shells2.Similarly, the stability of every A-framesupporting three catenaries was alsochecked (Fig 21).

As the main load-bearing members,the A-frames are carrying high compressionloads. The catenary beams are also undercompression when uplift windload acts onthem. The stability of each member waschecked and found to meet the Chinesecodes requirement on the basis of the

effective length obtained by both GSAandNIDAsoftware.

Due to the importance of the project, as wellas the unique structural system and complexshape of the building, the approval authorityheld separate expert panel review meetingsat the preliminary design stage and theconstruction design stage. The Arup teamsuccessfully presented the scheme andobtained construction approval for this newstructural system in China.

DetailingAn X-Steelmodel of the entire irregularly-shaped roof structure, including all theconnection details, was also built, so as to:

(1) determine the impact and intersectionlines of members running into each other

(2) check the connecting plates, stiffenersand welding, and

(3) satisfy the architectural design intent ofall visual connection details (Fig 23).


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Central hall roof

StatisticsThis roof is on a grand scale both in pand height. It covers a total area of ar54 000m2, including the entire 50 000departure hall, is some 350m longperpendicular to the platforms and amaximum of 190m wide, and overhahalls perimeter wall. A central glazedskylight extends the whole length andsome 25% of the total area. The roof a shallow dome in both directions froheight of 20m above the departure hato 40m at the centre.

Design developmentAs with the canopy roofs, this centralunderwent design development with during summer 2005. Initial schemesfrom sloping regular Warren trussed othrough to bowstring arches withcombinations of four or ve rows ofsupports, some with tree-like column

26.

25.


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As a foil to the draped roof of the side

canopies, a curved roof naturally suggesteditself, as opposed to the at roof solutionproposed at the early competition stage.To reect the grand scale, it was felt thatthere should be minimal columns, resultingin a 20.6m grid across the station as for theA-frames of the canopy roof, with four rowsof columns in the direction of the platforms.

Both TSDI and TFP felt, however, that thesecolumns should reect the A-frame motif,so instead of being simple vertical membersthey were initially all given an inwards rakeof up to 15 to the vertical. A total of 60columns support the roof.

Structural model

With a central width of 190m a large-spanstructure was inevitable, but it had to be aslight as possible to avoid overloading thesubstructure for which piling was alreadyunder way. Column locations were dictatedby the substructure grid, and this led to rowsof four columns initially with feet on avariable grid parallel to the platforms,giving spans of some 40.5m, 67.5m, and40.5m. The remaining edge zone is thelarge overhang (almost 21m) which partlycovers the surrounding perimeter road anddrop-off laybys.

The plan layout of the roof structure ties inwith the overall movement joint layout ofthe main building substructure. In each ofthe orthogonal directions, two movementjoints were introduced to split the buildinginto nine smaller oor plates so as to dealwith the temperature expansion andcompression of the structural memberson the departure hall oor plate.

Achieving these spans economically was

only possible with the use of steel, and sothey were conceived as sets of centralskylight beams spanning simply supportedbetween slightly extended tips of shapedportal frames formed with a gentlycurved sloping roof and inclinedcolumns (Fig 27).

Structural form

The initial architectural concept was to formthe main skylight beams as members taperedin section and elevation, but as this would bedifcult with normal rolled steel sections,Arups preferred solution was trussedmembers using simple straight rolled

sections that could be clad to form thetapered shapes.

The side portals were similarly conceived,using box trusses for the roof beams andtapered trusses for the inclined columns(Figs 27, 28). Again, these were assumed tobe clad. A possible exposed pinned footdetail was sketched as an idea to accentuatethe stations engineered nature again as afoil to the canopy A-frames, which adoptvisible connections (Fig 29).

28.

29.

27.

25. The complete central hall roof.

26. Initial structural concept forcentral hall roof.

27. Elevation and plan at roof level.

28. Arup-proposed structure for theside portals.

29. Arup-proposed pinned footing forthe side portals.


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The built form

Arups ideas were not initially acceptedby TSDI, and some of the designdevelopment went though several iterationswithout further input. However, after somecost analysis, Arups trussed memberconcept was adopted for the main side

portals (Fig 30).

Some adjustment in setting-out resulted inonly the inner columns having the 15 rake,with the outer ones being vertical. With up to6m cantilevers beyond the raking columns,the central skylight beams span some 40m.

The featured pinned feet detail for the portalframes was covered by cladding (Fig 31),but the 21m edge cantilever has remainedand forms a dramatic overhang to theperimeter access road around thedeparture hall.

30.

32.

31.


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Construction stage

Superstructure construction began inmid-2006, and during this Arup alsoprovided a design liaison service to:

carry out site walks and make sure thedesign intent was fully understood andproperly implemented by the contractor

answer major queries from the contractoron design intent

revise and develop typical connectiondetails as required when the steelworkcontractor developed his shop drawings

resolve interface issues with otherdesigners and contractors when thecontractors shop drawings weredeveloped, and the design of otherpackages such as the curtain wallingand the roong were developedduring construction.

Arup designers from Hong Kong, togetherwith local engineers from the mainlandChina ofces, visited the site regularly to

help answer queries in the initialconstruction stage. After a few months,it became possible for minor queries to beanswered quickly face-to-face or by phonecalls. Generally, construction ran verysmoothly within the extremely tighttimeframe. The entire superstructureconstruction took approximately two yearsbefore the opening of the Olympic Games.

Substructure

On the same building footprint, and beneathmuch of the canopy roofs and departure hall,is a large basement containing plant, carparking, back-of-house, and ancillary areas.

Basement 1 level is a transfer concourse forpassengers between the long-distance trainsat ground level and the metro lines M4 andM14 at basement levels 2 and 3 respectively.

The basement structure is a waterproofconcrete box on a concrete raft foundation.In some places where concentrated columnloads or substantial uplift loads due to windwould be expected, cast in situ bored pileswere used.

Arup was responsible for the detailed designof the canopy roof structures, which, fromtop to bottom, include the roof catenary

structure, A-frames above ground level, insitu concrete wall panels directly supportingthe A-frames within the basement levels, andtheir piled foundations. This designdemarcation was to ensure that the canopyroof design between superstructure andsubstructure was fully compatible, thoughthere were design interface issueshorizontally between the in situ concretewall panels and other elements in thebasement designed by TSDI. These interfaceissues were carefully checked and co-ordinated in the design liaison processduring construction, as already discussed.

Arups collaboration with TSDI alsoincluded advice on train loads and loadpatterns for the platform/track level supportstructure, and trackway issues.

Train loadingDesign loads were derived from normalplatform loads as well as from the rollingstock, using data supplied by TSDI.The structural framework at track level is atwo-way grid of reinforced concrete mainframing beams supported on reinforcedconcrete columns. A set of load patterns wasderived for various train congurationsacross the structure (ie at right angles to the

platforms) with different load factors, so asto arrive at maximum bending moments,shears, and axial column loads.

Longitudinally (ie in the direction of theplatforms), generic enveloped loads wereindicated to represent rolling loads of atypical train set. Part of the issue here was toadvise whether it was necessary to carry out

30. Inclined, tapered truss forside portal, before cladding,April 2008.

31. Pinned foot for side portal,before cladding, April 2008.

32. The platform roof dwarfs atrain beneath.

33 (overleaf). Inner portion ofplatform canopy roof, adjacent to theelevated perimeter road around thecentral departure hall.

2-D or even 3-D analysis to arrive atmaximum values. The team concluded given the scale of the basement structurthe effective restraint from the surround

soil, an overall 3-D analysis which wohave been very cumbersome and time-consuming was unnecessary. Even anoverall 2-D analysis was felt to be toounwieldy, and Arups recommendation carry out only local 2-D modelling wasincluded in the technical report to TSD

Trackway issuesAdvising on the practical considerationof trackway drainage, waterproong,vibration, and temperature variation(ie cold bridging effects) was an interesexercise. To minimisedrainage penetrations into areas under

the trackways, it was suggested to contathe drainage above the structure, transfit to catchpits, and then drain beneathaccessible areas under the platforms.

Waterproong was conceived as a memwith a concrete protection mat under thtrack support, while structure-bornevibration effects were solved by adoptinoating track slab design commonly ussuspended railways in Hong Kong,particularly where an air-rights developis supported by the railway structure.

As the platforms are effectively in the o

air, there is a tendency in Beijings extrcold winter months for the cold-bridge to be an issue, as the basement areas bethe trackway will be much warmer. Plaan insulation layer directly above the sustructure was seen to be of most beneteither by using an insulating material orintroducing a void of still air within a dslab structural system.

All these issues were discussed andillustrated with generic solutions in atechnical report, and used by TSDI in itnal detailed design.


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MEP/building physics

Sustainable station designArups Hong Kong building physics groupconducted a series of specialist studies for asustainable design, including dynamic

thermal simulation; annual energy analysis;CFD simulation and analysis of thedeparture hall for air-conditioning design;design of a combined heat and power (CHP)system; nancial analysis of the CHPsystem, district heating and cooling system;outdoor air quality analysis of the elevatedperimeter road underneath the central roof;and a photovoltaic (PV) system.

In addition, the energy efciency of theHVAC system, and economic andenvironmental protection issues, were takeninto consideration in the specialist study anddesign. The result achieved improved

effectiveness in the HVAC systemperformance, energy cost savings, and greenpower generation.

Energy simulation and analysis ofheating and air-conditioning demandThe building envelope of the roofstructure comprises composite aluminumsheets coupled with insulation, a high-intensity, tough, and decorative materialchosen for both sustainable and aestheticreasons. The design considerations for thebuilding envelope, such as solar heat gain,shading, and thermal comfort of passengersin the departure hall, were established by

integrated environmental simulation (IES)analysis (Fig 34).

This was done in order to review the overallthermal performance and mandatory Chinesedesign code compliance in accordance withthe mainland design standard for energyefciency of public buildings3.

Operation and control strategyfor HVAC systemThe thermal environment, ietemperature and humidity for theentire BSS, was predicted throughdynamic thermal simulation modelling.

Energy-efcient operation and controlof the HVAC system was developedand annual energy simulation andanalysis determined in various operationmodes (summer, winter and transitionseasons) for the detailed design review onannual energy consumption and itsoperational and maintenance cost.

CFD simulation and analysisof the departure hall for theair-conditioning designThe architectural design intent forthe departure hall was to give users aspacious and pleasant indoor environsheltered from intense heat, wind and

To achieve energy conservation, astratication methodology for the airconditioning supply system was usedsimulated and validated with CFD anto maintain acceptable indoorenvironmental conditions.

Successful implementation of thisstratication methodology requires cplanning planning for the indoor airdistribution by the air-conditioning syIts performance is also subject to pasows in the departure hall, local climconditions, and the design parameterbuilding envelope in terms of the ovethermal performance of the station.Comprehensive data on the resultant environment and prediction of userperception of the space were also reqfor detailed study and analysis. The ato predict, using computer simulationlikely summer environmental conditithe large departure hall space, takingconsideration local heat gains, includsolar and non-solar sources and thesurrounding environment (Figs 35, 3

34.

36.

Temperature(C)

27.0

26.0

25.0

24.0

23.0

22.0

21.0

20.0

35.


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Arups building physics team conducted aseries of precise and comprehensiveanalyses of materials selection, enhancementof indoor environment, resources, andenergy. Based on this, a cost-effectivesolution was developed for the overallsystem design of BSS to provide a

sustainable green building: a pleasantindoor environment for railway operations,with energy conservation, but withoutsacricing user comfort.

Perimeter road air qualityConsiderable trafc is anticipated on theelevated perimeter road around the departurehall and it was considered essential toexamine the outdoor air quality throughanalysing relevant emission of vehicleexhaust pollutants.

To achieve a sustainable air quality solution,trafc information was gathered for theultimate design year for various vehicletrafc ows, vehicle types, and vehicleemissions, noting the ratio of petrol anddiesel vehicles. The building physics teamthen reviewed the estimated pollutant levelsfrom vehicle exhausts at both short andlong-term peak-hour trafc ows. CFD wasused (Fig 37) to simulate the exhaustpollutants, with the aim of achievingChinese design code compliance for ambientair quality standards with acceptableconcentration levels of nitrogen dioxide andcarbon monoxide.

Sustainable energy: the CHP systemCombined heat and power (CHP), alsoknown as co-generation, is the name appliedto processes which, from a single fuelsupply, simultaneously generate heat andelectrical power. CHP uses either a gasturbine or gas-red engine to drive anelectrical generator and makes practical useof the heat that is an inevitable by-product.This waste heat can be used for makingprocess steam and for cooling throughabsorption chillers.

The overall efciency of CHP systems canbe above 80% far better than conventional

power stations leading to considerablereductions in emissions of CO2, nitrogenoxides and sulphur dioxide. Thus CHPsystems not only increase the security ofenergy supply, but also aid environmentalprotection. The stations system (Fig 39,overleaf) is a pioneering CHP design projectto provide a sustainable energy solution.

37.

34. Integrated environmentalsimulation model.

35. CFD model of elevated departurehall and arrangement of air-conditioning poles associated withsupply air nozzles.

36. Indoor temperature distributionof elevated departure hall.

37. CFD model of station showing(a-b) arrangement of vehicles on

perimeter road; (c-d) outdoor airquality of the perimeter road.

38. The elevated perimeter roadaround the departure hall.

38.

NO/ppm

0.3000

0.2786

0.2571

0.2357

0.2143

0.1929

0.1714

0.1500

0.1286

0.1071

0.8571E-01

0.6429E-01

0.4286E-01

0.2143E-01

0.0000

a)

b)

c) d)


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District heating and cooling systemThe CHP system provides electricity,cooling in summer, and heating in winterto the station and its ancillary buildings,as well as developing the heating andchilled water piping network for a districtheating and cooling system as an

integrated energy service.

Natural gas-red internal combustionengines have been adopted for powergeneration with the ue gas used forheating and air-conditioning.

This energy-saving technology can caterfor over 45% of the overall electricitydemand of the station and its ancillarybuildings, and the energy efciency canexceed 80% with less transmission lossin the surrounding district.

The Beijing Municipal Commission ofDevelopment and the Reform andConstruction Committee have supportedapplying the CHP system in thedevelopment of a pilot project for futurestation developments.

Performance and material specicareview for PV panelsThe large roof size and the height of tdeparture hall make it very suitable fosolar power generation system, and

integrated PV panels have been instalwith the transparent glazing material large skylight area.

They were carefully integrated into thdesign early on in the process so as tomaintain the aesthetics of the roof deThese solar panel systems are costly,they may exemplify renewable energtechnology in the design developmenfuture railway stations; it is hoped thaBSS design will highlight environmeprotection and energy-saving concep

The departure hall roof integrated wi

central portion of skylight and PV paprovides 350kW total power. Duringdaytime operation, the solar powergeneration system will be the stationauxiliary plant to cope with any suppuctuations from the local grid.

30. Schematic of the CHP system.

40. PV panels are integrated withthe skylight area.

41. Numerous stairs and escalatorsconnect the large open spaces.

42. Bracing stays at the perimeter ofthe platform roof.

Flue gas

Hotwater

Chilled/hot water

Condensingwater

Gas-firedboiler

Z

Z

Coto

Absorptionchiller

Electricchiller

Fuel gas

Exhaustflue

Generator

Switchboard

Chiller

Pump

Cooling tower

Control

Power supplyfor equipment

Flue gas

Generatorcontrol panel

39.

40.


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Fire engineering

The structural and re safety design ofbuildings in China used to be based onnational codes, but the national economysrapid expansion has led to more and more

large and complex buildings, notablyairports and railway stations.

Current building codes can thus nolonger cover the whole range of design,especially for re safety. Arup confrontedmany challenges in the structural and resafety design of BSS, which exempliesperformance-based re safety design in arepresentative piece of large-scaleinfrastructure.

OverviewTall, open canopy roofs at both ends ofplatforms are connected to the departure hall

area above by numerous stairs andescalators. The departure hall is surroundedby the open elevated roadand is designed with natural-ventilationopenings on the oor on the two sides of itscentral axis. Beneath the platform zone is theinterchange for buses, two MTR lines andcars, as well as undergroundcar parks. The whole station can befunctionally characterised as spacious,well-connected, with high re loads forspecic locations, and densely populated.

Fire safetyBeijing South station is a special case, with

great challenges in trying to apply currentcodes to the re compartmentation, controlof re and smoke spread, evacuation, andactive re prevention and re-ghtingfacilities. Fortunately, the latter can beoptimised and adjusted based onperformance analysis of actual re risk.Generally speaking, a re breaking out in arailway station is rare, althoughconsequences may be disastrous if it doeshappen, with interruption of normaloperations, heavy economic loss, and severesocial impact.

A performance-based re safety design

brings into consideration all the hiddenissues that may not be covered by the currentre codes. On the one hand it ensures thesafety of both occupants and structure; onthe other, it avoids conict with thearchitectural design concept.

42.

41.


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The island

When fuels burn in a large space, the smokeand around two-thirds of the combustionheat are convected to the upper ceiling layer;re radiation is the major effect of heattransfer between fuels.

The effective ignition radius can becomputed based on the re heat release rateand the minimum heat ux required to ignitethe target fuel. The heat radiation of redescends sharply with increase in distance,so if fuels are kept far enough apart, respread will not happen even withoutsprinkler protection. Thus islands areformed, and the spaces between are calledre separation zones. The re loads of theislands have to be controlled by prohibitingthe introduction of hazardous materials.

Phased evacuationMajor transport buildings are characterisedby their large spaces and different functionallayers. Emergencies such as res do not havea direct and urgent threat to occupantsoutside the immediate incident area, so thereis no need to evacuate the whole stationsimultaneously.

Sending out an evacuation alarm and givingpriority to the evacuation of areas that havere events does not mean limiting theevacuation of the areas outside thethreatened areas. Yet these areas should besecured with proper evacuation routes andsafety exits so that the whole station can bequickly evacuated in the event of extremeout-of-control events. The process ofevacuating the emergency area rst (andonly the whole area simultaneously inextreme events) is called phased evacuation.

Evacuation distance and exit widthThe functional requirements of the stof a large transport facility may lead improper placement of stairs and exitor overlong evacuation distances, butusually compensated by open and clespaces and obvious evacuation routes

signs. In this type of building, evacuadistance is much longer than in normcommercial buildings.

Evidence shows, however, that in denpopulated public places it takes a mushorter time for individuals to get to ethan for all the occupants to pass throso lengthening does not have a signiinuence on evacuation safety (Fig 4

The exit width should match the requof relevant codes as much as possibleotherwise a performance-based methshould be applied to analyse its evacusafety by comparing the ASET (availsafe evacuation time) and RSET (reqsafe evacuation time) and thus determthe appropriateness of the exit width.When predicting RSET, the buildingoccupancy should be properly estimaand a simulation should be carried ouwhile determining the ASET in a recan be based on quantitative andqualitative methods.

The performance-basedre safety scheme

Departure hall

The departure hall has localised two-zones at the four corners for ticketingbusiness, baggage handling, and custservice, while around its central axis extensive holes providing daylight tocentral platform zone below. Overallhowever, most of the departure hall aused for public circulation, with no load except for passengers hand lugg

This means that the re risk here is loalso true for the central waiting area wthe passengers seats are mainly madenon-combustible metal. In the premiucoach waiting room, the soft furnishicombustible, resulting in a high re loThe two-storey corner zones, open tolarge space area through ticket windoand doors, have a high load of combuso the re risk here is also high.

The other functional room areas are msmaller, protected by sprinklers and spartitioned from the large space, so thrisk here is again low.

The performance-based re safety

design concept

The cabinA re cabin is formed by a re-rated roofthat oversails high re load areas withautomatic re sprinklers and smoke exhaustand re alarm systems under the roof.The cabin can help extinguish res at anearly stage and prevent smoke from enteringthe adjacent large space. There are twoforms of cabin, open and enclosed.

For the open type, re-proof walls are notrequired around the cabin that holds smoke;an enclosed cabin can be totally or partially

closed, so long as any open part can beautomatically closed in the event of re(as by a re shutter). An enclosed cabin canbe implemented in the re safety design ofcritical areas in a large space, such aslocations with a large area and a high reload, or where functional operation may beaffected by a re.

With the integration of re prevention andre-ghting methods such as mechanicalventing, automatic re spray and repartition in the cabin, re can be localisedin a large space. There is thus no need forpartitions for limiting re and smoke

spread in the large space, ensuring the freemobility of people and continuity ofstation operations.

If there is no queue at the exit,escape time = travel time.

Furthest personreaches back ofqueue in "t" seconds.

In the same "t" seconds,a nearer person moves ashort distance in the queue.

If there is a queue at the exit,escape time = queueing time ifqueueing time exceeds travel time.

43.


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Table 1. Design fires.

Location Fire scenario Design fire Fire type Fire size

Departure hall

Premium coach waiting room Fast Sprinkler controlled 1.7MW

Business centre Fast Sprinkler controlled 2.4MW

Public passage Fast No sprinklers 1.2MW

Luggage consignment Fast Sprinkler controlled 1.7MW

Platform Train fire - - 16.0MW

By this analysis, the two-storey functionalrooms in the four corners of the hall arepartitioned as re cabins; there are no repartitions for the other areas of the hall.The four high-fuel-loaded premium coachwaiting rooms are also protected as recabins, utilising re detection, sprinklers,

a mechanical exhaust system, and re-resistant structural materials. The luggageconsignments at the entrance of the hall areprotected as islands and the surroundingwide re separation zone helps prevent respread. This is unlikely to occur in theordinary seat waiting and enquiries area, dueto the low or sparse fuel loading and thepartition effect of the public passages.

Smoke control

Fire size is an important parameter inperformance design. The design re sizes ofdifferent locations in the departure hall,determined through quantitative re scenarioanalysis, are listed in Table 1.

Mechanical smoke exhaust systems areinstalled in the four soft coach waitingrooms, the ticketing area in the four two-storey auxiliary functional rooms designedas re cabins, and the business and servicecentre, with smoke exhaust volume uxes ofat least 7.1m3/s and 10.2m3/s respectively,according to the re size and required clearsmoke layer height.

44

43. Relationship between timewalking to the exit and waitinat the exit in public places.

44. The departure hall has locatwo-storey zones.


24/80


The large open space of the departure hallforms natural smoke vents with an effectiveventing area not less than 263m2, and theHVAC system on the roof as an auxiliaryventing instrument. The natural smoke ventsare opened during a re, after which clearingof the cooled smoke is accelerated by theHVAC system.

The departure halls great volume enablesit to store smoke and heat during a re,

allowing time for evacuation and re-ghting. This capability to store smokeand heat was shown by CFD simulation(Fig 45) on a disadvantageous scenario thatassumed a fast-developing 10MW re, nosmoke exhaust system, and a disabledsprinkler system.

These results showed that 11 minutes intothe re scenario, the smoke layer height was10m above the oor with a visibility of morethan 15m, implying that it was still safe atthis time, with an ASET far greater than11 minutes.

EvacuationPeople in the departure hall can evacuate tothe passenger platforms, or to the perimeterroad. Once on the platforms they can scatterto the open areas beneath the canopy roof.All gates will be kept open in a reemergency, and there will be enough exitsof sufcient width in the low walls in thewaiting area (Table 2).

Fireproong for large space steelstructureChinese codes require a minimum reproofperiod of 2 hours for the columns on theplatform, 0.5 hours for the structural

components of the canopy roof, 2.5 hoursfor the departure hall columns, and 1.5 hoursfor the structural components of thedeparture hall roof.

To meet the required safety level, thetemperature proles of the criticalcomponents were analysed by aperformance-based method. The comacceptance criteria are:

(1) The load a component or structur

resist under normal conditions is not than the combined effect of all forcesprescribed re endurance time.

(2) The reproof time of the structurecomponents under a real re and variloadings is not less than the required

(3) The highest temperatures of struccomponents in a real re do not excecritical temperatures in the prescribedlimit. Critical temperature is dened cross-section temperature of a compostructure when it reaches its stress limunder loadings and a uniform temperrise longitudinally and laterally.

Criterion (3) is taken as the controlparameter. The temperature of the trunear the skylight zone of the departurbelow 3.2m was found to exceed the level, with a safety factor of 1.5, meathat the parts below 5m need two-houprotection based on the fuels combutime. Fire protection is not required ftrusses above the departure hall, as thanalysis indicated its maximum tempto be lower than critical after 1.5 houThe steel components in the canopy r

also do not need re protection becautoo meet the safety requirement.

For the tall A-shaped canopy columnre protection was suggested for thesections below 19m to improve their Considering the re size and developa train re, it was found that ash-ovthrough the train windows will not octhe initial stage. As a train carriage tyburns for around 80 minutes, Arup pra two-hour reproof protection for thA-shaped columns.

Conclusion

The re safety design introduced sevimportant performance-based designconcepts, emphasising the rationalitysafety of the departure hall smoke costrategy, evacuation, and re protectisteel structures. Detailed analysis of tprotection of the large steel space strushowed extra re retardant coating foroof steel structures to be unnecessarThe existing design was adequate forand for appearance, and at lower cost

45.

46.

45. CFD simulation results ofthe 10MW departure hall re(10 mins).

46, 47. Structural elements of theroof are designed to meet requiredre safety levels.

48. Acoustic design areas,approaches used, and keyacoustic issues.

Table 2. Evacuation analysis result of departure hall.

Total number of people to be evacuated 9142

Total width of evacuation exit 119m

Required safe evacuation t ime (RSET) 586 secs

Acquired safe evacuation time (ASET) 7660 secs

Determinat ion of sa fe evacuation ASET > RSET


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Acoustic Design Areaswithin Scope

Architectural sound insulation

Architectural acoustics

Services noise & vibrationcontrol

Approaches of theAcoustic Design Study

Provide station acoustic designstrategy including architecturalacoustics, sound insulationand services noise & vibrationcontrol design

Make references to variousacoustic standards, comparisonand recommendation ofappropriate acoustic standards

Provide station acoustictreatments to achieve the targetacoustic design standards

Provide room acousticsdevelopment assessment andinformation to support acoustictreatment designs

Recommend PA speechintelligibility criteria and providebasic requirements for PA soundsystem design

Key AcousticDesign Issues

Architectural curtain wall soundinsulation

Roof & skylight sound insulation -control of external noise intrusion

Departure hall & platformarchitectural acoustics andreverberation time control

Platform noise transmission

Services noise & vibration control

Acoustic separation of skylightbetween platform and departurehall

Acoustic separation of plant andplant room wall sound insulation.

Acoustic design

Special acoustic design considerationsand approaches were developed, playinan important role in the station designbecause of passenger safety in relation

public address emergency broadcasts.Acoustic design helps to provide acomfortable aural environment, enhancintelligibility of PA announcements, enthat M&E services noise does not affecsurrounding environment, and that noisimpact from the environment around Bminimised (Fig 48).

Acoustic criteria

The acoustic design took into account trelevant guidance in Chinese and otherinternational standards, and combined twith local requirements to establish theacoustic design criteria for achieving

a comfortable acoustic environment(Table 3). These were developed to redureverberation time and background nois(eg railway, road trafc, services equipmactivities noise, etc) important in enhanPA intelligibility.

Several special considerations were alstaken into account in developing the accriteria, including:

design heights for reverberation timeplatform and B1 level

tolerability above the indoor ambientlevels of slightly higher intermittentintrusive noise via the glass curtain wfrom external visible noise sources

environmental noise levels accordingto the PRC standard4in the semi-openspace under the canopy roof under thno train condition

train noise levels at platforms withhigh-speed trains entering and leavinwithout platform screen doors

reverberation times for very large roovolume at departure hall level

the relatively tall height of the platforarea under the canopy roof in a semi-open space.

47.

48.

Table 3. Summary of target acoustic criteria.

Floor AreaServices noise

standard (i)

Breakout noise limits

from plantrooms (ii)

Intrusive noise limitsthrough glass curtainwall (iii)

Reverberation time at

500Hz/sec (iv)

B1

Transfer area NR50 NR5010dB NR50 + 5dB 1.6sec

Entrance area NR50 NR5010dB NR50 + 5dB 1.6sec

Plant room NR70* - - -

Office room NR40 NR4010dB NR40 + 5dB 0.7sec

Car park NR60 NR6010dB - -

Platform

Platform NR50 NR5010dB NR50 + 5dB 1.5sec

Entrance area NR50 NR5010dB NR50 + 5dB 1.5sec

VIP NR35 NR3510dB NR35 + 5dB 0.5sec

Plant room NR70* - - -

Office room NR40 NR4010dB NR40 + 5dB 0.7sec

Canopy space NR50 - 70dB(A) **


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Curved surface acoustic analysis

The departure hall roof is elliptical an

concave. Generally, a concave surfac

introduces sound focusing an undes

acoustic effect.

Acoustic focusing analysis shows tha

sources (loudspeakers) and receiver

locations (the listening zone about 1.

above oor level) should be as far as

possible from the focusing zones tominimise the detrimental acoustic in

Acoustic treatment on the suspended

acoustic ceilings below the roof and t

frames under the skylight also helps t

reduce acoustic reection.

In addition, the curtain wall is incline

slightly upwards, reecting sound to

roof where it is absorbed, again impr

the acoustics.

Canopy space acoustics

The canopy is convex, and sound dir

towards it is reected and diffused toareas. Due to the semi-open design in

space under the canopy, sound partly

through the high-level louvre window

is partly reected/diffused, escaping o

through the open sides to avoid acous

focusing or echo. An acoustic model

also constructed for the canopy area t

the acoustic analysis (Fig 52).

Glass curtain wall/roof sound insulationIn designing curtain wall/roof soundinsulation, intrusive noise is controlled towithin the established noise limits.

The main noise sources outside BSS are therailway track fan areas and surrounding

roadways. As the existing background noiselevels were not appropriate to use due tovery low road trafc, the sound insulationdesign of the curtain wall is primarily basedon analysis of trafc noise results andestimation of the representative noise ofactivities at ground level.

Trafc data from the stations own roadtrafc assessment were used to assess theexternal noise levels. Noise surveys fromlocations such as the Olympics ExhibitionCentre and Dongzhimen TransportationInterchange were used to establish thetypical environmental noise spectrum forreference analysis. Railway noise mainlydepends on the entering/leaving speed oftrains through the fan areas and wasdetermined based on US methodology5.

The combined external noise levels fromroad trafc and railway were then used todetermine the minimum sound insulationrequirements for the external faade toachieve the indoor noise criteria. Soundinsulating glass in the curtain wallspecication delivered this.

Airborne sound insulation requirements for

the metal roof and skylight were similarlydetermined and analysed, as well as rainimpact noise.

Based on statistical data over the past 30years from the Beijing Observatory, theaverage annual rainfall was determined.The thunderstorms and heavy rain commonin July and August provided the basis todetermine the maximum sound fromrainfall onto the metal roof and skylight.This must not exceed the allowable noiselimit for the departure hall, and the metalroof and skylight design provides adequatesound insulation.

The roof mainly comprises double skinaluminium panels with glass wool insulationand a double-layer glass design for theskylight areas. The waterproof layer alsoprovides damping to insulate against rainimpact noise.

The entrance doors in the departure hall can

also be sources of trafc noise intrusion.

Here, two pairs of automatic doors in

parallel for each entrance create a vestibule

to minimise external noise intrusion.

Architectural acoustic design

To cater for the huge volume of the

departure hall, Odeonacoustic modelling

was adopted for acoustic and reverberation

time analysis. Elsewhere (eg platform, B1oor), reverberation time was calculated by

the more usual Sabineprogram.

One acoustic design challenge was large

skylight and glass walls in the departure hall.

Here the acoustic treatment took the form of

suspended acoustic ceilings under the roof,

with additional treatment behind the

aluminum tube ceiling xed by metal mesh

and on parts of the beams under the skylight.

Sound absorbent material is also provided in

column louvre locations and on top of the

four two-storey corner zones.

At the B1 oor level, a suspended

aluminium metal acoustic ceiling was

designed to achieve the reverberation time

criteria. Close co-ordination with the

architects was needed to achieve the

acoustic and aesthetic requirements, and an

acoustic model was created to verify the

analysis (Fig 51).

49.


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Table 4. High speed railway reference noise source terms.

Speed (km/h) Source level dB(A) Track condition Reference location Correction

300 89.5 Straight, continuous rail, 60kg/m rail

track, concrete sleeper, ballasted,track in good condition

At 25m from track

centreline, 3.5m aboverailway track

For non-ballasted track, app

3dBA; for non-ballasted traviaduct apply 6dBA.200 82.5

Platform acoustic design treatmentMajor noise sources here include rollingstock during train arrival/departure, air-conditioning noise from condenser units,the PA system, and passengers themselves.As trains are the major noise source, acousticanalysis was based on the established trainnoise data (Table 4).

Even when trains pass non-stop throughBSS, their speed does not exceed 55kph,so controlling reverberation time is alsoimportant. Acoustic treatment for thesuspended ceilings in the platform passengerarea is in the form of perforated aluminumpanels or tubeline ceiling.

Noise separation between platform anddeparture hall and B1 oorThe ceiling space in the platform is designedfor sound absorption, helping to minimiseand reduce the impact of noise transmissionfrom platform to departure hall. Soundinsulation requirements of the skylight weredetermined based on the source-path-

receiver analysis. Double-glazing andlaminated glass was designed for theskylight to achieve the noise criteria.Between the central portion of the platformand departure hall, there are a number ofstair and escalator openings through whichnoise can travel. Glass enclosures weredesigned for these openings to providethe screening effect during train arrivalsand departures.

Plantroom sound insulation designBreakout noise from the plantrooms iscontrolled primarily by acoustic walls adoors, rated STC (Sound TransmissionClass) 40-55. STC rating depends on thacoustic sensitivity of the adjacent roomAt locations near noise sensitive areas, sound insulation requirements are highThree types of acoustic walls weredeveloped for the project to achieve therequirements: Type 1: STC55; Type 2:STC45-50; and Type 3: STC40.

Services noise and vibration controlServices in the building include air-hanunits, ventilation shafts and fans, waterpumps, the air-conditioning system,escalators, generators, etc, all of whichgenerate noise. Major structure-borne nemanates from water pumps, lift machirooms, etc. Acoustic analysis, based onguidelines inBS EN 12354-4:20007andUS ASHRAE Handbook8, was conductdetermine the attenuation requirementscompliance with the indoor acoustic cri

Analysis was based on source sound polevel, reverberation time, distanceattenuation, and acoustic reection.

52. Odeonacoustic model ray tracingdiagram: departure hall.

53. Odeonacoustic model ray tracingdiagram: inner canopy space.

54 (overleaf). The complete BeijingSouth station and its fans of railtracks to the east and west.

49. Acoustic treatment to thesuspended ceiling.

50. Acoustic treatment on thesuspended acoustic ceilings belowthe roof and the frames under theskylight also helps to reduce acousticreection.

51. Aluminium perforated panelscontrol reverberation abovethe platforms.

50.

52.

51.

53.


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Apart from the technical challenges faced bythe designers, project co-ordination was onethe most complicated and difcult tasks,heightened by combinations of thefollowing factors:

The international design team of TFPand Arup was involved in the project

alongside the TSDI designers, andtime-consuming effort was needed toachieve mutual understanding.

Cultural backgrounds were different some common construction practices inHong Kong are not applicable in mainlandChina, and vice versa.

Some designers in the international designteam could not speak Putonghua andmost local engineers in the LDI could notspeak English.

The international design team was mainlyresident in Hong Kong while the LDI wasin both Tianjin and Beijing.

Measures to mitigate and solve thesechallenges included:

extensive use of electronic communicationincluding e-mail, teleconference and ftp(le transfer protocol)

all correspondence from the internationalteam in both English and Chinese

frequent ights by designers fromHong Kong or elsewhere to Tianjin orBeijing for face-to-face meetings as andwhen required

in the critical stages, some key designersresident in Tainjin or Beijing for longer,eg three months, to make sure issues weredealt with in a timely manner

key designers retained through the entiredesign period

involvement of bi-lingual projectco-ordinators throughout

meetings and workshops as necessary toalign all objectives.

Completing this project from a designcompetition nally won in autumn 20opening in August 2008 was a tremenachievement for all concerned. The pdesign rms TSDI, TFP, and Arup collaborated with the common aim toone of the best railway stations in theArup staff in ofces from Beijing, Ho

Kong, Shanghai, and Sydney workedtogether to achieve the multidisciplinengineering of this hugely ambitious design. In addition the contractors facovercame the daunting task of complthe entire building in 37 months frombreaking to railway operations.

Beijing South station has been includTV documentary entitled ManmadeMarvels China Worlds Fastest Railwwhich describes the development andconstruction of Chinas newest high-sline from Beijiing to Shanghai. ZhouZheng, chief architect of TSDI, Stefa

Krummeck, director of TFP Farrells, Goman Ho of Arup were interviewedvisit to the station.

As well as receiving various architecawards, the station topped a BeijingContemporary Top Ten Architectureattracting almost 3.5m votes from theBeijing public.

54.

Project co-ordination Conclusion


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References(1) Beijing National Stadium. The Arup Journalspecialedition, 1/2009.

(2) MINISTRY OF CONSTRUCTION. NationalStandard of the Peoples Republic of China.JGJ61-2003: Technical specication for latticed shells.The Ministry, 2003.

(3) MINISTRY OF CONSTRUCTION. NationalStandard of the Peoples Republic of China. GB50189-2005. Design Standard for Energy Efciency of PublicBuildings. The Ministry, 2005.

(4) MINISTRY OF CONSTRUCTION. NationalStandard of the Peoples Republic of China. GB50157-2003. Code for design of Metro. The Ministry, 2003.

(5) US DEPARTMENT OF TRANSPORTATION,FEDERAL RAILROAD ADMINISTRATION. Highspeed ground transportation noise and vibration impactassessment. FRA, Washington DC, 2005.

(6) AMERICAN SOCIETY FOR TESTING ANDMATERIALS.ASTM E413-04. Classication for ratingsound insulation.

(7) BRITISH STANDARDS INSTITUTION.BS EN 12354-4: 2000. Building acoustics. Estimationof acoustic performance in buildings from the

performance of elements. Transmission of indoor soundto the outside. BSI, 2000.

(8) AMERICAN SOCIETY OF HEATING,REFRIGERATION AND AIR-CONDITIONING

ENGINEERS. 2007 ASHRAE Handbook HVACApplications, Chapter 47: Sound and vibration control.ASHRAE, 2007.

AuthorsTristram Carfrae is an Arup Fellow, a Principal oAustralian Practice and a member of the Arup GrBoard. He led and developed the rened schemecanopy roofs.

Vincent Chengis a Director of Arup in the Hong building physics group. He was responsible for thbuilding physics and sustainability initiatives of

station design.

Liu Diis a senior structural engineer formerly baArups Beijing ofce. She carried out detail analythe canopy roof structure.

Goman Hois a Director of Arup China and led thBeijing ofce structural team for the detailed desthe canopy roof and support structure.

Eric Kwongwas a senior mechanical services enin Arups Hong Kong MEP group. He carried oumechanical services scheming for the station.

Barry Lauis an Associate of Arup in the Hong Kofce MEP group, and led the MEP team for thestation design.

Eric Lauis an Associate of Arup in the Hong Korailway infrastructure group. He acted as ProjectManager from scheme stage to station completio

Mingchun Luois a Director of Arup China and hoverall responsibility for the Hong Kong reengineering group. He acted as team leader for alaspects of the re engineering design.

Jane Nixonis an Associate of Arup in the Sydneyofce. She carried out the analysis for the renedscheme of the canopy roofs.

William Ngis an Associate of Arup in the Hong Kacoustics group, and led the acoustic design aspethe station.

Timothy Suenis a Director of Arup and leads theKong railway infrastructure group. He was ProjeDirector for the station design.

Bibo Shiis a senior re engineer in Arups Shangofce. He co-ordinated all the re engineering wthrough to completion.

Alex Tois an Associate of Arup in the Hong Konofce, specialising in wind engineering.He carried out the wind engineering aspects of thdesign and liaised with the wind tunnel laboratory

Colin Wadeis an Associate Director of Arup in thHong Kong railway infrastructure group.In collaboration with TFP Farrells, he conceived carried out the concept design of the roofs and thtrackwork support substructure.

Project creditsPromoter:Ministry of Railways, Government of the

Peoples Republic of ChinaClient/Architect:TFP Farrells in collaboration withThe Third RailwaySurvey and Design Institute GroupCorporationRoof structure and specialist structural input, MEP,

building physics, re, wind engineering, and acousticengineering designer:Arup Stuart Bull, TristramCarfrae, Hei-Yuet Chan, Henry Chan, Vincent Cheng,GY Cui, Stella Fung, Da-Gang Guo, Jun-Ping Guo,Sophy He, Goman Ho, Kenneth Ho, Cai-Xia Hong,Cheng-Gang Ji, Li Kang, Eric Kwong, Barry Lau,

Eric Lau, Ching-Kong Lee, Ryan Lee, Fu-Gui Li,Xing-Xing Li, Qu-Ying Ling, Di Liu, Tarry Liu, ZZ Liu,Li-Hua Long, Mingchun Luo, Lily Ma, Tin-Chi Ngai,Jane Nixon, Samuel Oh, Bi-Bo Shi, Hai-Ying Shi,Timothy Suen, Alex To, Isaac Tsang, Colin Wade,

Bai-Qian Wan, Yi-Hua Wang, Frederick Wong,Sui-Hang Yan, Raymond Yau, Rachel Yin, Rumin Yin,

Anna Zhang, Meng-Jun Zhang, Zhi-Qin Zhang,Juddy Zhao, Yue-Ci Zhao, Wayne ZhouPedestrian/trafc engineer:Atkins China LtdMain contractor: China Railway Construction

Engineering Group Steelwork contractor:JiangsuHuning Steel Mechanism Co Ltd.

Image credits

1, 6, 13, 25, 33, 38, 40-42, 44, 46-47, 49-51, 54 Zhou Ruogu Architecture Photography; 2-3, 39, 43,48Nigel Whale; 4 Zhiwei Zhou/Dreamstime.com;5, 8a-b TFP Farrells; 7, 9Nigel Whale/Colin Wade;

11-12, 14-18, 20-21, 23, 34-37, 45, 52-53Arup; 8c,26-29 Colin Wade;10 Tristram Carfrae; 19 TongjiUniversity of China; ;22, 30-31 Goman Ho; 24 James

Harris Photography; 32 Xiao-Meng Cui/Arup.


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The oceans as a driver of change

Life as we know it would not be possiblewithout the global oceans, though as is oftenstated, we know more about the external

universe than we do about our oceans, as95% of them remain unexplored1. The oceansystems are a complex series of physical andchemical interactions between land, sea, andatmosphere; they drive global weatherpatterns and the carbon (CO2/O2exchange)and hydrological cycles, which providethe foundation for much that humansdepend upon.

Introduction

The oceans have traditionally been reas not just vast, but effectively an endresource, capable of absorbing any an

natural and human impacts. There habeen a degree of cognitive dissonancbetween what humans put into the ocand subsequent impacts over time. It clear that as the human population haincreased exponentially, impacts havecompounded, and the oceans are revethemselves to be more fragile than onthought. As impacts compound, the e

1.

AuthorElizabeth Jackson

The oceans havetraditionally beenregarded as anendless resource,but they are revealingthemselves to be farmore fragile thanonce thought.


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2.

are potentially and systemically irreversible;systems-wide tipping points are more likelyto become a tangible reality. The availabledata should be considered carefully, andserve as a wake-up call to all of us, sincenumerous small and seemingly unrelatedimpacts are being shown to have enormouscumulative effects that are playing out on aglobal scale.

The oceans are thus neither entirelyinvincible system nor endless resource.As a system, they exist in a delicate balancebetween global surface temperature,chemistry, and physical systems and humanimpact on land and sea is changing thatbalance. Fortunately, evidence shows thatthe oceans can heal and rebound ifanthropogenic impacts are reduced oreliminated and if ecosystems are givensufcient time to recover. However, this

resiliency is more evident and possible inspecies restoration. Physical and chemicalsystems are slower to respond, as theyoperate on a longer timescale, which is whythe oceans as buffer systems remain asignicant concern.

Deep time

Life on Earth began in the sea, anddeveloped there before the rst terrestrialcreatures emerged on the land surface.Some 3bn years ago all life comprisedsingle-celled organisms, and aeons passedbefore more complex forms evolved.Ancient marine fossils are found today bothon land and under the sea; clearly, life onland would not have been possible withoutthe oceans2. Today 32 of the 33 differentanimal phyla occur in the sea, only insectsbeing exclusively terrestrial, while 15 phylaremain exclusive to the marine environment.The links between phyla in the animalkingdom further reinforce the relationshipbetween life and the oceans3.

Cultural historyand the oceans

Many historical accounts represent theoceans as the great unknown, places tofear and respect that have inspired aweand appreciation around the world.Horizons appeared to be vast and innite,journeys could take weeks, or even years.Tales of mermaids, shipwrecks, pirates,drowning, and erce storms permeate global

mythology and historic lore. In Westerncultural history, books like Moby Dick(1852) and paintings like GricaultsThe Raft of the Medusa (1818-19)

represent and perpetuate fear of the sea andits living systems. Such representations areoften based on a lack of understanding thatcontinues to be perpetuated by andsensationalised in lms like Jaws and thecontemporary media. Cetaceans (whales,dolphins, etc) hold places of great culturalsignicance in coastal indigenouspopulations like the Arctic Inuit and thePacic Islanders. Whales gure in the mythsof Paikea from the New Zealand Maori,and on the totem poles of the Haida, Tlingit,and other coastal peoples. The Coast Salishpeople in Northwest Washington and BritishColumbia referred to themselves as the

Salmon People, indicating a crucial linkbetween perception, cultural identity and thesea4. The tribal relationship between thepeople of the land and the people of the seais honoured and revered to this day.

Oceanic engines

The oceans play a crucial role in globallife support systems. This includes thethermohaline circulation, the macro-currentsthat facilitate the exchange of heat, oxygen,minerals, and other essential nutrients in theglobal marine environment. These currents

function as ushing and cleansingmechanisms for continental shelf andcoastal areas, helping to cycle nutrientsfrom the deep oceans to the surface waters.This circulation is crucial to maintainingclean and healthy ecosystems, coastal waterquality, and the deep-water areas of over75% of global shing grounds5.

The current transit time from the SouthOcean to the mid-level of the North PacOcean is between 500 and 1000 years6.Cold subsurface waters and warmer surcurrents mix via upwelling at a few keyplaces globally notably in the NortheAtlantic Ocean. The warmth of the GulStream current is one of the reasons whWestern Europe is more temperate thanwould be otherwise (Fig 2).

The timing of natural upwelling cycles changing in response to increasing globsurface temperature and additional coldfresh water on the surface of the oceansA decrease in salinity (due to melting sand glaciers) affects upwelling patternsthe saltier ocean water is denser andheavier8. As ocean surface waters getwarmer and become more static, less oxis exchanged between the surface and t

deep ocean

9

. An increase in freshwater North Atlantic Ocean is affecting full-dconvection mixing, most likely due to tincreased melting of the Arctic ice sheeThe models developed by climate scienpredict that the potential stalling of thecurrent will affect the climate on land,disrupting local weather patterns andresulting in areas of increased drought awell as increased moisture. The 2010 in Pakistan and the res of Northern Ruare excellent examples of changes on la

1. 32 of the 33 different animal phylaoccur in the oceans.

2. Oceanic engines7.

Cold subsurface current

Warm surface current


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Phytoplankton are responsible for one halfof global photosynthesis output, yet theirexistence is being threatened due to the

increasing acidity of the oceans10.The oceans have absorbed approximatelyhalf of all CO2emissions since the dawn ofthe Industrial Revolution, while pH hasdecreased by 30%, resulting in increasedacidity (Fig 3). This is due to the increase inCO2in the atmosphere, and the subsequentabsorption by the oceans. The oceanscurrently uptake between 30-50% ofanthropogenic CO2from the atmosphere

12,approximately equivalent to 9980 tonnesof CO2per day

13.

By absorbing much of the CO2from theatmosphere, the oceans have delayed manyof the anticipated impacts from climatechange, as they take signicantly longer toheat up than the atmosphere and containaround 50 times more CO2

14. This isattributed to their immense size, depth, andcomplex chemistry.

Ocean acidication is increasing and isexpected to reduce surface pH by 0.3-0.5units over the next century a faster rate ofchange than during the last 650 000 years15.Prochlorococcus(a blue-green bacterium)generates approximately 20% of the oxygenin the atmosphere16. The Southern Ocean

alone (from 40S) uptakes 40% of the CO2absorbed by the total global oceans17.The increase in the uptake of CO2changesocean chemistry by decreasing pH12.

The marine food web depends on thephysical chemistry of seawater. A decreasein ocean pH affects the ability of marinecalciers including phytoplankton, coralreefs, and shellsh to x dissolved calciumcarbonate (CaCO3) present in seawater andincorporate it in their exoskeletons. If theseorganisms are unable to calcify theyessentially dissolve, a phenomenon that hasalready been observed in several global

locations. In Willapa Bay in WashingtonState cultivated oysters have failed toreproduce since 2005. 80% of larvae havedied as a result of a more acidic ocean.

Chemistry andacidication

The larvae are unable to fully form anattach themselves to existing substrat(rocks, other oysters, etc.) If larvae unattach they fail to become adult oysteOystermen depend upon naturally occreproduction for their livelihoods18.

Regions like the North Pacic OceanAntarctic are particularly vulnerable decrease in pH. More corrosive waterto be shallower in depth, colder, and a

by upwelling patterns12. Surface wateto be supersaturated while subsurfaceare likely to become under-saturated calcite and argonite. In addition, the lsea ice during the summer months haexposed new areas of ocean to air-seaexchange, increasing the uptake of COMelting ice reduces the saturation of in seawater by reducing the alkalinity

In addition to altering the ability of morganisms to calcify, ocean pH is affelow-frequency sound transmission,respiration, and the behaviour of juvesh. The chances of survival of baby

reduce by 50-80% with lowered pH.The decrease in pH affects the sense osmell, ability to nd food, ability to a

predators, and reproduce9. Baby clowfor example, are unable to return to thhome reef under more acidic conditio

3.

4.

3. Variations in pH levels in theworlds oceans.11

4. Phytoplankton blooms form offthe coast of Argentina.

8.20 8.15 8.10 8.05 8.00 7.95

Less acidic More acidic

Antarctic

Ocean

Indian

Ocean

South

Pacific

Ocean

An

O

South

Atlantic

Ocean

North

Atlantic

Ocean

North

Pacific

Ocean

Arctic Ocean


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Coastal tourism

Trade and shipping

Offshore oil and gas

Fisheries

$161bn

$155bn

$132bn

$80bn

Benefits from marine and coastalecosystems and activities

US$/ha/year

0

24

000

20

000

16

000

12

000

8000

4000

Open ocean

Continental shelves

Coral reefs

Mangrove/tidal marsh

Seagrass/algal beds

Estuaries

Ecosystems have an economic value thatsurpasses the industrial output of the entireglobe. This is referred to as natural capital,

dened as the value of ecosystem servicesthat are the naturally functioning biologicalsystems provided for free by theenvironment21. These services are usuallytaken for granted, as most people do notconsider the equivalent monetary value thatecosystems provide. In a healthy biologicallydiverse equilibrium, ecosystem services arecontinually renewable resources if they aremaintained and not stressed to the point ofecological collapse.

What are these ecosystem services?They include climate regulation, wasteprocessing, nutrient cycling, storm surge

protection, recreation, transportation, andfood22. The open oceans account for some$8T in ecosystem services, while coastalecosystems account for $12T annually of the$33T global totalhigher than the value ofall industrial output20(Figs 5, 8).

The top ve stressors to global ecosystemservices are: climate change, fragmented andlost habitat, over harvesting, coastalpollution, and invasive species5, all of whichare facilitated by and enhanced by increasesin demand, in consumption, and in coastalpopulations. The impact of 7bn people isincreasingly profound. The nancial burdenof ill-functioning ecosystems means thathumankind will have to nd alternativemeans of providing such ecosystem services,which are currently free. Human diseaseattributed to coastal sewage pollution isequated to 4M lost man-years annually,and a $16bn economic loss23.

Value of ecosystemservices

7.

6.

5.

8.

5. Comparative values for marineecosystems20.

6. Deforestation of themangroves,Cear, Brazil.

7. The Pacic Oyster has becomeprolic along the coastal regions ofTasmania, Australia.

8. Benets from marine and coastalecosystems and activities20.


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Convergence zonesand plastic

Five major ocean gyres (large rotatingcurrent systems) are now laden with plastic(Fig 10). Traditionally, these are nutrient-rich convergence zones, where many marinecreatures gather to feed. Today, due to theuse and ubiquity of plastic, these gyres aresubsurface oating plastic islands. The North

Pacic Gyre off Hawaii in the Pacic Oceanhas, for example, been estimated to beanything between the size of the state ofTexas and the whole continental UnitedStates. Appropriately, this gyre has beennicknamed Great Pacic Garbage Patch.

Plastic pollution is a subject of greatconcern, as plastic takes longer to degrade inthe ocean than on land due to temperature.Plastic, which is photodegradable, breaksdown into minute particles that are ingestedby marine life and compete withzooplankton for surface area and sunlight25.In the Central Pacic it has been documentedthat for every 1kg of plankton there are 6kgof plastic debris. There are around 46 000pieces of litter per square mile of ocean14.

Micro-sized plastic particles absorb andconcentrate chemicals from surroundingseawater at up to 1M times the ambientratios in the water25.

The most prominent form of marinedebris over the last 40 years, plastic nowlitters beaches and the oceans (Fig 11).Its manufacture has increased 25-fold,yet recycling and recovery are less than

5%

27

due to the ubiquity of single-use plasticin current human life: packaging, consumerproducts, and the numerous shippingcontainers carrying goods that go overboardevery year. Marine-origin debris accountsfor 20% of pollut

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