COVER FEATURE

Precast Concrete CanopyOffers Innovative Designand Fast Track Construction

Bruno Elias Ramos, AlAPresidentBEA International, Inc.Coral Gables, Florida

Paul Martinez, RE.Chief Engineer

BEA International, Inc.Coral Gables, Florida

Peter G. Trolani, P.E., S.F.AssociateThe Consulting Engineers Group, Inc.Mount Prospect, Illinois

Ted Wolfstahl, P.E.Manager of Engineering

Coreslab Structures (Miami), Inc.Medley, Florida

John Colao, AlASenior Vice PresidentBEA International, Inc.Coral Gables, Florida

The canopy for the Port of Miami Terminals 3, 4,and 5 in Miami, Florida, provides shelter forembarking and disembarking cruise ship passengersas they transfer to buses, taxis and cars.Precast/prestressed concrete proved to be the fastestand least expensive solution to an innovativearchitectural and structural design.By creatively combining and connecting the precastcomponents together, the elegant lines and soaringarchitectural motif intended by the architect wasachieved on the fast track construction scheduledemanded by the owner.This article presents the architectural features,structural design considerations and constructionhighlights of the project.

The terminal complex at the Port of Miami Terminals 3,4 and 5 in Miami, Florida, was completed in 1999 andis now in full operation. One of the last portions of the

terminal facility to be designed were the canopy/pedestrianbridge structures.

The terminal receives very large cruise ships that can havecapacities close to 3500 passengers. It takes nearly two hoursfor all of the passengers to disembark from one ship. This operation creates significant congestion for passengers and terminal workers as passengers transfer to ground transportation. A complex of canopies with a pedestrian bridge wasdeveloped to provide shelter for passengers and porters asthey load and unload cars, taxis, vans and buses (see Fig. 1)or proceed to the nearby parking structure.

The terminal building is a large open plan type buildingthat serves as a gathering place for passengers as they embark or disembark the large cruise ships docked there. Themain terminal has a tent-like roof form.

14 PCI JOURNAL

A two-segment intermodal canopyprovides shelter for vehicles in twolanes on either side of the centralpedestrian aisle (see Fig. 2). Buses,cars and taxis load and unload passengers and luggage under the shelter. Atthe ends of the canopy segments, entrycanopies (see Fig. 3) provide shelterover the walkway to the main terminalbuilding.

The canopies also serve as architectural focal points for the designscheme. A pedestrian bridge providescovered and elevated access from anadjacent precast concrete parkingstructure to the terminal building (seeFig. 4).

These elements form a very elegantfront entrance to the $76 million terminal complex that includes the terminalbuilding, parking structure, site improvements, and canopies and pedestrian bridge. The budget for the canopystructures was approximately $2.8 million. The canopies and bridge structurewere the last portions of the projectand consequently had a very tight construction schedule.

DESIGN APPROACHThe program for the design of the

canopies and bridge was to providethose elements, delivered on time andwithin budget, but to provide a structure that related to the main canopybuilding architecturally. The owneralso wanted to have a low-maintenancestructure that would perform well andwithout corrosion in the strong windand high salty-moisture environment.

The architects initially investigatedseveral alternative designs. A tensile-fabric structure was considered inorder to acknowledge the design of themain terminal building, but was not Selected because it exceeded the budget.Structural steel and cast-in-place concrete solutions were also evaluated andfound to be more expensive and werenot able to be completed within the required completion time.

The design solution was to use precast concrete because of its low maintenance, low cost and fast deliverytime. The design includes principallybolted connections, which are groutedfor maximum weather protection. Thehidden connections also help achievethe architectural design intent. The

— -.--,-

L_ k

, -

Fig. 1. Overview of terminal complex. Tent-like roofs are the main terminal building.The blue entry canopies are visible as are the two segments of the intermodal canopy.

Fig. 2. Underside view of the intermodal canopy showing double tees and cross-beams.

Fig. 3. V-shaped entry canopy.

January-February 2001 15

cantilevers and soaring forms of theentrance canopies also help the canopystructure respond architecturally to thedesign motifs of the main terminalbuilding.

INTERMODAL CANOPYThe design concept of the inter-

modal canopy was to provide shelter

16

for the maximum number of vehiclespossible, but also to be as open ascould be achieved with the materialsselected. The canopy shelters vehiclesalong a length of 1500 ft (457 m). It isbroken into two segments by entrycanopies, that lead the way to the threeentrance points which convey passengers from the loading area into the actual terminal building.

During the initial stages of design,precastlprestressed concrete was identified through value engineering as thebest choice for the canopy. Precastconcrete was selected because it wouldcreate a structure that was easy tomaintain, could readily comply withthe high wind design requirements ofthe tropical coastal region, could be delivered very quickly, and would have alower initial and maintenance cost thancompeting solutions.

The canopy portion of the structureprovides shelter for travelers and employees as they load and unload fromground transportation (see Fig. 5). Thecanopy has a total of 28 structural baysdivided into two segments. The structure is comprised of 24 x 24 in. (610 x610 mm) columns on pile caps. Thecolumns are spaced 20 ft (6.10 m)apart. The column interval along theaxis of the canopy is 28 ft (8.53 m).

The canopy covers a width of 56 ft10 in. (17.3 m). The roof cantileversapproximately 18 ft 6 in. (5.64 m)from the colunms to provide shelter forvehicles on both sides. Both segmentsof the canopy together provide a sheltered area of approximately 11,000 sq

Fig. 4. The pedestrian bridge, with an entry canopy beyond.

Fig. 5. The intermodal canopy and terminal in use with cruise ship in background.

PCI JOURNAL

Fig. 7.Guttering detailat the intermodalcanopy.

CANOPY BEAM HIGH POINTELEV. 30—9 3/4”

Fig. 6. Section of the intermodal canopy.

OF PRECAST COL. & BEAM

I PRECAST CONC. BEAM

CONT. SEALANT AND BACKER—ROD(WP. C ALL PRECAST DOUBLE TEE JOINTS)

WATERPROOF TRAFFIC COATING OVERPRECAST CONC. DOUBLE TEES(TYP. 0 ALL BAYS)

10’•

FOR RWL CONNECTION

—f

BOTT. OF MTL. WELDED PIPE

—J

6 3/4”(FROM TO. COLUMN)

CL OF PIPE

JSLOPE GUTtER

TO DRAIN 1 /8”/FT.

S1’

CONT. 24” WIDE METAL GUTTERFASTENED TO UNDERSIDE OFCONC. DOUBLE TEES AS PER

MANUF.SPECIFICATIONS

4 FLEXIBLE CONNECTOR PIPE

2—0” x 2—0” PRECASTCONC. COLUMNS

4” PVC PIPE STUB—OUT

January-February 2001 17

ft (1020 m2) for up to 22 buses, 32baggage carts and 70 taxis and cars.

The columns support tapered precastconcrete beams. Two columns supporteach of the 30 beams. The beams cantilever out over the drive lanes on eachside of the canopy.

Between each of the beams, six precast double tees span between thecolumns which form the actual roofstructure. The tees bear on a combination of pockets and corbels, whichhelps achieve the designer’s objectiveof a sleek, clean-looking structure.

The roof has a slight V-shape, whichforces water to flow to the center of thecanopy. At the low point of the transverse section of the canopy, slots wereprovided to allow water to enter a hidden guttering system (see Fig. 7).

ENTRANCE CANOPIESThe intermodal canopy is broken

into two segments that form three entrance points to the terminal building.At each of the three entrance points, anentrance canopy provides shelter forthe travelers and workers. From thistransitional area, people can enter orexit the intermodal canopy or terminalbuilding (see Fig. 8).

The entrance canopies amplify theV-shape of the main terminal buildings’ architectural forms. They weredesigned to mimic the wings of a bird.The entrance canopies actually passover the intermodal canopies and theircolumns pass through the roof of theintermodal canopies.

Fig. 8. Elevation of the entry canopies.

Fig. 9. One of the entry canopy beams.

(2) Mk506[(1) EA. FACE)

(2) #5 x 6—0’[(1) EA. FACE)

Fig. 10. Detail of the entry canopy dog leg.

• (2) Mk407[(1) EA. FACE)

18 PCI JOURNAL

Fig. 11.Typical connection detailof pedestrian bridge.

The initial design of the entrancecanopies was contemplated by the architects to be curved. Subsequent discussions with the precast concrete producerindicated that curved components wouldultimately be difficult to move and produce, and would unnecessarily add timeand expense to the project. Regardless,the design intent was ultimatelyachieved with straight components.

The winged-shaped canopy struc

tures are each 21 ft wide, 142 ft longand 33 ft high (6.40 x 43.3 x 10.1 m).The three entry canopies are each comprised of four double tees, four dog legspandrels and two closure spandrelssupported on soffit beams andcolumns. Each of the structures aresupported by eight columns. The spanbetween the columns is 54 ft 5 in.(16.6 m). The overall length of thecomponents is 72 ft 7 in. (22.1 m).

Since the entry canopies are intended to mimic the shape of a bird’swing, the main canopy spandrels werecast with a dog leg monolithically appended to the ends at an angle of 14degrees. All members are set at a 14-degree slope. Horizontal bearing surfaces are used on all members to eliminate sliding forces from gravity loads.A precast concrete closure piece wasadded to provide the finished form (seeFigs. 9 and 10).

PEDESTRIAN BRIDGEA pedestrian bridge connects the

750-car, four-story precast concreteparking structure, the intermodalcanopy and the terminal building. Itcreates an elevated walkway as well asa canopy for pedestrians. The bridgeconnects the third level of the garagewith the terminal building by passingover one of the three V-shaped entrycanopies (see Fig. 4).

Architecturally, the pedestrian bridgeexhibits a somewhat different designmotif from the entry canopies and theintermodal canopies. Where the othertwo elements have V-shapes that relateback to the “soaring” architecture ofthe terminal building, the pedestrianbridge is comprised of entirely rectilinear structures acknowledging the design of the parking structure. This design keeps the sleek motif of the othercanopies, however. Almost all of itsconnections are bolted and grouted, aswas done elsewhere, so as to eliminatethe need for corbels or exposed connections.

The pedestrian bridge is 250 ft (76.2m) long and 33 ft (10.1 m) high. Itswidth varies from 20 to 30 ft (6.10 to9.14 m). The pedestrian bridge floorstructure consists of composite soffitbeams which support double tees. Thetee stems are pocketed into the beamwith a cast-in-place concrete pour thatencases the tee stems (see Figs. 11 and12). This creates a monolithic lookfrom below for the double tee to beaminterface. It also hides the connectionsand seals them from the aggressive environment.

The composite floor beams and theconventionally reinforced precast concrete roof beams act as a momentframe to provide lateral stability for thepedestrian bridge structure. No cross

TJSPANDRELEL. 34’—g 1rø 2—Oi’ fOIL ROD

W/i x 5 x 5 W.NSHCR& (2)lr’O COIL NUT

cl

3’ø PVC SLEEVE

4)#9 REBAR THREADEDOUPLER

r()#9 9—O

.o•

/6”x6’W/Ir’x COIL NUT

6” KS.

1”B HIGH STRENGTI -JCOIL RODS 2—2w/(2)1ø NUTS &WASHER 5’ x 5” -

if6—6”

(2)lr”O COuPLER COILW/lr’O H.S. COIL ROD

7,1 5’f

5” 4?5 L 5”

Non5 BARS MAS1 RE INSIDESTIRRUPS OF P/C SEMIBEFORE P/C BEAM IS ERECIED

(3)5

(4)B THREADED INTO COLUMNS

“—18R524

2—O

Fig. 12. Detail showing encasement of double tee.

January-February 2001 19

bracing is necessary to stabilize thestructure and thus a more open architectural form is maintained.

The connection between the floorbeams and the columns is through-bolted to connect the bottom reinforcement. The top reinforcement is connected with threaded rod couplers.

Note that bolted connections wereused throughout the pedesthan bridgestructure to maximize head room, andmaintain the clean uninterrupted linesthe designers intended. As a result, nocorbels are visible anywhere on thebridge walkway.

Table 1. Types of precast componentsand principal dimensions.

Note: 1 in. = 25.4 mm.

CONSTRUCTIONHIGHLIGHTS

Because the precast concrete supplier was involved in the project at theoutset and many standard componentswere involved in the project, the design was completed very quickly —

within three weeks. Production anderection of the precast concrete components was accomplished betweenJuly 7, 1999 to September 9, 1999.

A total of 173 precast concrete components were fabricated comprising asurface area of 17,000 sq ft (1581 m2).A breakdown of these products isgiven in Table 1.

The precast components were manufactured by Coreslab Structures

(Miami) at their plant in Medley,Florida. Coreslab Structures was alsoresponsible for both the transportationand erection of the precast concreteproducts.

During the design process, an attempt was made to keep the connections simple and the types of precastconcrete members as few and as standard as possible. The components weremanufactured at the precasters nearbyplant and transported by truck-trailer tothe project site. Access to the site wasgood. Components were able to beerected as they arrived at the site.

Because most of the componentswere comparatively small, production,shipping and erection were relativelystraightforward. The entry canopy

Fig. 13. Close-up of V-shaped entry canopy.

The precast concrete products used for theentrance canopies and pedestrian bridge arelisted below.

Prestressed Products:• Composite soffit beams, 18 x 24 in.• Beams, 24 x 30 in.• Double tees, 16 in. deep• Double tees, 28 in. deep• Spandrels. 14 x 50 in.

Mild Steel Reinforced Products:• Columns. 24 x 24 in.• Composite L-beams, 24 x 24 in.• L-beams, 24 x 40 in.• Spandrels, 8 x 40 in.• Spandrels, 8 x 50 in.• Spandrels, 8 x 74 in.

Fig. 14. Pedestrian bridge linking terminal building with parking structure.20 PCI JOURNAL

beams, which are 72 ft 7 in. (22.1 m)long, were shipped on their sides andthen rotated after being lifted from thetruck-trailer and set into place.

Because precast concrete was used,the structural frame served as a platform, on which work on secondary elements such as the guttering, lights,signs and painting could begin veryshortly after each bay was erected.

The repetition and symmetry of theproject simplified erection and greatlyenhanced the ability of the design-construction team to meet the owner’svery tight schedule. Because thecanopy structure was developed fromessentially standard components andcontained a large amount of repetition,the project could be designed in approximately three weeks.

The precast components were produced and erected in approximatelytwo months. The components werecast in steel forms and conventionallyshipped. The entrance canopies’ spandrels components were placed on theirsides for stability and stress reductionduring shipping.

The project was essentially completed by the end of 1999 and was inservice not long thereafter.

Fig. 13 through 15 show variousviews of the canopy structures andpedestrian bridge.

CONCLUDING REMARKS

The canopy structures and pedestrian bridge structure were constructedout of precast concrete because of thetime and cost constraints of the project.By careful design and detailing, manyof the elements that are ordinarilymaintenance items, namely, gutters,downspouts and precast concrete connections, are hidden from view. Theresult is a clean looking structure,which radiates architecturally withinthe entire terminal complex.

The project was able to be deliveredvery quickly, because the general contractor and the precast producer assistedthe architect with value engineering thestructure and ultimately in selecting materials and systems that would meet thebudget and schedule. The architect wasable to fulfill the design intent withinthe capabilities of the materials and systems ultimately chosen.

Precast concrete is able to be exposedand has very good weathering properties especially in moist, salty environments. The connections are groutedsolid and other potential areas of corrosion are provided with substantialweather protection. The combination ofa nearly maintenance-free material andwith the addition of protection for theconnections yields a structure that will

serve the owner for a long time to comewith very little maintenance.

Because the precast concrete producer and contractor were involved inthe project early on, they were able toshorten the design and delivery processdramatically and make the project successful for all of the project participantsand the passengers using the complex.

During the past year, the facility hasbeen fully operational and has beenperforming very well as initially expected. Indeed, the owner, design-construction team, and the cruise ship passengers are all pleased with thearchitecture and convenience of thenew facility.

CREDITSOwner: Royal Caribbean International,

Miami, Florida.Architect and Engineer: BEA Interna

tional, Inc., Coral Gables, Florida.Precast Concrete Manufacturer-

Designer: Coreslab Structures(Miami) Inc., Medley, Florida.

Precast Concrete Specialty Engineer(Entrance Canopies and PedestrianBridge): The Consulting EngineersGroup, Inc., Mount Prospect, Illinois.

General Contractor: C. G. Chase,Miami, Florida.

Fig. 15. Finished view of intermodal canopy.

S%

January-February 2001 21