PROJECT 05500 Patrick C.C. Hwang
INdex for Project 05500
03.26.99 > Competition winner announced: Rafael Vi単oly Architects edged out Skidmore, Owings & Merrill, Arquitectonica and Ceaser Pelli to design the $218 million, New David L. Lawrence Convention Center in Pittsburgh. 04.16.00 > Ground breaking ceremony 05.17.00 > Graduating from Columbia: A handshake with Bernard Tschumi completes the $37,000 twelve-month education. 06.05.00 > An interview at 7:15 pm with Mr. Jay Bargmann: the Senior Vice President of Rafael Vi単oly Architects. 06.25.00 > Jay makes an offer over the E-mail; it mark the BEGINNING OF THE 05500 EXPERIENCE. 07.10.00 > First day of work 08.14.00 > First deadline/ all nighter since 07.10.00 as the team prepares to complete an exterior bid set. 08.21.00 > Second official deadline since arriving RVA, as the bid set begin to develop maturity. Began designing the Riverfront Stair, which spans over 88 feet length and 28 feet in height. 04.01.00 > Architectural Record made a public announcement in the April, 1999 issue.
Rafael Vi単oly- "Even when you are right, you are wrong. You know that, don't you?"
07.10.00 > Brings me another step closer to the so called ELITIST- the architectural aristocrat. As felt many who shares this passage to architectural practice, what is the ultimate goal at the end experience? What are we looking for?
Bernard Tschumi- "To really appreciate Architecture you may even need to commit a murder"
A handshake with Bernard Tschumi completes the $37,000 twelve-month education.
FINALIST > 1 Skidmore, Owings & Merrill http://www.som.com Since its founding, SOM has completed more than 10,000 architecture, engineering, interior architecture, and planning projects in more than 50 countries around the world. The firm has had an international reputation for design excellence for over 65 years.
FINALIST > 2 Arcquitectonica Architects http://www.arquitectonica.com Laurinda Spear and Bernardo FortBrescia are cofounding principals of Arquitectonica. The firm’s work evinces movement and progress; it is a look to the future. One of the aspects of the firm’s work is its persistence in exploring modernism Arquitectonica’s work throughout the world, focusing on the Times Square Redevelopment.
FINALIST > 3 Pelli and Associates http://www.cesar-pelli.com Established in 1977, Cesar Pelli & Associates is a full service architectural practice of some 80 persons. The work of Cesar Pelli is not constrained by a personal style or a signature that would limit his architecture; instead, it tries to celebrate the unique characteristics of each project.
WINNING ENTRY > Rafael Vi単oly Architects http://www.rvapc.com Rafael Vi単oly Architects is an internationally recognized architectural firm with offices in New York, Tokyo and Buenos Aires. Founded in 1982, the New York office provides comprehensive services in building design, urban planning and interior design for new facilities, renovations and restorations. It has successfully completed fast-track and design/build projects, as well as conventionally scheduled and organized assignments.
07.10.99 > This winning entry rendering would be later recognized by many as the quintessential representation of the New Pittsburgh Convention Center. As in any public funded architectural competitions, this and other competition images would be the key to maintain original ideas.
Mies van der Rohe > 1953 Chicago Convention Hall
POSITIONING "A hall of this dimension doesn't depend on its environment: it creates its environment." Mies van der Rohe Mies commenting on Convention Centers as a typology during an interview on his design of the Chicago Convention Hall of 1953
Contrary to Mies theory on exhibition halls, the design of the New David L. Lawrence Convention Center draws upon formal and symbolic references from its environment: The City of Pittsburgh. Working guideline of the building was established via the geometry of Allegheny River and the City Street grid. By adopting the river and the city order as an operative geometry, it allows the building be responsive to the site. These two forces constantly served as a reminder to its positioning within the urban fabric. As the shape of the roof suggests, the bridges of Pittsburgh is a figurative and a symbolic embedment for the derivative of the New David L. Lawrence Convention Center. In many ways, these intuitively instigated guidelines are justifications for CONTEXT CORRECTNESS. Considerations of POSITIONING also involve linking the downtown to the Strip District and a water feature connecting the City to the River. Similar to Boston North End, where a separation was created by the interstate highway. The connection between Downtown and the Strip are bisected by I-376, which separates one neighborhood from another. To further establish the relationship between the City and the River, the Tenth Street Water Feature was devised. Essentially a passageway linking the street to the river, the water feature opens up toward the Allegheny as the horizontal surface descents with two diagonal, water cascading surfaces, the water feature becomes a public space that downtown Pittsburgh
The Strip District > A popular shopping destination in Pittsburgh, with fresh butcher shops and farmer's fruit markets. The Strip is also the few places in Pittsburgh where cultures activities are held, vendors and cafes. It was important to provide a sense of connection between Downtown and the Strip.
ER TY LIB
DOWNTOWN PITTSBURGH WEST
Le Corbusier > "The choice of a regulating line fixes the fundamental geometry of the work."
THE RIVER > Geometry One
THE CITY> Geometry Two Mies van der Rohe > "If you take the Pyramids in Egypt and make them only fifteen feet high, you know is nothing"
PANORAMA #1 > Standing on top of penthouse @ 111' above street level
The Highway and the City- Mark H. Rose > Before World War II, Pittsburgh was a dirty, decaying city Neglect during the early 1940s left it in the
worse condition; Pittsburgh was a city in decline. Thick smoke, the repeated flooding of polluted rivers, and a virtual absence of new industry and
highway distressed many residents.. ...During the war, business and professional leaders in Pittsburgh determined to arrest these developments.
Beginning on May 1943, a coalition of executives, led by Richard K. Mellon, professional planners, and leading academicians formed the Allegheny
Conference on Community Development. Conference members allied with the political machine of Mayor David Lawrence, drawing in architects,
engineers, and planners for technical assistance. Leaders of this group devised a program of smoke abatement, flood control, and physical restoration, all aimed at reviving prosperity in the Golden Triangle.
09.08.00 > Issuing Addendum 1, the beginning of many addendums to come. As the exterior cladding team begin to finish the cladding system, Centeria or Alpy? Integrated insulation or add on rigid insulation? At the construction managers' request, bent metal panel with plywood back up was drawn up to bid.
PUBLIC ACCESS > Providing access from the River and the City further strengthen the relationship between the via the building.
09.20.00 > Began developing the geometry for the north elevation curtain wall set out, as a result, three typologies were devised. The Straight, The Skew and The Skew/ Slope. The geometry study would developed into a series of work points that helped lay out the cantilever of the building. 10.01.00 > Issuing "interior fit out set", the set was to assure the owner a sense of progress in delivering the interior portion of the project. Left office at 5:30AM, had breakfast with Francesc, Keisuke and Edward before returning home.
NATURAL LIGHT > Providing natural light through skylights and shading devices.
10.13.00 > Attend a lecture at Columbia by MVRDV, first lecture since graduation. 10.17.00 > Was told the day before Aki and I are to attend a coordination meeting in Pittsburgh for the first time. Car service awaits downstairs at 5:00AM as we heads the Teterboro Airport in New Jersey. Hopped on the noisy/ bumpy but interesting RVA 6-seat propeller airplane and fly towards Pittsburgh. Arrived in Pittsburgh at 8:00AM. 951 Penn Avenue 3rd floor would later become our site office.
NATURAL VENTILATION > Fresh air are drawn from the river with curved roof that facilitate ait movement. Natural air flows through interior decrease air conditioning demand.
STRUCTURAL SYSTEM > Using long span cable structure to provide column free exhibition space, also makes a symbolic reference to the bridges of Pittsburgh.
SYMBOLIC ASSOCIATION > The form of suspension bridge pays homage to the early bridge designers.
PITTSBURGH > A city of bridge, defined by its rivers and sculpted as an urban wedge.
AERIAL PHOTO 1 > +2400'
AERIAL PHOTO 2 > +2000' 09.10.01 > Early stage of the roof construction, this series of aerial photos reinforced the idea of POSITIONING, establishing an explicit relationships between the New David L. Lawrence Convention Center to its context.
AERIAL PHOTO 3 > +1200'
AERIAL PHOTO 4 > +800' DIRECTIONS > First set of photos are viewed from northwest, the set below it is from northeast.
GEOMETRY > 15 rotated concentric radii defines the center line of steel roof cable. This and other studies generated the roof geometry and work points for the roof design and construction. The roof is described by the team as having Bull's horn shape.
CL OF CABLE
SCHEDULE > Individual roofing components are offet from the center line of the steel roof cable, this schedule also defines the extent of the roof
11.04.01 > Standing on top of the partial cladded roof looking out to North Side of Pittsburgh. Arrow points at FINE VIEW, A Hill side neighborhood.
11.04.01 > Looking from the North Hill side neighborhood of FINE VIEW in Pittsburgh. Using the transmitting pole as guide, I found my way up to this "not so popular" Pittsburgh destination.
Bounded by Interstate 279, David L. Lawrence Convention Center as seen from east
Philibert Delorme > the trompe at Anet, Perspective by Robin Evans
PROJECTION "Notations always describe a work that is yet to be realized. Even if already performed, the work it describes is open to interpretation and change in the course of future performance. In this sense notation is optimistic and anticipatory" Stan Allen Stan Allen's Practice: architecture, technique and representation P.41
To project is to translate and convey an idea; it is methods for multiplication and systematic growth and development. Plans, section, and elevations are objectified results of an intuitively devised thought. Without projection, there would not be a logical method for communication or construction, because the communicative platform would be different.
Projecting the Concept o A-100| Plans o A-200| RCP o A-300| Elevations and sections o A-400| Roof details o A-500| Exterior cladding systems and details o A-600| Interior drawing o A-700| Core and vertical transportations o A-800| Misc. drawings o A-900| Life safety, edge of slab drawings
EXHIBITION HALL- E
RAMP TO LOADING DOCK
EXHIBITION HALL- D
First Floor Plan > +732'-2" > The first floor contains two exhibition spaces of approximately 86,400 SF of display area. Exhibition Hall-D and Hall-E is separated by a movable partition, depending on the events required exhibition space can accomondate flexible and varied uses.
Trawling > A concrete contractor smoothing the topping concrete to meet specification
RAMP TO LOADING DOCK
EXHIBITION HALL- A
EXHIBITION HALL- C
EXHIBITION HALL- B
Second Floor Plan > +760'-2" > The second floor contains three exhibition spaces of approximately 259,200SF of column free display area. All five halls add up to 345,600 of total exhibition space.
TERRACE MEETING ROOM MEETING ROOM PEDESTRIAN BRIDGE
SERVICE MEETING ROOM SOUTH TERRACE
SERVICE MEETING ROOM PREFUNCTION
Third Floor Plan > +786'-2" > The third floor contains meeting rooms, ballrooms and primary services. A serivce bridge is located at X4.5 grid line which allows the north and south side of the convention center be connected and shared back of house functions.
SERVICE MEETING ROOM
SERVICE MEETING ROOM
Fourth Floor Plan > +806'-2" > The fourth floor houses meeting rooms, service functions and most importantly an urban terrace that allows Pittsburgh-ers to have an access to the Allegheny River.
TERRACE MEETING ROOM MEETING ROOM PEDESTRIAN BRIDGE
SERVICE MEETING ROOM SOUTH TERRACE
SERVICE MEETING ROOM PREFUNCTION
Exhibition Floor > +760'-2" > Hall A with the second show appearanceRecreation Vehicle show. Sales rate of mobile home since the 9/11 attack has risen 30%, as American feels safer not flying.
X-1 Bridge > This bridge connects on the north from the south side.
10.23.00 > Issuing Addendum2, as bids returned from potential bidders, cladding systems designed in Addendum 1 was too labor intensive, too costly. The construction managers advised issuing Addendum 2 to clad the building with Centeria insulated foamed panels. Left the office at 5:30AM as Keisuke and I attempt to find a diner, before heading home.
BAY ONE > Construction of bay was the most difficult and time consuming, a substaintial learning curve was felt by Birdair, it took five weeks to finalize the tensioning of X-1 cable line.
11.04.00 > Began developing a design for the Glass Elevator, will issue the design in Addendum3. The team is trying to finish an interior bid set that is due on 11.05.00. Left the office at 7:00AM, had breakfast with Darla. 11.08.00 > Began working with Charles and Wes Terry of Birdair on the cable clamping design, Rafael shows up at 8:00PM to make changes on a universal hanger cable mechanism. 11.13.00 > Issuing Addendum3, hot mop roofing system under evaluation, as it was too expensive, again, RVA was advised to design an alternate roofing/ waterproofing system that may be less expensive. Collaborated closely with technical specialist/ salesman Joe Derosa from Soprema to develop a SBS polyester reinforced waterproofing membrane system. 12.03.00 > Issuing Addendum4, Glass Elevator was valued engineered since the last submission. The two-cab design was modified to fit a single cab. Rafael suggests/ demands the opaque/ insulated roof to change to all glass roof.
SECTIONAL-izing CONSTRUCTION > Rather than a "tiered" construction sequence, David L. Lawrence Convention is constructed in sections or in bays. general individual bays are structurally independent from one another.
Second Floor > Depth of exhibition space increases from west to east, with back of house services feeding into exhibtion space from north and south
Glass Partition > Between Hall-A and Hall-B, a glass partition is sat on top of the SERVICE BRIDGE, providing a sound and light barrier so different exhibitions can occur simultaneously.
Suspension Cable > Using 169 parallel strands of cable, the main roof cables spans from the Bow to the Stern truss providing a column free space of over 250' depth and 800' in length. The lower dampening cable help forms the shape of the roof geometry, while the 1" vertical cables are used as a tensioning device.
Over 250'in depth
Pedestrian Bridge > Allows the connection between the City and the River to occur, a forced perspective is created by the two curtain walls, which frames and defines the views out to the North Side.
Pedestrian Ramp > Allows fourth floor direct access into the convention center.
Bow Truss > View from below
15 Truss Gridlines > Governs the structural diagram of the David L. Lawrence Convention Center.
North Elevation >
Sail Boat > Using sail boat as metaphor for the building structural component BOW TRUSS
West Elevation >
STRUCTURES "Locked in right angles, the assumption is of order as a rigorous delineation and within that the building as object. So the external boundary is set, and by grid and sub-grid a method of exact subdivisions begins; a diminution into regular, repetitive fixings of space. Within the rigidity nothing moves." Cecil Balmond Lotus 98: Construzioni/ Strutture Primarie P. 76
Contrary to the modernist structural rhetoric described by Cecil Balmond, which embraces clarity, rationality and rigidity, the structural diagrams of David L. Lawrence Convention Center involves fluidity, motion and a lot of movement. Using Rhino as the primary structural analytical software, engineers at Dewhurst MacFarlane "predict" anticipated movements to the building, most radically felt is the roof and the curtain wall. Rather than reinforcing rigidity to the mainframe structure, the strategy was to "accommodate" movement and deflection, they involve, rotation, in-plane, vertical, lateral and torsion movements. Adopting sailboat framing components as a metaphor, primary structure of the building is arranged around, the BOW, the STERN and the MAST. These three components provided a column free exhibition space. Due to the complex structural behavior, a stringent erection sequence was followed in order to provide a balanced equilibrium to the overall structure. The sequence begins with the erection of the Stern truss on the south and followed by the Bow truss, set with 6" rotation out from the node point. As the main roof cable is set in place, a series of vertical 1" cable tensions the main cable, which "pulls" the Bow truss into its designed node position. Each and every vertical cable help contribute to the roof geometry. The design team and the construction managers deal with problems movement on a day-to-day basis.
TENSION GRADE BEAM
Erection Sequence Diagram
12.20.00 > First official team lunch, celebrating the coming of Christmas. 12.21.00 > First RVA Christmas party @ Joe's Pub. 01.15.01 > First deadline for the New Year, issuing Addendum6 to revise the exterior cladding system (for the third time) with the "route and return" Alucobond system, thus the insulated paneling system was no loner relevant. 01.29.01 > Issuing addendum7, the massive undertaking of design miscellaneous steel. With all the bits and pieces in the building, it would prove to be almost impossible to split up contracts and assign "miscellaneous" versus contractor supplied back up steel. Because of this split in back up steel, the design team and the Construction managers would spend over 300 hours trying to coordinate all these pieces in the building, especially the back up steel for the curtain wall support. It would create endless amount of nightmares for Brian McConnell and myself. 02.29.01 > A minor addendum set, no one stay up over night, as the drawing set becomes thicker, it takes a longer time for the construction managers to browse through them, thus more time for us to sleep.
RIVER FRONT > The river front stair is a critical element in connnecting the convention center to the river.
Mies van der Rohe > Exterior corner of curtain wall at the Seagram Building
TECTONICS "The way things are put together" Philip Parker 1st day of first year design studio
"We don't ask to be eternal beings. We only ask that things do not lose all their meanings" Antoine de Saint-Exupery Study in Tectonic Culture
As manifestly explained to me by my first year design critic, definition of TECTONIC means "the way things are put together". Understood by architects as one of the most critical aspects of architecture, TECTONIC sometime is the instrument to a theoretical extension. The excessively published details of the column at the Barcelona Pavilion and the curtain wall corner of the Seagram Building best exemplify this notion. BY logically present material to its minimal essentials, Mies was able to convey the idea of rationality and standardization via these details. Similarly, High Modernist such as Gropius and Loos expresses structure and eliminates decorations not for practical implementation reasons but rather, to contribute towards an overall theoretical schema. The Post-Modernist would later challenge the notion of simplification and standardization profoundly. They argued for a more contradicted and complex strategy by using historical references. As the trend of styles and -isms evolved, the ideas of Modernism is revisited again. As Robin Evans would later conclude, Mies' Barcelona Pavilion was never rational, it only appears to be, the pavilion always had complexity and contradiction. TECTONIC thus holds tremendous implications to both the theoretical and the practical. This chapter examines how "FUZZY RATIONALIZM" would be integrated to "The way things are put together".
19B Curtain Wall > Ajay Glass installing the first unit of the 19B glazing units. The extrusions were ship to Rochester New York from China a month ago.
Uplifts > Once the glass is lift off the ground, the weight of the glass makes it difficult to manuver. Anytime when there's a sudden wind, the crew will quick unleash the cables to stop glazing.
Learning Curve > The most difficult part of the installation, as in all other trades, it is the first time. When the learning curve is understood, it became much easier and quicker to install the next time around.
L/ 360 > Over the 60'-0" span, the aniticipated live load deflection is expected to be 2". Using the Dow 123 flex-sheet silicone as weather barrier, the silicone sheet would be pre-attached to aluconond panel then site fastened to the mullion.
Times Up > First unit of the Ajay glazing took about thirty mintues, as more installation moves forward, the crew will eventually complete a whole section of the wall in four days.
02.05.01 > First panel of BANANA fabric being installed, prior to full tension at 200 PLF, some area of the panel are still warped.
03.15.01 > Tyvek being wraped around the concrete curb and the exterior sheathing cladded stud wall
05.05.01 > Alucobond panels finally installed but not all waterproofing flashings has been put in place yet.
X-1 Weldment > Defining the soffit/ fascia weldment interface, this is the area where more than 10 trades would have interface conditions. There is corrugated fascia panel from ACD, Birdair's fabric soffit panel, McDougall's alucobond metal panel, E/R stud work, Bow Weldment by Birdair, C/S louvers, Ajay glazing, Watt's insulation and Epic deck. The area would prove to be extremely difficult to enclose.
Mix > Various form of representations were used to convey the idea for enclosing the weldment. Demonstrating to the contractors involved all the different components necessary to conceal the soffit.
A detail was devised to allow fabric to wrap around the weldment, making it an absolute farbic soffit and ceiling.
3D Model > Using the model to confirm the "tent" shape fabric around the weldment. This 3D model would be e-mailed back and further between Tom McCoy of Birdair and myself. Various studies were made to make a complete "fabric" soffit, instead of a hybrid one- a mix between bent metal and fabric.
SCUPPERS > The Pennsylvania code requires a second form of drainage to assist in the case of drain clog or overflow. The scupper installers in this detail did not centered the scuppers in the center line of the control, instead he follow the previously cut out by another trade, thus the misalignment. The above photograph as issued as a Notice to Comply to the contractors. While the drawing on the left was re-drawn from the bid document to show what the design intents are. Due to the L/360 deflection criteria, all the edge condition takes in consideration of the vertical movement. The detail as drawn can accomondate 2" of vertical movement.
BANANA SOFFIT > Interface detail between fabric and curtain wall were finalized days before its installation. Since the cladding bid packages were split into many smaller packages. many parts of the enclosure system were left unaccounted for, thus on-site coordination became extremely important .
03.09.01 > Moving to Pittsburgh, began a long journey to on-site construction administration. Spent long hours trying to understand and establishing working relationships with the construction manager. This relationship would proved to be one of the most vital utilities to making thing work and have the most effective result without being caught in the politics during the maneuver. One person would later become a friend and the best comrade in tackling and resolving on-site problem, Brian McConnell from PJ Dick. 03.16.01 > First addendum in Pittsburgh, miscellaneous information is added to the drawing set, items such as surveillance camera, movable partitions, etc. 04.09.01 > As the bid for the skylight is about to finalize, the contractor, Linel Signature asked us to modify the glass size which will make a significant amount of cost saving. David and I look into how to make the change without much scarifies to the original intent. Drawings are developed to reduce the number of atypical glass units for the main skylight. The drawing would later proved to serve as a "conceptual" diagram for size reduction. William Smith and I would later converse back and further on how to make it work within 7 types of glass size. Using "swap" method to trade and negotiate between different phase requirements.
Cable casting > As assembled on site with rigging points attached for future display
Deflection Diagram > Drawings like this one predicts the anticipated movement at the curtain wall under maximum lateral force. The diagram also allow the curtain wall contractor to design the joint width and mechanisms necessary to accomondate the rotation.
This is where roof trusses are beared
Roof cable is clamped typically at every 10'-0"
"Ear" plates are used to as rigging points
Cable casting > 3D modelings were made to better understand how assembly and construction will occur.
A fabric closure will wrap the corner to finish the soffit system water tight
X-1 WALL > The unitized curtain wall (19-A) would have an in-plane movement of up to 26" under a 25 miles per hour wind load.
Skylight > Installation sequence for the stick-built skylight unit
Carrier > A custom built transport device was designed to carry skylight glazing units up and down the sloping roof, allowing maximum efficiency and minimum labor effort
Panorama > @ Roof > Panorama was frequently used to record the immense scale of the building.
Main Roof > +860' +/- > Standing at the southern edge of the stainless steel clad roof looking towards the Northside. The interface between the skylight and the main roof was left open so the two trades can work indepedently from one another. The flashing panel installed a few days later.
SPACES "Beyond a certain scale, architecture acquires the properties of Bigness. Bigness is ultimate architecture. It seems incredible that the size of a building alone embodies an ideological program, independent of the will of its architects. Of all possible categories, Bigness does not seem to deserve manifesto; discredited as an intellectual problem, it is apparently on its way to extinction- like the dinosaur- through clumsiness, slowness, inflexibility, difficulty. But in fact, only Bigness instigates the regime of complexity that mobilizes the full intelligence of architecture and its related fields." Rem Koolhaas S, M, L, XL P. 475
X-12 > Standing on top of the X12 mast, one of the last 3 to go up, this is about 210' above the floor level.
TECHNIQUE "The people who first built a path between two places performed one of the greatest human achievements. No matter how often they might have gone back and forth between the two and thus connected them subjectively, so to speak, it was only in visibly impressing the path into the surface of the earth that the places were objectively connected. The will to connection had become a shaping of things." Georg Simmel Bridge and Door
Architectural implementations require techniques, both conceptual and concrete. To transform an idea from its infancy to a developed proposition, a process or processes is needed. Technique is the means and methods that allow this process to transpire. Without techniques, would mean no architectural propositions, both built and un-built. Thus techniques become a part of the grand inquiry for architectural development. Technique exists in all facets of architectural implementation. During later stages of construction, a clear and decisive strategy was needed to avoid succumbed by the political scheme devised by the owner's consultant with intent to polarize the CM team and the design team. By encouraging and enforcing the "polarized" check and balance system. It was conceived by the owner, to create a "battle" between the two teams would ensure constant pressures for both sides, thus, provide adequate flow in the progress. However, this assumption or operative method did not add up to their expectation. Rather than producing effective solutions that will help meet schedule, falsified and exaggerated accusations were made. Thus, devising a technique that operates outside of this polarized sphere becomes crucial.
RFI > Request For Information RFI-1571We got a problem, what to do with the 3" pre-camber. Three of which should have gone away when concrete was poured. Solution #1: Dead load the bridge with all the available materials! CM response: Too complicate, No time, client reviewed it and says no. Solution #2: Built along the curve, maintain the vertical and horizontal relationship. CM response: Too complicated, contractor don't think it will work. Solution #3: God dame it! Just built it! Reality Check: The slight curve over 220'-0" length was insignificant to the overall appearance. It should have not been an issue to begin with. With all the proposition by the contractor for additional charges, we ended up erecting the designed system with simple modification to the base of the mullions.
X-4.5 Service Bridge> Installing the service bridge glazing caused some headaches for the CM and the contractor, as the bridge was supposed to be "flat" when the concrete was poured. It didn't. Therefore the design team had to come up with numbers and diagrams to prove the 3" camber over the length of the bridge is insignificant and shouldn't be a factor for installing the window units.
TO BE CONTINUED >