BUILDING STATISTICS
The Medical Center is an active hospital and medical research facility located at the cornerstone of an expanding medical district in Southeast, USA. Nestled in between pockets of urban residential construction, The Medical Center briefly interrupts the major urban grid of the existing environment. Existing as a mission-critical facility, the building’s proximity to a major network of highways enhances its public accessibility. The urban context of the site, totaling 37 acres in size, influences the boundaries of design of this building project.
General Overview
Building Name: The Medical Center
Location: Southeast, USA
Site: Withholding the address of the site per owner request
Occupant Name: Withholding the occupant information per owner request
Occupancy Type: Medical, Medical Offices
Occupancy By Code: I-2 (Level 1-Level 6) | Business-B (Level 1) | F-1 (Level 7)
Size: 570,000 square-feet
Number of Stories: 7 floors above grade | Height = 113 ft.
Construction Duration: December 2012 – November 2015
Cost: $190,000,000 (Base Bid)
Project Delivery Method: Design-Bid-Build
Project Team
Owner: Withholding the owner information per owner request
Withholding the owner contact per owner request
Construction Manager (at risk): Skanska
Architect: NBBJ
Joint Venture Architect: Blitch Knevel Architects
Structural Engineers: URS Corporation (AECOM)
MEP Engineers: URS Corporation (AECOM)
Fire Protection: URS Corporation (AECOM)
Exterior Envelope: IBA Consultants
Code
Zoning . . . . . . . . . . . . . . . . . Southeast, USA Codes and Ordinances
Building Code . . . . . . . . . . . International Building Code (IBC) 2009 Edition
Architectural . . . . . . . . . . . . American Institute of Architects (AIA) Guidelines for Design and
Construction of Hospitals and Healthcare Facilities
American with Disabilities Act (ADA)
Structural . . . . . . . . . . . . . . American Concrete Institute (ACI) 301
American Concrete Institute (ACI) 315
American Concrete Institute (ACI) 318
American Concrete Institute (ACI) 530
American Concrete Institute (ACI) 530.1
American Institute of Steel Construction (AISC) 13th Edition
Reference Standard . . . . . . American Society of Civil Engineers (ASCE) 7-05
Mechanical . . . . . . . . . . . . . International Mechanical Code (IMC) 2009 edition
Plumbing . . . . . . . . . . . . . . . Southeast, USA Plumbing Code
Southeast, USA Municipal Code and Jurisdiction
Electrical . . . . . . . . . . . . . . . National Electrical Code (NEC) 2008 edition
Fire Protection . . . . . . . . . . . National Fire Protection Association (NFPA) 72 2007 Edition
National Fire Protection Association (NFPA) 101 2009 Edition
Insurance Underwriter’s Requirements
Southeast, USA Fire Marshal Act
Architecture
The inpatient towers feature a polished and refined
design that influences the form and shape of the
medical district of Southeast, USA. The L-shaped
orthogonal design scheme introduces order and
logic into the overall program of the building. A
degree of programmatic intuition is demonstrated
through the relationship between the environmental
concerns of the region and the location of the mission-
critical components within the building.
Additionally, the architectural features of the design accentuate the overall form of the building, contributing to the subtle yet stark character of the medical campus. Creating pattern and visibility through the controlled use of vertical shading fins and horizontal louver systems, the staggered glazing system of the inpatient towers appropriately offers natural light to the occupants of the building. Linear material strips wrap the perimeter of façade, emphasizing the interface between building and environment.
Enclosure
Demonstrating an energy conscious design initiative, the building enclosure of the inpatient towers features a variety of design systems. The enclosure of the inpatient towers consists of an exterior metal stud wall tripled with a layer of insulation and vapor barrier that take the form of an interior skin and furring wall system. The exterior glazing is patterned and abundant, accentuating the linear strips of exterior façade running laterally across the building surface.
More specifically, the exterior envelope of The Medical Center features two different glazed framing system (GFS) in addition to an exterior precast concrete wall panel and/or composite metal wall panel. The GFS include a unitized aluminum curtain wall system and a unitized aluminum window wall system. The connection of curtain wall system to the primary building structure is designed to allow ½ in. of vertical deflection. The connections of both the GFS as well as the precast concrete or composite metal panels to the structure will be provided by the manufacturer/supplier.
The wall assembly includes 5/8 in. gypsum wall board framed by 8 in. metal studs spaced 16 in. o.c. The interior conditions are shielded from the exterior environment by means of gypsum sheathing, weather-resistant barrier, 3 in. rigid insulation or 5 in. wool insulation (depending on the design condition), and sealant materials.
Sustainability
The overall form of the inpatient towers emphasizes the energy-conscious design of the medical campus. The L-shaped towers are oriented in such a way in order to introduce as much natural light into the building as possible, reducing the amount of synthesized energy required to operate the facility. Additionally, the natural form of the building acts as a shading mechanism, reducing the solar heat gain of the building. Designed with the end goal in mind, the delicate balance of reasonable introduction of natural light and program-driven concern for thermal comfort set this project on target for LEED Silver.
Structural Systems
Foundation System
The foundation system of The Medical Center consists of timber composite piles and precast, prestressed concrete piles connected by reinforced grade beams. The timber composite piles are classified as D-25 untreated and designed to support an estimated loading capacity of 25 tons. The composite character of this foundation element is achieved by filling a 12” nominal light gage corrugated can section with 5000 psi concrete. The geometry of the composite timber pile varies along its length, measuring a minimum of 7” in width at the tip and 13” in width at the butt. The tip of the composite timber pile shall be driven 62 ft. below the original grade. The precast, prestressed (PCPS) concrete piles assist the timber composite piles in transferring the load from the above grade building structural elements into the ground. Similar in design, the PCPS concrete piles are sleeved with corrugated grout ducts that are configured to match the layout of the pile vertical reinforcement. The ducts are filled with 4000 psi grout. The pile system frames into a pile cap system, serving as the interface between the foundation and the above-grading framing system.
Framing System
The efficient geometry of The Medical Center generates a typical bay framing scheme. The typical bay framing in this building is classified into two bay categories: ordinary bay framing and corridor framing. An ordinary bay is approximately 30’-4” x 32’-0”, and a corridor bay is approximately 10’-6” x 32’-0”. The horizontal framing members are rectangular in section and vary in width and depth between dimensions as small as 8 in. and as big as 56 in. All joists, beams, and girders are reinforced concrete members, yielding a compression strength value of 4000 psi. All instances of structural framing depend on span and loading conditions.
The typical floor framing construction comprises of a 16 in. deep wide module NWC pan joist system with 5 ¼ in. slab. The total thickness of the structural floor assembly is 21 ¼ in., and the pan joist system is spaced at 66 in. Intermittent ¾ in. slab depressions, due to programmatic and engineering details, break the continuous plane of the structural concrete slab. The typical roof framing construction comprises of a 4 in. NWC slab on a 2 in. 20 gage composite deck. The total thickness of the structural roof assembly is 6 in.
Lateral System
The lateral load resisting elements of The Medical Center are a natural product of the material characteristics and framing scheme of the building engineering design. The pure geometry of The Medical Center allows for typical bay framing within the building. As a result, concrete moment frames define the lateral framing scheme of the engineered design solution. These concrete moment frames frame the building footprint, reducing the torsional effects of lateral loads on the building structure. The concrete frames are detailed to include designed lateral connections at the interface of column and beam. In addition, concrete walls contribute to the resistance of lateral forces acting on the building. The combination of concrete moment frames and walls generates a lateral load resisting system that is designed to resist wind loads resulting from severe environmental conditions, such as a Category 3 hurricane.
Mechanical
The Medical Center features separate systems dedicated to thermal comfort and ventilation. Fan coil units are utilized to control the building environment for thermal comfort, servicing such spaces as the stairwell cores and elevators. The ventilation of the building is addressed through the use of variable air volume (VAV) systems. Utilizing a maximum of 200 CFM, the VAV systems are equipped with air handling units (AHU) used to serve each individual private space throughout the building. Each of the AHU utilize sound attenuators, on both supply and return air vents, to address any unwanted noise within the sensitive spaces. With the exception of 2 units, all AHU are equipped with an energy recovery mechanism, and exactly 1/2 of the AHU have separate humidifiers to maintain an appropriate relative humidity within the conditioned spaces of The Medical Center.
Lighting/Electrical Systems
The Medical Center features a variety of lighting schemes to match the intended use of each space within the program of the building. The lighting design primarily utilizes fluorescent lighting complemented by occasional LED lighting. All lighting fixtures are recessed, wall-mounted, or utilize a decorative pendant presentation. All lighting systems are coordinated to be a color temperature of 3500 K. The Medical Center utilizes an electrical system that is fed with 480/277 V, 3-phase power. A variety of transformers, in the form of 15 kVA, 30 kVA, 75 kVA, 112.5 kVA, 150 kVA, and 225 kVA, serve to step-down the building power from 480/277 V to 208/120 V. In addition to conventional power, the hospital is equipped with emergency power capable of sustaining mission-critical operation after a category 3 hurricane for up to a week with no outside support.
Construction
The Medical Center was contracted as a design-bid-build project, with Skanska contracted as the construction manager (at risk). Construction of The Medical Center began in December 2012 and is scheduled to be completed in November 2015. The project was budgeted at $190 million, allocating a 7.5% structural foundation allowance to account for any variability in pile length due to the unfavorable and unpredictable conditions of the site soil.
Circulation
The Medical Center is a 7-story, 113 ft. tall hospital inpatient tower, amounting to 195,000 GSF in size per each tower. Averaging 28,000 SF per floor, the building provides occupant circulation paths by means of elevator service and common a stairwell core. The Medical Center features one passenger/service elevator and one passenger-only elevator, providing building transportation services from level 1 through level 6. Both elevators are located on the south end of the building. A common stairwell core, located on the north end of the building, serves as the other means of vertical transportation throughout the building. The stairwell core provides occupants with access to level 1 through level 7 of The Medical Center.
Due to the building's I-2 occupancy classification, various travel distance minimum requirements were established and enforced. A maximum travel distance of 200 ft. was established between any point in a room and an exit. Beyond this measure, a maximum travel distance of 150 ft. was defined between any room door intended as an exit and an exit. The common path of travel distance was established as 75 ft. and a maximum dead end corridor distance was set at 20 ft. All travel distance minimum requirements were established as a life safety measure within The Medical Center.
Fire Protection
Fire protection systems in The Medical Center consist of fire alarming systems as well as fire suppression systems. The fire protection systems were designed under the governance of the 2009 edition of the International Building Code as well as to meet the requirements of standards set by the National Fire Protection Association (13, 14, 72, 101).
The fire alarming system utilizes a class A digital audio loop to digital audio amplifier on each floor of the building. Additionally the system comprises of class B fire alarm audible notification appliance circuits (corresponding to each fire suppression zone), class A signaling line circuits (per floor, per tower), and class A networking loop to the main fire alarm control panel in the fire command center. All circuits are protected, using 2 hr. rated circuit integrity cable, 2 hr. rated cable system, or 2 hr. rated enclosures, until they enter the evacuation signaling zone. The alarming system is powered using 120 V supply power.
The Medical Center features an automatic sprinkler fire suppression system throughout the building. The system consists of a 6" combination standpipe and automatic sprinkler and organizes all fire suppression zones to correspond to the established smoke zones. The standpipes run vertically through the stairwell cores, rising floor to floor to assist the fire suppression system. All finished building spaces feature concealed sprinkler heads, located in the center of the ceiling tile, +/- 6 inches.
Figure 1 - Site Context (Aerial) courtesy of Google Maps
Figure 2 - Site Plan
Figure 3 - Horizontal Louver System
(courtesy of NBBJ Architects)
Figure 4 - Vertical Shading Fins
(courtesy of NBBJ Architects)
Figure 5 - Elevation West
(courtesy of NBBJ Architects)
Figure 6- Glazed Framing System Panel Perspective
Figure 7 - Wall Section at Parapet
Figure 8 - Roof Section
