Welcome to Elizabeth Hostutler's AE Senior Thesis e-Portfolio
General Building Statistics
- Morris, James, Hitchens & Williams
- WSFS Financial Corp.
- Primary Occupancy: Office (floors 2-15)
- Secondary Occupancy: (floor 1)
- Accessory: (floors 1-5, 1-3.7)
- Owner/Developer: Buccini/Pollin Group
- General Contractor: Gilbane
- Architect: Gensler
- Engineers:
- Civil: Landmark Engineering
- Geotech: Duffield Associates, Inc.
- MEP: BALA Constulting Engineers, Inc.
- Structural: O'Donnell, Naccarato & MacIntosh
BUILDING SYSTEM INFORMATION
Architecture
Gateway Plaza is the first new building to be constructed in Wilmington's Central Business District in 15 years. It is predicted to be a landmark among the CBD's office towers because it will have the first all-glass curtain wall in town. The North end has a bowed glass façade and is reminiscent of the rounded edges of the neighboring DuPont Hotel. Gateway Plaza has two distinct areas, a 15-story office tower and a 5-story parking garage attached to the South end.
The first floor of the tower will serve as a public area. It will offer patrons: WSFS Branch Bank, U.S. Post Office, retail shops, and a café. The café adds interest to the building because it protrudes out of the footprint of the main building and features a kinked roof. The protrusion creates a courtyard in front of the entrance and allows for outdoor seating, something that is new to Wilmington's CBD. The remaining 14 stories of the tower are tenant fit-outs and will serve as office space to the law-firm of Morris, James, Hitchens & Williams and the WSFS Financial Corp. With parking at a premium downtown, a 5-story, 600-car parking garage will replace the site's previous parking lot.
Building Envelope
Gateway Plaza's primary office tower is enclosed with a glass curtain wall system. It is characterized by the overlapping, shingle-type construction of clear glazing. The first floor, however, is a flat lock, zinc wall panel system over pre-cast panels. This is carried up the office tower on the spine of the south end. The parking garage is clad with pre-cast concrete panels. There is a painted, metal panel screen wall on the roof serves to hide the mechanical penthouse. The roof is an EPDM system using polyisocyanurate insulation over fiberglass sheathing on metal deck.
Construction
The site of Gateway Plaza was previously an asphalt parking lot and required demolition of the surface and site preparation before piers could be drilled. Construction began in July 2005 and is slated to continue until May 2006.
Zoning
Zone: C-4 Use Group: Business Use Group B, S-2 GarageConstruction Type: IB Type 1 Protected
Major National Codes
Building Codes: IBC 2003, ANSI A117.1, 2003 NFPA 101 Life Safety, 2003 International Plumbing, Mechanical, and Electrical Codes
Fire Code: 2003 Delaware State Fire Code
PRIMARY ENGINEERING SYSTEMS
Mechanical
The variable volume mechanical system of Gateway Plaza is located on the roof in a mechanical penthouse. Here, the 3-cell water cooling tower and heat pumps supply conditioned air to all 15 floors of the building. On floors 2-15, there are direct exchange air conditioning units using R-22 refrigerant. In the building's IT/Telephone room on the first floor, there is a Liebert Challenger 3000 air conditioning unit to provide up to 5 tons of cooling control the temperature and humidity required by the sensitive computing equipment.
Since the building is to be fit out, space for the risers has already been designated to a mechanical room found on each floor in the tower's service core. Return air from each floor is dumped into the mechanical room and is exhausted. There are outdoor air louvers in each room to replace the exhausted air and provide ventilation.
Electrical
Gateway Plaza's electrical system is powered by both 480/277V and 208/120V panel boards. Power is supplied to the building by two 2500/3325 kVA transformers. There are two main distribution panels that service floors 1-8 and floors 9-15 and the roof, respectively. There are electric rooms where the voltage is stepped down through transformers on the second, fifth, eighth, eleventh, and fourteenth floors. A 1600A bus riser supplies power to the typical office levels with for lighting and receptacles. There is a 750kW, 938 kVA emergency generator which services the fire pumps.
Lighting
Lighting for the service core of the typical office floors is provided with 6" open reflector down lights with compact fluorescent lamps. For these tenant spaces, the lighting plans will be finalized upon fit-out. On the exterior plaza area, metal halide downlights flood the walls of the first floor with light. Under trees on the plaza are illuminating strips with tempered glass lenses.
Structural
The main superstructure of Gateway Plaza's office tower consists of steel framing with composite concrete slabs on metal deck. Columns range in size from W14x43 to W14x455. On a typical floor, beams are W18x35 and W24x55, girders are W18x40 and W24x55, and slabs are 3-1/4" lightweight concrete on 3" 16 gage composite metal deck. Its lateral force resisting system uses three different frames. The first is a fully restrained moment frame, the second is a modified chevron frame, and the third is a typical X-frame. These frames are located on the east and west ends of the building and surrounding the service core. The steel super-structure bears on auger-cast piles and grade beams. The piles are 12" in diameter and drilled down to bedrock. Each column sits on a cap which clusters several of these piles.
The secondary parking garage is pre-cast, pre-stressed concrete double tee sections which rest on cast-in-place concrete girders and columns. The garage also bears on auger-cast piles and grade beams in addition to a 5" slab on grade over 6" crushed stone.
ADDITIONAL ENGINEERING
Fire Protection
Almost every area of Gateway Plaza is protected by a wet sprinkler system with a 4" wet standpipe in each of the two stairwells. The water is supplied to the standpipes by a fire pump and a jockey pump for the higher floors, both located on the 1st floor in the water service room. The fire pump has a capacity of 750 GPM and the jockey pump has a capacity of 109 GPM. These can run on emergency power supplied by diesel generator.
Transportation
Gateway Plaza has a central service core which will service most of the building's transportation needs. There are 5 public elevators, 1 service elevator, and one stairwell in this core. There is another stairwell on the west side of the building which is located near the lavatories. The elevators and stairwells will service all floors of the office tower.
There will be a main entrance to office workers on Delaware Ave. which will have a vestibule to control air loss. The service core can be accessed from this entrance, while the public areas will have separate entrances also along Delaware Ave.
Telecommunications
The building has a main technology/data center on the ground floor. It is located in the parking garage and will service all of the security systems and telephone lines in the building.
Since the building is to be fit-out in the near future, there is little design information that is finalized for the cable and computer networking systems for the tenants.