Steel parking garage structures are a minority in parking garage construction. The most common material used for parking garages is concrete. Most everyone has parked in a concrete parking garage. They serve their purpose, but aesthetically speaking, they’re lacking.
Below is a picture of a conventional steel framed parking garage that Allegheny Design Services provided structural engineering design in Morgantown, WV. At first glance, it may not even look like a parking garage but this is a six story fully functional parking structure with retail space at the bottom level.
University Place Parking Garage, Morgantown, WV
This was a design build project directed by the March-Westin Company, a Morgantown general contractor. The Architect of record for this project was Paradigm Architecture of Morgantown, WV. CEC of Maidsville, WV, were the steel fabricators. Allegheny Design Services provided the Structural and MEP design with the collaboration of Carl Walker, as specialty engineers.
This parking structure is six stories high with 390 parking spaces. It also has over 12,000 square feet of retail space at the ground floor.
The following are some of the main reasons for going forward with a steel framed parking garage.
Reasons for using steel in lieu of precast concrete:
- Precast concrete would have been shipped in from out of state, which would cause a long lead time
- The contractor is AISC certified and very proficient with conventional steel construction
- CEC is a nearby steel fabricator, which would expedite any changes during construction
- Conventional steel framing would have more architectural flexibility than precast structures
The question asked in everyone’s discussion concerning steel parking structures is “How do you prevent it from rusting?” This truly is the main challenge that needs to be considered when dealing with an exposed steel structure. But let’s not forget that even precast concrete structures need maintenance and will rust at various locations, such as connection points.
The Deck System
Galvanized vented metal form deck was used for the structural concrete slabs. The vents are meant to allow any water that might seep through the concrete slab to escape out of the deck form. This would prevent water build up between the bottom of the concrete and the form deck.
Ultimately the deck is non-structural, so if it were to rust and fall apart, the structure would still be sound. This precaution is to prevent excessive maintenance and eyesores, due to weathering damage.
Example of Vented Metal Deck- Reference: mmrdeck.com
Steel Beam and Column System
All of the steel columns and beams were painted with Carbozinc 11 FC. It was more cost effective to paint the main building columns and beams than to hot-dip galvanize them.
The connections were designed in such a fashion that no field welding was necessary. A composite beam system was used utilizing nelson studs on the top flange of the beams. The studs were welded to the beams before the painting took place. The form deck had to be single span, due to the fact that the studs were already welded to the beams.
Braced frames were used for the lateral resisting system while also utilizing simple bolted connections in these areas. The steel braces along with all other steel members were hot-dip galvanized.
Painted Steel Before Fireproofing
Painted Steel After Fireproofing
Cable Traffic Barrier System
Carl Walker designed a tension cable barrier for vehicles and pedestrians. All steel members for the barrier system were hot-dip galvanized. Connections were either welded in the shop before galvanization or bolted in the field.
This cable barrier system gave us an inclusive steel structure minus the masonry stair and elevator shafts that were designed as standalone structures.
Cable Anchorage Structure
Cable Barrier System
Allegheny Design Services
In conclusion, a steel framed parking garage is faster to build and extremely flexible for architectural aesthetics. Just like any exposed structures, there are durability and maintenance obstacles that have to be addressed.
In the end it can be done with steel and done with style. The University Place Parking Garage is a beautiful addition to downtown Morgantown, WV.
To learn more about Allegheny Design Services and see more projects we have worked on, visit our website!
Thanks for reading,
Jason Robinson
Written by Jason Robinson, PE, Senior Structural Engineer
Jason works as a Senior Structural Engineer at Allegheny Design Services. His responsibilities include but are not limited to project management, production of construction documents with CAD and structural engineering design. He attended West Virginia University where he received his bachelor’s degree in civil engineering. He has extensive engineering experience as both a field engineer and a structural engineer. He has also acquired skills in the Autodesk Revit 3D modeling system for the production of construction documents.
I’m curious about the selection of a vented metal deck vs. non-vented. How do you prevent moisture (from vehicles and wind-driven raing) from migrating through the concrete and dripping out as an efflouresecent? I have seen this problem on similar structures, it can be a real nuisance.
We used a moisture vapor reduction admixture in the concrete that should eliminate water migrating through the concrete floor. The vented deck is a “belt and suspenders” measure just in case water were to migrate through the concrete then it won’t get stuck between the concrete floor and the metal deck causing rust. The deck was used as a form and can essentially be removed since it isn’t a structural component once the concrete deck cured.
I hope this answers your question. Please e-mail me at jason@alleghenydesign.com if you have any other questions.
thanks!
Jason,
I’ve got a couple of questions:
1) What was the depth of concrete you specified, and what amount of reinforcing steel did you specify?
2) What was the design LL for the parking area?
3) Are there any seismic requirements in WV?
Just as a general question, what is the typical SF cost of constructing a steel framed metal deck parking structure?
Thanks,
Andy Carpenter, PE