Subject: RE: 4 STORY PRECAST PARKING GARAGE IN SEISMIC ZONE 4
From: "Sprague, Harold O." <SpragueHO(--nospam--at)bv.com>
Date: Mon, 13 Mar 2000 13:56:49 -0600
There are a lot of options, and some unique concerns regarding parking
garages with occupied spaces below.
Life Cycle costs:
You will need to look at life cycle costs. Maintenance of parking garages
is a major concern, especially with occupied spaces below. Depending on the
geographic area, consider traffic bearing or sandwiched membranes to keep
water out of occupied spaces. If future maintenance is extensive, you risk
shutting down the garage and the occupied spaces below. I have seen major
repairs required after only 10 years of service.
What is the intended level of service of the garage? Is snow removal a
concern, and where do you put snow?
Where is the structure relative to either air borne chlorides or chlorides
carried in from vehicles in snow country (salt belt, freeze / thaw)?
Be very cautious about fire separation requirements.
Post tensioning with shear walls may be appropriate, so might steel. You
need to check out the local market.
Look at the economics for the structure as a whole, looking not only at
initial cost but also life cycle cost, maintenance, and operations.
Check out: http://www.npapark.org/ and http://www.post-tensioning.org/ for
many good references on parking garages and post-tensioning. Do not
overlook AISC, Trade Arbed, and Muloch Parking for some clever ideas for
steel parking garages combining composite design, precast, and cast-in-place
concrete. I would also seek the wisdom of the nearest Walker Parking
Consultants in your area. Partnering with an experienced group gives you
the value of their experience in operations, maintenance, life cycle costs,
fire, and then you can do the actual design. At the least, get a copy of
Parking Structures. I believe that the new edition should be out. It was
written by some of the Walker people.
There are several programs that can design PT out there. Check out ADAPT at
> -----Original Message-----
> From: Teresa Dellies [SMTP:DelliesTM(--nospam--at)c-b.com]
> Sent: Monday, March 13, 2000 11:35 AM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: 4 STORY PRECAST PARKING GARAGE IN SEISMIC ZONE 4
> What are the most current references and programs to use for the design of
> a four story structure with upper 3 stories for parking in a seismic zone
> 4 (1997 UBC). We are considering a post-tensioned concrete structure with
> concrete shear walls. We will have occupied space on the first level with
> 40-55 foot clear spans. What computer programs would be recommended to use
> for the design of the post-tensioned members? Are post-tensioned beams the
> appropriate choice for this type of structure? Are structural Tees readily
> available? Any good references about the design of parking structures in
> seismic zone 4? All comments and recommendations are welcome and will be
> Thank you,