William M. Bollinger, PE, MLSE
Page 1
PRECAST CONCRETE PARKING GARAGES or STRUCTURES:
Dallas Center Parking Structure, Dallas, TX
Project Engineer for a seven-level parking structure right in the downtown area of Dallas to serve new
office buildings recently completed (1978). All the double tees were L8DT30 and L8DT24 units, using the
old 8-0 module popular with architect during the late 1970s. Everman Corporation was the precaster.
Allen Center Parking Garage, Houston, TX
Project Engineer for Everman Corporation (structural precast) for 3000-car 8-level garage with precast
shear walls (1978). At that time was the largest parking structure in the world, using the 10-0 wide 28deep double tees. Over 1 million s.f. floor area, $4 million precast concrete cost. The structural engineer
of record was Ellisor & Tanner Engineers, Dallas, Texas (now Thornton-Tomasetti Engineers).
Greenway Plaza Parking Garage, Houson, TX
Project Engineer for Everman Corporation (structural precast) for 2200-car garage with precast shear walls
(1978). Seven Levels, $3 million precast cost, Ellisor & Tanner Engineers, Dallas, Texas. Everman
Corporation was the precaster.
Kyle Field Expansion, College Station, TX
Project Engineer for Everman Corporation for precast components to form the pedestrian ramps at the
expansion of the upper deck at this sports facility in 1979. Double tees as deep as 48” were used to
support 30’-tall cmu walls, along with some intermediate inverted tee beam members.
Architect/Structural Engineer: HDR, Dallas, TX.
First United Bank Parking Structure, Fort Worth, TX
Engineer of Record for eight-story precast garage for Martin Industries with precast shear walls, 60,000
pound Cooling Towers at top level of garage for adjacent 50 story office complex, $2.75 million precast
project cost (1980-82). Garage used transverse ramps from street level to third floor parking level with
12-tall precast transfer girders supporting seven-story precast ramp walls. First Floor was Class Retail
space for IBM PC Computers. Architect/Foundation Engineer: Geren / CRS, Fort Worth, Tx.
Bell Helicopter Test Facility, Fort Worth, TX
Project Engineer for Everman Corporation for a single-story test cell facility with a mezzanine level. All of
the walls of the building were structural precast concrete. However, the speed of production and erection
allowed the owner to move into the facility and set up the testing equipment ahead of their original
schedule.
William M. Bollinger, PE, MLSE
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Two Energy Square – Office Tower & Parking Garage
Project Engineer for this sixteen-story office building with architectural precast spandrels attached to the
steel framing designed by HKS/Structural, as well as project engineer for the adjacent five-story precast
parking garage using typical 55-span L8DT28’s and normal-weight topping. Everman corporation was the
precaster. The garage had the “light wall” design (narrower width ramp wall panels with precast corbels
and architectural “buff” concrete with segmented spandrel beams (architectural openings made the top
of the spandrel like a handrail). I also designed the drilled pier foundations and the pre-tensioned shear
walls for lateral wind loads.
Los Colinas Urban Center Parking Garage – Project Engineer for HKS/Structural for this five-level double
helix precast garage founded on very deep drilled pier foundations (deep active clay layers). Everman
Corporation was the precaster. I reviewed the precast shop drawings and calculations. The garage was
also four supported precast levels using wider L10DT28 tees, light wall panels, and typical precast
columns. The lateral loads were taken by the stair and elevator towers that I designed using the pretensioned wall panels per 1979 Uniform Building Code.
Murray Saving Parking Structure - HKS/Structural Project Engineer for this two-bay single helix circulation
parking structure with a cross-over ramp at mid-height of each level (each side was a half-height floor
spacing) and kept the total height of the garage below the building code limit of 40-feet at that time in
Richardson, Texas. The special spandrels had pockets for the double-tee stems to eliminate the torque in
the edge load-bearing members. I worked with the architect and the pre-caster to provide a very tight
delivery schedule that completed the 300’-long garage in under three months. Everman Corporation was
the precaster.
USAA Towers, San Antonio, TX
HKS/Structural designed this 28-story retirement center with adjacent clinic all using architectural precast
with Featherlight Precast (now Coreslab/Texas in Cedar Lake, TX, north of Austin) as the cladding system.
I managed all the shop drawings, reviewed precast design calculations, inspected panels at the plant, and
handled a number field fixes in concert with Gordon Samuelson, PE of Featherlight, the Engineer of Record
for the precast components.
USAA Towers Parking Structure, San Antonio, TX
As a Project Engineer for HKS/Structural, I designed a four-story underground parking garage for USAA,
using a six-inch topping on all levels to handle very high lateral earth pressure loads due to expansive clay
soils and distribute them to the cast-in-place exterior walls and the precast shear walls. Once again I
worked again with Featherlight of Austin to review the designs and shop drawings for all the precast tees,
columns, beams, etc.
Stemmons Place Parking Garage, Dallas, TX
This eight-level facility by HKS/Structural was adjacent to the curved facade of the office building it served,
so curved vertical precast panels were required for the garage as well. The garage made use of the newer
William M. Bollinger, PE, MLSE
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10-0 module using lightweight concrete 10’-0”-wide and 28-deep double tee joists. To save money for the
precaster, a full 3-D model of the garage was developed and its sloping floors were modeled using
contemporary (SPACE V) finite element software that showed the number of shear walls for the garage
could be significantly reduced. Everman Corporation was the precaster.
Precast Component Designs - I was the Project Engineer on several precast structures for Coreslab
Structures (Phoenix and Miami), High Concrete - New Jersey), Monroc (Salt Lake City) and Montana
Prestressed Concrete. Recent designs included a maximum-security prison expansion (Monroc) and
parking garages in Phoenix, AZ; Naples, Florida; and in Billings, Montana.
Comercial Bank Parking Structure, Shreveport, LA – I served as a precast consultant for this six-story
parking structure that was designed by HKS/Structural and a double helix garage with special planters at
the exterior spandrels. The architect want the spandrels to project out from the garage façade plane,
giving a horizontal banded look accented by the plants in the spandrel beams. Everman Corporation was
the precaster.
Mizner Parking Garages, Boca Raton, FL
These structures were designed for Coreslab of Miami for a new business district expansion in an upscale
area of downtown Boca Raton. The project had strict height limitation due to local ordinances and was
designed for a 120-mph design wind load, since the garages were only about two miles from the Atlantic
shoreline and Highway A1A. The architect wanted precast panels only to form the stair risers, so painted
steel tubes were embedded in the panels to form the riser supports without any exterior stringer beams.
PRECAST CONCRETE INNOVATIONS:
1)
Use of 6-1/2 dia. 270ksi pre-tensioned strands for 24 square garage columns instead of typical 6#9 bars vertical with #3 ties at 16 oc. This allowed Everman Corporation to cast 60-tall columns and ship
them to Houston from Fort Worth without cracking due to handling and erection stresses. This change
also resulted in a $50.00/foot savings in cost for the precaster, or about $3000 per column. This change
was based upon the ACI 318 Chapters 10 and 18 which specified the minimum reinforcement for precast
columns (non-p/s) versus the minimum of 225 psi compression for pre-stressed, precast columns.
2)
For Fort Worth National Bank Motor Garage (1979), instead of post-tensioning the special Ishaped girders the architect wanted (not DOT beams) as the consultant had designed, I designed the
girders using standard pretensioned strands. We used an existing bed with buttresses that we had to
analyze to determine their capacity. We prestressed about 1200 kips using as many as 43 strands, and the
buttresses held. I used combination of unbonded strands for varying distances from the ends to satisfy
the initial transfer stress allowable at the ends of the beams to avoid cracking. This innovation saved
Everman Corporation about $40,000 on the project.
3)
For a small architectural precast concrete producer in Fort Worth, Texas, we broke up several
rather large canopy precast pieces into smaller load-bearing precast slabs that were post-tensioned rather
William M. Bollinger, PE, MLSE
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than pre-tensioned (since the plant only handled conventional reinforced panels). This allowed the
producer to handle the pieces with his existing equipment at his casting facility and then to ship the pieces
without requiring special escorts for the truck trailers. Since these pieces were used right at the groundlevel entry to the ten-story office building, this process allowed for few joints but better crack control
during shipping and erection.
4) At the early stages of my employment with Everman Corporation, all of the pre-tensioned member
designs had to be done on a remote terminal connected by phone line to a computer service bureau
(common during the 1970s). However, to eliminate this cost and time loss (the metro phone line was
periodically overloaded and dropped calls) of this process, I wrote a 2000-line BASIC program to run on
the company’s WANG 2000 computer to design the tees, beams, and slabs (on my own time). I also wrote
another BASIC program for this machine to handle column and wall panel designs. This move saved the
company about $20,000/year in computer service costs. (I own the copyright to these programs and they
have been used by other engineers for the last 20-plus years).
5)
During one of Everman’s first projects shipping double tees three-tees high on 55’-long trailers for
300 miles, the L8DT24 tees began developing cracks at the top of the tees at midspan during shipping.
The general contractor began rejecting the tees and sending them back to Fort Worth. I using the PCI
methodology and did a dynamic analysis of the tee shipping vibrations and changed how the tees were
transported, as well as added extra reinforcing to control the cracking. The tees were chained together
with additional dunnage points to provide additional damping which eliminated the cracking problem.