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EARTHLY CHALLENGES
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Geotechnology Inc. Provides Solutions from the Elements When Planning New Construction
By Linda F. Jarrett
Mother Earth holds a lot of surprises, and for companies planning new
construction, this can be a problem.
In 1984, six engineers recognized this need, and Geotechnology Inc. was born to provide geotechnical and environmental services.
These engineers, Ron Eckeldamp, Don McQueen, Mike Alizadeh, Pat Goeck, John Baker and Rich Frueh, founded the company with a focus of being responsive to customers’ needs. Within the first year, they purchased their first drill rig, and in 1986, formed the Environmental Division.
 (from left):John Baker, vice president project manager; Ed D. Alizadeh, P.E., president and CEO; Rick Pershall, vice president |
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The following year, the company won the first of many awards by developing a bubble screen that reduced fish kill during blasting conducted by the U.S. Army Corps of Engineers. Since then, Geotechnology Inc. has contributed to many projects including the proposed Mississippi River Bridge, St. Louis County Justice Center, Argosy Casino, the Jewel Box, and the Page Avenue Extension.
Now, it is involved with three of the
biggest projects occurring in the St. Louis area–the new Busch Stadium, the Lambert Airport Expansion and the MetroLink Light Rail expansion.
President Ed Alizadeh said while they started out doing geotechnical engineering, they moved quickly into environmental drilling and materials testing.
So, what kind of services does Geotechnology Inc. give its customers? Alizadeh gave an example using the Cross County MetroLink Expansion project. “We do an assessment of the properties along the route before they (the customers) buy them. We then issue a report saying, for instance, there was a dry cleaner there, or maybe an old gas station, so there might be some contamination.”
Foundation requirements are ascertained by drilling and taking samples of soil and rock.
“That structure goes underground in tunnels at some points,” Alizadeh says. “It also goes above ground in fairly elevated bridges in the area of I-44, so there are a lot of different structures that have to be put in place.”
The rock and soil conditions all along this extension changed tremendously from one end to the other,” says John Baker, principal of Geotechnology Inc. “So we drilled borings at fairly regular intervals along the alignment where we are concerned about a stable footing for the piers and pilings for tunnels and bridges. The analyses of these borings give their clients recommendations on how to deal with unstable situations.”
When Dr. Iben Browning predicted an earthquake of magnitude seven would strike the area of the New Madrid Fault Zone on Dec. 3, 1990, some people did not go to work, some schools closed, while
others stocked “earthquake kits.” Nothing happened except making the general
public realize that here in St. Louis,
the earth could, indeed, “move under
their feet.”
All along, however, the construction community knew this risk existed and had focused on the seismic retrofitting of area structures, new and old.
| Tim Goeline, lead field tech, rebar inspection |
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“We are definitely in an earthquake-prone zone,” says Alizadeh. ”I don’t think Browning’s prediction influenced the
construction community at all. The wheels were already in motion for the retrofits that have and are occurring. I think his prediction may have influenced the public’s awareness, but it was not given much credence by
professionals in the field.”
He added that the push for retrofitting was “probably due to the damage to elevated bridge structures that occurred during earthquakes in California and Mexico. The very visible damage that occurred in Oakland/Bay area was a catalyst. But, having said that, research has been going on in this area for at least 40 years as the risks have been known for a long time.”
One of Geotechnology Inc.’s retrofitting consultations was the I-70/I-270 Bridge in 1994. After numerous tests of the bridge superstructure and substructure including the foundation, the company found that a failure could occur at many points during an earthquake. The Missouri Department of Transportation made the Geotechnology’s retrofitting recommendations.
“Retrofitting has been ongoing for 20 years,” says Baker. “As well as the
technology and information about how structures respond, whereas the structure engineers and analysts will look at a
particular bridge and decide how it can be changed or modified based on that new information. The codes continue to get stricter to resist ground motions caused
by earthquakes.’
Flood plains present special challenges to developers, especially in the case of earthquakes.
“The significant challenge in this riverine area is the sandy soil,” Alizadeh says. “These soils have the potential to liquefy in an earthquake, so they would move more like a liquid than soil. On one project, the Stich-Tec Warehouse, our geotechnical engineers evaluated the potential for
liquefaction, then designed solutions to it.”
This solution involved filling craters, ranging in depth from two to nine feet, cleaning them and packing controlled fill into them. The fill was then pushed down by “deep dynamic compaction” whereby a 50 pound weight was picked up and dropped many times.
“That compressed everything around it and you end up with a stone column that is in the ground,” Alizadeh says. “Absent doing that, the building would have been on a deep foundation, so they were able to put it on a shell foundation. It saved them over $300,000, plus improved the soils’ resistance to liquefaction.”
Geotechnology won the award for
this project.
Missouri’s Karst topography also creates challenges for prospective developers. While there are many types of Karst from along the Adriatic Coast to the tropics, Missouri Ozarks Karst is defined as “textbook” with deep
hollows, springs, caves, sinkholes and all manners of obstacles to building.
Geotechnology Inc.’s vice president, Rick Pershall, says the “underground voids” in southern Missouri and Illinois do present a challenge as well as underground mines. “One of our niche specialties is geophysics. We map the underground layers of the surface in regard to where the voids are because that could be a big problem if someone is going to build over a void.”
Pershall said that they use a ground
penetrating radar which is shot into the ground. “It bounces off what is not native to the region’s soil and geology, and identifies those crevices. We also use it for environmental purposes like buried drums and tanks. They can actually identify where there might be some subsurface contamination.”
As the level of sophistication in
construction and geotechnology rises, so does the demand of consumer protection
and the role of the federal and state government in the process. Building codes are becoming more stringent and, as a consequence, inspectors must have a greater level of expertise with government entities more concerned with protecting the welfare of
the public.
“Once the engineering is done, and the project constructed,” Baker says, “building codes require that almost every element of construction be monitored and tested by a qualified technician or engineer. That includes everything from structural steel, reinforcing steel and concrete to the fireproofing that goes over the structural steel.”
| Brad Hicks, welding inspector, examines part of the new Busch Stadium. |
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“It’s our job to do that,” Baker says. “For example, the new Busch Stadium is one of the largest projects for which we’re providing that quality assurance and we’re making sure that the contractor installs and erects the materials in accordance with the plans and specifications that comply with the code.
The number of project inspectors has increased four or five fold over 20 years ago, since more materials have to be tested. Plus inspectors have to be more experienced. Previously, inspectors learned their trade by experience only. Now, they have to have a
college degree, plus on-the-job training by a licensed or certified inspector.
One of the other large projects Geotechnology is involved in is the Lambert Airport Expansion, and they are doing quality assurance testing for the new runway.
Explaining how testing is done, Baker
says, “We take a sample of the concrete that’s delivered to the project. We mix
specimen molds which are cured under
laboratory conditions and tested to
determine how strong the concrete is. We then go to the batch plant where the
concrete is batched to make sure that the ingredients put in the concrete are those
that were specified. We make sure that the proper amount of cement has been put into the concrete.”
So, when you travel the new MetroLink light rail system or watch a game at
the new Busch Stadium, realize that Geotechnology Inc. played a great role in
your safety. |
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