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By Richard
Rybka
Creating new facilities
to replace aging and outdated ones usually means working adjacent
to geographic features and developed areas that limit access
and add complications. These types of projects force a contractor
to rely on his expertise and develop new strategies to overcome
problems as they are encountered.
Branson, MO, has
attracted travelers since the 1800s. Over the years, the pristine
waters of Lake Taneycomo and the natural beauty of the Ozark
Mountains have led fishermen and sightseers to this area.
Today, Branson is one of Americas premier vacation travel
destinations.
Originally, the
White River flowed through the Branson area. In 1913, a power
dam was built downstream, raising the water level and creating
Lake Taneycomo. In 1958, Table Rock Lake was constructed upstream.
Rock cliffs rise up on the southeastern side of the lake.
A low floodplain remains on the northeastern side.
Bransons
downtown area extends to the shoreline of Lake Taneycomo.
Railroad tracks following the waters edge separate the
historic town core from the lakefront area. As the town developed,
recreational facilities were built along the river frontage.
This area became the site for a city park, a municipal ball
field, marinas, and campgrounds.
everal years ago,
a major redevelopment of this lakefront area was proposed.
A total of 95 acres with 1.5 miles of shoreline was acquired
by HCW Development. The plans for Branson Landing include
an extensive convention center, two hotels, a marina, Bass
Pro Shops, waterfront condominiums, and a spectacular $9 million
dollar fountain. Construction of the project finally began
this spring, and is scheduled for completion in April 2006.
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The Contractor
Tom Boyce founded his site work company in 1989. The company
is located in Branson, but has traveled to Kansas, Tennessee,
Arizona, and Arkansas to complete out-of-state projects for
local clients. Over the years, Tom Boyce Excavating has grown
to employ 65 people, including five project superintendents.
Scott Klempel, vice president, and Travis McKenzie, estimator,
work with Tom in managing the large number of projects the
company completes each year. The companys current workload
includes four subdivisions, two townhouse/condominium sites,
two tourist attraction sites, and a site prep/road improvements
project 10 miles south of Branson at Big Cedar Wilderness
Club.
Boyce realizes
that maintaining this workload and pace requires tight organization
and intelligent management. He hired Travis McKenzie earlier
this year because of his experience with civil engineering
firms. McKenzies responsibilities include estimating
and overseeing layout for field operations. He is also involved
in figuring the quantities and costs for change orders as
they occur. Tom Boyce frequently offers suggestions to improve
the way a project is constructed. As Travis McKenzie puts
it, There are too many unforeseen things underground
that you just cant anticipate. When we get in the field,
there are things that will work better than whats on
paper.
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Site Challenges
and Creative Solutions
Phase One of Branson Landing is located on a 35-acre portion
of the total development tract. Site preparation for Phase
One began in July 2004. The Killian/Turner joint venture team,
of Springfield and Kansas City, MO, is general contractor
for the entire project. Tom Boyce Excavating has been awarded
the site work and utility subcontracts for Phase One that
include demolition, mass grading for building pads, construction
of 1,450 feet of utilities, 2,480 feet of 30-inch and 60-inch
storm drainage pipe, 3,200 feet of perforated drain pipe,
rock stabilization for extensive retaining walls, and curb/base
for a contractor staging area.
Demolition of existing
roadways, utilities, sidewalks, a municipal pool and baseball
field, docks, and several buildings was the first construction
task. After demolition was completed, Boyce prepared for filling
operations. Topsoil was stripped from the site and stockpiled.
To elevate the finished floor levels of the buildings above
lake flood levels, approximately 300,000 cubic yards of imported
fill material were required.
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Photo: Tom Boyce |
The exposed subgrade
was inspected by the geotechnical engineers. The subgrade
soils were too silty and organictypical of soils found
in river floodplainsto serve as a firm base. Nearly
100,000 cubic yards of unsuitable material was stockpiled
on the site for removal at a later date.
The engineering
plans and specifications called for select earth fill. Boyce
looked ahead to the upcoming winter months when continuous
operations would have to be maintained to meet the time schedule.
He knew that earth fill would become waterlogged and site
access would be difficult, if not impossible. Strategically,
Boyce requested permission to use rock fill in place of earth.
This guaranteed a firm working surface for future operations
in the winter months.
Bransons
street layout presented a huge obstacle to trucking large
volumes of material into and out of the site. The main street
leading to Branson Landing comes down a long hill, with moderately
steep grades in some areas. It travels through the heart of
the downtown area, with narrow streets, passenger vehicles,
and heavy pedestrian traffic. Branson's popularity as a tourist
attraction creates car-stopping congestion, especially during
the summer months. To avoid these conflicts and expedite operations,
Boyce planned his trucking operations for the night hours
between 7:00 p.m. and 7:00 a.m. when traffic was minimal.
Ultimate Control
Boyces business philosophy focuses on timely completion
of projects. To reach this objective, Boyce constantly searches
for ways to maintain control over his field operations. Prior
to starting work on Branson Landing, the company decided to
explore the advantages of GPS technology. Boyce is ultimately
interested in GPS automated machine control systems for his
grading equipment, but decided to purchase a Topcon HiPer
Lite+ survey system to become better acquainted with the technology.
Local Topcon dealer,
Ozark Laser and Shoring, helped Boyce understand equipment
details so that he could make an informed decision. One feature
that was particularly important to Boyce was Topcons
GPS+ technology that enables access to Russian GLONASS satellites
in addition to the US GPS satellites. It provides more available
satellites and better sky distribution than GPS-only systems.
There are two main advantages to GPS+ technology: Downtime
due to insufficient satellite access is minimized, and horizontal/vertical
accuracies are improved.
To make the most
of his investment, Boyce wanted a construction survey system
that could be used by several individuals on his crews. He
chose Topcons FC-100 field computer and Pocket-3D software
to work with the GPS+ system. Pocket-3D was designed specifically
for field use by contractors and offers many functions that
suit their needs. Boyce discovered that this software enabled
his field crews to check grades, lay out storm drains and
utilities, collect topographic surveys of areas, and calculate
volumes of stockpiles and undercut areas.
Boyce finds that
the GPS+ survey system gives him better control over his field
operations and enables him to keep better track of his progress.
It eliminates time spent waiting for survey crews to come
to the site and set grade stakes. This was very important
during the summer months when rock fill was being trucked
in across the 35-acre site. Constant monitoring of fill depths
by Boyces site personnel enabled targeted guidance of
trucks to dumping locations. It eliminated reworking areas
that were too high or remobilizing to areas that were too
low.
Another challenge
to Boyces skills arose this past fall when the owner
added a service tunnel between the basements of two major
buildings. This change meant lowering the depth and flattening
the grade of the main storm sewer line that runs between the
two buildings and discharges into Lake Taneycomo. When the
pipe crew began excavating the trench, they encountered groundwater
and muck. Placement of several lifts of rock and earth fills,
separated by geotextile fabric (filter fabric), had to be
placed to provide stable bedding for the pipe.
As the trench was
excavated and dewatered, Boyces crews had to constantly
monitor the depth of the bedding to ensure the correct grade.
To enable placement of the pipe under the tunnel, the flowline
grade was flattened to 0.2%. Working under the unfavorable
conditions in the bottom of the trench, verifying grades with
conventional survey instruments would have been time-consuming
and difficult. Using the Hi Per Lite+ survey system, the crew
simply took the rover to the bottom with them and easily checked
elevations anywhere along the pipe.
GPS survey systems
require access to a minimum of five satellites to reach a
fixed position and maintain accuracy. Deep trenches with high
sideslopes can be problematic for GPS-only survey systems
because they can block access to some satellites. Access to
more satellites virtually eliminates operational downtime
while improving accuracy.
Projects like Branson
Landing provide opportunities for a contractor to develop
and implement creative operational strategies. Dealing with
tough site conditions, seasonal weather changes, and accelerated
time schedules create situations that compel a contractor
to utilize new resources to remain productive and competitive.
Richard Rybka,
an applications journalist with Topcon, has 30 years experience
in site engineering, land development, and construction.
GEC
- March/April 2005
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