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| For this 3D model of a dense subdivision, Bruce Flora of Data Pro Ltd. draped some simple textures over the TIN to visually convey the intent of an interim grading plan to the engineer, contractor and developer/owner. This modeling technique increased grading productivity and minimized import-export while maintaining aesthetics. |
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Setting Up the Business
To be successful, a data prep company must be set up wisely. In my experience
performing data prep, I learned that although the tools and technologies were
similar to the engineering I had done before, the actual business and related
services were unique to construction and came with different challenges. It
isn’t enough simply to know how to build a 3D model—you must structure your
business well around your modeling services.
For example, Flora created a second company in 1998 to perform data prep.
Although he already had his surveying company registered as a professional
corporation, Flora realized he did not need a surveying license to perform data
prep in the state of Virginia.
As a result, he created Data Pro Ltd. as a separate entity so the liabilities
inherent with data prep would be protected as a separate firm with limited
liability. Nowadays Flora is comfortable with the business and technologies
involved with data prep, so he no longer sees the need for this distinction and
is considering merging it all back into the survey company. But the point is
that data prep companies must be properly structured to deal with the demands
of this business.
Staffing for Data Prep
A data prep company should be staffed with people who have strong experience in
construction. The industry is just starting to understand the importance of
construction surveying in making 3D models, and the best person to create these
models is someone who has been pounding hubs and stakes for years. Flora relies
on staff members who have strong surveying backgrounds, and he also considers
construction engineers to be good candidates for this work. “The design engineers
who are good at developing plans for review and approval may have a hard time
understanding the construction aspects because they don’t get enough field
experience or mentoring in their jobs as designers,” he says, adding, “and
there are very few schools teaching it at this point.”
Because CADD was initially developed as a drafting tool, designers became
ingrained in the use of CADD for drafting and have had a difficult time
transitioning to 3D design. The career path of design engineers normally moves
them up to management so they spend little time becoming expert in CADD, the
tool of the trade. On the other hand, young design engineers may be familiar
with computer technologies but not have the experience to design yet. Flora
mentions that some construction firms have a company policy that an engineer
must spend a year in the field before working in the office. The idea behind
this policy is that the engineer must learn to build the project before he or
she is fully qualified to design it.
This leads to the question of whether data prep has outgrown the engineering
field. Or, in other words, has data prep matured to the point that it requires
a special skill set that is beyond the traditional engineer? According to
Flora, owners and developers now focus on regulatory approval, which does not
guarantee good design. “Is it really practical that the engineer is responsible
not only to get the job reviewed and approved, but to have it be constructible
as well?” he asks. Flora sees nothing wrong with dividing and specializing
roles so that the engineer continues with design and approvals while the data
prep expert focuses on constructability.
Companies that try to combine these two roles often face business-related
pressures that can cause them to lose focus. Flora tells of a meeting he had
with a developer who was intent on making a deadline to present before the
county commissioners and win project approval. The developer put pressure on
the designer to get the job done in time to meet with the council, but of
course something had to give—and that something was the quality of the work.
The meeting deadline was met, and the job was approved. But when the project
went to construction, it was quickly identified that the design wasn’t constructible.
So the data prep arm of the project went back to the developer and pointed out
that more money would be needed to complete a constructible design. Of course,
the developer had a short memory of the pressure he had placed on the designer
to make the deadline, which led Flora to call him the “Great
Forgetter.”
It is important to understand that staff members’ training and differing levels
of experience can affect the quality of the data prep. I have often said that I
can train an experienced engineer to do CADD in about three days, but I need at
least two weeks to train a CADD person to do engineering. I am only kidding,
but this cuts to the point: If you don’t know the field, you have little
business doing CADD work in it.
Establishing a Standard
When machine control was first introduced to the market, the pioneering experts
built the models. These individuals lived and breathed GPS, machine control and
3D modeling. They saw the whole picture and helped establish the industry. But
the industry is changing now that more data prep shops are opening, and some
poor models are going into construction.
“Machine control manufacturers are becoming concerned because it throws the
credibility of their equipment into question when something goes wrong in the
construction,” Flora says. “Some now demand that an expert build the first
model for new customers who purchase their equipment to ensure that they get
started on the right foot.”
Flora was once somewhat against licensure for data prep, but he now sees it as
a positive move to ensure that experts oversee the creation of these valuable
models. As an example, Flora cited a recent highway project where the developer
chose to save $3,000 on the creation of a model for the road construction, but
the model was poor and caused $30,000 in rework that could have been
avoided.
“This technology is now a two-way street with all of the magic and mystery
gone. Machine control is now a tool of the trade instead of an oddity.
Knowledge is now the critical aspect of the job,” Flora says, adding, “and the
knowledge of the individual is now paramount.” I agree with Flora on this point
because one of my mantras is “It is all about the data.” And, of course, a
skilled, qualified individual must create that data.
Offering Advanced Services
Anyone who chooses to enter the data prep field must understand the
expectations for the design plans, the resulting 3D model and the equipment
used to build the job. Each component has goals, projected accuracies and time
frames for completion, and each component also has limitations that should be
established ahead of time.
The highly experienced data prep provider is able to look at the entire project
from a macro level. This perspective encompasses the plans provided, the
interpretations that must be made to complete the model, the equipment being
used on the project and the local standards that are applicable. For example,
Flora was involved in a parking lot project that was switched from asphalt to
concrete due to the high cost of the asphalt. The site had a very complex
grading plan; the parking area had smooth contours grading to internal drainage
systems instead of cross site sheet flow. The machine to be used on this site
had a 14-foot straight-edged screed, but Flora identified that this wasn’t
suitable for a curved surface. As a result, he made some adjustments to the
model so that it could be used to maintain design intent without affecting
drainage areas.
The high-level concept behind this example is that the machinery, the standards
and the model must be synchronized for the project to be a success. The field
of 3D modeling and data prep now allows for a more sophisticated analysis prior
to building. By focusing on constructability, data prep providers can build the
model to serve the express purpose of the machines available to do the grading.
I see this synchronicity as a sign of the maturity of the field of data prep.
In another case, a well-thought-out model was developed and used for a dense
subdivision. The model included rough grading of house pads and surrounding
landscape berms. Following this rough grading, the finished grading for house
pads had to occur. Due to the tightness of the job, the contractor couldn’t
stockpile the earth in the road or on adjacent lots since the lots were being
sold and needed to remain pristine for the customers. When the contractor began
building the home, he stockpiled the earth on the berms that were accurately
sculpted into place, thereby destroying them. Summing up the lesson learned
from this project, Flora says, “Aesthetics is important during construction,
and import/export of material is critical. The site needs to be modeled in a
way that reduces grading twice and leaves enough dirt in the pad so that final
grading can occur while minimizing import and export. We find that the cost of
construction—the fuel and labor costs, wear and tear, operations and
maintenance—is driving this efficiency, and anything to minimize these costs is
valuable.”
Another of Flora’s projects in New England
required extensive boring, and subsurface granite was a major issue. Data prep
was used to prepare surfaces where the cut went to the subgrade, and all
trenches were included in the model. The surfaces were manipulated and included
modifying building pad elevations and raising and lowering pipes to minimize
the effect of the granite. These models were used to guide the driller, which
resulted in significant savings to the contractor.
Since many projects are being phased now, Flora notes that data prep providers
must analyze the entire project and all related tasks. Even though these
projects are slated to be long-term endeavors, they are broken into phases for
economic reasons, with each phase requiring completion prior to the next phase
starting up. However, when the designers look at the job, they often view it as
a single entity for earthmoving. One job Flora worked on called for 27,000
cubic yards of borrow at a cost of $225,000. According to the designer,
everything was fine since the entire site balanced well. However, the borrow
for this phase came from a future phase, and the erosion and siltation
(E&S) plans and work had not been performed yet. This borrow was
essentially inaccessible for the current phase. Data prep was done to rework
the stockpiles and borrow pits to be compatible with the current phase. This
model was then analyzed for the upcoming phases, and the $225,000 was saved for
the client. “Dirt management is becoming more important now than ever before,
and data prep is a great service provider for this type of analysis,” Flora
says.
There is a famous old adage in statistics that “all models are wrong, but some
are useful.”[1] Relating this to the world of 3D models for machine control, we
could add that some models are more useful than others. While some 3D models
offer the bare minimum of what one needs to grade a site automatically, others
offer far superior value that penetrates deep into the construction
technologies. Companies seeking a new business opportunity in data prep would
be wise to pursue the latter. Having the capability to provide advanced
analysis can pay back quickly in the high stakes world of construction.
Reference
1. Chris Anderson, “The End of Theory: The Data Deluge Makes the Scientific
Method Obsolete,” Wired Magazine July 2008.