
The
Las Vegas Convention Center at night. Photo courtesy of the Las Vegas News
Bureau.
When the Las Vegas Convention and Visitors Authority (LVCVA) board of directors decided to embark on an $890 million project in 2005 to provide a face-lift to the Las Vegas Convention Center, they didn’t fully anticipate the challenges of working with the existing structural grid system. Originally built in the late 1950s, the convention center had been expanded over time through the addition of new exhibit halls and meeting rooms and consisted of three major building components: a North Hall, a Central Hall and a South Hall. The visionary design for the newest renovation, crafted by master architect HNTB Architecture, involved a new Grand Concourse that would join the North Hall to the Central Hall and South Hall as well as an enclosed pedestrian bridge that would connect the monorail station to the convention facility. The renovation would also expand and renovate the meeting room facilities and make other site improvements designed to enhance the overall experience of visitors.
However, in the course of compiling the plan backgrounds of the existing facility, HNTB encountered a problem. While partial construction drawings were available for each of the buildings, there was no single unified floor plan or structural grid system that combined all of the building plans into one. Trying to piece together the record drawings with an ALTA survey revealed significant dimensional discrepancies--as much as 8 feet in some cases. To move forward with the proposed renovation, a more accurate approach was needed.
The LVCVA project team contacted a number of local surveying firms and were impressed with Heritage Surveying based in Las Vegas. Then, at the 2007 American Institute of Architects National Convention, one of the LVCVA project team members stopped by the exhibit of Irvine, Calif.-based Architectural Resource Consultants (ARC), a firm that specializes in as-built surveys. The exhibit featured a laser scanner that was on display through a partnership between ARC and Optira Inc., a specialist in high-definition as-built documentation headquartered in Omaha, Neb. After discussions with ARC and Optira, LVCVA and HNTB agreed that obtaining 3D models of the above-ceiling plenums as part of a comprehensive as-built survey would provide an effective way to unify the structural grid. However, the project management team wanted to keep Heritage Surveying involved in the project. The LVCVA made a request: Would the three firms--ARC, Optira and Heritage Surveying--be willing to work together to complete the as-built surveys?

Renderings
of the renovated Las Vegas
Convention Center. Images
courtesy of HNTB Architecture.
Defining the Boundaries
Eager for the chance to take on the project, the firms agreed to explore a possible collaboration. ARC and Optira had worked together on previous projects and bid on the Las Vegas Convention Center project together. Both companies thought it would be a good opportunity to go in as a team since each firm had strengths in different areas. However, neither firm had any experience working with Heritage Surveying.John Russo, AIA, president and chief executive officer of ARC, and Tim Beck, PLS, project manager for Heritage Surveying, admit that they were both a bit skeptical at the outset. “My initial thought was that I didn’t know these guys,” Russo says. “How were we going to establish a compatible work flow? What quality of a firm were they?”

Indeed, the alliance would prove crucial to meeting the project requirements. As negotiations among the three firms progressed, the LVCVA decided that the project would need to be completed in just three months. Additionally, the firms would have to conduct the surveys for the 3.2 million square foot property while all facilities remained fully operational, which would make access difficult. Precise planning and clear communication would be paramount.
Fortunately, all three firms had experience handling difficult projects, and each company brought a high level of skill and integrity to the table. After a number of in-person meetings and conference calls, ARC, Optira and Heritage Surveying felt confident that they would be able to work together.
They quickly outlined a plan for dividing the project. Heritage would establish a control network across the entire site and then bring that network into the buildings. The firm would also conduct as-built surveys for the exterior building shells, the primary road adjacent to the convention center (Desert Inn Road) and the monorail. Optira was given responsibility for conducting the above-ceiling plenum scans and creating 3D CAD models of existing conditions. ARC, as the prime contractor, would be the main liaison with HNTB and would coordinate between the teams. The firm would also architecturally document as-built floor plans of the complete structure and tie in the existing structural grid system, which included locating the interior columns and establishing the architectural grid lines. Deliverables would include 2D building floor plans, a unified structural grid system and 3D above-ceiling plenum models.

Surveyors
use a laptop interface that allows shots to go straight into CAD, which
eliminates the need for
office processing.
Fitting the Puzzle Together
With a basic outline in place, the teams began their work in September 2007. But the project wasn’t always clear-cut. “We’re all experts in a certain discipline,” Beck says. “ARC is an architectural firm. We’re professional land surveyors, and Optira is a laser scanning expert. Tying all three of those different entities together to put our data together was a challenge.”To further complicate the situation, the LVCVA also required the new data to be on the same rotation and fit within the boundary of the existing title survey. “That was a really big piece of the puzzle,” Beck says. “It required a significant amount of both field and office work for everyone involved.”
Heritage Surveying was the first team onsite. Using Trimble S6 3 robotic total stations along with Nikon auto and digital levels, four two-person survey crews retagged the boundary points related to the original boundary and set the exterior control around the site. According to Beck, this part of the project took about a week to complete.
After the exterior control was established, four two-person teams from ARC began their work, which started with the shell of the buildings. “We tied into the control network and then started shooting the shell using Leica TPS405 total stations along with Leica’s fieldPro,” Russo explains. The ARC teams then moved inside the buildings and started shooting the grid system and walls.
By using fieldPro, ARC was able to shoot all of its measurements straight into AutoCAD onsite. “We knew everything was closing and working properly; we were drawing in real time and were able to walk offsite with a 90 to 95 percent complete product in 2D. It was tremendously time efficient,” Russo says.

Survey
crews from Heritage Surveying establish the control boundary around the South
Hall.
To coordinate their efforts, the teams held weekly planning meetings with HNTB and the LVCVA in which they outlined a daily strategy for accomplishing the following week’s work. Flexibility was crucial. “We knew with pretty good certainty which halls would be filled each day, but the meeting rooms were tough,” Russo says. “They would have numerous conventions, conferences, etc., going on all at the same time. We had to roll with it and be able to change our plans as needed.”

A
survey team uses Leica HDS technology to scan the inside of the South Hall.
“Logistically, you’d think that you would always run into problems when you’re working with a company you’ve never worked with before,” Beck says. “But all three of us went out of our way to make the other firms feel comfortable, and it was a great work environment.”

Point
cloud data of an above-ceiling plenum scan.
“The ability to bring all three firms’ data sets into a common format (Autodesk Navisworks) and common forum (the online meetings) significantly strengthened our ability to work collaboratively,” adds Mitch Schefcik, president and chief executive officer of Optira.

A
plenum model derived from point cloud data and
modeled in Autodesk Architecture.
The Future of Surveying
The project was completed on time and on budget and has caused all of the firms involved to rethink the way they do business. “With the economy, everything is shrinking,” Beck says. “We like to take the approach that we can accomplish anything, but right now, it’s all about who you know and who you work with and being as efficient as you can.”Russo agrees. “Knowing our strengths and weaknesses helped us to understand where it made sense to divide our scope of work between our three firms so that we each focused on what we were experts in,” he says. “This was critical to the success of the project.

A plenum model fully rendered using
Navisworks.
Editor’s note: ARC, Optira and Heritage Surveying were awarded second place in POB’s 2008 Highlights in Surveying contest for their roles in the Las Vegas Convention Center project. To enter a project in the 2009 contest, visit his.pobonline.com. The deadline is Feb. 16.