By Luke Carothers
The Dr. Phillips Center for the Performing Arts recently celebrated the grand opening of its second phase. Located in downtown Orlando, Florida, the $200 million expansion is the culmination of a project that began when plans were announced in August 2008. The Dr. Phillips Center has been a two part project with the first phase of construction beginning when the project broke ground in the summer of 2011.
The project involved the construction of a two-level, multipurpose facility in the heart of Orlando. Phase I included the construction of a $201 million, 250,000-square-foot cast-in-place concrete and structural steel framed building that includes a 2,700 seat Broadway-style theater as well as a 300 seat multi-purpose hall for smaller performances and a 300 seat banquet room. Phase I was completed in November 2014, and it marked the grand opening of the Dr. Phillips Center for the Performing Arts.
The $200 million Phase II expansion broke ground in March of 2017. Phase II featured the construction of 127,680 square feet of new space including Steinmetz Hall and a 3,000-sqaure-foot performance space called Judson’s. On top of seating 1,700 and boasting world-class acoustic engineering, Steinmetz Hall is equipped with state-of-the-art machinery that allows for the reconfiguration of both seating and the stage. This high-tech machinery allows the space to transform and accommodate a wide range of performances.
The project’s location in downtown Orlando, as well as the weight of the structure, placed a particular emphasis on the geotechnical aspects of the project. Universal Engineering Sciences (UES) spearheaded all geotechnical exploration, design, and testing services. As the lead geotechnical engineer for both phases of the project, UES played a major role in the construction of the nine-acre facility. Headquartered in Orlando, UES has demonstrated expertise through a high quality approach to geotechnical problem solving and value engineering on large, complex projects. UES also provided threshold inspection and test pile services for both phases of the project.
The biggest challenge to the design and construction process in Phase I was that the most important part of the work was done below ground, installing 700 grout displacement pilings to support and stabilize the building. Ken Derick, a Senior Vice President at UES, led the geotechnical side of the project. According to Derick, the team overcame many of these challenges because they were able to add enough weight to “avoid structural tie-downs due to the buoyancy effect of the water table on the basement.” Derick has been with UES for the past 30 years, working as a licensed professional engineer, building official, plan examiner, and standard commercial inspector. His expertise was key though the project’s multiple iterations of foundation analysis and re-design.
During Phase I, one of the key steps in the design process was ensuring that the foundation settled uniformly. This was complicated by the weight of several walls, which had to be placed on piles. Derick notes that it is extremely important that the settlement of the piles and the shallow foundations match closely, or the differential movement could crack the foundation. The other challenge in this step of the design process was accounting for differences in the depth of the foundation, which varies throughout the project. Accurate planning was paramount at this stage because, as Derick points out, any crack in the foundation so far below the water table could result in significant flooding.
To ensure there would be no cracks in the foundation, Derick and his team performed various tests for a foundational support and settlement analysis. This included load tests on pilings where the team inserted strain gauges at various pile elevations, allowing the team to record movement and capacity at multiple zones of the pilings. Derick notes that this testing resulted in cutting the pilings down from 95 feet to 60 feet to “get the movement that would match up with the shallow foundations.” This not only ensured uniform movement, but also saved the project owner over $1 million. These piles prevented the foundation from settling unevenly, but they also posed challenges to the construction of the foundation itself. Because the piles protruded into the spread mat footings that make up the large mat foundation, the structural design team had to provide additional reinforcement to the foundation.
Throughout both phases of construction, the team had to contend with the constant presence of water trying to enter the site from both below and above. Michael Billings, Metals Project Manager, Certified Welding Inspector & Threshold Agent, led the threshold inspections work for UES on the project. Billings notes that one of the main aspects of the project during the construction phase involved dewatering efforts. To contend with the presence of water, the UES team recommended dewatering, which involved a series of pipes that worked around the clock to pump water out of the construction site. Billings also points out that, because the project is located in Florida, heavy rains caused problems for the project in the form of minor washouts and mild undermining in some slabs. To solve this problem, Derick proposed the use of flow fill materials and a host of other innovative solutions, with Billings and his team monitoring to ensure the correct product was used and that its placement would ensure the cavities were sufficiently filled.
While Phase I was built between 10-15 feet below the water table, Phase II was even deeper at about 30 feet below the water table. Whereas in Phase I, the team was able to avoid the use of structural tie-downs, the depth of Phase II made deep foundations necessary to tie down the structure since its buoyancy would make it want to “float.” Derick notes that, at that depth, every column location had to be tied down with displacement piles underneath the Phase II building. To compound this challenge, the team had to install tangent piles between the two phases to prevent Phase I building from sliding into the deeper, Phase II hole beside it. The properly designed tangent pile allowed for the deep digging necessaryitated for Phase II excavation to proceed without posing a risk to the existing Phase I structure.
Phase II also had to contend with other challenges stemming from the project’s depth. As the teams were digging out the foundation for the second phase, they encountered more and more clay soil that was holding water, making it difficult to pump that water out. Derick says that this resulted in several last minute changes such as removing soil and replacing it with rock to prevent settlement. Billings points out that it was critical when removing and replacing this soil that the fill was properly compacted to avoid any potential shift. Phase II also had to contend with a smaller job site, which made it harder to maneuver equipment such as cranes and lay out building materials. This smaller site meant that the cranes often had to be moved into the street, which resulted in UES designing crane matting and other safety measures.
During the second phase of construction, different aspects such as the moving components in Steinmetz Hall, complicated both the design and construction process. The hall’s stage area is constructed with metal tracks that are cast into the stage slab. The area’s “stage walls” move along these tracks to reposition to various configurations. Billings highlights the particular challenge of not only reinforcing the slab to support moving walls, but also doing so in a way that avoids the tracks themselves and maintains adequate spacing to allow for the proper consolidation of the concrete.
The conclusion of the second phase of construction was celebrated in January of 2022 with two weeks of events including performances by Jennifer Hudson, Leon Bridges, and a host of other notable performers. The opening of these new facilities represents a new space for world class art and entertainment for the city of Orlando, and the space’s fluidity attracts a wide variety of performers. Despite a near four year delay caused by Covid-19, the Dr. Phillips Center for the Performing Arts is a marvel of both technical engineering and construction and a beacon for a burgeoning artistic and performance community in the region.
Luke Carothers is the Editor for Civil + Structural Engineer Media. If you want us to cover your project or want to feature your own article, he can be reached at firstname.lastname@example.org.