PROJECT DESCRIPTION – Big Cat Crossing – Philadelphia Zoo Animal Exploration Trails
Krech Ojard & Associates (KOA) provided structural design services to CLR Design (Philadelphia, PA) for new and unique animal exploration trails at the Philadelphia Zoo. Sometimes called Zoo360 or Animal Exploration Trails, Krech Ojard’s involvement with these projects include enclosed mesh pathways for carnivores including the Big Cat Crossing, mesh canopy roofing, and trails for other animals in the future. Krech Ojard & Associates, Inc. provided customized, engineered solutions with a focus on aesthetics and reducing construction costs to help CLR Design realize the Philadelphia Zoo’s vision.
KOA was responsible for engineering steel support posts, footings, mesh rigging systems, and the carnivore exploration trails. These trails include a mesh ground trail along Bird Lake, an elevated Vierendeel truss trail, and a curved pipe bridge trail for carnivores crossing above the zoo’s main path. The structures, trails, and included vestibules allow the animals a much greater range of travel to explore new environments, while providing an intriguing, up close visitor experience.
KOA also provided engineering services for the roof retrofit of two big cat enclosures. Through the addition of mesh roofing to the lion and tiger enclosures, along with the new animal exploration trails, all of the big cats can occupy any of the enclosures for exhibit flexibility and rotation. Krech Ojard structural engineers enjoyed developing solutions with CLR Design and the Philadelphia Zoo for this unique task within their Zoo360 animal exploration trail system.
Read more about the interesting structural engineering aspects of this project at Civil Engineering Magazine’s weekly article, “‘Big Cat Crossing’ Opens At Philadelphia Zoo”.
Three Dimensional Scanning
Once the scope and geometric complications of this unique environment became clear, KOA suggested the use of 3D scanning. The zoo hired KOA to perform 3D scans of the zoo’s project areas which resulted in the consolidation of existing dimensional information into an electronic file package. The final electronic model allowed coordination between disciplines in areas where traditional field measurements were not possible or reliable.
The laser scans produce accurate point cloud data and panoramic imagery to create an accurate 3D model. This 3D electronic design environment was used to fit new structures and upgrades within the current environment with much greater precision. Even small tree branches reaching through truss systems were identified and evaluated by the designers. The use of 3D scanning greatly reduced field verification time, the need for field fabrication, and the number of field modifications.
