The University of Arizona’s Steward Observatory Mirror Lab has the capability of producing lightweight honeycomb telescope mirrors up to 8.4 meters in diameter. Within the facility is a mirror casting lab, polishing lab, integration lab and test tower all designed to provide the mirrors a clean, stable and climate controlled environment.
For more than a decade, M3 has provided ongoing architectural and engineering services to the mirror lab and assisted in the development and growth of the facility. We have continuously worked with mirror lab personnel in developing various expansions to the labs and upgrading the mechanical and electrical systems. The latest project involved the replacement of the existing steel test tower inside the polishing lab with a new structure providing greater versatility and capabilities to this operation. The new tower was designed so it can be erected within the space while the lab remained in operation.
The focus of the Arizona Portland Cement project was to install a new Polysius “Quadropol” Roller Mill, which at the time was the largest of its kind in the world. Supplementing this installation was a new set of additive bins, feed conveying system, process gas ducts, four cement cyclones, airslide conveyors, dust collection and a pneumatic conveying system.
This project posed several structural design challenges. Much of the equipment was located above the roller mill, yet the project required an open column free area around the mill and room for an 80 tonne pneumatic hoist to operate. A series of truss structures above the mill became the solution. Additionally, the height and weight of the roller mill tower required a 14-foot deep concrete foundation, installed next to an existing building and several cement bins, all vital to daily plant operations.
This design-build, 49,200 square foot Pre-Stressed Concrete Railroad Tie production facility is located in the Union Pacific Rail Yard, Tucson, Arizona. The new concrete ties manufactured at this facility replace old wooden ties on the railroad’s Southwest rail line and supply ties for a second set of tracks on the railroad’s El Paso-to-Los Angels route.
The plant includes a main concrete process area which has six 400 foot long automated pre-stressing/casting beds with components made up of an overhead concrete distributor, a sawing machine, and tie stacker. The facility casts 1,200 concrete ties a day, with each casting bed containing 18 steel cables stretched at a tension of 6,000 pounds. The process area is supported with a quality assurance lab, administrative office, conference and facilities support area.
The site included areas for cement and aggregate storage, an automated material handling system, concrete batching/mixing system and a crane system.
M3 designed a 110,000 square foot A-frame enclosure building to house the clinker stockpile. Before the enclosure, it was an open stockpile with environmental concerns. Along the building ridge, a new tripper conveyor was installed to evenly distribute the clinker transported via new conveyors from the kiln area. A new surge bin and electrical room addition completed the project.
During the project, it was discovered that an old 500-foot long x 16-foot diameter kiln made of 1 ½-inch thick steel plate was no longer in use and needed to be removed. Most of the kiln shell was relocated and reused as a stockpile reclaim tunnel. The remainder of the kiln was turned upright and used as a bin. This plant liability was turned into an asset, and saved the project money.