RECORDING AND ANALYSIS OF THE REC YARD AT ALCATRAZ ISLAND

Abstract. In the summer of 2012 students and professors from the Concrete Industry Management (CIM ) program at California State University Chico, along with their partners at National Park Service, invited Texas A&M students and professors to join forces and perform a condition assessment of the Recreation Yard at Alcatraz Island in San Francisco Bay. The Recreation Yard is a heavily visited area by tourists who are drawn to the island because of its history as a maximum security prison in the 20^th c. Because of its history, first as a military fort in the 19^thc., later as a military prison, and finally as a federal prison, many difficult historical and preservation related questions exist. This team was formed to begin research on the historical and preservation questions with respect to the Recreation Yard.

This paper and presentation will focus on the integration of documentation technologies employed to aid the research necessary for answering preservation and historical questions regarding the recreations yard. Since that yard was constructed on top of the historic 19^th c masonry fort it was requested that we also seek the location of tunnels below the Recreation Yard and their relationship with the walls. Teams were formed to perform Non-destructive testing of concrete walls to determine the size and location of rebar, Ground Penetrating Radar for determining the location of the masonry tunnels and photogrammetry and laser scanning to provide both overall and detailed dimensional information of the current state of material decay.