ADVANTAGES OF INCORPORATING FIBER REINFORCED POLYMERS INTO THE EARTHQUAKE SAFETY PROGRAM FOR THE BAY AREA RAPID TRANSIT (BART)

摘要

The Bay Area Rapid Transit (BART) system is a rail transit system in the San Francisco Bay Area that is located within close proximity to more than five active fault lines. For this reason, the BART Earthquake Safety Program was established in the early 2000's to protect the vital infrastructure through seismic retrofit. With two goals in mind - improving life safety during a seismic event and restoring operability shortly thereafter, it included addressing the vulnerability of many of the aerial and station structures built in the 1970's - BART began looking for cost-effective seismic retrofit options for these structures. With BART's proactive approach to seismic retrofit, fiber-reinforced polymers (FRP) were soon considered as an alternate to conventional repair schemes such as steel jacketing and reinforced concrete built-out sections. The lightweight and high strength composite materials served as one potential repair option that could be quickly installed while having minimal impact on the public. Working with industry leaders, BART engineers developed a strict performance based specification for FRP systems that focused on designing the FRP's for a structural requirement. The specification also ensured the use of tested and proven materials, experienced and trained personnel performing the installations and consistent field quality control measures. This paper will examine the utilization of FRP's in seismic retrofit as a means of reducing the impact to the public, minimizing the aesthetic impact on the structure and increasing life safety, while minimizing the overall cost and construction time for the owner.