INSPECTION POLICY AND PROCEDURES FOR RAIL TRANSIT TUNNELS AND UNDERGROUND STRUCTURES

This synthesis will be of interest to transit agency general managers; design, maintenance, and standards engineers; and inspection and maintenance staff. This synthesis describes the current state of the practice for specific management policies and procedures and engineering/physical techniques used to inspect rail transit tunnels and underground structures. It discusses the available data on, different approaches of, and potential data inadequacies for agency rail transit tunnel inspection policies and procedures and inspection techniques. This report presents data obtained from a review of the literature and a survey of North American and international transit agencies. In addition, five case studies are presented to look more closely at the tunnel inspection practices of four domestic and one foreign transit agency.