Evaluation of Seismic Resistance of a Fire Protection Riser Pipe System with a Line Segment Analysis Approach

Abstract

Effective stresses due to a seismic occurrence are prevented in piping systems by means of seismic bracings and piping supports. A line segment analysis determines if each pipe segment in a pipe system has enough flexibility to survive the target seismic event with a calculated, optimal use of supports. These ideal support locations, or anchor points, are determined by modeling the stresses at each pipe segment and using several iterations based on different anchor locations. From these iterations, the combined stress from the pipe system is compared against a predetermined seismic stress. If the combined stress is less than the seismic stress, then the pipe system is capable of surviving these seismic stresses with a calculated amount of supports. This evaluation gives designers the confidence that the resulting support layout for a given pipe system meets the demanded resistance for a modeled seismic event. This study was made in hopes that this approach becomes a standard procedure for engineers everywhere. It allows the successful positioning of seismic supports in a pipe system in order to satisfy its seismic design criteria by lending the right amount of flexibility to the system. Key Terms - Anchor Point, Effective Stress, Line Segment Analysis, Pipe System.