Seismic response of viscously damped braced thin-wall piping system: a proof-of-concept case study

Thin-wall water piping systems are key to the functionality of important facilities, such as hospitals and schools. Recent earthquakes have demonstrated the vulnerability of these systems. Conventional bracing of thin-wall water piping systems does not guarantee adequate seismic performance. Due to their flexibility, dynamic amplification of long piping runs between bracing elements can occur. This paper evaluates, through a case study, the feasibility of introducing viscous dampers within bracing elements of suspended thin-wall water piping systems to improve seismic performance. Three-dimensional dynamic response analyses were conducted on a suspended thin-wall water piping system under seismic floor motions of various intensities. The dynamic response of the piping system with viscously damped bracing is compared to that of the unbraced and conventionally braced piping system. The numerical results indicate an improvement in seismic response for viscously damped braced configurations. The properties of the viscous dampers that causes the largest reductions in the seismic response of the piping system are noted and practical implementation aspects are discussed.