Seismic Analysis of Above Ground Piping in Process Plant

The recent natural calamities, especially earthquakes, are making engineering design requirements stringent. The Process Plant Piping is no exception to it. Analyzing the seismic effect by ‘Static Equivalent Method’ is a common practice compared to performing ‘Dynamic Analysis’. This paper starts with the basic reason of earthquake and its effect on the above ground piping system. Further it compares between the results opted based on computer based ‘Spectrum Analysis (Dynamic Analysis) Method’ and ‘Static Equivalent Method’ as per the requirements of ASCE 7. One of the assumptions in Static or Dynamic seismic analysis is — ‘Pipe supports are rigid’. However, in reality the supports, especially structural supports, show elastic behavior based on their material and geometric properties. At the end, this paper compares between the results of seismic analysis performed by considering ‘Supports as rigid’ and ‘Supports as elastic’ and comments on it along with minimum requirements for safe design.