Mitigation of Impacts on Petrochemical Projects in Areas of High Seismic Risk

Several earthquake related items should be considered in order to have a successful petrochemical project in a region of high seismic risk. One of the first things that should be established for the project is the seismic design criteria. The essential seismic parameters required for design include the design response spectra, Seismic Design Categories (SDC) assigned to structures, and liquefaction potential of local soils. These are essential for proper seismic evaluation of a petrochemical facility. Over estimation of these parameters can lead to costly over design. Under estimation of these parameters can only be corrected by even more costly retrofit. There are many petrochemical plants located in areas where there is a high probability of large ground motions due to earthquakes. Structures within these facilities are typically assigned to higher Seismic Design Categories which trigger special seismic detailing of structural steel, concrete, and equipment. The impact of these seismic detailing requirements is that there will be increased design and engineering man-hours, increased fabrication costs, and increased construction costs compared to comparable projects without seismic detailing. It takes knowledge of the applicable codes and standards, experience in planning and executing such projects, and coordination of efforts between engineering disciplines to mitigate the impacts of high seismic risk considerations. This paper not only identifies the major considerations for petrochemical projects in areas of high seismic risk but also makes recommendations for the mitigation of impacts due to these considerations.