Tangshan earthquake: Performance and retrofit of industrial facilities

Following the disastrous 1976 Tangshan earthquake, the Chinese government took steps to modify the seismic codes and to mitigate earthquake damage. This paper includes many illustrations. Special attention is focused on petrochemical facilities where inflammable and explosive materials are processed, stored, and transported. The performance of these facilities and methods of seismic evaluation are presented. Retrofitting measures are outlined for a number of structures and structural systems ranging from towers and furnaces to cylindrical and spherical vessels. The majority of the recommended retrofits include strengthening the tie between the structure and its support(s) by increasing the number of anchor bolts, and increasing the strength of welding ribs or plates. Although these measures were undertaken in China, the problems are by no means unique to China; they are universal.