Damages to Building Structures Caused by the 1999 Chi-Chi Earthquake and Related Issues in Taiwan and Okinawa

At local time of 1:47 a.m. on September 21st 1999, a 7.7 Richter scale earthquake struck Taiwan at its geographical center a mountainous village called Chi-Chi. The measured maximum seismic accelerations at the epic center were 990 gal east-west, 563 gal north-south, and 520 gal vertical, respectively. The quake is the strongest ever recorded in Taiwan for the past 100 years. This earthquake caused approximately 2,400 dead and 12,000 injured. Collapsed and heavily damaged buildings exceeded 18,000 and an estimated property loss reached to 100 billion US$. Based on the field investigation conducted in Taiwan, damage to building Structures caused by the 1999 Chi-Chi earthquake is introduced. Special emphasis is placed on the damage to the reinforced concrete buildings. These earthquake damaged or collapsed buildings gave a hard lesson to us. Also, they made us discuss problems on the seismic design codes and seismic performance of buildings in Taiwan and Okinawa