921 Earthquake Disaster Survey and Follow-up Studies

921 Earthquake Disaster Survey and Follow-up Studies

A disastrous earthquake, also known as 921 or Chi-Chi Earthquake, measured 7.4 in Richter magnitude scale hit Taiwan on Sept 21st, 1999, and caused severe damages to many infrastructures and human lives. Two major hydraulic infrastructures, the Shih-Kang weir in Tongshih and the Shuisheh Dam in Sun-Moon Lake, also suffered damage by this massive quake. DPWE the very next morning was assigned by the Water Resources Agency (WRA) to initiate a disaster survey. A few months post quake, the DPWE also worked jointly with US specialists to carry out a detailed disaster survey and data collection in Caotun area under the institutional support from National Science Council (NSC), Executive Yuan, Taiwan.
A measured 6.4 quake, which hit Chiayi at 10 A.M. Oct 22 1999, caused a serious rupture on the top of the Renyitan Dam. Abnormal seepage also happened accordingly. DPWE specialists arriving at 8 P.M. deployed a detailed investigation and filed a report to the WRA.
Post 921 Earthquake, Prof. An-Bin Huang carried out a study on the dynamic behaviors of silty fine sand and liquefaction potential assessment in central western Taiwan, sponsored jointly by the WRA and NSC. In this study, Laval sampler was first introduced in Taiwan on the undisturbed soil samples for dynamic triaxial tests. Results were published in several well-known journals. Prof. Huang was also invited as the keynote speaker in conferences.
Profs. Yii-Wen Pan and Jyh-Jong Liao focused on the landslide dam caused by the 921 Earthquake for a long-term investigation and analysis. Their experiences were also shared with the Chinese specialists after the 2008 Sichuan Earthquake. Profs. Pan and Liao are being appointed as the principal investigators by the NSC to carry out the study on landslide dam behaviors after the 2009 Typhoon Morakot disaster.

Serious failure on the Shih-Kang dam

Serious failure on the Shih-Kang dam

Ruptures on the top of the Renyitan dam

Ruptures on the top of the Renyitan dam

Laval sampler

Laval sampler