A Study of the Major Cause for the 2018 Hualien Earthquake Disasters

• Main Authors: Chang Hung Chia, 張弘佳
• Other Authors: 許澤善
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/6x9476

博士 === 逢甲大學 === 土木水利工程與建設規劃博士學位學程 === 107 === All buildings and seaport piers in the seismic zone in Taiwan must meet the seismic design specifications, However, although the Tongshuai building and piers of Hualien Port met the requirements of the current seismic design specifications, they still suffered fall failure and soil liquefaction during the 2018 Hualien earthquake. Since 1974, the regulations of seismic resistance design for buildings and seaport piers in Taiwan have continued to improve the ground vibration resistance level. After the occurrence of the 1999 Jiji earthquake (magnitude ML = 7.3), the ground vibration resistance level was further greatly improved by about twice its previous level. However, building fall failure and soil liquefaction still occurred during the 2018 Hualien earthquake (magnitude ML=6.4) . This indicates that the earthquake hazards were not fully mitigated despite the smaller magnitude of the earthquake and the improvement in ground vibration resistance level. Under the premise that the main effect of tectonic earthquakes is shear banding and the secondary effect is ground vibration, the formation of fall failure and the formation mechanism of soil liquefaction in tectonic earthquakes are first proposed, taking the Tongshuai building and piers of Hualien Port as examples. After the analysis and simulation tests, it is concluded that the main cause of the marginal damage to the Tongshuai building and the soil liquefaction of the piers of Hualien Port was shear banding. Finally, it was found that the previous regulations of seismic resistance design did not include shear banding effect. As a result, even though the ground vibration resistance level had been greatly improved and the design method adopted seismic resistance design, buildings and piers were destroyed during the tectonic earthquake. Therefore, it is recommended to incorporate shear banding effect into the seismic resistance design regulations in the future. Only in this way can we ensure that buildings and piers that comply with the seismic resistance design regulations are stable and safe during tectonic earthquakes. Keywords：Tectonic earthquakes, shear banding, ground vibration, fall failure, soil liquefaction, seismic resistance design.