Environmental Effects Of Kobe Earthquake

The Kobe Earthquake, also known as The Great Hanshin Earthquake occurred January 17th, 1995, resulting in the second most deadly and most damaging Japanese earthquake of the 20th century behind The Great Kanto Earthquake of 1923. The epicenter was 20 km southwest of Kobe, with a moment magnitude of 6.9. Figure 1 shows the location of the epicenter with respect to the island of japan. The main ground shaking lasted about 20 seconds as a result of a right lateral strike-slip faulting system.
A considerable portion of the areas infrastructure, which at the time was considered to be able to withstand a major earthquake was destroyed. The worst damage occurred in heavily developed regions built upon poor soils and artificial fill (loose and soft soil) leading to amplified ground motions and longer durations. (EQE) Kobe city was the most populous city in the region which suffered most infrastructure destruction and loss of life. Other densely populated regions affected include the towns of Ashiya and Nishinomiya, which lie east of Kobe. The event resulted in an estimated 6,000 casualties and about 41,500 people were injured (NIST). The majority of damage, both in loss of life and monetary loss was seen in building structures (89% of all
These were usually non-seismically engineered residential structures, in which the walls were not designed to resist the significant lateral loads created by the heavy tile roofs during shaking (EQE). The more engineered building structures, particularly reinforced concrete and some steel reinforced concrete (SRC) construction will be examined in this report. There was also damage to steel structures; they generally performed better due to their flexibility, but failure and collapse of steel buildings coincided with lack of code development as will be discussed regarding concrete buildings.