SPECIAL ISSUE OF SOILS AND FOUNDATIONS 1-5, Jan. 1996 Japanese Geotechnical Society

DAMAGE STATISTICS

MAKOTO KIMURAi)

ABSTRACT

Statistical results of the damage which occurred mainly in Hyogo Prefecture from "the 1995 Hyogoken-Nambu " are given. Introduction of Hyogo Prefecture, earthquake overview, and earthquake damage and its recovery to lifeline, highway, railroad, and harbor are presented.

Key words: earthquake damage, statistics (IGC: E8)

1995). In Japanese "ken" and "nambu" represent a INTRODUCTION prefecture and southern part respectively. It is also At 5:46 am (local time) on Tuesday, January 17, 1995, referred to as "the Great -Awaji Earthquake an earthquake of magnitude 7.2, with its epicenter at the Disaster" by Japanese Government as a reference to the northern part of , occurred. The earthquake disaster caused from the earthquake. This report gives was a right-lateral strike-slip type and caused violent statistical results of the damage which occurred mainly in shaking in urban areas. As a result, urban facilities Hyogo Prefecture as a result of the earthquake. around city experienced serious damage. The earthquake was named by JMA ( Meteorological HYOGO PREFECTURE Agency) as "the 1995 Hyogoken-Nambu Earthquake" (News Letter of the Seismological Society of Japan, Hyogo Prefecture is located 450 km southwest of Tokyo, with a population of 5.466 million (1992) and area of 8,383 km2, as shown in Fig. 1. Kobe city, the capi- tal of Hyogo Prefecture, is located in the southern part of Hyogo Prefecture, with a population of 1.477 million (6th largest city in Japan). Kobe Harbor is the second largest in Japan. city, with a population of 2.644 million, is located east of Kobe. Between Osaka and Kobe, a few cities like Ashiya (population of 88 thou- sands), (population of 427 thousands) and Amagasaki (population of 499 thousands), are located which form a zone of high density population. These areas including Kobe city and Osaka city are called the "Hanshin" area .

EARTHQUAKE OVERVIEW Table 1 presents an overview of the earthquake as con-

Table 1. Dimension of the 1995 Hyogoken-Nambu earthquake

Fig. 1. Location of "Hyogoken" and Kobe in Japan

i) The Editorial Committee of the Special Issue of Soils and Foundations. (Associate Professor, University.) Manuscript was received for review on September 4, 1995. Written discussions on this paper should be submitted before August 1, 1996 to the Japanese Geotechnical Society, Sugayama Bldg. 4F, Kanda Awaji-cho 2-23, Chiyoda-ku, Tokyo 101, Japan. Upon request the closing date may be extended one month.

1 2 KIMURA

cluded by JMA. As shown in Fig. 2, the seismic intensity in each area is, EARTHQUAKE DAMAGE AND ITS RECOVERY according to the JMA scale, as follows; VI: Kobe and The 1995 Hyogoken-Nambu earthquake is the first one Sumoto, V: Kyoto, Toyooka and Hikone, IV: Osaka, that directly impacted a modern city in which urban facili- , Wakayama etc. In a large area from Kyushu to ties were highly concentrated. Many people died in the the middle of Honsyu, the earthquake was also felt. In earthquake. Not only buildings, but also highway addition, according to JMA, an earthquake survey team bridges and railway bridges including system was sent to make observations on the day the earthquake (inter city high speed railroad system in Japan), were des- occurred. The survey team found that violent shaking troyed. The liquefaction of soils, the disruption of life- with seismic intensity VII occurred in part of the area line systems, all caused a fatal damage to civil facilities along Kobe, Ashiya, Nishinomiya, Takarazuka cities and which form the nucleus of a modern city. on Awaji island. The seismic intensity VII (approximate- According to the report dated August 24 by the Coun- ly equal to XI in modified Mercali intensity) is defined termeasure Headquarters of the Great Hanshin-Awaji based on the 1948 earthquake and this means that Earthquake Disaster in Hyogo Prefecture, the death toll for such an intensity, 30% of the wooden houses would was 5,480 (total 5,502 including other prefectures), in- be destroyed. jured were 34,900. The number of houses damaged

Fig. 2. Location of epicenter and map of JMA seismic intensity (Asahi Newspaper, January 18, 1995) after the 1995 Hyogoken-Nambu earth- quake (After Bardet et al., 1995)

Fig. 3. Detailed map of JMA seismic intensity VII in Hyogo Prefecture and on Awaji Island (After News Letter of the Seismological Society of Japan, 1995) DAMAGE STATISTICS 3

Table 2. Estimated damage value (After references)) Table 3. Damage to lifelines (After references))

Table 4. Damage to highways (After references))

reached 200,162, among which 92,540 were completely Table 5. Damage to harbors (After references)) collapsed and 7,456 were "burned out". The families affected by the damage reached a total of 415,659. Ac- cording to the estimate (up to April 5), shown in Table 2, the assessment value of the damage from the earthquake amounts to 9926.8 billion Japanese yen. Table 3 shows the damage and recovery situation for lifeline systems. The situation for the highway, harbor and railway systems is described in Tables 4, 5 and 6 re- spectively. Figure 4 shows the sections of railway and highway which were interrupted one week after the earth- quake occurred. Up to September 1, almost all these out- of-service transportation systems, except for the Kobe line of the , had service restored as a result of 24 hour rehabilitation and repair work. Table 7 gas pipes were severely damaged over a wide area. The shows the population and financial requires allocated for Shinkansen, expressway, new transportation system and these support activities. mass-transit systems were also severely damaged. Finally, the extent of earthquake damage can be con- 2) In the area where wooden houses are concentrated, cluded from the statistical investigation as follows; collapses and fires occurred everywhere, 294 fire disasters 1) Since large cities were directly affected by the earth- were reported according to National Land Agency (1995). quake, "lifeline" namely electricity, water supply and Especially in Hyogo and Nagata wards of Kobe City, 4 KIMURA large-scale fire disasters occurred frequently. curred however and caused serious damage on a huge 3) During the 50 year period after World War II, no scale. Since the Hanshin area has one of the most concen- large earthquake occurred in the area affected by this trated populations in Japan, many persons whose houses earthquake. Preparation for emergency in every field was were destroyed in the earthquake were severely impacted not really adequate. This unexpected earthquake oc- in their daily live in shelters.

(a) Railway conditions

(b) Road conditions

Fig. 4. Sections of railway and road interruption due to earthquake damage on the morning of January 24 (After Asahi Newspaper, January 24, 1995) DAMAGE STATISTICS 5

Table 6. Damage to railways (After reference5)

Table 7. Support systems for recovery (After referencess) and6)) REFERENCES 1) Asahi Newspaper, Wednesday, January 18, 1995 (in Japanese). 2) Asahi Newspaper, Tuesday, January 24, 1995 (in Japanese). 3) Bardet, J. P., Oka, F., Sugito, M. and Yashima, A. (1995): "The disaster (The 1995South Hyogo Prefec- ture Earthquake), Preliminary Investigation Report". 4) Disaster Prevention Bureau, National Land Agency (1995): The Great Hanshin-Awaji Earthquake Disaster, August 7, 1995 (in Japanese). 5) The Countermeasure Headquarters of the Great Hanshin-Awaji Earthquake Disasterin Hyogo Prefecture (1995a):Restoration Con- ditions for the Great Hanshin-Awaji Earthquake Disaster, August 24, 1995 (in Japanese). 6) The Countermeasure Head-quarters of the Great Hanshin-Awaji Earthquake Disaster in Hyogo Prefecture (1995b): The Great Han- shin-Awaji Earthquake Disaster, Records of one month of Hyogo Prefecture (in Japanese). 7) News Letter of the SeismologicalSociety of Japan (1995):"Gener- al earthquake conditions, Japan Meteorological Agency", Vol. 6, No. 6, pp. 23-25 (in Japanese).