Slope failures and tailings dam damage in the 1978 Izu-Ohshima-Kinkai earthquake

摘要: The Izu-Ohshima-Kinkai earthquake (M = 7.0 on the Richter scale) occurred at 12h24 Japan Standard Time 14 January 1978 in Sagami Bay, and caused hazards eastern to central Izu Peninsula. meizoseismal zone extended 15 km from east west by 20 north south. The aftershock shifted westward interior of peninsula. largest 5.8) struck western part peninsula January, causing severe damage its mountainous terrain. Most related slope failures sea cliffs, river cliffs road cuttings convex vertical section with upper parts sloping gently lower steeply. Large close activated faults, indicating that shocks displacement were locally amplified along faults. In zone, high embankments roads housing sites natural slopes damaged slides tension cracks between embankment ground. Subsidence tilting retaining structures generally observed. Damage concrete walls gravity type was due insufficient bearing capacity foundation soil. Any structure, even if seismic-resistant, would be considered ineffective case failure back slope. Buildings sliding underlying ground faults. Falling rock blocks soil masses cars houses foot steep slopes, many deaths injuries. A number middle shoulders threatened cause secondary failures, rockfalls avalanches during heavy rain. At a gold silver mine, tailings dam concentration plant failed liquefaction tailings. The above experience may throw some light possibility seismic countries seismically active regions world.