前言在危及公共土木设施的各种自然灾害中,地震灾害可以说是一种特殊的灾害。地震与季节、时间、气象条件完全无关,而且发生时几乎没有明显的前兆现象。在日本,从北海道至九州,几乎整个领土都有可能发生破坏性地震。可是,从一个地区来看,大地震的发生频度低,大地震袭击同一个地区要几十年一几百年才有一次,因而,同一代人经历过两次以上大地震的情况极其罕见。因此,过去的受灾经验很难用于下次地震。 Preface Earthquake disaster can be described as a special kind of disaster in various natural disasters that endanger public civil installations. Earthquakes have nothing to do with the season, time and meteorological conditions, and there is almost no obvious precursor phenomenon. In Japan, a devastating earthquake can occur in almost the entire territory from Hokkaido to Kyushu. However, from a region’s point of view, the magnitude of the major earthquakes is low, and it only takes decades or centuries before a major earthquake strikes the same area. As a result, it has been extremely rare for the same generation to experience more than two major earthquakes . Therefore, past experience of disaster is hard to use for the next earthquake.