RISK ANALYSIS AND ADVANCED TECHNOLOGIES FOR INFRASTRUCTURE

利用地理数据库进行城市地震危险性评估是去年提出的。在该方法中，用于评价城市地震危险性评估的阈值在测量线上是不同的，并且该方法没有考虑液化。这些问题都是在今年修改的。波的传播模型采用三维地质边界条件，浅层采用一维模型。可以得到相同的阈值。对于沿海地区，考虑液化影响进行有效应力分析，得到的损伤分布与计算的结果吻合较好。研究了地面运动估计方法。在没有考虑场地局部放大特性的情况下，已经提出了形状插值法。为了加强这一方法，分析了基于微震的地面信息，提出了一种估计地面卓越周期的方法。结果表明，H/V谱比积分与频率传递函数积分有很好的对应关系。将改进的方法应用于1999年台湾集集地震中集集村至震中的微区划，提出了两种基于地理信息系统的滑坡灾害防治技术。它们是1)利用DEM和土地利用数据提取危险坡度和崩塌地带的技术；2)提取降雨引起的斜坡崩塌危险区域并将结果显示在地图上的技术，以便将信息分发给当地居民。这些技术可以应用于许多可以获得这些数据的地方。选择横滨市南区作为研究区域，取得了令人满意的结果。

Urban risk assessment for earthquake was proposed last year by using geo-data base. In that method) the threshold value employed to evaluate the urban risk assessment for earthquake was different at the measuring line, and the liquefaction did not considered in that method. These some problems ware modified in this year. The wave propagation model in which three-dimensional geological boundary condition was taken into was used and one-dimensional model was used for shallow layers. The same threshold value can be obtained. And for the coastal area, the damage distribution of wooden house was agreed to the calculated one that was obtained by the effective stress analysis that was made in order to consider the influence of liquefaction.The ground motion estimation methodology was researched. The shape interpolation method has already been proposed without consideration of local site amplification characteristics. In order to enhance this methodology, the ground information based on microtremor was analyzed and then an estimation method for the ground predominant period was introduced. It has been shown that the integral of H/V spectra ratio has a good relation with that of the frequency transfer function. The enhanced methodology was applied, to microzonation of Chi-Chi Village to the epicenter during the 1999 Chi-Chi, Taiwan Earthquake.Two techniques using GIS for the measure against slope failure disaster are proposed. They are 1) a technique of extracting dangerous slopes and zones suffered from slope failure, by DEM and land use data, 2) a technique of extracting dangerous area of slope failure due to the rainfall and show the result in the map to distribute the information to local residents. These techniques can be applied to many places where these data are available. Minami Ward in Yokohama City was selected as the study area, and the obtained result was a satisfactory one.