前言由于近来在都市中普遍地存在高层的建筑物和巨大的结构物,因而搞清深土层的构造和了解在地震时周期范围在10秒内的地表特征就非常重要了。为此目的,曾在东京市区用爆破法进行了地震勘探,结果清楚地表明东京市区的深土层是由三层土组成的,并且用时项法表示了地震 Preface Due to the widespread presence of tall buildings and immense structures in the cities, it is important to understand the structure of the deep earth and to understand the features of the earth’s surface within a period of 10 seconds during an earthquake. To this end, seismic exploration was conducted by blasting in the urban area of ​​Tokyo, and the results clearly showed that the deep soil layer in Tokyo’s urban area is composed of three layers of soil and the earthquake term is used to express the earthquake