美国明尼苏达大学地下空间中心主任雷·斯特林说:“随着土地的使用压力和公众对拥有一个更好的清洁环境的要求日益突出,人们将越来越多地利用地下大搞建设。”日本政府和各大建筑公司早在5年之前就已开始了地下规划,当时,日本的地价正被炒成“天价”。今天,建筑公司希望到2020年时建成一座小型的地下城市。 Ray Sterling, director of the Center for Underground Space at the University of Minnesota, said: “As the pressures of land use and public demand for a cleaner environment become more prominent, more and more people are going to make use of underground constructions. ”The Japanese government and major construction companies started underground planning as early as five years ago when land prices in Japan were being speculated to be“ sky-high. ” Today, construction companies want to build a small underground city by 2020.