精巧的工程技术也被发展来解决地下建筑的特殊问题。钢制品在挖掘工程以及安装诸如地下商业街和通道等设备方面起着重要的作用。近年来,日本的地铁建设得到了大规模的发展,它已成为主要城市中满足稳定的人口流动需要的运输网。在毗邻主要地铁站的地下商业区,地面上的铁路与地铁连接的终点站也建造 Exquisite engineering techniques have also been developed to solve the special problems of underground construction. Steel products play an important role in excavating works and installing equipment such as underground commercial streets and passageways. In recent years, Japan’s subway construction has achieved large-scale development. It has become a transportation network for major cities to meet the needs of stable population mobility. In the underground commercial area adjacent to the main subway station, the terminal for the rail and subway connections on the ground is also built.