Transition of the pipe jacking technology in Japan and investigation of its application status

Pipe-jacking is one of the trenchless methods being widely used for the construction and maintenance of urban underground pipelines. As an eco-friendly construction method, it has the capacity for the installation of pipelines with diameters from 100 mm (4 in.) to 5000 mm (200 in.) covering the majority needs of municipal pipeline construction and is considered the most widely used trenchless method in Japan. However, there is little English literature that systematically introduces the research and application status of pipe jacking technology in Japan, resulting in a serious underestimation of Japanese research achievements in this field. This paper briefly reviews the origin, evolutionary stages, and classification system of the pipe jacking method in Japan, and representative technological advances are also introduced through case statistics. Meanwhile, the deficiencies in the current classification system of the International Society of Trenchless Technology (ISTT) are discussed as well. In addition, the application status of this method is investigated based on survey data from the Japan Society for Trenchless Technology (JSTT). According to the survey data from 5232 projects, a systematic analysis is carried out on the selection of pipe jacking equipment, the scale of jacking construction, the profile of curved projects, and the geological adaptability of the pipe jacking method in Japan. The emphasis of this paper is to introduce the current technical situation and analyze the development trends of the pipe-jacking method based on Japan's experience, and to popularize this method in other countries that need this simple, effective, and economical construction technique under the background of climate change.