Development of rectangular pipe jacking systems for urban infrastructure utilization

In constructing infrastructure in urban area, circular pipes have been used for a long time. But recently, construction in rectangular pipes has been increasing gradually. As a background of this situation, it is thought that rectangular pipes are very efficient because effective cross-section area becomes larger, and maintenance of the lifeline becomes easier compare with circular pipes. In constructing rectangular pipe lines, open cut method has been mainly adopted. But because of the increase of underground structure and the influence to the neighboring environment along with the formation of the city, it has been shifting from open cut method to trench-less technology and the demand for this method has a tendency to increase. But there are little rectangular pipe jacking machines. It is thought that this machine is very useful for small scale construction, and the demand for those constructions is increase gradually now. This paper shows the process about the development of the rectangular pipe jacking machine with closed type, and shows the examination contents and the results in an experiment and two work sites, and examines the contents those are constructed by this rectangular pipe jacking machine.