Abstract:

The Kaohsiung MRT Orange line, CO1, has 2 different sections where shield tunneling work is going on. These 2 areas pass through the 3rd canal of the Kaohsiung harbor and JenAi River respectively. Besides that, for this project, there are a total of three out of four Crosspassage that are situated underwater, however the loose silt sand with a high ground water table, made it even more difficult to excavate the area. 2 Crosspassage had already been completed using the original design of JSG (high pressure jet grouting) method to improve the soil condition and then followed by the compressed air method. However, the other 2 Crosspassage were unable to use the original tunneling construction method because of a major accident that happened at the neighboring Crosspassage which involves the construction water well. Hence, taking into considerations the special soil condition of that area, it was decided that the compressed air method should still be used so as to beble to lower the risk of any accidents from happening.
　　This paper aims to explain the choice of using the compressed air method in design, construction and solving problems. It is expected that the concept described in this article can be served as a reference for future similar projects.