Experimental Investigation on Flexural Behaviors in Framed Structure of PST Method

Authors: S. Hong, H. Kim, D. Cho, S. Park

Abstract:

Existing underground pipe jacking methods use a reinforcing rod in a steel tube to obtain structural stiffness. However, some problems such as inconvenience of works and expensive materials resulted from limited working space and reinforcing works are existed. To resolve these problems, a new pipe jacking method, namely PST (Prestressed Segment Tunnel) method, was developed which used joint to connect the steel segment and form erection structure. For evaluating the flexural capacity of the PST method structure, a experimental test was conducted. The parameters considered in the test were span-to-depth ratio of segment, diameter of steel tube at the corner, prestressing force, and welding of joint. The flexural behaviours with the effect of load capacity in serviceability state according to different parameters were examined.. The frame with long segments could increase flexural stiffness and the specimen with large diameter of concave corner showed excellent resistance ability to the negative moment. In addition, welding of joints increased the flexural capacity.

Keywords: PST method, Pipe jacking method, Flexural behavior, Prestressed concrete.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1058701

References:

[1] T. Nanno, "A method for driving curved pipe-jacked tunnels," Trenchless Technol. Res., vol. 11, pp. 3-25, Dec. 1999.
[2] D. C. Mathy, R. A. Kahl, "TBM vs. MTBM: Geotechnical considerations," in Proc. 2003 Int. Conf. Pipeline Engineering and Construction, pp. 1261-1270.
[3] C. S. Yoo, "Deformation behavior of tunnel face reinforced with longitudinal pipe-laboratory and numerical investigation," Tunneling and Underground Space Technology, vol. 18, pp. 303-319, Nov. 2002.
[4] K. K. Kim, "A study on the structural safety of the complex underground structure using steel tubular roof," Master Thesis in Yonsei University, 2007.
[5] KSCE, "Bridge Design Specification," Korea Society of Civil Engineer, 2005.