터널용 강관다단공법의 설계기법에 관한 연구

초록

Pipe roofing or umbrella arch method is usually emplouee as a reinforcing technique when a shallow tunnel is excavated over a weak rock or soil. However, proper analysis and design method on the pipe roofing method is not fully established so far, and site-oriented experience is accepted in most cases. In this study, two approaches on the analysis/design of the pipe roofing method are introduced to better understand the behavior of the reinforced tunnel:the one is based on the mean field theory;and the other on the mechanics of composite material. As a result, the orthotropic material properties of the composite made up of pipe, grout and in-situ rock are derived and these are directly used to analyze the reinforced tunnel structures. It is found that the design method based on the mean field theory which includes the shape factor of the pipe is more efficient.