Abstract
It is important to establish a planning and design method of countermeasures for existing mountain tunnels in service deformed by earth pressure, in order to perform maintenance management of tunnels pertinently.
This paper discusses basic ideas on countermeasures for the mountain tunnels deformed by plastic earth pressure and loosening vertical earth pressure as follows ; 1) case studies on railway tunnel deformation due to plastic earth pressure and loosening vertical earth pressure ; 2) evaluation of deformation behavior of the various tunnel lining structures by two kinds of tunnel loading experiments ; 3) development of a numerical prediction method of tunnel deformation using a time-dependent ground strength reduction method ; 4) recommendation of necessity to examine tunnel deformation mechanism from an engineering geological view.
