ABSTRACT
Abuchiragama is karstic cave in Ryukyu limestone. There is a increasing tendency that ground water is seeping in from top of cave after rainfalls. For the safety of entrants, it is necessary to evaluate the stability of the cave. This study is concerned with the risk managment of this cave utilizing RMQR as a new evaluation method of the quality of rock mass, and the stability evaluation of the cave was carried out through an empirical method and analytic methods. It is understood that it is necessary to examine in details the areas accessible to entrants, in particular, the entrance and exit areas. These areas are now being investigated in details and we have been considering to review the counter-measures master plan for rehabilitation.
