A Study for improvement of the credibility of evaluation method for the long-term dynamical behavior of near-field rock mass, 2; A Study for the influence of inner pressures caused by buffer material and overpack

Hiramoto, Masayuki; Kobayashi, Yasushi; Aoyagi, Shigeo*; Miyanomae, Shunichi*

For improvement of the credibility of evaluation method for the long-term dynamical behavior of near-field rock mass, the influence that swelling pressure caused by buffer material and expansion pressure caused by the erosion of overpack gave long-term stability of near-field rock mass was studied in this report. As a result, because swelling pressure caused by buffer material and expansion pressure caused by the erosion of overpack acted on near-field rock mass as inner pressure, long-term stability of near-field rock mass improved. And it was shown that conventional evaluation method gave results of safe side. But as an exception, when stiffness property of buffer material is large and initial stress of rock mass is small, a possibility that tensile fracture occurred in near field rock mass was shown. In such a case, a possibility that functional decline of artificial barrier happens is concerned, because buffer material flows out into the crack that occurred in rock mass.