高温および低温が岩石の圧縮破壊特性に及ぼす影響

抄録

In order to get the strength and deformation characteristics of Class II rocks which show a positive gradient in the post failure region of their stress-strain curves obtained by uniaxial compression tests, several methods have been tried and devised. One of them is a method of controlling the strain velocity and stress at the same time proposed by Nishimatsu et al.. However, this method needs a troublesome process to choose different gradients before and after failure. The present authors are proposing a method controlling the strain velocity before failure and then the stress and strain after failure.
In this study, the strength and deformation characteristics of rocks at high and low temperatures obtained by our method using a trial machine were described and discussed. The results are useful as the basic information to store high and low temperature materials in caverns in rock mass. The results obtained are as follows:
(1) The strengths of both Dry and Wet rocks used in this study, such as granite, andesite, sandstone and tuff, became lower with rising temperature and the strain at peak became larger.
(2) The returning gradient of Class II rocks in the post failure region of the stress-strain curve at high temperature became lower with rising temperature, while it was a gentle change in Class I rocks.
(3) The strength of rocks at low temperature became higher with falling temperature, and the strain at peak became smaller. On the other hand, the strength of wet tuff became higher, and the strain at peak became larger.
(4) The returning gradient of Class II rocks in the post failure region at the stress-strain curve at low temperature became larger with falling temperature, while it was a steep change in Class I rocks. On the other hand, the gradient of wet tuff became gentle with falling temperature.