Laboratory experiments on strength and deformation of granite and tuff subjected to thermal hysteresis of high and low temperatures

摘要

The authors have been proposed and discussed temporary storage of high and low temperature materials in openings excavated in rock mountain. Here, high temperature materials means such as heated water which is produced by surplus heat from garbage burning plants, while low temperature materials means such as LNG, LPG, frozen food etc. In this case, as the storage quantity of heated water; LNG and LPG will change with these use continually, rock masses around openings to store these materials willreceive effects of thermal hysteresis of high and low temperatures. Therefore, obtaining the strength and deformation characteristics of rock affected by the thermal hysteresis becomes important for discussing the stability of the openings. In this study, strength and deformation characteristics of granite and tuff were examined after undergoing thermal hysteresis of high and low temperatures. From the results, it was found that the decreasing ratio of strength and deformation of rocks decrease with theincreasing number of thermal hysteresis, and it is supposed that the value will converge to a constant value.