In this study, a series of creep and fatigue tests are carried out on soft and hard rocks in Japan. These tests are performed by means of both the conventional loading procedure and a newly developed procedure, which we have named the "creep/fatigue loading and after load increase test." By using the latter test, a complete stress-strain path of the failure process of creep or fatigue loading of the specimen can be obtained, and the current residual strength along any point of the path can also be determined. Finally, the relationship between the failure process of creep or fatigue loading and the failure process of conventional compressive loading on rock is discussed, and the creep or fatigue limit is discussed based on the stress level required to cause the specimen to fail.
Dans cette enquête, une serie de tests de fluage et de fatigue est effectuee sur des rochers tendres et durs au Japon. Ces tests sont faits au moyen du precede de chargement conventionnel et aussi d'un procede nouvellement developpe que nous avons appelle "test de chargement par fluage/fatigue et augmentation postcharge". En employant ce dernier test, il est possible d'obtenir une complete route de charge/tension du procede de defaillance de fluage/fatigue; et I'actuelle force residuelle de n'import quel point sur cette route peut être determinee aussi. Enfin, la relation entre Ie procede de defaillance de chargement de fluage/fatigue et Ie procede de chargement compresif conventionnel du roc est discutee; et la limite de fluage ou de fatigue est discutee par rapport au niveau de stress necessaire pour faire faillir Ie specimen.
In dieser Studie machen wir einige Versuche urn das beim Kriechenbelastung auftretende Bruchverhalten vom Gestein Japans zu analysieren und zu deuten. Erstens, machen wir die regelmassigen Kriechenpruefungen, und danach werden einige Untersuchungen durchgefuhrt, mit der Hilfe der neu entwickelten Methode, die in der Mitte des Weges das Belastungs-zustand von Kriechen zu konventionelle einaxale umgestellt werden können, urn die gegenseitigen Beziehungen zwischen Abnameverlauf von Gesteinsfestigkeit und dabei Belastungszustand feststellen.
Recently, underground rock constructions have been attempted in efforts to build such large-scale rock structures as underground hydroelectric plants or oil storing plants. Thus it is necessary to establish methods for estimating the long-term properties of rock and rock-mass characteristics.
One of the problems in estimating the long-term stability characteristics of rock is the acquisition of data, not only of the stress-strain relations and strength properties, but also of the time-dependent deformation properties.
In this study, a series of creep and fatigue tests were carried out on soft and hard rocks in Japan. These tests were performed by means of both the conventional loading procedure and a newly developed procedure, which we have named the "creep/fatigue loading and after load increase test"(;CALI/FALI test). The latter test is carried out in such a way that the first creep or fatigue load is maintained during a controlled period or times on the specimen, and after that the load is increased to the maximum value, which causes the failure of the specimen. The load is then sustained to determine the post-failure stress-strain curve of the specimen.
