二, 三の堆積岩のクリープについて

抄録

As a part of the fundamental studies on the underground pressure, we have engaged in the investigation on the creep of rocks, on which a few studies have been published. This paper describes our experimental and theoretical studies on the creep characteristics of some sedimentary rocks. The results obtained are as follows:
(1) Izumi Sandstone fails due to creep under the stress about 80% of its mean compressive strength lasting a long period of time. It is supposed that the similar tendency may probably be found in most sedimentary rocks.
(2) The creep characteristics of rocks are approximately explained by means of the Burgers model, from which an equation to represent the creep strain under relatively high stresses is derived.
(3) The constants concerning with the creep properties of shale, sandyshale and sandstone are determined.