Year: 1992
Type: article
Abstract: In practice, rock mass is neither subjected to pure creep or pure relaxation but to a torce-cisplacement condition dictated by surrounding rock.But few are available in the literature about this problem.Generalized relaxation test of Sanjoume-andesite and Kawazu-tuff was conducted under uniaxial condition.The generalized relaxation test investigates the property of time-dependent decrease (or increase) of stress under increasing (or decreasing) strain.Concretely, the increment of force-displacement relation was kept as follows;where 4FR is the increment of force, 4 YR is that of displacement, kR is the stiffness of rock sample in the elastic region and 7 is the direction factor of relaxation.Considering all possible boundary conditions (the relationship of the stress-strain), the direction factor of relaxation can be all real number.By plotting all results on a stress-strain diagram, it can be said that the stress-strain curve shrinks as time goes by.In other words, rock characteristic line changes with the lapse of time.A strain rate at an arbitrary time in the region where the strain rate is signified by a continuous increase is inversely propotional to the time up to final failure.If this law is applied to rock mass, the failure of underground constructions may be predicted.
Source: Shigen-to-Sozai
Institutions: Taisei (Japan), The University of Tokyo
Language: English
Topic: Rock Mechanics and Modeling
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2332908591