Relation between the shear and uniaxial strength of rock materials
The trap, in the translating formulation of the shear strength parameters(cohesion c, friction angle ϕ) and uniaxial strength parameters (tensile strength σt compressive strength σc) of rocks as Crude Kuroiwa, sandstone and etc., is discussed by comparing with the relative parameters measured from experiments. A statistical formula between the parameters of the deduced and measured uniaxial strength is represented, and a theoretical formula is derived and verified in the transmission process between the deduced and measured shear strength parameters.
Strength of rock-like materials
Abstract This paper deals with the strength of rock-like materials under triaxial stress conditions. The most common theories of brittle fracture are reviewed. Some methods of triaxial strength determination are described and the results compared. The strength dependence of lateral pressure, pore pressure and size of the test sample is described. Some standard tests are suggested. A method for determining the shear strength at high normal pressure has been used as a measure of the strength of a number of Swedish rocks and ores.
Time and Heritage
As a historian studying what can be considered a form of intellectual history, I have slowly come to adopt Michel de Certeau’s observation made at the end of the 1980s that ‘objectifying the past, for the last three centuries, has undoubtedly left unconsidered time within a discipline that has continued to use it as a taxonomic instrument’. To a certain degree, time has become commonplace for the historian who has preserved or instrumentalized it. It is not considered because it is inconceivable, but because we do not think of it or, more simply, we do not think about it. As a historian attempting to pay attention to the time I’m living in, I have thus, like many others, noticed the swift development of the category of the present until it has become obvious that the present is omnipresent. This is what I refer to here as ‘presentism’.