Study on the Shrinkage Error of Similar Material Simulation Experiment
Shrinkage error will impact the results obtained from the observation data when studying subsidence by the method of similar material simulation experiment. Using digital industrial close-range photogrammetry system in the experiment, high-precision observational data is collected. By comparative analysis on the subsidence of the points at different locations, we obtained the distribution law of shrinkage subsidence and horizontal movement which has great significance for the study on how to reduce the shrinkage error effectively.
EXPERIMENTAL RESEARCH ON EFFECTS OF INITIAL JOINTS ON SURFACE DISPLACEMENT DUE TO COAL MINING
Surface displacement caused by underground coal mining is influenced by many factors such as the depth and thickness of the coal seam and joints in overburden rocks. Extensive efforts have been devoted to the ground surface displacement. Nevertheless, the joints have not been taken into consideration for a long time. In fact, there exist numerous joints and cracks in rocks. As a result, the joints in overburden rocks have to be taken into account. The joints in rocks can be treated as initial damage theoretically. In this paper, two kinds of physical model, one containing no initial joints and another containing some initial joints, are employed to systematically investigate effects of initial joints on surface subsidence. Moreover, within the framework of damage mechanics, the statistical relationships between the characteristic value for surface displacemerit and damage variable are obtained.
The Cosmopolitan Imagination: The Renewal of Critical Social Theory
Gerard Delanty provides a comprehensive assessment of the idea of cosmopolitanism in social and political thought which links cosmopolitan theory with critical social theory. He argues that cosmopolitanism has a critical dimension which offers a solution to one of the weaknesses in the critical theory tradition: failure to respond to the challenges of globalization and intercultural communication. Critical cosmopolitanism, he proposes, is an approach that is not only relevant to social scientific analysis but also normatively grounded in a critical attitude. Delanty's argument for a critical, sociologically oriented cosmopolitanism aims to avoid, on the one hand, purely normative conceptions of cosmopolitanism and, on the other, approaches that reduce cosmopolitanism to the empirical expression of diversity. He attempts to take cosmopolitan theory beyond the largely Western context with which it has generally been associated, claiming that cosmopolitan analysis must now take into account non-Western expressions of cosmopolitanism.