Forming Mechanism of Dissipative Structure in the Softening Process of Saturated Soft Rocks
Cuiying Zhou · Earth Science-Journal of China University of Geosciences · 2009
Aiming at the complex issue of system evolution in softening process of saturated red-bed soft rocks,the research on softening characteristics of soft rocks is carried out from the aspects of systemic openness,far-from equilibrium behavior and internal nonlinear mechanism to affirm the occurrence of dissipative structure in softening process.On this basis,dissipative structure theory is adopted to systematically analyze the formation mechanism of dissipative structure in softening process of saturated soft rocks.The result shows that softening process contains three stages:Near-equilibrium state,far-from-equilibrium self-organizing state and far-from-equilibrium critical state,and ultimately,the way of non-equilibrium phase transition leads to the generation of soft rock dissipative structure.Finally,based on the evolution law of structure fractal dimension,a bifurcation evolution model is preliminarily established to describe the formation process of soft rock dissipative structure.The result of applying this model to analyze the critical bifurcation phenomena occurring in softening tests of saturated soft rocks indicates that this soft rock dissipative structure is formed after experiencing the process of period-doubling bifurcation and destabilization for many times,and the times of three months and six months present obvious critical characteristics which are two breakthrough points for further study on dissipative dynamic softening process of soft rocks in future.