RESEARCH ON COUPLING CHARACTERISTICS OF FLUID FLOW AND STRESS WITHIN ROCK

Based on the review of the current research achievements in the field of coupled fluid flow and stress in rock,the research methods can be boiled down into 3 types.The first is drawing empirical formulas from coupled fluid flow and stress experiments directly.The second is establishing function according to existent empirical formulas,deducing the variable expression in the established functions by mechanical method and then determining the formulas.The third is establishing coupled relational expression by mechanical tool based on various physical models that simulate seepage phenomena.Based on this classification,the current research works are introduced with their rationality and applicability analyzed.Moreover,future development and the possible improvement are briefly discussed.Firstly,in order to fulfill the requirement of engineering application,the research of coupled fluid flow and stress in combination of porous rock and fractured rock and the corresponding numerical model should be developed.Secondly,there is great research space in the field of anisotropic coupled fluid flow and stress in rock and this work is necessary.New coupled triaxial fluid flow and stress experiment equipment should be developed to study the seepage property under true triaxial stress.Thirdly,because of non-reversible characteristics of rock deformation influence rock permeability,it is necessary to enhance the testing study on rock permeability under stress that changes in a non-monotone way.Fourthly,the research of coupled between fluid flow and stress and research of rock failure should be combined.It is very helpful to explore the inherent seepage mechanism that promotes the combination of macro-research and micro-research.Finally,it is important to take physical,mechanical and chemical effects into account in the coupled research because the three effects appear at the same time when water flows in rock.