Study On The Coupled Seepage-Deformation Test And Numerial Simulation Of Fracture In Deep Rock Mass

With the rapid development of rock engineering in western China, more and more underground excavationclusters of hydropower station and inter-basin diversion tunnels with the buried depth more than 1000 m willbe built. Stress field, seepage field and other mechanical response of the deep rock mass are fundamentaldifference of the shallow rock mass. So, study on the coupling relationship between seepage and deformationof fracture in deep rock mass under high in-situ sterss, has become a general concern in rock engineering field.In the previous seepage experiment studies of Rock fracture,most of them are single fracture of small scalelaboratory tests or seepage-deformation tests under normal stress, lack of the field test of fractureseepage-deformation under high in. In this paper, according to coupling problem between seepage anddeformation of fracture in deep rock mass under high in-situ stress, a set of in situ fracture seepage anddeformation coupling field test method is established, and theoretical analysis, field test and numericalsimulation are used to study seepage and stress - deformation characteristics of rock fractures.The majorresults are as follows:(1)The theory of Groundwater dynamics is used to analysis seepage characteristics and stress–deformation coupling relationship of fracture in the process of fracture seepage and deformation coupling fieldtest. Meanwhile, the principle and devices of fracture seepage and deformation coupling field test areintroduced, and the theoretical analysis is coMPared with the laboratory results.(2) The characteristics of the fracture seepage in deep buried rock mass is studied by field test. Theresults indicate that the characteristics of the seepage and stress-deformation are clearly divided into two stages.In the low pressure stage, the fracture transmissivity is very small, the seepage quantity is almost zero, and thechange of fracture aperture and normal stress of fracture are changed with the test pressure increases is alsovery small. And in the high pressure stage, the fracture transmissivity is larger, and the seepage quantity isincreasesed rapidly with the test pressure change.The change of fracture aperture and normal stress of fractureare changed with the test pressure increases is very rapidly.(3) According to the felid test result of the second stage, the three fluid flow calculation modes are usedto simulate the seepage and deformation coupling field test of fracture. The simulated results indicate that theresults of the three modes are almost same. In the beginning of the test, pressure, flow and deformation of thefracture are all rapidly incressed with the test time increase. when the pressure, flow and deformation reachedits maximum, stable and not increasing. These characteristics are very similar to the field test.