It is important to investigate and evaluate the stress-deformation relation and fracture behavior of discontinuous surface of rock masses during shear process. Therefore, this paper firstly obtains the residual geometrical information of rock discontinuous surface after block shear test in-situ. through measuring rock discontinuous surface with special-designed laser scanning system. Then, by implanting GIS technology, the topography of rock discontinuous surface can be conserved as digital data in GIS database management system. Furthermore, this paper proposes a new analysis method for simulation of shear process in the rock discontinuous surface through the use of the TIN and GRID models of GIS. The simulating and visualizing results shows that this analysis method can tolerably quantify the change of fracture region and distribution of inner stress during shear process.
It is important to obtain the strength and deformation parameters of rock masses quantitatively for the stability evaluation of rock foundation of structures. However, in-situ shear tests of rock masses, usually conducted in many cases, can only get the macro-data of the strength and deformation parameters through stress-deformation curves. It is not clear to the deformation mechanism, fracture mechanism and rock fracture process inside the rock masses. On the other side, it is difficult for long-term conservation of rock discontinuous surface after block shear tests in-situ. Therefore, it is necessary and possible to conserve rock discontinuous surface, to investigate and evaluate the stress and fracture behavior of fracture surface during shear process, through the use of geographic information system (GIS). In the recent years, as a new information technology, GIS has attracted extensive attention. GIS is described as " an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information" (ESRI.1994). Simplistically, GIS is a computer system capable of holding and using data describing places on the earth's surface. The residual geometrical information is rock discontinuous surface after block shear test in-situ. Because rock discontinuous surface is geographically spatial data. GIS can be valuable tools for conservation of rock discontinuous surface and simulation of shear process. This paper firstly obtains the residual geometrical information of rock discontinuous surface after block shear test in-situ, through measuring rock discontinuous surface with special-designed laser scanning system. By implanting GIS, the topography of rock discontinuous surface can be conserved as digital data with GIS database management system. Then, this paper explores the use of the TIN and GRID models of GIS for simulation of shear process in the rock discontinuous surface. The simulating and visualizing results show that the method can quantity the change of fracture region and distribution of inner stress during shear process.
2.1 Block shear tests of rock masses in-situ The rock masses in this research consist of slate of Mesozonic Jurassic Period, distributed in rock foundation region of an expected construction site in Japan. The block shear tests of rock masses.
