The Program Exploitation Of Block Stability For Underground Caverns And Engineering Application

The 21st century is a hopeful century; it is also a century of development and utilization of underground space. With the increase of investment in the infrastructure in china, especially construction of western development and south north water transfer project, people pay more and more attention to stability problem of rock engineering, and that rock mass stability is also related to protection of ecological environment, resources utilization and sustainable development, so its study is significant for engineering and society.Block theory is an effective engineering analysis method for the stability of fractured rock mass. With development for twenty years, its study is more and more perfect; its engineering application is more and more wide. On the basis of the block theory, the paper studies stability of rock mass on underground caverns. Thinking about some problems, such as the theory just considers orientation of structural surface without position of structural surface; it is also difficult to make sure block volume and stability index, in addition, engineering geological condition of many fracture lead to low computation efficiency, vector analysis method of block theory is adopted to rapidly analyze block by computer. According to the elements of vector analysis method, combining local three-dimensional coordinate of underground caverns, the paper applies Visual Basic to compile calculating program VATS. The calculating program needs input joints occurrence, measuring point coordinate, radius of underground caverns, vertical wall height of underground caverns and other relevant engineering datum, search existent unstable rock blocks in ranges of underground caverns and analyze boundary condition, geometric parameter, failure mode and stability factor of each block in turn, and obtain key blocks' vertex three-dimensional coordinates, volume, stability factor and other relevant information at last. The program uses ActiveX Automation technology to achieve re-development of AutoCAD, applies AutoCAD to build entity model of underground cavern, and shows three-dimensional geometrical form and space position of the key block.The rock mass fracture is very developed for underground caverns in HuangGou hydropower station, so it is signality for engineering construction to predefine whether there are unstable blocks on excavation planes, of underground caverns. Thinking about above-mentioned condition, the paper applies the software to analyze stability of surrounding rock masses of underground caverns in HuangGou hydropower station, obtain blocks' geometric parameter and space position. Then the paper analyzes calculation result in detail, make certain key region and key fracture, the information will provide guidance for engineering excavation.