The Multiscale Analysis And Study Of Underground Structure

A great mount of variety underground structure have been construct and widely used in various industries in the past few years, because of the nowadays space and energy resources shortage. Now the hydraulic resources is the best way to solve the’energy and environment problem. Along with China’s hydropower energy development and utilization, large number of world-class hydraulic power station is being constructing in the southwest area of China. Moreover, large span underground structures appear at the same time. However how to protect the underground structure from being damaged now draw the all society attention.The increasing numbers of underground engineering lead the probability of these projects suffer from vibration damage increasing fast. In transportation system and hydraulic power station, the underground structure is normally the key protect. If the underground protect become invalid, the all transportation system will be inefficient and the hydraulic power station will be completely in dangerous. The costly underground structure is so important that the higher safety requirement is put forward to keep them safety and effectiveness.The way study seismic character of underground structure based on rock foundation today is always being numerical simulation and indoor experiment. With the higher safety requirement of underground structure, the traditional method (using smaller grid to get more accurate result) to improve simulation accuracy cannot satisfied the engineering requirement. How to calculate the underground structure stress status and safety factor efficiently will be the problem, which need to be solved first. An efficient and accurate numerical simulation method needs to be raised to meet the underground structure safety requirement.Multi-scale analysis has been used in many fields and get a lot of achievement, solved the complex phenomena simulation problems. The multi-scale reflects a huge advantage in complex problem simulation, which also brought a new breath to the underground structure. In this paper, based on the idea of multi-scale, multi-scale simulation of the rock and underground structures, mainly for the following work:(1) The scale effect of jointed rock has been studied, to show the regular of physical parameter in different scale. Conductivity ratio has been select as the example to give the way to study the scale effects.(2) The joint fissures of the rock mass similarity between different scales. Therefore, the fractal characteristics of joint rock of a special distribution characteristics.is studied. Fractal box dimension has been applied to fissure system get from both Monte Carlo simulation and the digital image to reveal the fractal characteristics in different scale. The result show that the traditional Monte Carlo method cannot describe the full fractal message in different scale, the new digital method should be applied in practice.(3) The transit method between different scales in multi-scale analysis has been researched. The multi-point constrains method and interface element method has been done in ABAQUS business finite element software. The result shows that both the two method can lead to a rather accurate result and can satisfy the requirement of multi-scale analysis.