The Mechanics Behavior Of The Half-open And Half-hidden Structure Tunnel And The Characteristic Of Stress And Deformation Of Surrounding Rock Supporting

Following the strategic direction of insisting sustainable development and protecting ecological environment and limited land resources, and to satisfy the rapid development of economy and transportation, small spacing highway tunnel with the half-open and half-hidden structure seems be of great demand. This type tunnel has the advantage of optimizing the whole road allocation plan under special geologic and topographic conditions; however, owning to its particularity, and infrequence, the interaction between two tunnels is fairly serious. Thus, there are still several key problems needed to be solved during the design and construction procedure, and it's necessary to make a systematic and considerate analysis on it.In this paper, Basing on the tunnel of Jiaowu tunnel, combining with MIDAS/GTS program, the continuous excavation by load steps is simulated through the"activation and passivation"method. The mechanics behavior of the half-open and half-hidden structure tunnel and the characteristic of stress and deformation of surrounding rock supporting system are studied, and then the regularity of these is gained. By comparing the analysis results with in-situ testing data, some useful regularities are also gained. The research is of great practical significance for the plan and design upon the construction of the highway. Moreover, since guiding the project and optimizing the construction, this essay sheds light on the further similar work.