Structure Analysis On Rock Tunnel Boring Machine Pipe Liner

Developing and utilizing underground space, it is very important for stability of underground structure engineering. In this paper, it is studied and analyzed characteristic of stress, distortion etc. of pipe liner structure combining Dahuofang transport water tunnel practice project, Tunnel Boring Machine construction, and it is considered that affects internal force of pipe liner for early stress of underground structure and digging load. In nonlinear finite element calculation model, folium cells have been simulated among pipe liner and pipe liner and wall rock.Under varies load condition, it has educed that changing rule of stress, distortion and load characteristic pipe liner in kinds of wall rock tunnel by analysis and calculation.1. Under the same kind of wall rock and the same condition, displacement of pipe liner is symmetry, for tunnel structure and suffered load are symmetry. As level terra stress is bigger, the maximum of displacement and the first main stress occur in tie-in of pipe liner structure, and its direction is radial and points in hole; the direction of the third main stress is annular and its maximum occurs in top and bottom hole inner.2. Under the same kind of wall rock and different conditions, the maximum of displacement and the third main stress of pipe liner structure in construction period is bigger than these of operation period, and the maximum of the first main stress of pipe liner structure in construction period is smaller than these of operation period.3. Under different kinds of wall rock and the same condition, from II III V kinds of wall rock, and conditions of construction period and operation period, it gradually increases that the maximum of displacement and the first main stress third main stress of pipe liner structure. But displacement relatively value of pipe liner structure is very smallness, the tie-in of pipe liner would not move and come away. And it is bigger that the level displacement value of substrate tie-in of pipe liner than upper.4. There are similitude rule in suffered force and distortion in different kinds of wall rock and different conditions, the place by tunnel is of diversification and the other place has hardly changed. The mechanics character of wall rock distinctly affects suffered force and distortion of pipe liner structure. If the character of wall rock is finer, it is smaller for suffered force and distortion of tunnel pipe liner structure, contrarily it is bigger.