Abstract:

The control effect of large squeezing deformation of inclined shaft and main tunnel of Maoxian Tunnel on ChengduLanzhou Railway is not good. Hence, the anchoring technology is improved, and the deformation status of inclined shaft and main tunnel and construction schedule are analyzed. The results show that: (1) The horizontal convergence deformation characterized by long time and high rate is prominent in large deformation section, and the deformation of partial inclined shaft shows a leap upward. (2) The deformation of inclined shaft section is affected by the shape of tunnel crosssection obviously, and the excavation size and buried depth of tunnel have obvious influence on deformation rate. (3) The construction quality of anchor bolt plays a key role in controlling large deformation, and the anchoring technology can be improved from the aspects of water consumption, poreforming quality, watercement ratio and grouting method. (4) By improving the anchoring technology, the average deformation is decreased by 32.11%-58.86%, and the construction speed of left and right lines is increased by about 172.73% and 77.23%, respectively.

Key words: railway tunnel, large squeezing deformation, anchor bolt, process adjustment, deformation control, construction schedule optimization