Abstract:

Jiubao tunnel is located in the junction of regional tectonic whose main strata is old archaeozoic metamorphic rocks. The fault structure is developed well due to the geological structural movement. The groundwater is rich; and there is confined water in partial sections. Technologies, such as the temporary inverted arch, the temporary retaining wall, strengthening and avoidance are used so as to solve the water inrush and collapse of tunnel face. In order to guarantee the safety of tunnel lining structure, advance grouting, advance pipe roof and double primary support layers are adopted. In light of the rich groundwater, the drainagetype waterproofing plate, additional macadam blind drains and increasing drainage holes are adopted to guarantee the running safety of the tunnel.

Key words: railway tunnel, confined water, water inrush, large deformation, drainage hole