In order to study the fluid-solid coupling of tunnels with small clear spacing

the Qingdao Metro Line 2 # and Metro 1 # northern extension line were selected as an example for testing and numerical simulation. Results show that the compaction area of confining pressure is compacted after reaching the peak stress resulted from construction disturbance

which leads to the weakening of permeability. When the peak value of rock stress reaches a certain value

the permeability coefficient of rock tends to be stable and does not change with water pressure. The surface settlement caused by seepage is larger than that caused by excavation

and the width of the settlement trough is also increased apparently. Excavation is the main factor for tunnel deformation

and the tunnel structure can be highly stable under seepage. The pore water pressure of surrounding rock decreases sharply due to tunnel excavation

and a funnel-shaped pore water pressure zone is formed around the tunnel. The tunnel grouting support is beneficial to reduce the pore water pressure around the tunnel and reduce the influence of groundwater on the tunnel.