Abstract：The support system between are analyzed and discussed. It is found that，if the forces in the lining are less than the limit ones during and after excavation，there is no need to consider bolt or other assistant support methods for the surrounding rock between two tunnels. The distance between two tunnels can be 1.0 m，or even more narrow，as Munich subway had done. For closely-spaced tunnels，the excavation sequence has visible impact on the both tunnels. If one tunnel is finished firstly and the other is completed subsequently，results show that the first tunnel has larger compression forces in the lining and even some tension happens at the invert of the lining during the excavation of the second tunnel. If the two tunnels are excavated by alternant way，the surrounding rock between the two tunnels has more disturbances. The crown of the second tunnel and the invert of the first tunnel are easy to be in tension. But generally，the forces are less than the ones when the tunnels are excavated in the first sequence. For both excavation sequences，the surrounding rocks between the two tunnels are both in compression. Munich subway which had been built successfully validated the dependability of the results.
