Abstract：For the utility of underground space，the number of closely spaced two-tube tunnels gets more and more. Different excavation sequence makes the results different. The second tunnel is constructed in the ground disturbed by the first one，so that the ground stiffness is unsymmetrical. The construction of the second tunnel has effect on the first excavated one，which is related to the distance between two tunnels and the method of excavation and lining. The ANSYS program is used to analyze the laws of the settlements of the surface and arch，under the conditions of different distances between tunnels and different methods of excavation and lining. The results show that the excavation of second tunnel has significant effect on the first tunnel.
1Soliman E，Duddeck H，Ahrens H. Two and three-dimensional analysis of closely spaced double-tube tunnel[J]. Tunnelling and Underground Space Technology，1993，8(1)：13～18
2002, Vol. 21 
