When constructing tunnels in landslide areas

the stability of landslide is severely affected by the crossing position of tunnel. At present

the problems of tunnel excavation and the stability of landslide were separately investigated by many researchers. However

very little attention has been made on these two kinds of engineering problems together. In this study

a formula was deduced to calculate the disturbance range of surrounding soil and rock mass induced by tunnel excavation

according to the slip line theory. Combined with the analysis of loosened rock over the tunnel opening

an analytical expression was developed for the minimum safety distance of the tunnel orthogonally crossing the landslide. Moreover

its influencing factors were discussed. Besides

the stability of landslide body above the tunnel was analyzed using Sarma method

and the corresponding safety factor was also obtained. At last

a series of numerical simulations was carried out to investigate multiple examples of tunnel orthogonally crossing landslide. The accuracy of the deduced formula was verified by the analysis of rock plastic zones. Therefore

the results can provide a theoretical basis for the accurate selection of tunnel position in the landslide area.