Field investigation and numerical analysis of landslide induced by tunneling

The landslide induced by tunneling is very complex, since it may be influenced by not only geological condition, designed tunnel structure, construction environment or method, but also construction deficiency without in-time treatment. In this paper, a case of landslide induced by excavating a large-span multi-arch tunnel is studied by field investigation, in terms of tunnel profile, construction deficiencies, stability of surrounding rocks and landslide situation. Moreover, the landslide induced by tunneling is simulated based on the field investigation, even taking account of the observed construction deficiencies in the transverse section of tunnel within the area appeared landslide, resulted from tunneling without in-time treatment. Especially, a fictitious material is proposed for modeling the construction deficiency of cavity arisen from over-breaking of surrounding rocks without in-time backfilling, assumed as lightweight and always elastic without cracking, linked with primary lining and surrounding rocks using elastic spring. The numerical result is similar with that observed from field situation.