The Influence of Underground Cavity on The Stability of Tunnel Excavation

Yongxia Zhao; Jiajun Wu

doi:10.62051/ijnres.v2n1.08

Authors

Yongxia Zhao
Jiajun Wu

DOI:

https://doi.org/10.62051/ijnres.v2n1.08

Keywords:

Cavity; numerical simulation; excavation stability; bad geology.

Abstract

In order to study the influence of cavity on surrounding rock stability,a tunnel in Yunnan Province was taken as the research object,and the problem of voids in the tunnel was qualitatively analyzed and evaluated.FLAC3D was used to simulate and analyze the distribution location of voids,the number of voids,and the influence of voids in the excavation process.The influence of plastic zone,stress field and displacement field on the stability of surrounding rock was evaluated.The results showed that the onsite measured data were consistent with the simulation results.When the cavity existed at the top and side,bottom and side,the cavity at the side had a greater impact on the tunnel than the cavity at the bottom and top,and the cavity at the bottom had a greater impact than the cavity at the top.When the annular cavity was encountered in the excavation process,the displacement value of surrounding rock decreased under the support of primary lining and bolt,and the reduction range of arch bottom was greater than that of arch top.This study can provide a certain reference for the excavation stability of similar tunnel projects with cavities.

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