Study on Super-small Interval in Optimized Small Interval Tunnel with Surrounding Rock Damage

Abstract:

Construction technology of small internal tunnel is more favorable because of its simple and economy than double-arched tunnel without limitation on topographical condition and line type. Numerical simulation was made on the thickness of mid-pillars in small internal tunnel with finite element method; fitting curve of maximum tensile stress, yield function criteria and small interval was obtained through Griffith damage criteria and Drucker-Prager criteria. And analysis was made on most reasonable interval of small interval tunnel.

Key words:small interval tunnel; finite element method; damage criteria; reasonable small interval