How to Estimate the Squeezing Problem in Tunnels

Squeezing can occur during tunnel excavation in relatively weak rock mass such as shale and mudstone where the low-strength rock forms the plastic zone around the tunnel, resulting in radial convergence (deformation). Hoek (1998) suggested that the ratio of the uniaxial compressive strength of the rock mass to the in situ stress can be used as an indicator of potential tunnel squeezing problems. The chart explained in this video gives estimates of the percentage strain which is defined as the ratio of tunnel closure to tunnel diameter in respect to the strength/stress ratio.
To learn how to estimate rock burst and spalling problems in tunnels, watch this video • How to Estimate the De...

[@fredbwaise4911]

Very helpful as we are facing a similar issue but with no stress measurement done yet so this is handy.

[@atulshulka3544]

knowledge content sir. Sir I'm Geologist, Can you please suggest me any book or notes for how to design tunnel or how to predict tunnel support.Plz