Hi, I am using modified Hoek-brown model for a rock tunnel simulation. I have been checking the in-situ stresses with and without hbt (Hoek-brown Tension cut-off component). I see that when I don’t use ‘hbtension’, then the model shows exact insitu stress distribution. whereas, upon using ‘hbtension’ the stresses are either zero or very high in magnitude. What could be the reason for this error?
Here is code I have used for zone modelling:
zone model mhoek
zone shear=33e9 bulk=14e9
zone hbsigci=100e6 hbmb=1 hbs=0.1 hba=0.5 hbt=-10e6
zone hb_do = 0.333
zone dens = 2700