Research About The Effect Of Weak Intercalation To Tunnel Surrounding Rock And Supporting Structure

Many engineering implemention shows that weak intercalation has decisive effect of stability of tunnel surrounding rock and satety of construction.There are many literature which take study on this.Firstly this paper put forward stability of tunnel surrounding rock's"shear stress leading principle",the JRC - JCSmodel formula for analying land stability in geotechnical engineering is introduced,put forward tunnel surrounding rock's instability determinant conditions about structure surface shear failure, weak intercalation glide.Secondly,structure surface rough coefficient calculated by fractal theory is given,use finite element numerical simulation method to calculate weak structure plane stress field,the working program using JRC - JCS model formula to judge if the tunnel surrounding rock is stable;thirdly,finite element numerical simulation method is used to study the effect to stability of tunnel surrounding rock from drive,interactive,half drive weak intercalation's slice thickness,dip, sandwich material,surrounding rock material etc;finally,through taking comparative analysis to 4 different digging method of tunnel surrounding rock containing iteractive structure surface, the conclusion that the best digging method is got.Tunnel surrounding rock instability evaluation model and numerical simulation results given by this paper have important reference value about stability analysis of tunnel surrounding rock containing weak intercalation and the selection of the best digging method of this kind of tunnel.