Study on Stress and Displacement of Axisymmetric Circular Loess Tunnel Surrounding Rock Based on Joint Strength

The development of an effective evaluation method suitable for loess-tunnel excavation is necessary to avoid the collapse accidents caused by tunnel and any secondary disasters. Although Fenner formulas modified are widely used in engineering, a defect still exists these because Mohr–Coulomb (M–C) criterion exaggerates tensile strength surrounding rock loess tunnel. A newly formula was derived based on joint overcome this deficiency. First, expressions stress radius plastic zone radial displacement were stress-equilibrium equation axisymmetric plane strength. Then, difference two kinds criteria compared. results showed that determined larger than those M–C However, smaller. comparative analysis reveals can evaluate plastic-displacement field more reasonably.