Prognosis of surface settlements during tunnelling in loose rock


  • Determination of settlements, tangential inclinations and curvatures on the surface during tunnel driving
  • Assessment of the damage potential


Procedure: Mathematical description of the settlement trough

Unknown variables are:

  • volume loss Vls
  • Turning point distance i and iy in transverse and longitudinal direction

Proceed as follows:

  • Evaluation of the measurements of more than 350 settlement troughs
  • Consideration of a probability of occurrence
  • 2D and 3D FE calculations to transfer empirical information to other conditions


Formulas for determining Vls and i as a function of:

  • the tunnelling method
  • the tunneling depth
  • the soil stiffness
  • the geological situation
  • the breakout cross section
  • the probability of exceeding the limit

And therefor:

Assessment of the risk of building damage to conventional buildings, e.g. according to Kramer 1974 or Burland 1995.