The effect of gravitational loads on the stability of horizontal circular tunnels excavated in an elasto-plastic (softening) materials is analyzed. Gravity loading in included in the analysis as body forces added to those due to the in situ stresses. The analysis considers the occurrence of a minimum in the ground reaction curve, i.e. the graphical representation of the radial support pressure required for equilibrium, of the excavation as a function of radial deformation at the excavation wall. The analysis is also extended to the face of the tunnel, where the three-dimensional is treated analytically under restrictive assumptions. Results obtained from the numerical analysis are presented; they confirm the results from the limit-depth analysis.
|Original language||English (US)|
|Number of pages||1|
|Journal||International journal of rock mechanics and mining sciences & geomechanics abstracts|
|State||Published - Apr 1997|
|Event||Proceedings of the 1997 36th US Rock Mechanics ISRM International Symposium - New York, NY, USA|
Duration: Jun 29 1997 → Jul 2 1997