Naslov
The Stability Conditions around a Tunnel Excavation

Autori
Frgić, Lidija ; Hranilović, Marko ; Tor, Krešimir

Izvornik
World Scientific and Engineering Academy and Society - WSEAS Transactions on Information Science and Applications (1790-0832) 2 (2005), 12; 2303-2309

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Tunnel; Primary support; Bearing capacity; Rock mass; Boundary element method

Sažetak
Stress and strain analysis for an area in vicinity of an underground room is a complex issue considering difficulties encountered when attempting to determine the natural stresses in a rock mass. The natural or primary state of stress is a function of all previous geologic and tectonic processes that have acted on the rock mass. Rock masses are heterogeneous and usually discontinuous assemblages of material. The stress and strain analysis require availability of a number of rock mass mechanical parameters, which are not known in advance. Such situation makes correct and advance assessment of necessary excavation protection activities difficult, although it is a known and accepted fact that stratification and fissure system of a rock mass make it a discontinuous. Actual mechanical characteristics of underground rock mass are very hard to determine. Resolving of problems related to the primary support carrying capacity usually follows the stress and strain analysis of the underground rock mass by the tunnel opening. Such problem could also be resolved by using an inverse method which means by assuming the ultimate limit state of the support elements and checking whether such reactive pressures of the support elements will retain the underground rock mass in stable state, namely does the underground rock mass meet the failure criteria. This would prove possible ultimate equilibrium in the primary support system - underground rock mass interaction. The computation of stress and strain condition in whole-profile and multi-phase excavation of tunnel profile is performed by numerical methods and the inverse method to estimate stability condition. Reliable data on the rock mass failure criterion are sufficient for checking of the effect the support has on the rock. This is the principal advantage of the inverse method since an input material constant on which the results depend is reduced to a very small number.

Izvorni jezik
Engleski

Znanstvena područja
Građevinarstvo

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