Numerical study on the continuity factor and the limits between continuous and discontinuous behaviors
2012 (English)In: ISRM International Symposium 28-30 May 2012, Stockholm, 2012Conference paper (Refereed)
Discontinuum approach or equivalent continuum approach is usually adopted in order to model the behavior of rock masses. The latter approach is more frequently used. However, this approach might be unacceptable for slightly-jointed rock masses. The continuity factor (CF), mainly derived from empirical experience, is defined as the ratio of the tunnel span to the block diameter. It is commonly used to determine whether a rock mass should be modeled as a continuum or a discontinuum material. Only a few analyses regarding the CF have been performed previously. In order to study the limits between continuous and discontinuous behavior, nu-merical analyses with UDEC have been performed. In these analyse, a rock mass with two sets of orthogonal joints are initially generated. From this rock mass, square areas corresponding to a certain CF are randomly chosen as models in UDEC. Confined compression test is conducted on the mentioned model and the constrained modulus (Dm) regarding this rock mass is calculated. Due to the variations of the relative loca-tions between the square and the joints cut inside, as well as the joint quantity and the joint lengths, several Dm are yielded for each CF. Several CFs are also analyzed and the results are compared with previous suggested limits between continuous and dis-continuous behaviors.
Place, publisher, year, edition, pages
rock mass behavior, continuity factor, excavation, joint
IdentifiersURN: urn:nbn:se:kth:diva-138851OAI: oai:DiVA.org:kth-138851DiVA: diva2:681851
QC 201404282013-12-202013-12-202014-04-28Bibliographically approved