THE SQUEEZING POTENTIAL OF ROCKS AROUND TUNNELS - THEORY AND PREDICTION

Citation
O. Aydan et al., THE SQUEEZING POTENTIAL OF ROCKS AROUND TUNNELS - THEORY AND PREDICTION, Rock mechanics and rock engineering, 26(2), 1993, pp. 137-163
Citations number
22
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Geosciences, Interdisciplinary","Engineering, Civil
ISSN journal
0723-2632
Volume
26
Issue
2
Year of publication
1993
Pages
137 - 163
Database
ISI
SICI code
0723-2632(1993)26:2<137:TSPORA>2.0.ZU;2-#
Abstract
The deformational behaviour of tunnels, which underwent large deformat ions, so-called squeezing, have been recently receiving great attentio n in the field of rock mechanics and tunnelling. Contrary to rockburst ing phenomenon in which the deformation of the medium takes place inst antaneously, the deformation of the surrounding rock in squeezing phen omenon takes place slowly and gradually when the resulting stress stat e following the excavation exceeds the strength of the surrounding med ium. Although there are some proposals for the definition of squeezing rocks and prediction of their squeezing potential and deformations of tunnels in literature, it is difficult to say that they are concise a nd appropriate. In the first half of this paper, the squeezing phenome non of rock about tunnels and its mechanism and associated factors are clarified by studying carefully observed failures in-situ and laborat ory model tests. Then, an extensive survey of tunnels in squeezing roc ks in Japan is presented and the results of this survey are summarised . In the second half of the paper, a new method is proposed to predict the squeezing potential and deformations of tunnels in squeezing rock . Then, the method is applied to actual tunnelling projects, where squ eezing problems have been encountered, to check its validity and appli cability. As a concrete example, an application of the method to predi ct the squeezing potential and deformations of the rock along a 300 m long section of an actual tunnel was made.