@Article{cmes.2020.08270,
AUTHOR = {Hongtao Wang, Ping Liu, Lige Wang, Chi Liu, Xin Zhang, Luyao Liu},
TITLE = {Three-Dimensional Collapse Analysis for a Shallow Cavity in Layered Strata Based on Upper Bound Theorem},
JOURNAL = {Computer Modeling in Engineering \& Sciences},
VOLUME = {124},
YEAR = {2020},
NUMBER = {1},
PAGES = {375--391},
URL = {http://www.techscience.com/CMES/v124n1/39396},
ISSN = {1526-1506},
ABSTRACT = {Layered rock strata are observed to be common during the excavation
of tunnels or cavities, and may significantly affect the deformation and failure
characteristics of surrounding rock masses due to various complex forms and
mechanical properties. In this paper, we propose a three-dimensional axisymmetric velocity field for roof collapse of shallow cavities in multi rock layers,
by considering the influences of roof cross-section shapes, supporting pressure,
ground overload, etc. The internal energy dissipation rate and work rates of external forces corresponding to the velocity field are computed by employing the
Hoek-Brown strength criterion and its associated flow rule. Further, the equations
of the collapse surfaces and the corresponding weight of collapsing rock masses
are derived on the basis of upper bound theorem. Furthermore, we validate the
proposed method by comparing the results of numerical calculations and existing
research findings. The change laws of the collapse range under varying parameters are obtained for the presence of rectangular and spherical cavities. We also
find that the three-dimensional mechanism is relatively safer for engineering
designing actually, compared with the traditional two-dimensional mechanism.
All these conclusions may provide workable guidelines for the support design
of shallow cavities in layered rock strata practically.},
DOI = {10.32604/cmes.2020.08270}
}