DBPapers
DOI: 10.5593/sgem2017/12/S02.111

THE DETERMINATION OF CRACK RESISTANCE OF THE CIRCULAR SHAPED FIBER REINFORCED CONCRETE TUNNEL LINING BY MEANS OF LINEAR FRACTURE MECHANICS

E. Khoteev, M. Zertsalov, V. Merkin
Sunday 10 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-99-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 12, 873-880 pp, DOI: 10.5593/sgem2017/12/S02.111

ABSTRACT

In the paper the results of the study of the crack resistance of circular shaped fiber reinforced concrete tunnel linings are presented. On the basis of laboratory testing of linings and numerical simulation of their behavior (FEM) is shown that the deformation of fiber concrete can be considered as the deformation of solid, elastic, homogeneous medium. In addition, the analysis of stress–strain state of these linings shows that their failure is caused by stable propagation of the single crack, which usually forms in the ceiling of the tunnel in accordance with the lining stress distribution. The described mechanism of failure of the circular shaped lining allows using the linear fracture mechanics for the analysis of its crack resistance. Due to symmetry of the stress distribution, the crack forms on the inner contour of the lining and propagate under pure tension in its own plane. In this case, the criterion for the crack propagation is the critical stress intensity factor - K...‬‬¹, which is constant mechanical characteristics of the material.The article also presents the results of experimental determination of K...‬‬¹ values, which allowed obtaining the formula to calculate K‬‬...¹ of fiber-reinforced concretes of various compositions. On the basis of the conducted experimental studies, numerical simulations of the experiments and laws of fracture mechanics was developed the method of calculating of the crack resistance of the circular shaped fiber reinforced concrete lining.

Keywords: fiber-concrete, linear fracture mechanics, transport tunnels, crack resistance.