Applicability of a constitutive model to jointed block mass

Singh, M

M. Singh, Applicability of a constitutive model to jointed block mass, ROCK MECH R, 33(2), 2000, pp. 141-147

4

INGLESE

Article

Geological Petroleum & Minig Engineering

ROCK MECHANICS AND ROCK ENGINEERING

0723-2632 → ACNP

33

2

2000

141 - 147

ISI

0723-2632(200004/06)33:2<141:AOACMT>2.0.ZU;2-Q

Deformational behaviour of jointed rocks is governed both by the properties of the joints and the intact rock. The applicability of a constitutive mod el to predict the stress-strain behaviour of a jointed block mass is discus sed in this note. The stress-strain curves predicted by the model are compa red with the experimental curves from physical model tests. It is observed that the model predicts the tangent modulus of the mass very closely. The f ailure strains are, however, underestimated, which may be due to the consta nt value of shear stiffness, resulting in linear stress-strain response by the model. The non-linear response of stress-strain curves can be obtained by using a variable value of the shear stiffness of the joints. A simple ap proach has been presented to assign variable stiffnesses, based on direct s hear test results on joints. It is found that by assuming a variable stiffn ess the axial strains can also be predicted accurately. The transverse stra in, however, remains highly underestimated by the model.