Impact of post-failure rock mass behavior on excavation response

摘要

In this. paper the authors combine three ingredients to analyze the response of deep tunnels in granite rock masses. First, some servo-controlled tests on granite rock are presented and interpreted to estimate dilation. Then, the authors recall a method to characterize rock masses behaving in a strain-softening manner to estimate the most relevant parameters of three rock masses. Finally, this behavior model is introduced in a numerical model to study the response of a tunnel. Results show that whereas variable dilation models affects significantly tunnel displacement response, post-failure strength models control the extent of the failure zones. It is therefore shown that standard behavior models (namely, perfectly plastic models) may not well represent actual tunnel face response.