Abstract
Inhomogeneity of the ground affects the deformation behavior around a tunnel when tunnel excavation analysis is carried out. However, it is hard to evaluate the inhomogeneity of the ground quantitatively before tunnel excavation. So, numerical analyses of tunnel excavation were carried out under inhomogeneous analytical model that material properties have triangle distribution approximately. The displacements around a tunnel were collected after tunnel excavation. Back analyses assuming a homogeneous rock mass were carried out by using measured displacements. From back analysis, it was found that the young's modulus and initial stress from back analysis are different from them of numerical analysis. As a result, the range that should consider the inhomogeneity was revealed under the tunnel excavation analysis.
