ABSTRACT
In this study, the elastic modulus along a borehole for the construction of a national highway tunnel in ground consisting of volcanic and pyroclastic rocks was estimated by using dynamic elastic modulus. The data used in estimating the elastic modulus were the P-wave velocity measured in the velocity logging during the boring and the P- and S-wave velocities, wet density, Poisson’s ratio, and unconfined compressive strength of cores measured in the laboratory. As the results of analysis, in-situ elastic modulus along the borehole wall is used to assume the rough value of deformation modulus in the ground classification for a tunnel. And predicted tunnel deformation by in-situ strain along the borehole wall based on in-situ elastic modulus along the borehole wall is useful for setting the continuous control standard values of displacement in tunnel excavation.
