모드중첩법에 의한 터널 라이닝의 동적거동

Abstract

This study purposed to examine the effect of ground reaction coefficient, which is one of mediating variables influencing dynamic behavior of the structure under the ground, and for this purpose, we calculated the ground reaction coefficients suitable for in？]situ rock conditions such as hard rock, moderate rock, soft rock and weathered rock and applied them to analysis. Conclusions drawn from this study are as follows.

1. In the results of calculating the axial compressive stress and transverse bending stress of the tunnel using the seismic waves for both the operating basis earthquake(OBE) and the safe shutdown earthquake(SSE), the stresses were high in order of hard rock > moderate rock > soft rock > weathered rock in both the axial and transverse directions regardless of the boundary end conditions, and the displacements at the various points in the longitudinal direction of the tunnel were somewhat different according to boundary end conditions.

2. The natural frequency in the axial free vibration of the tunnel showed an almost constant tendency regardless of the variation in ground reaction coefficients according to the rock type. However, the natural frequency increased with increase in the vibration mode number.

3. In the dynamic analysis of the tunnel on the effect of tunnel lining thickness according to rock classification, the displacement caused by the axial vibration was less when the lining was thick but displacement caused by traverse vibration was constant regardless of lining thickness.