Seismic contact forces betwee ndrifts of a stacked-drift-type tunnel in a dry sand layer were investigated by a centrifuge using an electro-magnetic shaking table. The test resutls were compared with tangential seismic axial forces in the cross section of a buried pipe with an uniform flexural rigidity. Seismic contact forces can be estimated usign an existing analytical formula based on a model of a ring-with-elastic-support, provided the shear modulus of the soil corresponding to the resonant strain is used in the calculation.
展开▼
