3-DIMENSIONAL DYNAMIC-RESPONSE OF TWIN CAVITIES DUE TO TRAVELING LOADS

An analytical procedure is proposed to determine the three-dimensional response of a multiple-cylindrical-cavity system deeply buried in a v iscoelastic medium subjected to moving or seismic loading. The tunnels arc treated in the local coordinate systems. The interaction between the tunnels is taken into account by a coordinate system transform. Th e accuracy of the coordinate transform has been investigated. A numeri cal study describes the dynamic through-soil interaction between a mai n tunnel and a service tunnel when the main tunnel is subjected to veh icles moving with constant velocity and applying pressure over rectang ular areas. The effects of the Mach number of the traveling load, the space between the tunnels, and the vibration frequency of the travelin g load arc examined. The numerical results show that the through-soil interaction is important for the service tunnel when it is close to th e main tunnel where vehicles travel at high speed.