Seismic design method of immersed tunnel and effects of flexible joints

摘要

The immersed tunnels in Japan are constructed in vigorous earthquake activity areas and in soft ground. Since rigid joints are often disadvantageous, flexible joints should be used for absorption of large deformation due to earthquake force. For this reason, various studies and analyses have been conducted to develop higher deformation performance flexible joints. Dynamic response analysis has been introduced to estimate sectional force and displacement at the immersed tunnel. Seismic design method and effect of flexible joints for the earthquakes are presented in this paper. Newly developed flexible joint that is called Crown Seal Joint is mainly discussed.