A Study of Shield Tunnel's Earthquake Prevention Under a Big Earthquake

Currently, the most commonly used approach for determining the aseismicity of a shield tunnel is the 'Response Displacement Method.' This is based on analysed results of tests performed during an earthquake of magnitude equal to that indicated by the 'Criterion Utility Tunnel Design.' In addition for the following reasons this shield tunnel is also thoroughly checked for aseismicity using the 'Dynamic Analysis Method.' (1) As part of the Telecommunications Disaster Prevention Project in the Tokyo Metropolitan Area, this shield tunnel has been designed to maintain uninterrupted data transmission during natural disasters. (2) The natural crosses Class A rivers. During large earthquakes the structures along the river embankments are sometimes damaged. (3) The soil through which the shield tunnel drives changed from diluvial clay to sand. This reports on the results of studies performed to check the aseismicity of the shield tunnel under a large earthquake.