Tunnel Under the Severn and Wye Estuaries.

Tunnelling

“…The device needs not only to have correct stiffness in compression and in shear but also to represent the surface of the structure in position and in roughness. Records of the instrumentation for the Severn Cable Tunnel (Haswell 1973), which appear to indicate high out-of-balance forces, illustrate the problem. For a continuous ring, where bending moments are derived from measurements of stress, missing data may be estimated from the knowledge that:…”