Uql

Cs CS

VR 2 j. , t^aR ■ ± 2 j. e = — cos2f + Y—j sin f cos2f

CR CR

where

VP = peak particle velocity of P-waves at the tunnel location VS = peak particle velocity of S-waves at the tunnel location VR = peak particle velocity of R-waves at the tunnel location AP = peak particle acceleration of P-waves at the tunnel location AS = peak particle acceleration of S-waves at the tunnel location Ar = peak particle acceleration of R-waves at the tunnel location CP = apparent propagation velocity of P-waves CS = apparent propagation velocity of S-waves CR = apparent propagation velocity of R-waves, and

Y = distance from the neutral axis of the tunnel cross-section to the extreme fiber of the lining

TABLE 28.3 Strain and Curvature Due to Three Wave Types

Wave type

Longitudinal strain

Curvature

P-wave

S-wave e = (Vp)cos2f emax = Vp for f = 0o Cp e = Íc j sin f cos f emax = ( 2C I for f = 45o

0 0

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