Vibration Characteristics of Underground Structure and Surrounding Soil Underneath High Speed Railway Based on Field Vibration Tests

Figure 23

(a) IMF1 of the autocorrelation function of W1 and the cross-correlation functions between W1 and the other two points W2-W3 on the wall for the determination of vertical wave velocity and (b) the same plot for IMF2.

(a)

(b)