Nonparametric Monitoring for Geotechnical Structures Subject to Long-Term Environmental Change

Figure 8

The PCA mode shapes with the error bars of one standard deviation before and after the damage of the bottom tilt gauge. The 𝜇 and 𝜎 are the mean and standard deviation of the corresponding eigenvalue, which is normalized to the summation of the eigenvalues of all modes. (a)–(c) shows the mode shapes before the bottom tilt gauge was permanently damaged in 2006 Q1, and (d)–(f) shows the mode shapes after the sensor was damaged.

(a) Mode 1 (μ = 97.3%, σ = 2.1%)

(b) Mode 2 (μ = 2.3%, σ = 2.0%)

(c) Mode 3 (μ = 0.4%, σ = 0.3%)

(d) Mode 1 (μ = 82.3%, σ = 14.3%)

(e) Mode 2 (μ = 14.8%, σ = 14.4%)

(f) Mode 3 (μ = 0.9%, σ = 0.6%)