Quantitative analysis method for the importance of stress influencing factors of a high arch dam during the operation period using SPA–OSC–PLS

Abstract

Stress analysis is an important part of the health monitoring and evaluation of a high arch dam. At present, a reasonable quantitative analysis method for the importance of stress influencing factors of a high arch dam during the operation period remains lacking. According to measured data of strain gauge groups, a quantitative analysis method is proposed integrating succession projection algorithm (SPA), orthogonal signal correction (OSC), and partial least squares (PLS). First, based on the stress calculation of the strain gauge group of a concrete dam, the statistical model of high arch dam stress is established.Second, independent variables are preprocessed using SPA and OSC to screen out effective influencing factors without noise signals. Finally, the principal component with the strongest explanation for the dependent variable is extracted using PLS, and the importance of stress influencing factors of a high arch dam during the operation period is quantitatively separated. Results show that the SPA-OSC-PLS method can effectively eliminate the effects of multiple correlations, information overlap, and noise among influencing factors. In addition, the predictive ability and interpretability of the SPA-OSC-PLS method are superior to the PLS and SPA-PLS methods, which can reasonably obtain the importance of stress influencing factors of a high arch dam. The proposed method can accurately reveal the change law and action mechanism of the stress of a high arch dam during the operation period.

Stress Prediction Model of Super-High Arch Dams during Their Initial Operation Stages

“…Common strain gauge groups include three-, five-, and six-direction types (Figure 1) [16]. The stress should be calculated using the measured data of the strain gauge group.…”

“…According to the test data, the creep curve of the concrete can be fitted. Under the condition of measured strain and creep test data, the deformation method can be used to calculate the stress along all directions [16]. Among them, the three-direction and six-direction strain gauge groups are not balanced.…”

“…Then, the measured values of the strain gauge group and stress-free strain meter can be converted into actual stress. The complexity of the conversion process and errors in the observation process have made research into stress prediction models very limited compared to that concerned with deformation [14][15][16].…”