A new early warning method for dam displacement behavior based on non-normal distribution function

Abstract

Traditional methods for early warning of dam displacements usually assume that residual displacements follow a normal distribution. This assumption deviates from the reality, thereby affecting the reliability of early warning results and leading to misjudgments of dam displacement behavior. To solve this problem, this study proposed an early warning method using a non-normal distribution function. A new early warning index was developed using cumulative distribution function (CDF) values. The method of kernel density estimation was used to calculate the CDF values of residual displacements at a single point. The copula function was used to compute the CDF values of residual displacements at multiple points. Numerical results showed that, with residual displacements in a non-normal distribution, the early warning method proposed in this study accurately reflected the dam displacement behavior and effectively reduced the frequency of false alarms. This method is expected to aid in the safe operation of dams.