Reliability Analysis of Tensile Crack Resistance in High Asphalt Core Based on Mixed-Level Uniform Design and Response Surface Method

For embankment dams over 150 m in height, there is a strong tensile effect on the core near the bank slope under the action of water storage. The cracking of the core due to tension can threaten the overall safety of the dam. Therefore, it is very crucial to perform a reliability analysis of the tensile crack resistance of a high asphalt core. In this study, the tensile crack of the core is considered the basis of failure. Taking the ultimate tensile strain as the control index, a calculation method is established for the crack resistance reliability of a high embankment dam core based on a mixed-level uniform design (MLUD) and the response surface method (RSM). Considering the Duncan–Chang E-B model parameters, the random variables for the reliability calculation assessment are determined by the single-factor sensitivity analysis method. Based on the combination of the MLUD and the RSM, the explicit expression of the core strain is derived. Further, the checking point (JC) method is used to evaluate the performance of the core. The Quxue dam with a dam height of 171.2 m is used as an engineering example for verification. The results show that the random variables K, n, and φ, and the upstream water level H are highly sensitive parameters. The core crack resistance reliability index β is 4.2695, which is greater than the standard reliability index. The calculated results are in good agreement with the collected actual measurement results.