Impact of concrete face cracks on the saturated and unsaturated seepage behavior of rockfill dams

In the design and operation of rockfill dams, an in-depth understanding of the impact of concrete face cracks on the seepage behavior of rockfill dams is of great significance. Despite extensive research that has been conducted, the impact of concrete face cracks on the seepage behavior under saturated and unsaturated conditions is still under-clarified. In this article, the seepage behavior of rockfill dam was simulated by employing numerical simulation and the Van Genuchten (VG) unsaturated seepage model. Then, based on the equivalent block continuum medium model, a method for calculating unsaturated seepage with consideration of concrete face cracks was proposed. By employing kernel density estimation methods to investigate crack distribution, objective data support was provided for subsequent numerical simulation. Then, taking a real-world rockfill dam as a case study, the impact of concrete face cracks on the seepage behavior of rockfill dams under saturated and unsaturated conditions was systematically analyzed using abovementioned theoretical methods. The research results show that concrete face cracks mainly affect the seepage behavior of rockfill dams in the vicinity of the cracks, and the location of cracks has a significant impact on the seepage discharge of the dam, with cracks located in the upper part of the face slab causing the smallest discharge. In addition, the permeability anisotropy of dam materials and the presence of cracks have obvious effects on the seepage behavior of rockfill dams. The research findings are expected to provide a new perspective for examining the seepage characteristics of concrete face rockfill dams, and have important value for the evaluation of structural safety and stability in engineering practice.