<p>Piping failures induced breach of tailings dams present substantial hazards that can lead to significant damage to the lives of downstream residents. A comprehensive understanding of the causes and mechanisms behind piping failures is necessary. To this end, a large-scale physical model experiment was conducted to investigate the breach processes and characteristics of tailings dam due to piping failure. The pore water pressures, flow velocity, and evolutionary processes of breach were monitored in the experiment. The evolutionary stages and pore water pressure surges were analyzed. The potential piping failures, post-failure processes of the dam, and the impact on downstream villages were also discussed. The results show that four phases including stable stage, initial leak stage, piping enlargement stage, and breach formation and expansion stage are observed. Pore water pressure surge induces a force on the soil particles of the dam, triggering their movement and ultimately resulting in the collapse of the dam. Under the occurrence of dam breach, the risk of drowning downstream is significant, with a maximum depth of accumulation sand is approximately 29&#xa0;m in prototype, indicating catastrophic disasters after the tailings dam break. The findings from this study contribute to the understanding of the pre-failure behaviors, failure processes, and post-failure impacts of piping failures in tailings dams. This study also provides an important reference for understanding the breach mechanisms of tailings dam due to piping failures, as well as aids in ensuring the safety and reliability of such structures.</p>