Study of Hydraulic Failure Mechanism in Core of Earth Dam (A Case Study: Taj-Amir Norabad Dam)

The occurrence of hydraulic failure is one of the most important geotechnical problems in the core of dams. Excessive water pressure increase during the first impounding period results in a significant reduction in the effective stress and consequently reducing the shear strength of the core materials of the earth's dams, which can overcome the water pressure on the effective stress and the underlying hydraulic cracking. In this research, the hydraulic failure of Taj-Amir earth dam with static loading conditions was completed at the end of construction and the steady state period was studied by Plaxis software with Mohr-Coulomb behavioral model. The analyses show that water pressure ratio (Ru) and stress-strain values are acceptable and there is no problem in terms of failure of dam. Also, the critical ratio of arching is 0.53(47%), which is about one-third the height of the core from the foundation, it is conventional, and the hydraulic failure does not occur even with the occurrence of an arching phenomenon at the core of the dam.