Abstract：Two major faults are located in the heel and toe of Guangzhao gravity dam with height of 200 m. A nonlinear 3D numerical simulation is conducted on a typical monolith to analyze the impact of faults on stress-deformation status of the gravity dam and stability of the abutment. Simultaneously，the impact on the gravity dam，which is caused by the increase of fault deformation modulus induced by the variation of confining pressure after the dam completion，is also analyzed. Sensitivity analysis of faults is conducted；safety of abutment impacted by faults is calculated by strength reservation method；and different reinforcement methods on the two faults are simulated respectively. The results show that the F2 fault located near the dam toe makes a great impact on stress status of the dam，and it is a major factor to control stability of the dam. Not only is the stability increase，but also the stress status is improved after consolidation grouting. It is suggested that F1 fault near the heel should not be excavated deeply. The increase of fault deformation modulus，which is induced by the variation of confining pressure after the dam completion，has an advantageous impact on the stress status of dam.
