The Geomechanical Model Test on Stability of Arch Dam Abutment under Complex Geological Conditions

With the method of combination of overload method and strength-decreasing method, the geomechanical model test on the stability of abutment is applied in this paper, and combined with the concrete double arch dam in Sichuan province. The destruction test is made to discuss the failure pattern, process and mechanism of dam abutment, with the temperature analogous material simulating the weak structural planes. The factor of safety of abutment is obtained by combination of overload method and strength-decreasing method, which is 3.12～3.51. In normal operation condition, the abutment can keep stable. And obvious fissures appear in abutments during decreasing strength period, especially in the left abutment. So reinforcements to dam abutments, especially to the left abutment,are necessary.