Geomechanical model test for stability analysis of high arch dam based on small blocks masonry technique

► Block masonry technique is invented to simulate the deformation and strength of rock.
► The technique has been applied in the rupture test of Xiluodu arch dam in China.
► Three overloading factors are defined to evaluate the safety of arch dam.
► Failure process, mode and mechanism are derived for identification of weakness.
► Comparation with other dams has been done for evaluation of global stability.

Rock mass deformation and strength property simulation plays a key role in the rupture tests of arch dam geomechanical model. Subject to the limit of geometry scale, usually the simulation of tectonic discontinuities, such as faults, disturbed belts, crush belts and weak interlayer were ignored as safety buffer, which may yield overstated safety factors. In this paper, small block masonry technique and low strength binder invented make the simultaneous simulation of the rock mass and tectonic discontinuities available, which is more coincident with real engineering conditions. Based on the material test of blocks and binder, the small blocks masonry technique has been successfully applied in the rupture test of Xiluodu arch dam. With the assistance of high-accuracy monitoring and measuring system, the stress (strain) and displacement distribution of the dam, abutments and rock foundations are obtained. By analyzing these monitoring results, the failure process, mode and mechanism of the dam body and abutments are derived for further identification of weakness. At last, the comparative analysis with other arch dam geomechanical rupture test results yields the evaluation of the dam's global stability and necessary reinforcement measures.