Mutual construction of underground caverns on the right bank of Baihetan hydropower station caused complex microstructures and rupture mechanism of surrounding rock of intersecting caverns. In this study

the IMS system was introduced to investigate microseismic characteristics of surrounding rock of caverns and rupture mechanisms under high stress

multi-faceted unloading stress conditions. According to the lithology

fault zone and fault distribution in the underground powerhouse area

the sensors with perfect monitoring effect were chosen and rationally arranged. The accuracy of the source location was analyzed by using the velocity inversion through the fixed point percussion test. Based on the case of failure of the #10 omnibus cave

this study analzsed the spatial-temporal evolution of microseismic events and energy release of the intersected chambers. Meanwhile

according to the energy ratio (ES/EP) criteria

the evolution mechanism of rock mass rupture was discussed

which included a large number of tension events (blasting shock caused)

pull-shear and pressure-shear events

tension and shear events alternately (the effect of concentrated stress and joint) and failure (the effect of gravity and joint) in the order of occurrences. This study is helpful to optimise the excavation scheme of the underground section on the right bank of Baihetan hydropower station

and it is of significance for the excavation and support of similar projects.