Large-scale underground cavern group arrangement design method

The invention discloses a large-scale underground cavern group arrangement design method applied to hydraulic and hydroelectric engineering and underground storage cavern engineering. According to the arrangement design method, principal factors, especially the essential factor of the rock strength-stress ratio, influencing underground cavern surrounding rock stability can be comprehensively taken into account, the designing scheme for large-scale underground cavern group arrangement can be more scientific, and considered factors are more comprehensive. The position of a main cave is determined at first, the orientation of an axis of the main cave is determined, then the thickness of a rock pillar in the main cave is determined, and at last the shape of the main cave is determined. When the orientation of the axis of the main cave is determined, the trend of a rock mass main structural surface on a construction site and the orientation of the maximum principal stress are measured at first, the orientation of the axis of the main cave is determined according to an included angle between the axis of the main cave and the trend of the rock mass main structural surface and an included angle between the axis of the main cave and the orientation of the maximum principal stress, the included angle between the axis of the main cave and the trend of the rock mass main structural surface is not less than 40 degrees, and the included angle between the axis of the main cave and the orientation of the maximum principal stress is 0-40 degrees.