Underground cavern group layout method

The invention discloses a large-scale underground cavern group layout method applied to water conservancy and hydropower engineering and underground storage cavern engineering. The underground cavern group layout method can give overall consideration to major factors having influences on underground cavern adjoining rock stability, particularly gives overall consideration to the crucial factor of the rock strength-stress ratio, enables a large-scale underground cavern group layout designing scheme to be scientific, and is overall in considered factors. The method includes the following steps: firstly, determining the positions of main caverns, then determining the axis directions of the main caverns, determining the thickness of a rock pillar between the main caverns, and finally determining cavern shapes of the main caverns. When the cavern shapes of the main caverns are determined, each main cavern is divided into an underground main power house, a main transformer chamber and a tail water surge chamber according to functions, the hole shape of each underground main power house and the hole shape of each main transformer chamber are in circular arch straight wall shapes or egg shapes, and each tail water surge chamber is in a cylinder shape or a gallery shape.