Method for optimizing form of caving body and reducing loss and dilution of sill-pillar-free sublevel caving method

The invention discloses a method for optimizing the form of a caving body to reduce loss and dilution of a sill-pillar-free sublevel caving method, and belongs to the technical field of mining. According to the method, the form of the caving body is changed by setting broken-line-shaped arrangement of fan-shaped blast holes, high-density charging of blast holes in a middle section and a certain detonating sequence. Two rows of blast holes symmetrical to the center line of the drift are arranged in the same ore caving step pitch, the first blast hole in each row is arranged at the center line of the drift and is closest to the free surface, the other blast holes are sequentially arranged towards the two sides of the drift in the withdrawing direction, and high-density charging operation is carried out in the middle area of the rock mass to be caved in the ore caving step pitch with the explosive loading amount 10%-15% higher than the explosive loading amount of other ranges. During blasting, a millisecond blas