Grouting method for fracture zone of karst stratum

The invention provides a karst stratum fault zone grouting method which comprises the following steps: performing a tracing test on a first branch drill hole arranged in a fault zone of a karst stratum to obtain a diffusion range of a tracer agent, and determining a hole arrangement pitch of the fault zone according to the diffusion range; according to the transverse distribution length of the fault zone and the hole distribution distance, the branch transverse position of a second branch drill hole is determined; according to the top positions of aquifers in the karst strata on the two sides of the fault zone, the branch longitudinal position of a second branch drill hole corresponding to each branch transverse position is determined; and according to the transverse position of each branch and the longitudinal position of the branch corresponding to the transverse position of each branch, second branch drill holes are formed in the fault zone, and grouting is conducted on the second branch drill holes. Accor