What is the standard proportion of mine backfill?

1.2: 1。 According to the Technical Specification for Construction Quality Inspection of Foundation and Foundation Engineering of Building Engineering, certain measures should be taken when the backfill ratio of earthwork excavation in mine should be greater than or equal to 1.2: 1, the settlement scale between local foundations is less than 0.5m, the deviation between two sides of foundation structure is less than 0.3m, and the settlement between local foundations is greater than 0.1m..