Прочитайте и переведите текст. напишите аннотацию. mine development mine development is the excavation work done before starting full scale extracting of ore in a mine or stope. in most cases, development excavation continues throughout the life of the mine. development objects are vertical shafts, horizontal drifts, inclined ramps and steep raises. drilling and blasting rock excavation is usually used with exсeption of raises. the extent and type of development work required depends on the depth, size and geology of the ore body, on the chosen mining method and expected life of the mine. caving methods in particular demand substantial development work, normally 30–40 % but sometimes up to 60 % of total costs. sublevel stopping also needs extensive preparation work before production can start. much of this preparation work is done in waste rock, and is an extra cost that the mining operation just has to accept. mine layouts are 3-dimensional and complicated, and must be designed with great accuracy to achieve maximum mining efficiency. today computers provide modeling programs that make it possible to plan accurate layouts for optimal mining efficiency
