FLYING STONE PREVENTIVE METHOD IN BLASTING UNDER RAINING CONDITION

摘要

PURPOSE:To promote a safe and efficient blasing work even in case of rain, snow or water splashing by a method wherein a desired amount of explosive is filled in a hole to be blasted, a cement is mixed in all or a part of objects to be filled in the hole over the explosive, the formed mixture is filled in the hole to perform the blasting work. CONSTITUTION:For example, in case that it is assumed that a hole diameter of a hole 1, R=80mm, a hole length L-4m, an explosive filling length L1=2m, an filling object length L2=2m, a total amount of a filled object 3 is about 8kg in weight. During a normal rain fall, a cement 4 of about 2kg of about 1/4 of a total amount of 8kg of the filled object 3 is mixed in the filled object 3 and then the mixture 5 is fed into the hole 1 filled with the explosive 2. During a heavy rain fall, the cement 4 is increased up to about 1/2 of the maximum filled object to form the mixture 5. In this way, an amount of cement to be mixed in the filled object is set in a range of its 1/4 to 1/2 of the filled material. If the cement in the filled object contains moisture due to rain fall, snow or flashed water or the like, the cement is rapidly hardened, the entire filled object is not muddy state, resulting in that its resistance force is increased and the flying stones can be prevented.