Negative excavation blasting structure and method for nuclear island corridor foundation pit

Abstract

The invention discloses a negative excavation blasting structure and method for a nuclear island corridor foundation pit. A blasting area of a corridor foundation pit is defined by an inner ring line and an outer ring line; the blasting area of the corridor foundation pit is divided into a plurality of blasting sections; a plurality of first pre-splitting holes are formed in the inner ring line at intervals, and a plurality of second pre-splitting holes are formed in the outer ring line at intervals; at least one row of first slotting holes are formed between every two adjacent blasting intervals; a plurality of first main blasting holes are formed in each blasting section at intervals; and the first pre-splitting holes, the second pre-splitting holes, the first slotting holes, second slotting holes and the first main blasting holes are each provided with a charging section and a filling section. Ideal inner and outer circumferential cracks of the corridor can be formed at a preset position of a rock foundation, then main explosion with the purpose of removing rock in the corridor can be carried out, meanwhile, corresponding reasonable measures are taken in consideration of technical requirements such as vibration and allowance, so that the construction operation of negative excavation of a nuclear island corridor foundation pit can be quickly completed with high quality.

Description

technical field [0001] The invention relates to the technical field of nuclear power engineering, in particular to a negative excavation blasting structure and blasting method for a nuclear island ring gallery foundation pit. Background technique [0002] In the prior art, there are certain technical defects in the method of excavating the ring corridor of the nuclear island. For example, the Chinese patent whose publication number is CN101368812A discloses a pre-splitting blasting method for the ring corridor of the nuclear island. The steps are as follows: The position is dug down according to the elevation of the center of the nuclear island, and a reserved layer is reserved; holes are drilled at equal intervals along the inner and outer circumferences of the ring corridor; flexible materials are placed at the bottom of the holes as a cushion layer; And the hole with the plugging depth left at the orifice is divided into three sections of charge, the bottom is the reinfor...

AI Technical Summary

Problems solved by technology

This patent can only be used for the formation of pre-cracks in the ring corridor of the nuclear island to reduce the damage to the wall of the ring corridor by the blasting of the main body, but cannot be used for the removal of rocks that need to be excavated by blasting in the foundation pit. The ultimate purpose of pit excavation, and when the foundation pit is excavated, there will still be a large blasting vibration, which will affect the surrounding buildings

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