Advanced adit hole-by-hole delayed blasting network in tunnel blasting

Abstract

The invention discloses an advanced adit hole-by-hole delayed blasting network in tunnel blasting. The network is characterized in that blasting excavation is performed by using a three-step method for an underground excavated metro interval tunnel; longitudinal excavation is performed along the tunnel to form an upper step, a middle step and a lower step in sequence; the excavation of the upper step is performed by prearranging each external contour overhead hole at equal intervals along the upper arch of an excavation contour line of the upper step; an advanced adit is arranged at the bottom; a central blast hole is positioned in the geometric center of the advanced adit; four central overhead holes are prearranged at the positions of four vertexes of a square ring with the central blast hole as the center; the advanced adit and an upper step expanded excavation region are blasted at two steps; the advanced adit hole-by-hole delayed blasting network is arranged in the way that each layer of expanded slot blast holes is arranged at the periphery of the central blast hole at intervals from near to far away from the central blast hole; the first layer of expanded slot blast holes are crosswise distributed at the periphery of the central blast hole and form the square ring together with four central overhead holes. The detonation explosive load of the same section is greatly reduced by using hole-by-hole delayed blasting.

Description

technical field [0001] The invention relates to a blasting control shock absorption method, more specifically to the shock absorption control method adopted in the blasting of tunnels passing through cultural relics protection buildings, in order to reduce the damage caused by the harmful effect of blasting vibration to ground cultural relics protection buildings. Background technique [0002] With the vigorous development of my country's urban subways, more and more subway projects have been constructed through the bustling urban areas by using the drill and blast method, and some cities still have a large number of national-level cultural relics protection buildings. The harmful effects of vibration generated by the blasting may endanger the surrounding buildings, especially the ancient cultural relics protection buildings. How to effectively control the harmful effects of blasting vibration and ensure the safety and smooth construction of cultural relics protected buildin...

AI Technical Summary

Problems solved by technology

[0005] In engineering blasting, there are many single shock-absorbing measures, but in the case of using a single shock-absorbing measure, when the distance between the protected point and the blasting area is 20m, the blasting vibration velocity of the measuring point is 2-5cm / s, which is Obviously far from meeting the control requirements of 0.5cm / s

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