Blasting construction method adopting equal-distance fan-shaped hole distributing method for tunnel slotting and enlarging area

Abstract

The invention discloses a blasting construction method adopting an equal-distance fan-shaped hole distributing method for a tunnel slotting and enlarging area. The blasting construction method is characterized in that a graphing method is adopted for performing equal-distance hole distributing for face holes, hole toes and the like, so that a joint of extending lines of blast holes with fan-shapeddistributed holes is taken as a precise reference point for drilling. Mapping results are utilized for perpendicularly drawing out a perpendicular line on a profile surface at the position of the joint, a sampling rod or an existing anchor rod is fixedly arranged on the perpendicular line; a hanging nylon rope is taken as a drilling and sampling line, and fan-shaped sampling is adopted on the horizontal plane, so that hole-bottom resisting lines between cutting holes and enlarging holes are uniformly distributed at equal distance according to fan-shaped characteristics; and each row of blastholes has evidence in drilling direction, angle, depth and position, and the theoretical method and practice can verify and inspect with each other. The construction method can eliminate an uneven hole distributing phenomenon of three-dimensional blind-region holes in bottoms of the blast holes between an inclined-hole wedge-shaped slotting area and the enlarging area, so that explosive energy distribution in the inclined-hole wedge-shaped slotting area and the enlarging area is uniform and reasonable, and therefore, combined effects of holes is further strengthened.

Description

technical field [0001] The invention specifically relates to a blasting construction method for equidistant fan-shaped holes in a tunnel digging and expansion area. Background technique [0002] Tunnels and underground projects play an important role in the construction of the national economy. With the rapid development of national construction, the construction of tunnel projects increasingly needs to solve the problem of how much, how fast, and how cheap. In the short term at present and in the future, the drilling and blasting method will still be the main method of tunneling, and the success of the blasting depends on whether the cutting is successful, and the size of the footage depends on the depth of the cutting, so it is necessary to study the cutting method suitable for the surrounding rock conditions. Groove technology maximizes the blasting footage on the premise of ensuring the stability of the surrounding rock. Cut blasting involves the whole process of blasti...

AI Technical Summary

Problems solved by technology

[0003] With the continuous excavation of the tunnel, the height of the upper mountain where the excavation face is located is increasing, and the stress of the rock is increasing. At the same time, the toughness and strength of the surrounding rock are increasing, the integrity of the surrounding rock is improved, the explosiveness is reduced, and the cutting effect is often not good. Ideal, with the same drilling depth, the circular footage after blasting is reduced, and even the clamping force of the surrounding rock is too large, the cutting is squeezed to death by blasting, and half of the hole is not stripped by blasting, requiring re-drilling and supplementary blasting

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