Fast and highly-efficient tunneling method for large section of hard-rock tunnel in coal mine by combination of fully-mechanized tunneling and blasting driving

Abstract

The invention relates to a fast and highly-efficient tunneling method for a large section of a hard-rock tunnel in a coal mine by combination of fully-mechanized tunneling and blasting driving. As shown in the figure 1, a cut hole with the borehole diameter of Phi 40.0 mm and a reliever hole with the charge diameter of Phi 35.0 mm are arranged in the section of the hard-rock tunnel with the protodyakonov coefficient f larger than 10.0 for digging out a groove cavity with s approximately equal to 14.0 m<2>. As shown in the figure 2, the cut hole adopts a three-stage oblique cut with stages deepening and angles of inclination increasing stage by stage. The consumption of charge in unit volume is determined based on the hard-rock protodyakonov coefficient and shot hole depth according to quantification of the figure 3. Three stages of oblique cuts respectively select I, III, IV-section millisecond delay detonators. A V-section millisecond delay detonator is selected by the reliever hole. The oblique cuts and the whole section of the reliever hole are detonated once with the total delay time no more than 130.0ms. After the groove cavity is formed in a blasting method. The reasonable tooth parameters are selected to rapidly expand the groove cavity to the design section and contour is finished under effect of a free surface of a fully-mechanized coal winning machine. Due to millisecond delay detonation of the oblique cut in three stages and larger borehole diameter, stemming is blocked to increase so that rocks do not affect the fully-mechanized coal winning machine after the working surface during the throwing process. The safe and efficient effect can be achieved.

Description

technical field [0001] The patent of the present invention relates to a fast and efficient tunneling method for a large-section hard rock roadway in a coal mine, in particular to a method for fast and efficient tunneling of a large-section hard rock roadway in a coal mine by combining mechanized excavation and blasting excavation. Background technique [0002] Mechanized excavation is widely used in roadway excavation due to its fast excavation speed and high excavation efficiency. However, for rocks with high hardness, the advantages are not obvious. For hard rocks, the excavation speed and efficiency are significantly reduced or even cannot be excavated normally. Engineering practice shows that: when the rock Platts coefficient f<6.0, the effect of fully-mechanized excavation is obvious; when f=6.0-8.0, the speed and efficiency of fully-mechanized excavation will be reduced; At 10.0, because the cutter teeth cannot form notches in the roadway section, it is almost impos...

AI Technical Summary

Problems solved by technology

[0002] Fully mechanized excavation is widely used in roadway excavation due to its fast excavation speed and high excavation efficiency. However, for rocks with high hardness, the advantages are not obvious. For hard rocks, the excavation speed and efficiency are significantly reduced or even cannot be excavated normally.

Engineering practice shows that: when the rock Platts coefficient f<6.0, the effect of fully-mechanized excavation is obvious; when f=6.0-8.0, the speed and efficiency of fully-mechanized excavation will be reduced; At 10.0, because the cutter teeth cannot form notches in the roadway section, it is almost impossible to mechanize excavation, and blast excavation must be used

When blasting hard rock with f>10.0, when the section of the roadway increases to a certain extent, due to the large number of blastholes and the limit of the number of detonators that can be detonated at one time by the detonator, detonation must be detonated in stages, and detonation of the entire section cannot be achieved at one time; In practice, when f>10.0 hard rock roadway section s≥14.0m 2 At the same time, the excavation efficiency and speed are obviously reduced; for the roadway with gas, the total delay of the differential blasting cannot exceed 130.0ms, and the number of detonator segments in the differential blasting cannot exceed 5, which is serious Affect the speed and efficiency of hard rock blasting

Images