Precise control method for smooth surface blasting of fractured rock mass of highway tunnel

Abstract

The invention relates to a precise control method for smooth surface blasting of fractured rock mass of a highway tunnel. The method comprises the following steps: step S1, acquiring the parameters required by precise control on smooth surface blasting; step S2, performing precise control on smooth surface blasting, namely arranging explosives according to a rule that no explosive cartridges are arranged at fractured positions inside a drilling hole; calculating the single-hole explosive load; determining the amount of water in a water bag; respectively controlling according to the drilling holes which are different in completeness; step S3, after blasting is ended, regulating the single-hole explosive load and water amount according to the overbreak and underbreak amount and the value of the half-hole ratio; step S4, drilling again and blasting again according to the updated single-hole explosive load and water amount, sequentially circulating until the tunnel is accomplished. According to the method, dynamic regulation is continuously performed and the explosion effect is precisely controlled as far as possible, so that the aim of controlling the overbeak and underbreak of blasting is realized, the utilization of the explosives is increased, loss of the explosives is reduced, and the engineering cost is lowered.

Description

technical field [0001] The invention relates to the field of tunnel blasting, in particular to a refined control method for smooth blasting of cracked rock mass in highway tunnels. Background technique [0002] With the rapid development of the national economy and the continuous advancement of urban construction, my country has built a large number of urban roads, railways, and subway tunnels, and has become the country with the most tunnels and underground projects, the most complex, and the fastest growing in the world. [0003] The current general process of tunnel smooth blasting is as follows: firstly, according to the actual situation of the geological structure of the tunnel section, the smooth blasting design is carried out. coefficient, linear charge density, number of light blasting holes, etc.). The layout of blastholes should be based on the excavation design outline, and appropriate adjustments should be made considering the amplification of reserved deformati...

AI Technical Summary

Problems solved by technology

When blasting existing tunnels, a uniform and single charge structure and method are used for all boreholes, and the influence of cracks in the boreholes of the fractured rock mass on the blasting is not fully considered, which is likely to appear in the joints of boreholes. In addition, the use of explosives in the existing blasting is usually based on empirical values, but not based on the nature of the drilled hole and the specific lithological description of the rock formation where the drilled hole is located. Therefore, It is also easy to cause the blasting effect to be uncontrollable. After the blasting, a large amount of blasting dust is generated, which affects the construction environment. At the same time, it also reduces the utilization rate of explosives, resulting in waste of explosives and increasing project investment.

2. The fragmentation degree of the broken rock after blasting in the prior art is large, and the degree of rock fragmentation is not ideal

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