Blasting excavation method for side slope rock mass with deep fissures

Abstract

The invention discloses a blasting excavation method for a side slope rock mass with deep fissures. The method comprises the steps of drilling holes and obtaining the distribution of joint fissures, dividing each blast hole penetrating through the fissure area into a lower coupling charging section, a fissure area weakening charging section and an upper conventional charging section according to the distribution of the fissure area in the blast holes, charging the blast holes in a segmented mode, plugging the blast holes, and detonating in a networking mode. The blast holes with joint fissurescommunicated with one another are detonated in a segmented and networking mode in areas, the other blast holes are detonated in a conventional networking mode, and each hole adopts hole-bottom detonation. According to the invention, segmented charging is adopted, the charging is weakened in the fissure area, gaps between explosive cartridges and blast hole walls are filled with rock debris, and adetonation gas can be prevented from leaking too early through the joint fissures, so that the pressure peak value and the duration time of the detonation gas can be increased, and the gas wedge effect of the detonation gas can be brought into full play; and the blast holes with joint fissures communicated with one another are detonated in a grouping and networking mode in areas, so that the adverse effect of the first detonating blast holes on the later detonating blast holes through the joint fissures can be avoided, and the occurrence of an explosion rejection accident is avoided.

Description

technical field [0001] The invention belongs to the technical field of engineering blasting, can be applied to the blasting and excavation operation of slope rock mass with joints and fissures, and relates to a method for blasting and excavating rock mass of a slope with deep fissures. Background technique [0002] There are many mountains in our country, especially in the western region. With the continuous development of the national economy, various engineering constructions extend to the western region. When carrying out various engineering constructions in alpine valleys, blasting excavation of slope rock mass is essential. Under the action of various geological structures and long-term physical, chemical and biological weathering and erosion, there are usually a large number of cracks in the rock body. It is generally believed that rock fragmentation under blasting is the result of the joint action of the blast stress wave and the blast gas. After the explosive explod...

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Problems solved by technology

[0003] Grouting the rock mass requires additional drilling of grouting holes, which increases the working time of the drilling rig, and when the blasting area is large, the number of grouting holes and the amount of grout required to be drilled are large, which increases the cost and economy of the project. Poor; pouring cement slurry in the blast hole, the space is narrow, the construction operation is inconvenient, and it is difficult to guarantee the filling effect of the tiny cracks around the blast hole; the method of putting explosives into the PE soft water pipe needs to cut the water pipe according to the depth of the blast hole and Bind the lower end of the water pipe, which brings great inconvenience to the charging process

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