Method for blasting and excavating dam foundation and rock foundation

Abstract

The invention discloses a method for blasting and excavating a dam foundation and a rock foundation. The method comprises the steps of step 1, drilling blast holes, and paving buffer layers at the bottom parts of the blast holes; step 2, vertically installing energy dissipation seats on the buffer layers, and filling explosive, wherein the energy dissipation seats are prepared by adopting concrete, the concrete is formed by cement, water, iron sand, superplasticizer and gel, the water-cement ratio is 0.24-0.28, the mass ratio of the iron sand and the cement is (1.6-3.0):1, and the mass of the superplasticizer is 1.0%-2.0% of that of the cement; step 3, blasting through a detonator. The method disclosed by the invention has the advantages that the operation is quick and convenient, the construction cost is low, the blast shock waves are reflected for multiple times through the energy dissipation seats, the energy of the blast shock waves is induced to gather in the horizontal direction, the full crushing of rock bodies between adjacent blast holes can be realized, the blasting efficiency can be further increased, meanwhile, the damage to the bottom parts of the blast holes can be further reduced, and the flatness of an excavation surface is increased.

Description

technical field [0001] The invention belongs to the technical field of engineering blasting, in particular to a blasting excavation method for dam foundations and rock foundations, which is applied to blasting excavation in large-scale civil engineering. Background technique [0002] In large-scale civil engineering, there is a common contradiction between excavating rock damage and protecting surrounding rock when blasting is used to excavate rock mass; in addition, there are also problems that it is difficult to realize rapid construction and excavation at the same time, and fine damage control is difficult to wait for solutions. Southwest China is rich in water resources. A large number of water conservancy and hydropower projects under construction and proposed to be constructed generally face the contradiction between the large-scale rapid excavation of rock slopes and the formation of slope horse tracks, as well as the cumbersome construction progress of rock foundation...

AI Technical Summary

Problems solved by technology

[0003] In recent years, the sequential detonation method between holes in small steps with a flexible cushion at the bottom of the blast hole, due to the limited buffering effect of the flexible cushion material on the blasting shock wave, the damage to the bottom of the blast hole is still relatively large, and the undulation of the foundation surface of the excavation is relatively large. large, resulting in a large amount of manual excavation; at the same time, ordinary energy-concentrating blasting using wedge-shaped charge tanks cannot achieve ideal results due to the limited energy-concentrating effect of the device.

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