Comprehensive damping method for mixed explosion of hard rock tunnel closely attaching to existing underground building

Abstract

The invention discloses a comprehensive damping method mixed explosion of a hard rock tunnel closely attaching to an existing underground building. The method is characterized in that below the base plate of the existing structure of the existing building, an explosion working face is sequentially divided into a metal expansion explosion area, an emulsion explosive underholing area and an emulsion explosive explosion area towards the depth direction. By the method, explosion vibration speed during tunneling, attaching to the existing underground building, in a hard rock stratum can meet the requirements, the existing underground building is not damaged by explosion shock waves, and project progress is guaranteed.

Description

technical field [0001] The present invention relates to a mixed control blasting method, more specifically, a comprehensive damping method for mixed blasting implemented in construction tunnels in hard rock formations close to existing structures, in order to reduce the impact of blasting vibration and blasting shock waves on existing underground structures damage. Background technique [0002] With the development of my country's economy and the acceleration of the urbanization process, the land resources in my country's big cities are becoming increasingly scarce. The development of underground space is an inevitable choice, and the development of underground space is developing in the direction of three-dimensional intersection. It is more and more common to develop underground space under existing underground structures. When new structures are built under existing underground structures, blasting operations are required. How to avoid damage to existing structures by bla...

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Problems solved by technology

[0004] According to the existing design, the blasting vibration velocity in this section needs to be controlled within 1.5cm / s, but it cannot be achieved in actual construction. For Line 2 and underground shopping malls, the blasting vibration velocity is controlled within 4.0cm / s to ensure the safety of concrete structures

However, since the underground excavation at the west end is a station and flat-roofed underground excavation structure, which is close to the floor of the existing Line 2 and the underground shopping mall, the blasting vibration speed still cannot meet the requirements when using general explosives for construction, and when the existing structures are far away from the drilling and blasting holes When it is too close, the blasting shock wave will also destroy the existing structures; although the rock metal expansion agent can be used for static blasting, the static blasting metal expansion agent will not start to work until more than ten hours later, and the cycle time is long and the cost is quite high. Difficult to apply

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