Blast method for realizing vibration attenuation and protection of early-age concrete lining during tunnel construction

Abstract

The invention relates to a vibration attenuation and protection technology for blasting and digging of tunnels and aims at providing a blast method for realizing vibration attenuation and protection of early-age concrete lining during tunnel construction. The method comprises the following steps of: determining a safety vibration speed of the early-age concrete lining according to the most unfavorable value in combination with the age of the concrete, an explosion center distance and a rock geological condition; forming explosion holes; forming vibration attenuation holes; calculating a mass point vibration speed of the protected early-age concrete lining during explosion, and determining an allowable maximum explosive load under the condition that the mass point vibration speed is smaller than the safety vibration speed of the early-age concrete lining; and filling explosive and performing explosion. By adoption of the method, during tunnel explosion and construction, vibration harm of explosion to the early-age concrete lining can be reduced effectively when a distance between an explosion point in front of a tunnel and the poured concrete lining is closer due to an engineering progress requirement or because working surfaces are crossed; therefore, the tunneling efficiency is improved and the engineering can be constructed safely and successfully.

Description

technical field [0001] The invention relates to a vibration reduction and protection technology for tunnel blasting excavation, in particular to a blasting method for realizing vibration reduction and protection of early-age concrete lining in tunnel construction. Background technique [0002] Blasting is an important construction method in civil engineering, water conservancy, transportation, mining and other industries. It is widely used in earthwork excavation, tunnel excavation, slope improvement, building demolition, blasting embankment and other fields. During the construction process, concrete pouring and blasting excavation may be carried out synchronously due to crossing of working faces or progress requirements. At this time, the distance between the blasting construction face of the tunnel and the newly poured concrete lining is very close. Generally, the full-age concrete has high strength, and the lining has a strong ability to resist blasting vibration. Howeve...

AI Technical Summary

Problems solved by technology

Blasting vibration can be reduced by adopting segmented charge and reasonable differential time, but the vibration reduction effect achieved by this technology has a certain limit. When the newly poured concrete lining to be protected is very close to the explosion source, the blasting vibration still cause damage to the lining

In addition, if step excavation or pilot tunnel excavation is used to reduce the scale of blasting and reduce blasting vibration, it will delay the progress of excavation, increase the number of blasting, and reduce construction efficiency.

In short, the traditional vibration-reducing blasting technology still has significant deficiencies in the protection of newly poured concrete linings in tunnels, and it is urgent to develop new and more effective comprehensive vibration-reduction methods

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