Shallow-buried tunnel blasting-cut explosive quantity optimizing method considering void effect

Abstract

The invention discloses a shallow-buried tunnel blasting-cut explosive quantity optimizing method considering a void effect. The method comprises the steps of establishing a blasting-cut testing scheme; symmetrically arranging N measure points at equal intervals with a tunnel face as the center on the earth surfaces of an excavation area and a non-excavation area of a shallow-buried tunnel; carrying out experiments according to the established blasting-cut testing scheme, and collecting an earth-surface blasting vibration peak velocity and a main frequency of each measurement point; fitting anearth-surface blasting vibration peak velocity model and a main frequency model of the non-excavation area of the shallow-buried tunnel; determining an earth-surface blasting vibration peak velocitymodel and a main frequency model of the excavation area of the shallow-buried tunnel; according to the position of a protected building, completing optimization of the shallow-buried tunnel blasting-cut explosive quantity. The method fully considers a local enlarging phenomenon, caused by the shallow-buried tunnel void effect, of earth-surface blasting vibration of the tunnel excavation area, it is strictly ensured that the protected building on the earth surface is safe in a tunnel blasting excavation process, and the shallow-buried tunnel blasting tunneling efficiency is improved to the greatest extent.

Description

technical field [0001] The invention belongs to the fields of tunnel blasting construction technology and blasting vibration effect control, and in particular relates to an optimization method for blasting cutting charge in shallow buried tunnels considering cavity effect. Background technique [0002] With the large-scale development of urban rail transit construction, there are more and more shallow buried tunnel projects passing through densely built urban areas for blasting construction. During the blasting construction of shallow buried tunnels, since the blast source is close to the surface, the vibration effect of the surface buildings caused by blasting seismic waves is more prominent. Coupled with the phenomenon that the cavity formed in the excavated area of ​​the tunnel causes the vibration velocity of the upper surface to be greater than that of the unexcavated part, that is, the existence of the tunnel cavity effect, the problem of the blasting vibration effect ...

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Problems solved by technology

Due to the differences and complexity of the terrain and geological conditions of the tunnel engineering site, the uncertainty of the rock mass constitutive model parameters and the roughening of the blasting load loading model, the blasting design proposed in this public achievement is mainly based on the engineering numerical simulation results. The reliability and universality of the method of the scheme are poor, and it can only be applied to the specific blasting scheme formulated under the specific engineering conditions whose feasibility of the numerical model has been verified.

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