An optimization method for cutting charges in shallow tunnel blasting considering cavitation effect

Abstract

The invention discloses a method for optimizing the amount of cutting charge in blasting of a shallow buried tunnel considering the cavity effect, comprising: formulating a cutting blasting test plan; Arrange N measuring points equidistantly and symmetrically; carry out the test according to the established cutting blasting test plan, and collect the peak velocity and main frequency of surface blasting vibration at each measuring point; fit the peak value of surface blasting vibration in the unexcavated area of ​​the shallow tunnel Velocity model and dominant frequency model; determine the surface blasting vibration peak velocity model and dominant frequency model in the shallow tunnel excavation area; complete the optimization of shallow tunnel blasting cutting charge according to the location of the protected building. The invention not only fully considers the local amplification phenomenon of blasting vibration on the surface of the tunnel excavation area caused by the cavity effect of the shallow buried tunnel, but also strictly guarantees the safety of the protected buildings on the surface during the tunnel blasting and excavation process, and at the same time improves the performance of the shallow buried tunnel to the greatest extent. Efficiency of blasting excavation in tunnels.

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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