Test device and method for simulating blasting excavation unloading

Abstract

The invention discloses a test device and method for simulating blasting excavation unloading, the device comprises two Hopkinson bars and a rock mass sample fixed between the Hopkinson bars, one end of each Hopkinson bar is fixed, the other end of each Hopkinson bar is provided with an unloading assembly, the Hopkinson bars are provided with strain gauges, and the strain gauges are connected with the Hopkinson bars. The strain gauges are connected with the super-dynamic strain gauge, the transient waveform memory and the data processing center in sequence; the unloading assembly comprises a rectangular steel frame, one side of the rectangular steel frame abuts against the Hopkinson bar, the other side of the rectangular steel frame abuts against the brittle bar, a bullet barrel and bullets are arranged in the inner space of the rectangular steel frame, and the bullets are the same as the rectangular steel frame in horizontal height and face the direction of the brittle bar; and the other side of the brittle rod abuts against the loading assembly. The Hopkinson bar device is adopted to simulate the transient unloading process, the change of the strain state and the transmission mode of stress waves in the unloading process are measured to be more accurate, in the research process of transient unloading, a bullet impacts a brittle bar at a high speed to damage the brittle bar, and the unloading efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of rock mass blasting, in particular to a test device and method for simulating blasting excavation and unloading. Background technique [0002] Due to the complexity of crack expansion in the process of rock blasting and the resulting gas movement and high-speed escape, the stress boundary conditions and initial stress conditions are used to accurately describe the excavation load that occurs with the formation and development of a new excavation face in the rock mass The way of transient release, the starting position and its spatial evolution law are quite difficult. In the past, the excavation and unloading methods were mostly carried out through numerical simulation and theoretical analysis, and the stress-strain state in the transient unloading process could not be analyzed. The existing excavation unloading simulation device has slow unloading and cannot achieve The shortcoming of instantaneous unloa...

AI Technical Summary

Problems solved by technology

[0003] The present invention aims at the problem that the previous excavation and unloading simulation device cannot quickly unload, and proposes a test device and method for simulating blasting excavation and unloading, which realizes the high-speed release of excavation load and makes the test closer to the actual project. It is more consistent with the unloading state in actual engineering

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