Numerical simulation method of tunnel blasting

Abstract

The invention relates to a numerical simulation method of tunnel blasting. The method includes the following steps that S1, a tunnel model is established, and the stress status of a tunnel and surrounding rock before blasting is acquired; S2, a three-axis coordinate system is established, and blasting stress applied to the positions of the walls of blast holes during blasting of all the blast holes during peak values of all sections is calculated; blasting stress, caused by blasting of each blast hole, at the different positions away from the blast hole is calculated; blasting peak value stress vectors at all the positions of the contour surface of the tunnel caused during blasting of each blast hole are calculated; the blasting peak value stress vectors caused by all the blast holes in the same section are superposed; S26, blasting dynamic loads at all the positions of the contour surface of the tunnel at all moments are calculated; and S3, blasting load values are loaded to the contour surface of the tunnel in software for simulation. The blasting loads are calculated, meanwhile, the factors of superposition of the blasting loads of the multiple blast holes and gradual attenuation of the blasting stress of different regions are considered, thus, the blasting loads applied to the excavated contour surface of the tunnel are calculated more accurately, and the calculated blasting vibration velocity is also more accurate.

Description

technical field [0001] The invention relates to the technical field of tunnel engineering, in particular to a numerical simulation method for tunnel blasting. Background technique [0002] Blasting will cause strong vibrations in the surrounding medium and adjacent buildings (structures), which may cause damage to adjacent tunnel structures, cracks or even collapse of surface buildings, which directly affects construction safety. For example, the Badaling Great Wall Station of the Beijing-Zhangjiakou high-speed railway (hereinafter referred to as the Beijing-Zhangjiakou high-speed railway) is a complex cavern group project. There is a problem that the excavation and blasting of the excavation and blasting of the excavation and blasting of the tunnel excavation in the separation section of the three caverns, and the excavation of the upper caverns The impact of blasting on the blasting vibration of the excavated tunnel structure in the lower layer, etc. Therefore, prediction...

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Problems solved by technology

When using the triangular wave blasting load model for tunnel blasting simulation, multiple blastholes that are detonated at the same time are approximated as concentrated blasting, or the equivalent load for peripheral hole blasting is calculated and applied to the centerline of the blastholes, but they are not really considered. Influence of blasting load in each blast hole when blasting is initiated separately

Moreover, when considering the blasting stress decay from the blast hole to the tunnel profile, the decay index varies with the gradual decay of the blasting energy, and a single stress decay index cannot reflect this effect

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