Tunnel blasting excavation damage prediction method and blasting plan optimization control method

Abstract

The invention provides a tunnel blasting excavation damage prediction method and a blasting scheme optimizing regulating method, aims at reflecting the preparation and evolution processes of blasting exaction damage areas and actively regulating the processes through optimal blasting design. The vibration speed based tunnel blasting excavation damage prediction method is characterized by comprising the following steps: 1, performing on-site blasting test under certain blasting design parameter conditions; detecting the depth of damage caused by the blasting in each section; detecting the speed of vibration caused by the blasting at each section in a preset distance; 2, building fitting relation between the vibration speed at each section and the damage depth; 3, arranging a blasting vibration detector at part in a preset distance from a blasting source while the blasting footage excavation is carried out; detecting the actual speed of the vibration cause by the blasting in each section; calculating the depth of the damage caused in each section on the basis of each actual vibration speed and according to the fitting relation obtained in step 2.

Description

technical field [0001] The invention belongs to the field of tunnel blasting, and in particular relates to a vibration velocity-based tunnel blasting excavation damage prediction method and a blasting scheme optimization control method. [0002] technical background [0003] With the advancement of hydropower, mining and other fields, more and more underground caverns are being constructed. Therefore, a large number of cavern rock mass excavation and unloading and rock mass loosening problems are faced. In the actual excavation process, the blasting of the tunnel The formation of excavation damage area is a complex three-dimensional change process. The impact of blasting excavation deflection on rock mass is mainly related to the repeated blast load, rock inhomogeneity, free surface and redistribution of surrounding rock stress. , and the blasting excavation of the cavern is often completed after multi-stage blasting, and the effect of the blast load on the surrounding rock i...

AI Technical Summary

Problems solved by technology

[0008] In the process of actual engineering blasting detection, the particle vibration velocity can be used as an index to measure the blasting vibration intensity, which can be obtained through on-site detection, but it is often difficult to directly detect the depth of damage caused by blasting to the rock mass. The methods of detection, drilling TV and sound wave testing can determine the size of the excavation damage area in actual engineering, but these methods can only reflect the macroscopic damage effect, and have no effect on the mechanical change process and stress state during the evolution of the excavation damage area. Changes are difficult to evaluate, and it is impossible to specifically reflect the whole process of gestation in the damaged area. In recent years, the continuous development of detection technologies (such as rock mass acoustic emission and microseismic detection) has made further progress in the exploration of this problem; the URL underground laboratory in Canada Using the method of surrounding rock hydraulic penetration and acoustic wave testing, the excavation damage of the rock mass was divided into two areas, which can be roughly divided into outer damage area and inner damage area. However, this result is only a reflection of the final state of the development of the excavation damage area. Does not reflect the aging mechanism of the damage zone breeding, it is difficult to optimize the blasting design according to the conclusion of the research

[0009] Therefore, in order to solve the difficulties encountered by the direct measurement method in the tunnel excavation environment, such as high cost, long time-consuming, only the final damage can be detected, which is not conducive to the smooth progress of engineering construction

Moreover, the traditional damage depth detection method can only detect the final damage degree, and cannot reflect the damage induced by each differential section, and it is difficult to optimize the blasting design based on the final surrounding rock damage detection results.

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