Identifying Delay Time of Detonator for a Millisecond Blasting

Song, Zhifei; Man, Ke; Liu, Xiaoli

doi:10.1155/2021/5592696

Cited by 6 publications

(2 citation statements)

References 9 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Afterward, with the decay of the explosion energy, the shock wave is converted into a stress wave and propagates in the rock mass. At this time, the influence of the stress wave is not enough to crush the rock mass (Song et al 2021, Song et al 2019). The shear strength is higher than the tensile strength of the rock mass, resulting in tensile damage and continuous expansion of the rock mass.…”

Section: Damage Crack Analysismentioning

confidence: 99%

WITHDRAWN: Theoretical analysis model and optimization scheme of shape-effect damage in cut blasting

qin,

Zhao,

wang

et al. 2023

Preprint

View full text Add to dashboard Cite

To explore the rock-breaking mechanism of cut blasting under the influence of empty holes, based on the principles of the empty hole effect, stress concentration effect and expansion space theory, the stress distributions of empty hole walls are calculated, and a two-dimensional damage analysis model of shape-effect segmented blasting is established. On this basis, the theoretical analysis model of square hole cutting is given as an optimization scheme, and the model is demonstrated by numerical simulation. The results show that the optimized load function γq2sinθ with time is consistent with the actual stress of the hole wall, and the change trend of the theoretical calculation is consistent with the simulation results. The change in the shape of empty holes in a rock mass will affect the stress distribution of the surrounding rock mass. The stress waves with square holes cause tensile–shear failure in a wide range of rock around the hole wall, while the rock near the circular hole wall produces ring-shaped failure. The reflected tensile stress waves are influenced by the impedance of the circular hole. In the optimized scheme, the cracks around the holes are uniformly connected, the rock mass collapses inward under the influence of the holes and the two-stage stress waves, and the utilization rate of the hole space reaches 56.091%.

show abstract

Section: Damage Crack Analysismentioning

confidence: 99%

WITHDRAWN: Theoretical analysis model and optimization scheme of shape-effect damage in cut blasting

qin,

Zhao,

wang

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Because the actual and the nominal delay of detonator have large discreteness [37][38][39], there is normally a delay error. Terefore, in the actual initiation process, a hole-by-hole initiation with a small delay time was adopted [40][41][42][43]. Te time settings of hole initiation sequence are shown in Figure 4.…”

Section: Detonation Tubes Detonated Hole-by-holementioning

confidence: 99%

Experimental Study on Frequency Modulation Damping Effect of Digital Detonator in Road Clearance Blasting

Gao

Cheng

Ren

et al. 2023

Shock and Vibration

View full text Add to dashboard Cite

To measure and evaluate the impact of vibration on the surrounding buildings and structures during highway rock burst removal and to formulate scientific and reasonable protective technical measures, the authors used the blasting perilous rock removal project of the K2227+920–K2228+000 section of the Shaanxi G316 road as a case study. The application of frequency modulation blasting vibration damping technology adopting digital electronic detonators was investigated. The difference in vibration peak and frequency between the perforation-by-hole initiation of the detonator and the frequency modulation initiation of the digital electronic detonator is compared. The results showed that by adopting an accurate delay of digital electronic detonators and the damping scheme of adjusting the blasting vibration frequency using the electronic detonators a reduction in blasting vibration velocity can be achieved. For an unchanged blasting scale, hole mesh parameters, and explosive unit consumption, the total blasting time was adjusted in the test. Compared to the hole-by-hole initiation, the blasting vibration velocity at a pier of the G85 Baohan highway bridge located 52 m away was reduced from 0.367 cm/s to 0.229 cm/s, a decrease of 36.7%. The field test demonstrated that frequency modulation and vibration attenuation using digital detonators can reduce blasting vibrations and effectively reduce the influence of blasting construction on surrounding buildings and structures.

show abstract

Damage prediction and improvement method based on cutting mode of circular empty hole

Qin,

Zhao,

Wang

et al. 2024

Sci Rep

View full text Add to dashboard Cite

Based on the theory of empty hole effect of cutting blasting, the Hopkinson effect and Saint–Venant principle are integrated to establish a two-dimensional calculation model of dynamic stress evolution of the holes wall, and then the dynamic fracture mechanism and damage distribution mode of the rock mass in the cutting area under the action of longitudinal waves are predicted. The results of the calculation and numerical simulation are verified by experiments, and the results show that: The time-varying stress function of the circular cavity wall conforms to the periodic dynamic evolution of the trigonometric function, and the theoretical calculation is consistent with the simulation results. Through the calculation of the round holes cut model and the square empty hole cut model, the change of the shape of the holes in the cut area changes the failure form of the surrounding rock mass. The circular empty hole wall is affected by the stress wave to produce "interval ring" destruction, and the effect of the reflected stretch wave is inhibited. The large range of rock mass in the square empty hole wall produces tensile and shear failure, and the rock mass collapses inward under the influence of the second stage stress. Among them, the empty space utilization rate of the square empty hole model is about 8.5 times that of the circular holes model. Vibration monitoring in the center of the cutting area shows that the vibration effect of the circular empty hole is larger than that of the square empty hole, and the proportion of rock breaking energy is lower.

show abstract

Identifying Delay Time of Detonator for a Millisecond Blasting

Cited by 6 publications

References 9 publications

WITHDRAWN: Theoretical analysis model and optimization scheme of shape-effect damage in cut blasting

WITHDRAWN: Theoretical analysis model and optimization scheme of shape-effect damage in cut blasting

Experimental Study on Frequency Modulation Damping Effect of Digital Detonator in Road Clearance Blasting

Damage prediction and improvement method based on cutting mode of circular empty hole

Contact Info

Product

Resources

About