Efficiency of cut configuration in driving tunnels with a set of deep blast holes

Shapiro, V. Ya.

doi:10.1007/bf02528560

Cited by 13 publications

(9 citation statements)

References 1 publication

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“…Several researchers have studied wedge cut blasting and have obtained significant findings, some of which are reported here. Shapiro [8] compared the blasting effects of different cutting methods and proved that wedge cut is more effective than other cutting methods used for shallow hole blasting. Dai and Du [9] theoretically analyzed the mechanism of cavity formation and proposed a design method of blasting parameters for wedge cut.…”

Section: Introductionmentioning

confidence: 99%

A Study on Cut Blasting with Large Diameter Charges in Hard Rock Roadways

Cheng

Wang

et al. 2020

Advances in Civil Engineering

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To overcome the problems of poor cutting effects in hard rock roadways, a cut blasting technique with large diameter charges was developed; that is, the cut holes employ 50 mm diameter blast holes and 45 mm diameter explosive sticks, while the other holes adopt 42 mm diameter blast holes and 35 mm diameter explosive sticks. First, the effect of charge diameter on damage range and cut cavity formation was analyzed. Next, simulation of wedge cut for different charge diameters was conducted to reveal the stress wave developments and compare the stress field intensities. Finally, field tests were conducted to verify the viability of this technique. The results indicate that large diameter charges can increase the damage range around cut holes to improve the fragmentation degree of the rock mass in the cut cavity and significantly enhance the cavity formation power to better expel the rock mass fragments. The stress wave evolution of wedge cut was visualized using numerical simulations, which confirmed that the use of large diameter charges in cut holes increases the stress field intensity in the cut cavity and hence increases the damage degree of the rock mass. In this study, the use of a large diameter charge for cut blasting increased the average footage by 0.30 m, and the average utilization rate of blast holes increased by 12.5%. Therefore, the cutting effects in hard rock roadways can be improved by using large diameter charges, which increase the blasting footage and the utilization rate of blast holes.

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Section: Introductionmentioning

confidence: 99%

A Study on Cut Blasting with Large Diameter Charges in Hard Rock Roadways

Cheng

Wang

et al. 2020

Advances in Civil Engineering

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“…Shapiro [4] compared wedge cuttings with other cuttings and believed that wedge cuttings ensured maximum efficiency in soft rock with relatively shallow blast holes, that is, shallower than 2.5 m. Cardu and Seccatore [5] offered statistics of industrial trends in which wedge cuttings appeared to be adopted in a wider variety of applications.…”

Section: Introductionmentioning

confidence: 99%

Experiment and Analysis of Wedge Cutting Angle on Cutting Effect

Yang

Wang

et al. 2020

Advances in Civil Engineering

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In the process of tunnel excavation, large charge wedge cutting blasting is widely used to improve the effect of cut blasting and speed up the excavation rate, which is tantamount to increasing the construction cost. In order to save economic cost and improve cutting blasting effect, wedge cutting models with five different cutting angles were experimented and studied by using concrete materials on the basis of similarity theory analysis. The relationships among cutting depth, blasting volume, blasting fragment, and cutting angle are studied and deduced by the dimensional analysis method. The polynomial fitting of cutting depth, blasting volume, blasting fragment, and cutting angle is carried out according to the experimental data, and the corresponding fitting formula is obtained. The optimum cutting depth, hole utilization rate, blasting volume, and blasting fragment were obtained when the wedge cutting angle was 67° under the same charge. The values were 1.665 × 10−1 m, 92.5%, 8.390 × 10−3 m3, and 49.07 mm, respectively. With the use of TC4850N type blasting vibration meter, the blasting vibrations on the wedge in four directions are tested and analyzed. The results show that when wedge cutting inclination is 65 degrees, the peak vibration velocity is the minimum and the vibration intensity of the wedge cutting inclined side is generally smaller than that of the vertical side. Considering the cutting depth, blasting volume, blasting fragment, blasting vibration hazard, drilling error, tunneling construction cost, and other factors, the 65°∼69° wedge cutting blasting in engineering practice can improve the blasting tunneling rate and increase economic benefits. The experimental results show that the blasting tunneling rate is increased and the economic benefit is increased with the minimum construction tunneling cost, which has certain engineering significance.

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“…In terms of the cutting method, Shapiro [7] performed a detailed analysis on different soft rock cutting arrangements (e.g., V-cut, parallel cut, parallel cut compensated with big cuthole, and composite cut), revealing that V-cut outperforms the other arrangements in blasting efficiency when the hole is less than 2.5 m deep. Soroush et al [8] analyzed the effect and sensitivity of the hole diameter and tunnel face area on blasting results in different blast models, pointing out that V-cut needed more cutholes than parallel cut in similar conditions.…”

Section: Introductionmentioning

confidence: 99%

“…Shan et al [9] invented the quasiparallel cutting with a center hole, which combines the merits of parallel cut and angled cut, and achieved desirable blasting and economic effects with the cutting arrangement. Shaprio [7] investigated the feasibility of replacing many shallow cutholes with a few deep ones in tunnelling. Over the years, some innovative methods have been developed for cutting blasting.…”

Section: Introductionmentioning

confidence: 99%

Theoretical and Numerical Research on V‐Cut Parameters and Auxiliary Cuthole Criterion in Tunnelling

Lou

Bao

et al. 2020

Advances in Materials Science and Engineering

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This paper aims at providing a sound theoretical solution to auxiliary central hole and the cutting parameters. For this purpose, the forming mechanism of V-cut cavity for cutting blasting was performed based on the hypothetical rock breaking mechanism of V-cut blasting. A theoretical solution for increasing the critical depth of the auxiliary center cuthole and the criteria for increasing the cuthole diameter of various types of cutholes when the rock attributes, explosive properties, and cuthole dip angle are constant are proposed. (1) If charging length le < 0.75H/sin θ, no auxiliary cuthole is needed. (2) If 0.75H/sin θ < le < 0.75H/sin θ + (2∼4) × 0.1, a central vertical auxiliary hole is needed. (3) If 0.75H/sin θ + (2∼4) × 0.1 < le < 0.75(H/sin θ + Hi/sin θi), a shallow inclined hole is needed. (4) If le > 0.75(H/sin θ + Hi/sin θi), both the central vertical cuthole and the shallow inclined cuthole are needed. Meanwhile, the theoretical solution was verified by numerical modelling with ANSYS/LS-DYNA. Moreover, the field implementation of the V-cut and the auxiliary hole effectively improved the blasting effect in both efficiency and economy.

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Efficiency of cut configuration in driving tunnels with a set of deep blast holes

Cited by 13 publications

References 1 publication

A Study on Cut Blasting with Large Diameter Charges in Hard Rock Roadways

A Study on Cut Blasting with Large Diameter Charges in Hard Rock Roadways

Experiment and Analysis of Wedge Cutting Angle on Cutting Effect

Theoretical and Numerical Research on V‐Cut Parameters and Auxiliary Cuthole Criterion in Tunnelling

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