Determining the critical blasting load of cracked strip bauxite pillars

Author(s):  
Li-chun Jiang ◽  
Bin-bin Shen ◽  
Luan-luan Xue
Keyword(s):  
2008 ◽  
Vol 22 (09n11) ◽  
pp. 1443-1448
Author(s):  
YUE-XIU WU ◽  
QUAN-SHENG LIU

To understand the dynamic response of transversely isotropic material under explosion load, the analysis is done with the help of ABAQUS software and the constitutive equations of transversely isotropic material with different angle of isotropic section. The result is given: when the angle of isotropic section is settled, the velocity and acceleration of measure points decrease with the increasing distance from the explosion borehole. The velocity and acceleration in the loading direction are larger than those in the normal direction of the loading direction and their attenuation are much faster. When the angle of isotropic section is variable, the evolution curves of peak velocity and peak acceleration in the loading direction with the increasing angles are notching parabolic curves. They get their minimum values when the angle is equal to 45 degree. But the evolution curves of peak velocity and peak acceleration in the normal direction of the loading direction with the increasing angles are overhead parabolic curves. They get their maximum values when the angle is equal to 45 degree.


2020 ◽  
Vol 26 (2) ◽  
pp. 243-256
Author(s):  
Xin Qi ◽  
Hu Xu ◽  
Zhixiang Yu ◽  
Keqin Sun ◽  
Shichun Zhao

ABSTRACT Both active and passive flexible protection methods are effective against rockfalls, but they can result in a secondary hazard due to cumulate rocks inside the structure. To solve this problem, guided flexible protection systems are receiving increased attention in the engineering community. In this study, a full-scale test of a guided flexible protection system was carried out, where the bottom of the mesh was anchored under a blasting load, which can be considered as an extreme loading event related to rockfall hazards. The fluid-solid coupling method was employed in a finite element model to simulate the entire process from the blast to the accumulation of rocks at the bottom of the slope. Based on the experimental and numerical results, a two-stage process was revealed, the internal force and the dissipated energy of each component were compared and analyzed, and the load-transferring path within the system was obtained. The internal forces of the support ropes reached their maximum values in the intercept stage. The posts experienced two peak values, the first of which, in the guide stage, was twice that in the intercept stage. The brake rings were the main energy-dissipating components, and the energy dissipation in the intercept stage was much greater than that in the guide stage. Furthermore, the interaction in terms of collision and friction between the rocks, the slope, and the system was not insignificant, particularly in the guide stage, which can account for more than 40 percent of the consumed energy of the rockfall.


2020 ◽  
Vol 108 ◽  
pp. 102559
Author(s):  
Liyun Yang ◽  
Qingcheng Wang ◽  
Longning Xu ◽  
Renshu Yang ◽  
Yuh J. Chao

2014 ◽  
Vol 580-583 ◽  
pp. 268-272
Author(s):  
Xue Yong Xu ◽  
Sheng Jie Di ◽  
Wan Qiang Cheng ◽  
Wei Li ◽  
Wen Bo Du

Calcareous sand is a special marine geotechnical medium that exhibits interesting physical and mechanical properties resulting from its composition and structure. In the current paper, the blasting compression wave (P-wave) attenuation mechanism of calcareous sand under explosion was studied through explosion experiments. The decay law of the P-wave was obtained based on the earth pressure at different distances from the blast center. The results show that, the broken, compress, and damage zones were formed under the effect of blasting load, many particles were broken near the blasting zone. Calcareous sand exhibits strong absorption and attenuation effects on the P-wave because of its particle breakage characteristics.


2006 ◽  
Vol 306-308 ◽  
pp. 673-678
Author(s):  
Hui Peng Liu ◽  
Qun-Liang Han ◽  
Zhi-Guo Yan ◽  
Wen Ming Gao ◽  
Ying Ming Li ◽  
...  

This paper present an analysis of the mechanics characters of a safety structure with steel liner under near blasting load, by the methods of numerical study. Through the ANSYS/LS-DYNA numerical analysis, we get the reasonable thickness and position location of steel. This paper put forward the curve of the steel at different thickness and position in the safety structure, that provide a reference to the designing of the safety structures and other relevant project.


2019 ◽  
Vol 36 (6) ◽  
pp. 1835-1851 ◽  
Author(s):  
Chao Liu ◽  
Mingyang Yang ◽  
Haoyu Han ◽  
Wenping Yue

Purpose To study fracture characteristics of jointed rock masses under blasting load, the RFPA2D analysis software for dynamic fracture of rocks based on the finite element method and statistical damage theory was used. Design/methodology/approach On this basis, this research simulated the fracture process of rock masses in blasting with different joint geometrical characteristics and mainly analysed the influences of distance from joints to blasting holes, the length of joints, the number of joints and joint angle on fracture of rock masses. Findings The calculation results show that with the constant increase of the distance from joints to blasting holes, the influences of joints on blasting effects of rock masses gradually reduced. Rock masses with long joints experienced more serious damages than those with short joints. Damages obviously increased with the changing from rock masses without joints to rock masses with joints, and when there were three joints, the further increase of the number of joints had unobvious changes on blasting effects of rock masses. Joints showed significant guidance effect on the propagation of cracks in blasting: promoting propagation of main vertical cracks deflecting to the ends of joints. Originality/value The research results are expected to provide some theoretical bases in practical application of engineering blasting.


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