scholarly journals PENGGUNAAN EXPLOSIVE LOW DENSITY PADA PELEDAKAN AREA DI BAWAH RADIUS AMAN MANUSIA DAN PENINGKATAN PRODUKTIVITY ALAT GALI DI AREA TERSEBUT PADA PENAMBANGAN BLOK B1 PIT C2 SAMBARATA MINE OPERATION PT BERAU COAL

2020 ◽  
Vol 1 (1) ◽  
pp. 317-326
Author(s):  
Sutami Sitorus ◽  
Elfizar Diando
Keyword(s):  
Ground Vibration ◽  
Buffer Zone ◽  
Drill Hole ◽  
Low Density ◽  
Hole Depth ◽  
Vibration Effect ◽  
Bench Height ◽  
Blasting Pattern ◽  
Segmentation Pattern ◽  
Electronic Detonator

ABSTRAK Pit C2, merupakan salah satu blok penambangan Site Sambarata Mine Operation yaitu masuk ke dalam blok B1. Merupakan pit aktif hingga sekarang dimana penambangan dari 2018 hingga akhir 2019 telah mengarah ke pemukiman hingga boundary pit (2019) berjarak 200 m ke pemukiman terdekat dan area tersebut penambangan menggunakan peledakan.Volume overburden pada area tersebut yang termasuk zona dibawah 500 m jarak aman peledakan adalah 1.340.281 bcm dan coal sebesar 175.237 ton dengan SR 7,65. Telah diterapkan beberapa taknik peledakan pada area tersebut ,yaitu salah satunya dengan sistem peledakan elektronik detonator dengan berbagai improvmentnya diantaranya : pola segementasi, segmentasi bufferzone, electronic detonator with air decking dan penggunaan matrial stemming full gravel. Kendala yang timbul adalah masalah efek peledakan yaitu vibrasi dan fly rock dengan jarak tersebut serta pembentukan bench height yang tidak maksimal karena adanya limit kedalaman lubang maksimal 5 m di area 500-300 m dari pemukiman, sehingga produktivity unit (PC 2000) tidak maksimal dan menimbulkan blasting cost yang tinggi. Penggunaan Explosives Low Density (0,7-0,8 gr/cc), di area < 500 m dari pemukiman bisa menambah kedalaman lubang bor hingga kedalaman 7 m, sehingga menambah volume peledakan tanpa mengubah parameter peledakan sebelumnya yaitu : pattern peledakan, charging weight dan penggunaan sistem elektronik detonator dan juga bisa menggunakan sistem peledakan nonel. Dengan explosive low density pengingkatan column raise lubang ledak menjadi 1,3 m. Dari data digging time unit loader (PC 2000), mampu mencapai 9,9 detik dari target maksimal 11 detik, produktivity di atas 700 bcm/jam dan vibration effect yang dihasilkan masih di bawah 2,2 mm/sec (PVS) yang menjadi patokan site. Sehingga penggunaan explosive low explosive ini bisa mempercepat sekuen penambangan di pit C2 sesuai dengan boundary disain 2019 Kata kunci : Low density,Ground vibration, fly rock , productivity  ABSTRACT Pit C2, is one of the Mining Samntbarata Mine Operation mining blocks, which is included in Block B1. It is an active pit up to now where mining from 2018 to the end of 2019 has led to settlements to the boundary pit (2019) within 200 m to the nearest settlement and the area is mining using blasting. Overburden volume in the area which includes zones below 500 m safe blasting distance is 1,340,281 bcm and coal of 175,237 tons with SR of 7.65. Several blasting techniques have been applied in this area, one of which is an electronic detonator blasting system with various improvements including: Segmentation pattern, buffer zone segmentation, electronic detonator with air decking and the use of full gravel matrial stemming. The obstacle that arises is the problem of blasting effects namely vibration and fly rock with that distance and the formation of bench height that is not optimal because of the maximum hole depth of 5 m in the area of 500-300 m from the settlement, so the productivity unit (PC 2000) is not optimal and causes high blasting cost. The use of Explosives Low Density (0.7-0.8 gr / cc), in the <500 m area of the settlement can increase the depth of the drill hole to a depth of 7 m, thus increasing the volume of blasting without changing the previous blasting parameters namely: blasting pattern, charging weight and the use of an electronic detonator system and can also use a nonel blasting system. With explosive low density the column raising the explosive hole to 1.3 m. From the digging time unit loader data (PC 2000), it can reach 9.9 seconds from the maximum target of 11 seconds, productivity above 700 bcm / hour and the resulting vibration effect is still below 2.2 mm / sec (PVS) which is the benchmark site . So that the use of low explosive explosives can accelerate the mining sequence in pit C2 in accordance with the 2019 design boundary. Kata kunci : Low density,Ground vibration, fly rock , productivity

Evaluation of ground vibration effect of blasting operations in a magnesite mine

2009 ◽  
Vol 29 (4) ◽  
pp. 669-676 ◽  
Author(s):  
Hakan Ak ◽  
Melih Iphar ◽  
Mahmut Yavuz ◽  
Adnan Konuk
Keyword(s):  
Ground Vibration ◽  
Vibration Effect

IceCube CFD Drilling Model

2006 ◽  
Author(s):  
Richard A. Martin ◽  
Tim Thompson ◽  
Naseem Ansari ◽  
Chokri Guetari
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Drill Hole ◽  
Hole Diameter ◽  
Spray Angle ◽  
South Pole ◽  
The South ◽  
Hole Depth ◽  
Ansys Cfx ◽  
Multi Phase

A numerical model of a hot water drill used to produce deep holes in clear ice at the South Pole for the IceCube neutrino observatory program scheduled for completion in 2010 has been developed. The model was built using the ANSYS commercial computational fluid dynamics (CFD) code, ANSYS CFX. This drill model is helping us to understand the water/ice melting process near the bottom of the drill hole, and to evaluate the influence of nozzle size, spray angle, water flow rate, and water temperature on the drill hole shape, and on drilling speed. The basis for the model is ANSYS CFX, which has multi-phase, conjugate heat transfer capabilities. The model utilizes a multi-phase approach, and simulates motion of the drill with respect to the ice. The sensitivity of model predictions to mesh resolution, turbulence model, and interfacial heat transfer coefficients, area, and drag coefficient was studied, and the results were used to determine preferred values in each case. This multi-phase model was selected after evaluating an equilibrium model and obtaining results showing not completely satisfactory comparisons to experimental data from the South Pole. Computations at a drill depth of 1292 m allowed validation of code results using actual field data obtained during the 2004–2005 IceCube drilling season at Antarctica. A series of steady-state runs using two drill sizes, two drill speeds, and one spray angle were performed for conditions at 1292 m to determine if a smaller nozzle orifice would enable faster drilling, preferably by a factor of two. The model predicted a drill hole diameter of from 18 in to 25 in and an up-flow water temperature of from 20°C to 28°C. The drill hole diameter is consistent with values measured at the IceCube site, but the water temperature is about 10°C low. No evidence of the nozzle tip impacting the bottom of the hole was found in the drill speed range 3.5 ft/min to 7 ft/min. A nozzle spray angle of 25 degrees was found to make little difference in hole depth or diameter. Reducing the nozzle diameter from 1 in to 0.75 in at the same water volumetric flow rate resulted in an increase in the drill hole depth by from 16% to 20%. The latter result implies that faster drilling is expected when using a smaller size orifice with zero degree spray angle. The IceCube drill model is now available to determine the effects of key variables, to evaluate the performance of new nozzle designs, and to specify drill speed versus depth. Recommendations specific to faster drilling speeds resulted in a near doubling of actual speed during the 2005–2006 season at the South Pole.

scholarly journals Increasing safety at rock preparation by blasting in open pits

2019 ◽  
Vol 134 ◽  
pp. 01017
Author(s):  
Igor Katanov ◽  
Sergey Kondratyev ◽  
Andrey Sysoyev
Keyword(s):  
Rock Mass ◽  
Explosive Charge ◽  
Integrated Approach ◽  
Variable Density ◽  
Low Density ◽  
Angle Of Incidence ◽  
Firing Time ◽  
High Quality ◽  
Minimal Deviation ◽  
Electronic Detonator

The topicality of the present work lies in justification of the means of increasing safety during mass explosions in opencasts. The solution to this problem is possible due to the orientation of downholes in the array, taking into account the angle of incidence and extension of the strata, high-quality stemming and initiation of downhole charges by delay detonators with a minimal deviation from nominal values of their firing time. The most promising way to increase the safety and efficiency of blasting is an integrated approach, including drilling downholes, normal to the strata, and using the design of the downhole charge, rationally distributing the explosion energy in the space of the rock mass due to the use of stemming of a variable density, low-density gap between the parts of the explosive charge and the bottom a downhole compensator based on foam gel and the use of hybrid electronic detonator Iskra-T.

scholarly journals Experimental and Numerical Simulation Study on the Shock and Vibration Effect of OD1422-X80 Mainline Natural Gas Pipeline Explosion

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Huayuan Ma ◽  
Mingshou Zhong ◽  
Xinghua Li ◽  
Quanmin Xie ◽  
You Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Natural Gas ◽  
Ground Vibration ◽  
Gas Pipeline ◽  
Experimental Results ◽  
Maximum Speed ◽  
Impact Compression ◽  
Time Frequency ◽  
Vibration Effect ◽  
Natural Gas Pipeline

In this paper, the explosion experiment of the OD1422-X80 natural gas pipeline was carried out. The phenomenon of pipeline explosion was recorded, and a large amount of data on vibration effects were obtained. The data showed that the ground vibration during the explosion was mainly caused by the physical explosion process, and the subsequent gas explosion did not produce strong vibration. Based on the ANSYS/LS-DYNA platform, a numerical calculation model of this experiment was established. The numerical results agreed well with the experimental results. Simulation and experimental results showed that when the gas pressure in the pipe was lower than 7 MPa, the pipeline cracks stop growing. The maximum speed of the pipe wall moving outward reached 50 m/s, which formed a huge impact compression effect on the surrounding soil. This state spread to distant places and gradually decayed into an elastic stress wave, which formed a ground vibration effect. Time-frequency analysis was introduced into the vibration signal processing. The analysis results showed that the main frequency of pipeline explosion vibration was distributed around 10 Hz and had a long duration. The research results provided a reference for subsequent gas pipeline explosion test and numerical simulation research.

Assessment Study on Impact of Pile Driving Vibration on Surrounding Houses

2012 ◽  
Vol 457-458 ◽  
pp. 325-329
Author(s):  
Luo Yi ◽  
Sen Wei Xia
Keyword(s):  
Social Problems ◽  
Ground Vibration ◽  
Engineering Practice ◽  
Pile Driving ◽  
Effective Management ◽  
Vibration Effect ◽  
Vibration Detection ◽  
Assessment Study

It’s common to see the dispute caused by pile driving construction vibration effect, which has become a concern of social problems. The paper analyzes the mechanism and law of ground vibration caused by the pile driving construction. Combined with the engineering practice, discussion about the defects in the criteria of vibration detection is presented. It is necessary to do assessment study on impact of pile driving vibration on surrounding houses. Project practice indicates that application of assessment study on impact of pile driving vibration on surrounding houses is an effective management.

scholarly journals Indirect Determination Approach of Blast-Induced Ground Vibration Based on a Hybrid SSA-Optimized GP-Based Technique

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhaoxin Jiang ◽  
Hongyan Xu ◽  
Hui Chen ◽  
Bei Gao ◽  
Shijie Jia ◽  
...  
Keyword(s):  
Particle Velocity ◽  
Accurate Determination ◽  
Ground Vibration ◽  
Predictive Performance ◽  
Peak Particle Velocity ◽  
Superior Performance ◽  
Ann Model ◽  
Indirect Determination ◽  
Bench Height ◽  
Gp Model

The accurate determination of blast-induced ground vibration has an important significance in protecting human activities and the surrounding environment. For evaluating the peak particle velocity resulting from the quarry blast, a robust artificial intelligence system combined with the salp swarm algorithm (SSA) and Gaussian process (GP) was proposed, and the SSA was used to find the optimal hyperparameters of the GP here. In this regard, 88 datasets with 9 variables including the ratio of bench height to burden (H/B) and the ratio of spacing to burden (S/B) were selected as the input variables, while peak particle velocity (PPV) was measured. Then, an ANN model, an SVR model, a GP model, an SSA-GP model, and three empirical models were established, and the predictive performance was evaluated by using the root-mean-square error (RMSE), determination coefficient (R2), value account for (VAF), Akaike Information Criterion (AIC), Schwarz Bayesian Criterion (SBC), and the run time. After comparing, it is found that the proposed SSA-GP yielded a superior performance and the ratio of bench height to burden (H/B) was the most sensitive variable.

scholarly journals Effects of Controllable Blasting Variables on Number of Boulders Generated after Blasting in Ratcon and NSCE Quarries, Ibadan, Oyo State, Nigeria

2013 ◽  
Vol 2 (2) ◽  
pp. 105
Author(s):  
Abiodun Ismail LAWAL ◽  
Akande Jide Muili
Keyword(s):  
Research Work ◽  
Drill Hole ◽  
Hole Diameter ◽  
Average Charge ◽  
Specific Charge ◽  
Microsoft Excel ◽  
Hole Depth ◽  
Independent Variables ◽  
Spss Software ◽  
Input Variables

The research work examines the effects of controllable blasting variables on number of boulders generated after blasting. The objective of the research was achieved through collection of data related to blasting which are drill hole depth, drill hole diameter, burden, spacing, average charge per hole, and specific charge. The collected data were analysed statistically using both Microsoft Excel Software and SPSS Software. The result of the analysis reveals that all the input controllable blasting variables which are drill hole diameter (X1), drill hole depth (X2), hole spacing (X3), burden (X4), average charge per hole (X5), specific charge(X6) that participated as independent variables in the models are found to be significant and the R2 values obtained from the graph show a very strong correlation between the number of boulders generated after blasting and the input variables except that of drill hole diameter which shows a very weak correlation. The equation generated using the SPSS could be used to determine number of boulders generated after blasting.

scholarly journals Hollow Effect of Ground Vibration Induced by Electronic Detonator in Shallow Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Weijie Ding ◽  
Bei Jia ◽  
Dianshu Liu
Keyword(s):  
Field Experiments ◽  
Optimal Parameter ◽  
Ground Vibration ◽  
Dominant Frequency ◽  
Tunnel Construction ◽  
Shallow Tunnel ◽  
Horizontal Distance ◽  
Mode Decomposition ◽  
Blasting Excavation ◽  
Electronic Detonator

Blasting excavation is extensively used in tunnel construction, and the adverse effect of ground vibration induced by blasting on surrounding structures and inhabitants is a critical problem. This study aims to investigate the tunnel hollow effect on triaxial peak particle velocities (PPV) and dominant frequencies induced by electronic detonator. Field experiments were conducted in a shallow tunnel construction site and the ground vibration waveforms were recorded. Variational mode decomposition (VMD) was applied to denoise and correct the zero-drift phenomenon, and the proposed method of selecting the optimal parameter was verified. A series of statistical analyses and tests were performed to evaluate the differences of peak particle velocity and dominant frequency among various monitoring points. The results showed that the hollow effect on Z-axis PPV is significant, and triaxial PPV is also affected when the horizontal distance exceeds 30 m. The hollow effect on dominant frequency could not be identified since the hollow of tunnel is a free face, and the dominant frequency of reflected wave remains unchanged. An augmented factor of 1.229 is determined carefully as the hollow effect factor on PPV. Therefore, blasting vibration induced by electronic detonator of the excavated zone should be attached with greater importance, and hollow effect on PPV should be considered in the blasting design of tunnel excavation.

scholarly journals Experimental study on ground vibration attenuation induced by heavy freight wagons on a railway viaduct

2018 ◽  
Vol 37 (4) ◽  
pp. 881-895 ◽  
Author(s):  
Jingjing Hu ◽  
Yi Luo ◽  
Zaitian Ke ◽  
Penghui Liu ◽  
Jiayun Xu
Keyword(s):  
Ground Vibration ◽  
Dominant Frequency ◽  
Vertical Vibration ◽  
Correlation Factor ◽  
Frequency Bands ◽  
Vibration Effect ◽  
Significant Difference ◽  
Normal Speed ◽  
Train Speed ◽  
Freight Wagons

Studies on ground vibration induced by railway operation usually focused on wagons running on ground or abutments, while vibration from a railway viaduct is often assumed to be much lower. Based on field test in the vicinity of a heavy freight railway viaduct above Shenshan Village, China, the attenuation of ground vibration induced by heavy freight wagons for coal transportation is studied. And evaluation is conducted on an adjacent house to access vibration disturbance to residents near a viaduct. Propagation and attenuation of vibration induced from viaduct are studied by analyzing peak particle velocity and spectra of ground and house vibration in the vicinity of the viaduct. Vibration signals were collected for 34 trains with different train speed and wagon weight. In all monitored situations, vertical vibration is generally larger than horizontal vibration. The relationship between distance to pier and PPV is revealed by a power function modified from Sadovskii formula with high correlation factor. Analysis also indicates a much lower dominant frequency induced by low-speed trains with or without acceleration than normal speed trains. A dramatic amplitude reduction is shown within frequency between 25 Hz and 35 Hz when train speed is reduced. Empty wagons also show smaller amplitude in most frequency bands, with significant difference in 15–25 Hz. Analysis on the house also shows larger vibration in vertical than horizontal, and vibration amplitude in some frequency bands has exceeded relative criteria. Analysis result shows significant ground and house vibration effect form a viaduct, and piers should be considered as vibration sources for ground and houses in future studies.

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