Ren Shu Yang

Rapid Excavation Research of Half Coal Rock Lane in Liu-Wan Mine

In order to solve the question of excess or under excavation, poorly forming around the lane, low rate of excavation caused by less drilling, arbitrarily drilling, non-standard charging, unreasonable initiation network in the construction process of half coal rock lane in Liu-wan mine. According to coal and rock conditions at the scene and through theoretical calculations and engineering analogy, made a scientific and rational borehole layout and correct initiation network, strengthened temporary support and changed operation modes. The driving rate of the single circulation was improved from 1.6m to max.2.75m. The utilization rate of the blasting boreholes was improved from 89% to previous 94.7%. The unit consumption of explosives was significantly reduced from the original 1.24kg/m3 minimum to 0.74 kg/m3.Thus the profile shape results would be good and the driving speed could be highly increased. Research results will be the same geological conditions for excavating to provide reference.

Experimental Study on the Technology of Middle Empty Hole in Parallel Hole Cut Blasting

In order to reduce the adverse effect of the blasting vibration velocity to residents in the urban subway blasting excavation construction, and made it meet the requirements of design, based on the stress concentration effect of empty hole, carried out the research of middle empty hole in parallel hole cut blasting. Adopted the technology of middle empty hole in parallel hole cut blasting, by measuring the blasting vibration velocity, the utilization rate of borehole, the half eye tracking rate, and so on, the results showed that the blasting vibration velocity of cut blasting was 0.69cm/s, the blasting vibration of expansion slot blasting was 1.27cm/s, the borehole utilization was 90%, and the half eye tracking rate of periphery holes was 90%. The test results showed that this technology could effectively reduce the blasting vibration under the residential areas in blasting excavation, the effective experiences could be used in the similar projects.

Numerical Simulation of Air-Deck Slotted Charge Blasting

Air-deck ratio plays a decisive role in blasting engineering. Researchers have conducted extensive work to study the optimal air-deck ratio. But consensus has not been achieved. Especially slotted charge blasting, the study on it just starts. For its complicated physical process in blasting, it is difficult to perform theoretical analysis to obtain the law between blasting result and air-deck ratio. The numerical simulation method is adopted to study the effect of different air-deck ratio on stress distribution at first. And then laboratory tests are carried out to validate the simulation results. The conclusion may be drawn that good directional fracture could be obtained with air-deck ratio 33.3% ~ 50%. The achievement could provide reference for blasting engineering.

Mechanical Effects and Existing Problems Analysis of Anchor Frame Combination Supporting Structure

This paper aims to reveal the mechanical effects of metal holder and bolt (anchor) in anchor frame combination structure, then shows existing problems of anchor frame combination supporting structure being used in present coal mine, and gives corresponding solution on the basis of modern mechanics theory. By specify examples and on the basis of having administered the pull test of bolt (anchor), the article has calculated and analyzed the stress distribution rule of metal holder in anchor frame combination supporting structure according to the statically indeterminate principle in solid mechanics. In contrast to single metal holder structure, the consequence comes to be that the bearing capacity was significantly increased. However, the actual stress values of bolt (anchor) in field measurement shows that the bearing capacity of bolt (anchor) has hot been given full work. So the essay not only reveals the good bearing capacity of anchor frame combination structure but also points out that there is plenty of scope for optimization in anchor frame combination structure, and its research results have a certain reference for supporting theory and technology research in deep level and high ground pressure soft rock roadway.

Application of Loose Blasting in Fully-Mechanized Coal Face Crossing Faults

Loose blasting technology is applied to the problem of fully mechanized coal face passing through fault. The paper gets safe and practical loose blasting parameters and blasting process, achieves no re-open-off cut for the fully mechanized coal face, reduces loss of coal pillars for faults and improves the coal recovery rate. At last, the goal of high yield, steady yield, and increasing yield for fully mechanized mining face is realized.

Hard Kaolin High Yield and Stoping Technology in Suoli Mine

The backward blasting of the mine technology and stoping technology will lead to a long time of blasting, high labor intensity and low production efficiency, which also cause roof collapse and the blast of fly rock, support fall and overthrowing the chain-trigger, which cause a larger hidden of production. Through using the mechanical mining technology of the high yielding and efficiency of kaolin, which fundamentally improve the working conditions of workers and safety working condition, will laid the foundation for the increasing of production and efficiency. The production has been promoted from 250-300t/d to 550-650t/d now, which the efficiency is increasing more than 120%. Meanwhile, the optimal of blasting parameters is benefit to roof control after blasting, which can improve the efficiency of blasting, reduce the unit consumption of dynamite, which can save about 0.115kg/ m3; and reduce the intensity of the workers and the damage of the support. This construction technique can provides a reference significance for safe and efficient construction of the mine under similar geological conditions.

Experiment on Different Length/Diameter Ratio Charge Explosive Strain Wave Propagation in Rock

In order to explore the blasting effect with charged by different length/diameter ratio in rock, adopted ultra-dynamic strain testing system to test the blasting strain wave with charged by little amount of explosives and different length/diameter in the rock models. Analyzed the radial blasting strain wave signal in the medium under the conditions of coupling charging explosive loading, got the generalities and difference of the explosive strain waveform features with charged by different length/diameter ratio, and relationship of peak strain with the relative distance. The results show that peak strain was greatly affected by the change of length/diameter ratio and charge mass in the area of close blasting source, when the relative distance is more than 45, the influence is less. Made the length/diameter ratio is 20 to be the boundary, when the length/diameter ratio is greater than 20, the peak strain attenuated slowly. The explosive energy of the big length/diameter ratio is relatively decentralized to the medium, improved the energy utilization ratio of explosives. The measured results provided a new experimental basis to further understand correctly the rock blasting mechanism.

Experimental Research on Technology of Medium Deep Hole Blasting in Large Inclination Rock Diphead Roadway

For improve the efficiency of large inclination diphead excavation, according to the actual construction of field, rock and explosives properties, parameters of smoothing blasting technology for medium deep hole blasting in large inclination rock diphead tunnel is researched, especially improved the blasting parameters of bottom hole and construction technology, present technologies of double bottom hole and casing for disblocking. Experimental study has obtained the good blasting effect, utilization ratio of blasting hole achieved 89.0% on average.

Numerical Simulation of Stress Wave Propagation Induced by Cut Blasting in Multi-Media

Explosive blasting in rock and other media could induce strong shock wave. Near blasting zone, the blasting energy mainly break rock. Slightly far away from borehole, the blasting energy induces plastic damage. Farther afield, this kind of energy presents elastic deformation. In cut blasting, multi-boreholes initiate at the same time, multi-column stress waves occur superimpose and converge. Especially in multi-media, this process is extremely complex. Adopt numerical simulation method, set up multi-media model, which include weathered rock, highly weathered rock and plain fill. This paper simulated the propagation process of stress wave in these medias. Revealed the propagation mechanics of stress wave.

Simulation Research of Blasting Vibration Prediction with Cylindrical Dynamite

Blasting vibration not only damages architectural structures but also harms people heath. Numerical simulation provides an effective method to study explosion and shock problems. Herein, the paper performed numerical simulation to predict blasting vibration. At first, analyzed the propagation velocity of stress wave, which validated the feasibility of the model. The simulation and test agreed well both at vibration waveform and at the order of magnitude of both nodes 1 and 2. The simulation could provide reasonable accuracy. The achievement provided reference for other researches.