scholarly journals Study on the Effect of Blasting Vibration on Rock Bolt and Shotcrete

2022 ◽  
Vol 2160 (1) ◽  
pp. 012077
Author(s):  
Yanlong Ren ◽  
Xuanli Yang ◽  
Chang Li ◽  
Mingzhe Lü ◽  
Jinzhao Zhuang
Keyword(s):  
Adverse Effects ◽  
Negative Impact ◽  
Great Influence ◽  
Time History ◽  
Construction Method ◽  
Rock Bolt ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Finite Element Software ◽  
The Impact

Abstract The blasting tunneling construction method is often used in the underground engineering projects such as tunnels, coal mines roadway, chambers and so on, rock bolt and shotcrete support is used. Although the blasting construction method has many advantages, but also will be accompanied by adverse effects. Blasting vibration of blasting construction not only to the surrounding environment, building (structure) and other adverse effects, but also on the support of the underground project itself has a negative impact. In order to discuss the impact of blasting vibration on shotcrete and rock bolt support in the process of blasting tunneling of roadway, a certain amount of explosives is detonated in the hole of the working face, the finite element software ANSYS/LS-DYNA was used to establish the numerical calculation model, through time history analysis calculation, the distribution law of the vibration velocity on the shotcrete surface along the section and the variation law of the longitudinal tension and compression stress of the rock bolt are obtained. The results show that the blasting vibration produced by blasting tunneling has a great influence on the shotcrete at the shoulder, but little influence on the axial force of the rock bolt.

scholarly journals The use of social networking sites and their relation to the behavior of the university student: استخدام مواقع التواصل الاجتماعي وعلاقتها بالسلوك الانحرافي لدى الطالب الجامعي

2017 ◽  
Vol 1 (5) ◽  
Author(s):  
Djeboub Walid
Keyword(s):  
Adverse Effects ◽  
Social Networking ◽  
Social Networking Sites ◽  
Deviant Behavior ◽  
Negative Impact ◽  
Sampling Technique ◽  
Simple Random Sampling ◽  
The University ◽  
The Impact ◽  
University Community

This study aimed to show the extent of teenagers who represent students Tèbessa University contents of violence and crime that is seen or published or traded them through the media and communication affected, especially through social networking sites and networks, such as Facebook and stringing YouTube and Skype, etc., which may contribute to the formation and strengthening of behaviors negative in these through the following problem: Do you contribute to social networking sites through the implications of violence and crime in a negative impact on the behaviors of the students within the university community ?, also deliberately researcher to sample the estimated inventory of 50 students schooled at the Faculty of Economics and Commercial Sciences and Management Sciences of each section by an estimated 10% of the study population as a whole's (2000) the adoption of simple random sampling technique, the results have also been addressing the adoption system (SPSS) , Which resulted in the results: the presence of a statistically significant correlation between the students' use of social networking sites and the spread of deviant behavior within the university community?, And no statistically significant differences in the adverse effects of the use of social networking sites on the behavior of students depending on the sex variable, the largest of any female average for the benefit of, No statistically significant differences in the adverse effects of the use of social networking sites on the behavior of students depending on the variable physical level ?,No statistically significant differences in the adverse effects of the use of social networking sites on the behavior of the students due to the level of scientific student ?,The study also called attention to the recent media study the impact of the implications of violence and crime across social networking on the behavior of young people and adolescents sites, spreading awareness programs to help solve the problems of this phenomenon.

Impact Dynamics Analysis of Shed Tunnel Structure Hit by Collapse Rock-Fall

2011 ◽  
Vol 99-100 ◽  
pp. 1023-1026 ◽  
Author(s):  
Lu Yang ◽  
Shi Min Li ◽  
Dai Heng Chen ◽  
Zhi Min Wu
Keyword(s):  
Contact Force ◽  
Impact Energy ◽  
Incident Angle ◽  
Great Influence ◽  
Rock Fall ◽  
Tunnel Structure ◽  
Protective Structure ◽  
Additional Energy ◽  
Finite Element Software ◽  
The Impact

This paper bases on the prototype of the actual shed tunnel structure, study on contact force, displacement, damage, energy of shed tunnel under impact of rock-fall. By ABAQUS finite element software to simulate the process of roll-fall impact knowable: Rock-fall at different speeds and incident angle shocks on shed tunnel has great influence to concrete protective structure of contact force and displacement; Concrete protective structure damage the worst hit area of occurred with roll-fall contact area, the second is inclined leg column top and in connection with the pillars of the beam damage is also very serious, In practical projects first should pay attention to strengthen the intensity of the pillars with beam joints and prevent damage; From the angle of energy we can see that shed tunnel is mainly through the concrete protective structure to absorb and consumption impact energy, soil cushion absorption and consumption impact energy is very limited, to alleviate the impact of concrete protective layer rolling damage, and suggestions in shed tunnel bearing place additional energy shock absorber to increases protection structure system soft degrees under the condition of minimize the shed tunnel weight, achieve the purpose of decrease shock energy.

scholarly journals Experiment and Simulation Study on the Dynamic Response of RC Slab under Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yue Wang ◽  
Jun Liu ◽  
Zhimin Xiao ◽  
Futian Zhao ◽  
Yi Cheng
Keyword(s):  
Dynamic Response ◽  
Impact Loading ◽  
Impact Resistance ◽  
Great Influence ◽  
Time History ◽  
Reinforcement Ratio ◽  
Slab Thickness ◽  
Drop Hammer ◽  
Rc Slab ◽  
The Impact

Reinforced concrete (RC) slab is an important component in civil construction and protection engineering, and its dynamic response under impact loading is a complex mechanical problem, especially for two or multiple continuous impact loads. In this paper, a series of drop hammer impact tests were carried out to investigate the dynamic response of RC slabs with two successive impacts. The time history of impact force and the failure characteristic of the slab surface were recorded. Moreover, four influence factors, including slab thickness, reinforcement ratio, impact location, and drop hammer height have been discussed. Besides, a 3D numerical model based on the finite element method (FEM) was established to expand the research of constrained force, deflection, and vertical stress of an RC slab. The results show that increasing the slab thickness and reinforcement ratio can improve the impact resistance of an RC slab. The impact point location and drop hammer height have a great influence on the dynamic response of the RC slab. In addition, the RC slab will have more obvious damage under the second impact, but the dynamic response becomes weaker. It may be because of the local damage in the concrete caused by the first impact that would weaken the propagation of vibration.

scholarly journals Prediction of Blasting Vibration Velocity of Layered Rock Mass under Multihole Cut Blasting

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jie Zhu ◽  
Haixia Wei ◽  
Xiaolin Yang ◽  
Huaibao Chu
Keyword(s):  
Differential Equation ◽  
Rock Mass ◽  
Prediction Accuracy ◽  
Time History ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Underground Engineering ◽  
Layered Rock ◽  
Propagation Law ◽  
Layered Rock Mass

In the blasting construction of underground engineering in layered rock mass, the mechanism of cut blasting and the propagation law of blasting vibration waves are very complex. In this paper, a new method for predicting the blasting vibration velocity of layered rock mass under multihole cut blasting is proposed. The key steps include determining the equivalent elastic boundary and load, establishing the multidegree freedom model of blasting vibration and its motion differential equation, and solving the motion differential equation by time-history analysis method. Two multihole cut blasting tests of different schemes were carried out in the construction site of layered rock mass, and the measured results of blasting vibration waves were obtained. By comparing the time-history curves of the predicted and measured blasting vibration velocity, it can be seen that the time-history curves predicted by the proposed method can reflect the characteristics and attenuation law of blasting vibration waves, and the predicted waveforms are similar to the measured waveforms. By using the proposed method, the prediction accuracy for the peak velocity of blasting vibration in the two tests is 93% and 94%, respectively, and the prediction accuracy for the dominant frequency of blasting vibration in the two tests is 86% and 94%, respectively. The prediction accuracy of the main characteristic parameters of blasting vibration waves is high. So it can be proved that the prediction method proposed in this paper is feasible in effectiveness and accuracy, which can provide important theoretical guidance for the optimization of blasting design and the control of blasting vibration in underground engineering in layered rock mass.

scholarly journals Homophily in co-autorship networks

2018 ◽  
Vol 8 (2) ◽  
pp. 119-128 ◽  
Author(s):  
Adelina-Alexandra Stoica
Keyword(s):  
Negative Impact ◽  
Positive Impact ◽  
Structural Characteristics ◽  
Great Influence ◽  
Network Size ◽  
Hierarchical Regression ◽  
Full Time ◽  
Sociology Departments ◽  
Number Of Citations ◽  
The Impact

Abstract The main purpose of this paper is to measure the impact that homophily, structural characteristics of the networks, number of citations of the alters and their Hirsch score have on the number of citations of an ego. I have chosen co-authorship networks as a subject of research because they have a great influence on knowledge and on the diffusion of ideas. The studied populations are represented by full-time academics affiliated to sociology departments in Romania, Poland and Slovenia. Ego-network analysis was used as research design. The data was analyzed using linear hierarchical regression. For all three populations the average number of citations of the alter has a considerable positive impact on the number of citations of the ego. Conversely, the Hirsch score of the alter has a negative impact on the number of citations of the ego. The data analyzed in this article claims that the assumptions about the positive impact of alter citations, network size and the betweenness score on the number of the authors citations are supported empirically.

Analysis of the Seismic Response of Long-Span Tube Shell Structures under Multi-Support Excitations

2012 ◽  
Vol 446-449 ◽  
pp. 751-755 ◽  
Author(s):  
Meng Hong Wang ◽  
Fei Da Song ◽  
Peng Zhuang ◽  
Song Song Shi
Keyword(s):  
Shell Structure ◽  
Time History ◽  
Peak Displacement ◽  
Finite Element Software ◽  
Long Span ◽  
History Analysis ◽  
Time Histories ◽  
Internal Forces ◽  
The Impact ◽  
Tube Shell

Analysis earthquake response of the long-span tube shell structure under multi-support excitations. The response of the long-span structure in the earthquake is different between multi-support excitations and uniform excitation. Using sap2000 finite element software with time history analysis, this paper analyzes the impact of the different visual velocities combining with the engineering Projects, and its internal forces and displacements. The results show the impact of the long-span tube shell structure under multi-support excitations. Draw structure peaking acceleration and displacement of time-histories. Result shows that: The appearances of structure under multi-support excitations and under uniform excitation have the same trend. The peak of acceleration and displacement of the structural is different from multi-support excitations and uniform excitation, and the time of occurrence of the peak acceleration and peak displacement is also different.

Study on the Impact Properties of a New Debris Flow Dam Based on Steel-Concrete Composite Structure

2014 ◽  
Vol 638-640 ◽  
pp. 2056-2059 ◽  
Author(s):  
Ya Xiong Liang ◽  
Xiu Li Wang ◽  
Chang Wu ◽  
Zhi Gang Lv
Keyword(s):  
Finite Element ◽  
Debris Flow ◽  
Impact Force ◽  
Impact Load ◽  
Weak Link ◽  
Time History ◽  
Type Model ◽  
Finite Element Software ◽  
New Type ◽  
The Impact

The impact force is one of the most weak link of the dynamics studies of debris flow for many years. To make the structure or components are better able to suffer the impact load such as debris flow, explosions, a new debris flow dam is designed by introducing this new type model with spring. It is simulated under boulder impact by using finite element software LS-DYNA.The stress distribution, impact and displacement time history curve under typical conditions are obtained. The results show that the resist impact effect of new debris flow dam is very obvious.

Numerical Analysis of the Impact of the Stope Blasting Vibration on Tailings Dam Stability Based on GeoStudio

2014 ◽  
Vol 501-504 ◽  
pp. 200-206
Author(s):  
Qing Nan Wei ◽  
Shu Ran Lv
Keyword(s):  
Vibration Monitoring ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Tailings Dam ◽  
Vibration Acceleration ◽  
Tailings Dams ◽  
Stability Against Sliding ◽  
Dam Stability ◽  
The Stability ◽  
The Impact

In this paper, based on the establishment of the finite element calculating model, the influence of the blasting vibration to tailings dams stability was analyzed in accordance with actual stope blasting vibration monitoring data. The laws of the blasting vibrations impact on tailings dam stability was reached by importing different vibration amplitude of vibration wave intensity. When the blasting vibration acceleration remained under 0.333g and vibration velocity remained under 17.005cm/s, the coefficient of the healthy tailings dam stability against sliding has a increasing trend with the increase of vibration strength. When the vibration acceleration and the vibration velocity reached the maximum value, the coefficient rapidly decline; But the influence of stope blasting vibration on the stability of the risky tailings dams is more significant. The coefficient of stability against sliding had a straight-line decrease to the risky tailings dams. In Engineering, more than 4 times margin is considered to find the control vibration velocity. The value is 4.25 cm/s. An analysis shows that the effect of blasting vibration on healthy tailings dam stability has two sides. When the blasting vibration intensity remains within control vibration velocity, it can be beneficial to the stability of tailings dam. Otherwise it will be harmful.

The Blasting Test with Precise Delayed Time Interval and Wavelet Pocket Analysis for Vibration Signals’ Energy

2014 ◽  
Vol 1023 ◽  
pp. 198-204
Author(s):  
Li He ◽  
Dong Wang Zhong
Keyword(s):  
Total Energy ◽  
Vibration Signal ◽  
Propagation Distance ◽  
Vibration Velocity ◽  
Time Interval ◽  
Blasting Vibration ◽  
Vibration Signals ◽  
Slope Test ◽  
The Impact ◽  
Delayed Time

As a physical carrier, blasting vibration signal includes much information about blasting method, explosive charge structure and propagation medium. Based on the indoor concrete slope test with millisecond blasting and wavelet pocket analysis technology, the blasting seismic signal was analyzed in the features of energy distribution in order to control the blasting vibration hazard better. The attenuation law of the energy and the peak vibration velocity (PPV) with distance decreased were researched. The effects of delayed time interval on PPV and energy are investigated, and the paper have analyzed the weakening degree of energy and PPV of vibration signals when damping ditch exists, so was its effect on the distribution of energy. The conclusions show that: the impact is great about delayed time interval on the total energy of signals in millisecond blasting; the damping ditch made the predominant frequency for energy concentrate on the low frequency band, damping effect of the damping ditch reduced with the delay time interval increasing. When the propagation distance increased, the attenuation trend of the PPV and total energy slowed down gradually near blasting area. The PPV and energy are not necessarily meanwhile the maximum; the energy of the vibration signal is not only determined by the PPV.

scholarly journals Comparison and analysis of seismic isolation, energy dissipation structure and traditional seismic structure

2021 ◽  
Vol 248 ◽  
pp. 01001
Author(s):  
Shu-jiang Jiang ◽  
Shun-zhong Yao ◽  
De-wen Liu
Keyword(s):  
Seismic Isolation ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Seismic Structure ◽  
Base Shear ◽  
Finite Element Software ◽  
History Analysis ◽  
Rare Earthquake ◽  
Nonlinear Time History ◽  
The Impact

This paper uses SAP2000 finite element software to perform nonlinear time history analysis of nine structural systems, and compares the period, total floor displacement, base shear force, vertex displacement, and top acceleration of the structure under the action of an 8-degree rare earthquake. The research results show that seismic isolation and damping technology can effectively reduce the impact of earthquakes on structures.

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