The division of damage area under blasting vibration in rock mass slopes

2012 ◽  
pp. 761-766
Keyword(s):  
Rock Mass ◽  
Blasting Vibration ◽  
Damage Area ◽  
Rock Mass Slopes

scholarly journals Study on the Deformation Mechanism of Soft Rock Roadway under Blasting Disturbance in Baoguo Iron Mine

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hong-di Jing ◽  
Yuan-hui Li ◽  
Kun-meng Li
Keyword(s):  
Rock Mass ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Deformation Monitoring ◽  
Underground Mines ◽  
Blasting Vibration ◽  
Iron Mine ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to study the deformation mechanism of soft rock roadway in underground mines, it is necessary not only to study the influence of the dynamic disturbance caused by the cyclic mining blasting vibration on the stability of the soft rock roadway but also to study the degradation of the roadway surrounding rock itself and other factors. The paper presented a synthetic research system to investigate the factors that influence roadway rock structure deterioration in Baoguo Iron Mine. Firstly, the stability of rock mass was analyzed from the perspective of the physical and structural characteristics of the rock mass. Afterwards, according to monitoring data of mining blasting vibration, a suitable safety blasting prediction model for Baoguo Iron Mine was determined. And then, combining the results of mining blasting vibration monitoring and deformation monitoring, the effect of cyclic mining blasting on the stability of the soft rock roadway was obtained. By systematically studying the intrinsic factors of rock quality degradation and external environmental disturbances and their interactions, this paper comprehensively explores the deformation mechanism of soft rock roadway and provides the support for fundamentally solving the large deformation problems of soft rock roadway in underground mines.

scholarly journals Slope mass rating of rock slopes of the Malekhu River, central Nepal Lesser Himalaya

2014 ◽  
Vol 47 (1) ◽  
pp. 36-46
Author(s):  
Naresh Kazi Tamrakar ◽  
Jaya Laxmi Singh
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Failure Mode ◽  
Rock Mass Rating ◽  
Rock Slopes ◽  
Plane Failure ◽  
Central Nepal ◽  
Slope Mass Rating ◽  
Unstable Slope ◽  
Rock Mass Slopes

The Malekhu River is one of the major tributaries of the Trishuli Ganga River fl owing from the south in Malekhu region, central Nepal. Riverbank slope stability is a topic of concern as rock mass condition and slope stability of riverbank slopes are important parameters for riverbank erodibility. Fourteen sites in the Malekhu River were selected for rock mass rating (RMR) and then slope mass rating (SMR) by using a graphic method. The potentially vulnerable sites were identifi ed after conducting field study in different slopes. The results indicate that there occur modes of failures ranging from stable (good rock mass) to partially stable (normal rock mass) in all the study sites. The unstable (bad rock mass) and completely unstable (very bad rock mass) slopes are, however, distributed only in some slopes. The unstable slope of plane failure mode is Ka1, whereas the completely unstable slopes of plane failure mode are Rb2, Ml1 Slope 1 and Ml2. The unstable slope of toppling failure mode is Ml2. When wedge failure mode is considered, the slopes at Ti1 and Ka1 are unstable while the slopes at Kh1, Ka1, Ml1 Slope 1 are completely unstable. The rock slopes with unstable to completely unstable states are considered bad (SMR Class IV: 21–40) to very bad (SMR Class V: 0–20) rock mass with fair to poor rock mass rating, respectively. These bad to very bad rock mass slopes are vulnerable to slope movements and river erosion, and they require mitigative measures.

scholarly journals Back Analysis and Calculation of Dynamic Mechanical Parameters of Rock Mass with Measured Blasting Vibration Signals

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Zhaowei Yang ◽  
Wenbo Lu ◽  
Qidong Gao ◽  
Peng Yan ◽  
Ming Chen ◽  
...  
Keyword(s):  
Rock Mass ◽  
Elastic Modulus ◽  
Blasting Vibration ◽  
Dynamic Parameters ◽  
Improved Method ◽  
S Wave ◽  
Vibration Signals ◽  
S Waves ◽  
Measured Field ◽  
Wave Identification

How to obtain dynamic parameters of rock masses quickly and precisely is a popular and difficult problem, which plays a very important part in engineering design or construction. Currently, the methods used to obtain these parameters are in situ testing method, empirical formula, and so on. However, these methods have some shortcomings, such as large investment and long construction period, which cannot obtain the dynamic parameters precisely and quickly in the engineering scale. In this study, a new method of estimating the rock parameters based on the measured field blasting vibration signals is proposed according to theory of elastic stress wave. In addition, an improved method for S-wave identification used in engineering scale was proposed and then the numerical simulation is given to verify the feasibility. Comparison of the numerical identification results and theoretical results clearly show that the improved method is available in S-wave identification with errors less than 2%. By identifying the arrival times of P and S waves, the propagation velocities of P and S waves are calculated and the parameters of rock mass can be obtained at last. Through analyzing the measured field blasting vibration signals in Fengning pumped-storage power station, the dynamic elastic modulus of rock mass inversed by vibration signals is about 2.2~2.9 times of its static elastic modulus, while the inversed dynamic Poisson's ratio is 0.9~0.975 times of the static.

Dynamical Response of Circular Tunnel with Steel Lining under the Action of Blasting Vibration

2010 ◽  
Vol 163-167 ◽  
pp. 4037-4042 ◽  
Author(s):  
Chang Ping Yi ◽  
Wen Bo Lu ◽  
Ling Feng ◽  
Gang Wang
Keyword(s):  
Rock Mass ◽  
Velocity Distribution ◽  
Expansion Method ◽  
Surrounding Rock ◽  
Vibration Velocity ◽  
Dynamical Response ◽  
Blasting Vibration ◽  
Circular Tunnel ◽  
Steel Lining ◽  
Wave Function Expansion Method

The wave function expansion method is used to analyze the interaction process of the blasting seismic wave and the adjacent circular tunnel with steel lining, the stress expression, displacement expression and vibration velocity expression of circular tunnel under the action of blasting vibration are deduced, the stress, displacement and vibration velocity distribution of surrounding rock mass and steel lining are presented under the definite condition. In terms of the stress and vibration velocity distribution and the tensile strength of the rock mass, the critical failure vibration velocity of surrounding rock mass is obtained.

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 Geotechnical Behavior of Eastern Senegal Rock Mass Slopes by Geomechanical Classifications and Applications

2018 ◽  
Vol 06 (05) ◽  
pp. 11-24
Author(s):  
Déthié Sarr ◽  
Mathioro Fall ◽  
Oustasse A. Sall ◽  
Papa Malick Ngom ◽  
Yves Berthaud
Keyword(s):  
Rock Mass ◽  
Rock Mass Slopes

Monitoring and Analysis of Blasting Vibration of Diversion Tunnel Excavation in Layered Rock Mass

2012 ◽  
Vol 249-250 ◽  
pp. 1047-1052 ◽  
Author(s):  
Hua Feng Deng ◽  
Min Zhu ◽  
Le Hua Wang ◽  
Ji Fang Zhou
Keyword(s):  
Rock Mass ◽  
Vibration Monitoring ◽  
Damage Effect ◽  
Good Effect ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Diversion Tunnel ◽  
Tunnel Excavation ◽  
Layered Rock ◽  
Layered Rock Mass

In order to insure the safety and stability of the existed dam body and dam curtain during the diversion tunnel excavation, the vibration velocities were analyzed based on in-site blasting vibration monitoring. Result shows that the elevation difference between explosion point and monitoring points has a great impact on the vibration velocity in addition to single fire dynamite and blast center distance. During data analysis, the traditional empirical formula of attenuation of blasting earthquake must be amended. Through contrasting and analyzing, the amended formula of attenuation of blasting earthquake wave is precise relatively. At the same time, two collapses during the diversion tunnel excavation were analyzed based on the characteristics of layered rock mass and fault distribution, and the explosion parameters were optimized, so that the damage effect of blasting vibration was controlled effectively. This research also takes a good effect in other similar works.

The characteristics of blasting vibration frequency bands in jointed rock mass slope

2020 ◽  
Vol 79 (23) ◽  
Author(s):  
Shenghui Zhang ◽  
Wenxue Gao ◽  
Lei Yan ◽  
Jiangchao Liu ◽  
Liansheng Liu
Keyword(s):  
Rock Mass ◽  
Vibration Frequency ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Blasting Vibration ◽  
Frequency Bands
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