Investigating ground vibration to calculate the permissible charge weight for blasting operations of Gotvand-Olya dam underground structures / Badania drgań gruntu w celu określenia dopuszczalnego ciężaru ładunku wybuchowego przy pracach strzałowych w podziemnych elementach tamy w Gotvand-Olya

2012 ◽  
Vol 57 (3) ◽  
pp. 687-697 ◽  
Author(s):  
Saeed Soltani-Mohammadi ◽  
Hassan Bakhshandeh Amnieh ◽  
Moein Bahadori
Keyword(s):  
Minimum Distance ◽  
Hybrid Methods ◽  
Ground Vibration ◽  
Charge Weight ◽  
Underground Structures ◽  
Scaled Distance ◽  
Maximum Charge ◽  
Safe Level ◽  
Surrounding Environment

Abstract Ground vibration, air vibration, fly rock, undesirable displacement and fragmentation are some inevitable side effects of blasting operations that can cause serious damage to the surrounding environment. Peak Particle Velocity (PPV) is the main criterion in the assessment of the amount of damage caused by ground vibration. There are different standards for the determination of the safe level of the PPV. To calculate the permissible amount of the explosive to control the damage to the underground structures of Gotvand Olya dam, use was made of sixteen 3-component (totally 48) records generated from 4 blasts. These operations were recorded in 3 directions (radial, transverse and vertical) by four PG-2002 seismographs having GS-11D 3-component seismometers and the records were analyzed with the help of the DADISP software. To predict the PPV, use was made of the scaled distance and the Simulated Annealing (SA) hybrid methods. Using the scaled distance resulted in a relation for the prediction of the PPV; the precision of the relation was then increased to 0.94 with the help of the SA hybrid method. Relying on the high correlation of this relation and considering a minimum distance of 56.2 m to the center of the blast site and a permissible PPV of 178 mm/s (for a 2-day old concrete), the maximum charge weight per delay came out to be 212 Kg.

A Re-Look Into Modified Scaled Distance Regression for Prediction of Blast-Induced Ground Vibration

2021 ◽  
Vol 12 (1) ◽  
pp. 22-39
Author(s):  
Saha Dauji
Keyword(s):  
Performance Measures ◽  
Ground Vibration ◽  
Blast Waves ◽  
Charge Weight ◽  
Mining Activities ◽  
Weight Estimation ◽  
Industrial Practice ◽  
Scaled Distance ◽  
Conservative Values ◽  
Distance Approach

Underground blasts are conducted for deep excavations, tunneling, or mining activities. Scaled distance regression analysis is performed in industry to estimate peak particle velocity from charge weight and distance. For addressing the uncertainties in estimating safe charge weight for controlled blasting, 95% confidence expression is generally used. For addressing inaccuracies arising from superimposition of blast waves in multi-hole blasting when using attenuation equation developed from single-hole blast data, a modified approach was proposed in literature. This article presents comparisons to establish that industrial practice of scaled distance regression would be as satisfactory as the proposed modified approach, when various performance measures (including parsimony) are considered together. Furthermore, industrial practice of using 95% confidence expression generated from sufficient data (say, 40 numbers) would result in safe charge weight estimation, whereas modified scaled distance approach (mean expression) could still result in few non-conservative values.

scholarly journals Effect of Blast-induced Ground Vibration on Factor of Safety of Pit Wall Stability

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Pirat Jaroonpattanapong ◽  
Kittikun Pantachang ◽  
Thungfung S. ◽  
Petthong N.
Keyword(s):  
Slope Stability ◽  
Natural Condition ◽  
Factor Of Safety ◽  
Limit Equilibrium ◽  
Ground Vibration ◽  
Open Pit ◽  
Charge Weight ◽  
Plane Failure ◽  
Maximum Charge ◽  
The Stability

The regulated maximum peak particle velocity (PPV) from blasting operations of an open-pit coal mine is less than 2 mm/s to prevent mainly any public disturbance such as ground vibration and air blast. However, the blast-induce ground vibration can also decrease the stability of pit slope, which has not been intensively studied. A claystone pit wall, which is geotechnically investigated as having a plane failure type and the natural condition factor of safety (FS), has been selected for this study. The FS is selected to measure the effect of blast-induced ground vibration on the slope stability. The limit equilibrium, pseudo-static 1 (), and pseudo-static 2 () methods are used to determine the FS. The vibration results of blasting monitored at three slope positions: crest, middle, and toe, from two areas at the same pit wall, are recorded by blasting seismographs. Maximum charge weight per delay and the distance from blast areas to seismographs are collected to construct the scaled distance. The percentage change of FS of three methods from both areas compared to natural condition FS are all less than 4 percent considered that the slope stability is safe from blasting vibration (less than 15 percent). The relationship between the FS and maximum PPV from the limit equilibrium, pseudo-static 1 (), and pseudo-static 2 () methods indicate that the adverse maximum PPVs given the unity FS are 16.60 and 4.58, and 4.74 mm/s, respectively. The regulated PPV less than 2 mm/s at the mine is reasonable to prevent any possible plane failure. However, many impact parameters have not been included in this study, and their effects may disturb the pit wall stability.

Determining The Minimum Distance Between Centers of Two Parallel Tunnels to Apply The Law of Super Position in Order to Calculate Subsidence by Using The Software FLAC 3D

2015 ◽  
Vol 1 (1) ◽  
pp. 13-20
Author(s):  
Hamid Reza Samadi ◽  
Mohammad Reza Samadi
Keyword(s):  
Minimum Distance ◽  
Surface Subsidence ◽  
Urban Traffic ◽  
Underground Structures ◽  
Rapid Population Growth ◽  
The North ◽  
Flac 3D ◽  
The Law ◽  
3D Software ◽  
Twin Tunnels

Due to the development of cities as well as rapid population growth, urban traffic is increasing nowadays. Hence, to improve traffic flow, underground structures such as metro, especially in metropolises, are inevitable. This paper is a research on the twin tunnels Of Isfahan's metro between Shariaty station and Azadi station from the North towards the South. In this study, simultaneous drilling of subway's twin tunnels is simulated by means of Finite Difference Method (FDM) and FLAC 3D software. Moreover, the lowest distance between two tunnels is determined in a way that the Law of Super Position could be utilized to manually calculate the amount of surface subsidence, resulted by drilling two tunnels, by employing the results of the analysis of single tunnels without using simultaneous examination and simulation. In this paper, this distance is called "effective distance". For this purpose, first, the optimum dimensions of the model is chosen and then, five models with optimum dimensions will be analyzed separately, each of which in three steps. The results of analyses shows that the proportions (L/D) greater than or equal 2.80, the Law of Super Position can be applied for prediction of surface subsidence, caused by twin tunnels' construction

scholarly journals A seismologically motivated survey of blasting activity in the northern Rhine area

2000 ◽  
Vol 79 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Klaus-G. Hinzen ◽  
Stefan Pietsch
Keyword(s):  
Charge Weight ◽  
Time Interval ◽  
Maximum Charge ◽  
Comprehensive Test Ban Treaty ◽  
Comprehensive Test ◽  
Explosive Charges ◽  
Chemical Explosions ◽  
Working Day ◽  
Test Ban ◽  
Natural Earthquakes

AbstractDiscrimination between quarry blasts and earthquakes has gained importance due to signature of the Comprehensive Test Ban Treaty. In this context, large chemical explosions are significant. In the routine analysis of data from local seismograph networks, discrimination between smaller blasts and micro-earthquakes is not always clear. Many quarries are in operation and blasts far outnumber natural earthquakes in the highly industrialized northern Rhine area.We compiled a list of active quarries in the Northern Rhine Area and mapped their locations. We then created a database from a questionnaire sent out to all quarries on the list. From the 33% of questionnaires that were returned, we discerned some representative values for the main blasting parameters and explosive consumption. In the study area of 72,000 km2, approx. 21,000 blasts are fired per year (80 per working day). Most of the blasts (72%) have total explosive charges between 400 and 4500 kg. Shots with charges above 10 tons are rare (20-30 per year). Some 80% of the blasts are ripple-fired with a nominal firing time interval of 20 ms.Based on empirical amplitude vs. distance curves from vibration control measurements, a relation between maximum charge weight per delay time, L (kg), and a ‘quarry blast’ magnitude, MQB, is derived: MQB = 0.6·log10(L) + 0.131. Using this relation and extrapolating the database from the questionnaire shows that for magnitudes between 1 and 2, blasts occur 200–250 times more frequently than micro-earthquakes in the Northern Rhine area.

Determination of the Minimum Distance Between Moving Objects Including Velocity Information

1993 ◽  
Author(s):  
Meyer Nahon
Keyword(s):  
Minimum Distance ◽  
Moving Objects ◽  
Rapid Determination ◽  
Computation Time ◽  
Optimization Techniques ◽  
Real Time Control ◽  
Time Step ◽  
Time Control ◽  
Velocity Information

Abstract The rapid determination of the minimum distance between objects is of importance in collision avoidance for a robot maneuvering among obstacles. Currently, the fastest algorithms for the solution of this problem are based on the use of optimization techniques to minimize a distance function. Furthermore, to date this problem has been approached purely through the position kinematics of the two objects. However, although the minimum distance between two objects can be found quickly on state-of-the-art hardware, the modelling of realistic scenes entails the determination of the minimum distances between large numbers of pairs of objects, and the computation time to calculate the overall minimum distance between any two objects is significant, and introduces a delay which has serious repercussions on the real-time control of the robot. This paper presents a technique to modify the original optimization problem in order to include velocity information. In effect, the minimum distance calculation is performed at a future time step by projecting the effect of present velocity. This method has proven to give good results on a 6-dof robot maneuvering among obstacles, and has allowed a complete compensation of the lags incurred due to computational delays.

scholarly journals ADAPTIVE ALGORITHM FOR DETERMINING THE PARAMETERS OF AN INACCESSIBLE POINT OF AN OBJECT

2021 ◽  
pp. 58-70
Author(s):  
Aleksandr Brailov ◽  
Vitaliy Panchenko
Keyword(s):  
Adaptive Algorithm ◽  
Minimum Distance ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Multiple Variables ◽  
The Common ◽  
Relative Errors ◽  
The Given ◽  
Real Experimental Data

In the present research the optimizing approach to the determination of the parameters of an inaccessible point of an object is developed. The common issues are revealed and essential steps of their resolution are identified. The essence of the problem is an objective contradiction between a requirement for the location of points A and B of the centers of the sighting tubes of optical devices in the same horizontal plane P1 and the lack of a real possibility to perform such to achieve this an identical one-level arrangement without error. The aim of the study is to develop strategies for determining the position of an inaccessible point of an object in the minimum domain between intersecting sighting rays as well as an adaptive algorithm for determining the values of the parameters of an inaccessible point under the given absolute and relative errors. To achieve this aim, the following problems are formulated and solved in the paper: 1. Develop strategies for determining the position of the inaccessible point of the object in the minimum domain between the intersecting sighting rays. 2. Develop an adaptive algorithm for determining the values of the parameters of an inaccessible point based on the specified absolute and relative errors. In the proposed optimizing approach, the three-dimensional geometrical model with crossed directional rays for the determination of coordinates of the inaccessible point of an object is developed. It is discussed that points С and C', coordinated of which to be determined, locates in domain [CDM, CEM], [C'D'M, C'E'M] of the minimum distance ρmin between crossed directional rays. The optimizing problem of the determination of coordinates of an inaccessible point of an object in space is reduced to a problem of the determination of the minimum distance between two crossed directional rays. It’s known from the theory of function of multiple variables that function ρ = f (tC'D', tC'E') reaches its extremum ρmin when its partial derivatives by each variable are equal to zero. Three strategies for selecting the position of the inaccessible point C (xC, yC, zC) in the found minimum region [CDM, CEM] are proposed. The required point C' (xC', yC', zC') can be located, for example, in the middle of the minimum segment [C'D'M, C'E'M]. The essence of the adaptive algorithm is in optimizing the variation of the initial values of data α, α', β, γ, γ', AB, at which the absolute and relative errors of the coordinates of the inaccessible point satisfy the error values set by the customer (0.0001-1.2%) The proposed approach is verified using real experimental data.

Influence of PGV on the Internal Forces of Subway Station

2011 ◽  
Vol 90-93 ◽  
pp. 1987-1991 ◽  
Author(s):  
Hong Bing You
Keyword(s):  
Response Spectrum ◽  
Simulation Method ◽  
Peak Ground Velocity ◽  
Subway Station ◽  
Underground Structures ◽  
Peak Displacement ◽  
Time Histories ◽  
Internal Forces ◽  
Acceleration Response Spectrum

A hybrid simulation method is used to generate two group artificial ground motions that are compatible with the same acceleration response spectrum, same peak displacement and different peak ground velocity (PGV). The influences of PGV on the internal forces of subway station are studied. For the time histories with the same response spectrum and same peak displacement, the larger PGV of input motions may lead to the great plastic deformation of the soil, and then cause the larger internal forces for the most elements of subway station. The influence of PGV should be considered reasonably in determination of design ground motion parameters for underground structures.

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