.*'t';'l''^"'*Vf' 1 ?/i.. ^m if- 'a i' ^^; 0^ 'o *'T7r»' ^^ <, '.-.7 ^:rs^ > -^..^^ o V 'bV" ^^\^::%ik^'-.. J.^mk,% .//:V^";-/^, .^'.i;^*.V .^^' -•' r^^'^' v^ 05°.*^ ^./^9^ .\,j>, 'V" ^'a IC ®®^® Bureau of Mines Information Circular/1982 Noise and Vibration Control for Surface Mines Program Document By Bradley V. Johnson, Richard J. Seibel, and David E. Siskind UNITED STATES DEPARTMENT OF THE INTERIOR r Information Circularj 8876 Noise and Vibration Control for Surface Mines Program Document By Bradley V. Johnson, Richard J. Seibel, and David E. Siskind UNITED STATES DEPARTMENT OF THE INTERIOR James G. Watt, Secretary BUREAU OF MINES Robert C. Norton, Director This publication has been cataloged as follows: Johnson, Bradley V Noise and vibration control for surface mines: program document. (Information circular ; 8876) Includes bibliographical references. Supt. of Docs.: I 28.27:8876. » 1. Strip mining— Noise control. 2. Blasting— Noise control. 3- Vibra- tion. I. Seibel, Richard J. II. Siskind, D. E. III. Title. IV. Series: In- formation circular (United States. Bureau of Mines) ; 8876" TN295.U4 [TD893.6.M5] 622s [622.31] 82-600499 AACR2 OS 2 CONTENTS ^ Page \j Abstract 1 Introduction 1 Program goals 2 Current status 2 Research approach 4 In-house research 4 Contract research 6 Appendix A. — In-House Bureau research projects 8 Appendix B. — Contract Bureau research projects 9 NOISE AND VIBRATION CONTROL FOR SURFACE MINES Program Document By Bradley V. Johnson, 1 Richard J. Seibel, 2 and David E. Siskind3 ABSTRACT This publication summarizes the in- house and contract research and develop- ment projects conducted since 1974 by the Bureau of Mines for the control of noise and vibrations from surface mine blasting. INTRODUCTION Noise, ground vibration, and airblast-produced structure vibrations are unwelcome side effects of surface mining operations. Uncontrolled, these effects can result in an irritated public and in cracked walls or broken windows. The Bureau's study of blast-produced ground vibrations dates back to 1930, when a study was initiated to determine the damage caused by ground vibration. Initial conclusions quantified ground vibrations and developed some predictive techniques for magnitude based on charge weight and distance to a structure.'* Statistical studies of structural response to both ground vibrations and airblasts were conducted in the late fifties and the sixties; research included analyses of data published by others and field tests and analysis of blasting vibrations at 25 quarries. ^Manager, Branch of Mine Waste Control, Bureau of Mines, Washington, D.C ^Chief , Branch of Mine Waste Control, Bu- reau of Mines, Washington, D.C. ■^Supervisory geophysicist. Twin Cities Research Center, Bureau of Mines, Twin Cities, Minn. '^Thoenen, J. R. , and S. L. Windes. Seis- mic Effects of Quarry Blasting. Bu- Mines Bull. 442, 1942, 83 pp. Areas of investigation consisted of seismic instrumentation, safe vibration levels for residential structures, gener- ation and propagation of ground vibra- tions and airblasts, and prediction of ground vibration and airblast levels. For quarry blasting, relatively small blasthole diameters and charge weights are used. However, in surface coal mines, over a ton of explosives can be loaded into a hole over a foot in diam- eter. Coal mine blasts are often designed to fracture the rock in place rather than throwing it onto the pit floor. This can reduce airblast but at the risk of increased ground vibration. To make reasonable recommendations for surface coal mining, a new set of vibra- tion data was needed. The Bureau began this study of surface coal mine blasting in 1974. Currently over 15,000 blast records are being analyzed and new recom- mendations are being formulated. In 1978, the Bureau began a study of noise produced from sources other than blasting. This work initially gathered information on general noise abatement techniques and then listed major noise sources. Large haulage trucks have been found to be a major source of noise both in the mining pit and on public roads. Research is now being focused on con- trolling this noise. PROGRAM GOALS The goals of the Bureau's noise and vibration control program are to develop and demonstrate (1) proper mine blasting practices and (2) proper ground vibration and noise controls for surface mining operations. To accomplish these goals, the following objectives have been established: 1. To control blast noise contour mining in Appalachia. from 2. To determine the fatigue effect of repeated surface mine blasting on res- idential structures. 3. To develop blast designs that minimize airblast and ground vibration and to develop a handbook of blast design, all consistent with good blasting principles and fragmentation. environmental impact and improve fragmentation. 5. To determine propagation and frequency characteristics in low-velocity geolgic media. 6. To develop a simple weather assessment technique and criteria for adverse weather applicable to mines with potential airblast problems. 7. To develop remote monitoring methods. 8. To improve flyrock control. 9. To improve stemming techniques. 10. To identify, categorize, and rank surface mine noise sources. 4. To apply precision blast ini- tiation devices to control adverse 11. To develop noise large haulage trucks. controls for CURRENT STATUS Adverse environmental effects from surface mining activities continue to be a major problem for the mining industry, the public living near mining operations, and the governmental agencies responsible for setting environmental standards. Congress, in recognizing this problem, passed the Surface Mining Control and Reclamation Act of 1977, which addresses many specific environmental effects, including the noise and vibrations from blasting and other mining operations. Blasting in the mining, quarrying, and construction industries used 4 bil- lion pounds of explosives in 1980. The necessity of blasting for most mineral production, or wherever rock must be excavated, has led to two sets of techni- cal problems: environmental effects and design variables influencing fragmenta- tion. Large surface coal mines have had to close because of widespread complaints. Other mines have had to abandon many tons of previously purchased coal rights because of blasting vibration or have been required to agree to exces- sively strict vibration levels for their operating permits. The regulatory agencies have been asked to close down "irresponsible blasters." Public interest groups have claimed widespread damage from airblasts, ground vibrations, and flyrock. Con- flicts abound at the State and local level concerning environmental regulation of these effects, permit granting, hear- ings, and lawsuits. Even prior to the 1977 Surface Mining Act, 17 States had regulations on blasting vibrations based on Bureau research, and in 1974 blast noise standards were proposed in Illinois that threatened to halt all blasting in the State. The Bureau completed four major studies of blast effects from coal and other types of surface mining in 1980.^ These studies identified the major fac- tors in the design of production blasts that influence airblast and ground vibra- tion levels. They also determined levels of ground vibration and airblast that correspond to acceptable structure response and damage potentials, and made a comprehensive analysis of measurement systems. Results were needed by the min- ing industry and the regulatory agencies for realistic, technically based, and defensible criteria for allowable blast- induced ground vibrations and airblasts. The Bureau's research program emphasizes improved minerals production and the establishment of essential and realistic environmental, health, and safety guidelines. For blasting in par- ticular, there have been efforts to determine safe-level criteria for ground vibration and airblast. These criteria should provide the basis for realistic, technologically established, and defen- sible regulatory levels, and also for practical blast design for the industries that use explosives. The work on noise control is not as advanced. An annotated bibliography on noise abatement techniques has been ^Siskind, D. E. , V. J. Stachura, M. S. Stagg, and J. W. Kopp. Struc- ture Response and Damage Produced by Airblast From Surface Mining. BuMines RI 8485, 1980, 111 pp. Siskind, D. E., M. S. Stagg, J. W. Kopp, and C. H. Dowding. Structure Response and Damage Produced by Ground Vibra- tion From Surface Mine Blasting. Bu- Mines RI 8507, 1980, 74 pp. Stachura, V. J., D. E. Siskind, and A. J. Engler. Airblast Instrumenta- tion and Measurement Techniques for Surface Mining. BuMines RI 8508, 1981, 53 pp. Stagg, M. S., and A. J. Engler. Mea- surement of Blast-Induced Ground Vibrations and Seismograph Calibra- tion. BuMines RI 8506, 1980, 62 pp. established. Under existing contract JOlOOOOl, "Technology for Environmental Noise Control in Surface Mines," the Bureau is investigating the sources and relative levels of noise from surface mines. One of the sources identified has been the large haulage trucks used in the surface mines. Because they are built for off-highway use they are not designed to meet EPA noise criteria. Most of the techniques used to protect the workers have taken the form of special cabs which, while they protect the driver from excessive noise, do not reduce the noise radiated to the surrounding areas . A follow-on contract will use recommenda- tions from contract JOlOOOOl to develop techniques for reducing the noise from large haulage trucks. Prototype tech- niques will be applied to trucks and demonstrated under actual operating conditions. Comprehensive blast design work is continuing. One important parameter, delay timing, is now being researched with the goal of developing a precise blast initiation system to insure proper blast delay intervals. A system is now undergoing laboratory development, with field tests scheduled for 1983. The fatigue effect of repeated blasts is not known. The Bureau of Mines has built a full-scale test structure to study this and other effects, such as settlement, at the Ayshire Mine near Evansville, Ind. Field data are now being gathered, and analysis will begin soon. Future work will also include a study of the effects of blasting on hydrology and fugitive dust generation. Another aspect is the human response to blast noise and vibrations. Determination of safe technical criteria is only one factor in the establishment of environmental control. To insure that recommended controls are practical for the mining industry, the social, legal and economic effects of a control must also be considered. The end results of the program will be a conprehensive set of operating paraneters that, when followed, will help guard against environmental damage while enabling mines to supply the country with the necessary minerals in an economical manner. RESEARCH APPROACH The Bureau of Mines is in continual contact with the raining industry and other Federal agencies. The Bureau learns of current mining problems through interactions at mining symposia and through visiting and working in mining operations. The industry makes numerous requests for Bureau information and receives additional data through Bureau publications and presentations. The Bureau also has a close working relation- ship with both State and Federal agencies that have programs relevant to the Bureau ' s concerns . It is through these continual inter- actions that the Bureau identifies mining problems and their priorities; such interactions are also essential for tech- nology transfer. Formal vehicles for technology transfer include presentations at mining symposia. Bureau publications, open industry briefings, technology transfer seminars, journal articles, technology demonstrations, films, and exhibits at professional and industrial meetings. The involves — process cycle typically 2. Problem identification. 3. Problem prioritization and Gov- ernment interaction. 4. Research. 5. Problem solution. 6. Evaluation and feedback, 7. Technology transfer through industry interaction, briefings, presen- tations, and publications. This cycle is made possible through expertise gained under a strong in-house research program. If personnel is limited, portions of set 4 in the cycle are contracted out. The result is an integrated program that is responsive to the needs of the mining industry and of the Nation, Technology transfer seminars on Ground Vibrations and Airblast Control were presented on November 5, 1980, in Chicago, 111,; on December 3, 1980, in Denver, Colo,; and on December 17, 1980, in Washington, D,C, 1. Industry interaction. IN-HOUSE RESEARCH^ Assessment of Damage from Blast-Induced Ground Vibrations This project determined the thresh- olds of damage for cyclic repetitions of low vibration levels as well as for sin- gle exposures to high levels of vibra- tion. Existing or new structures were subjected to blast-induced vibrations at levels that actually produced observable damage. Also small structures were "Dates and funding appear in appendix A. subjected to many repetitions of simu- lated blast vibrations on large-scale shaking tables, with the results corre- lated to previous studies and field tests on similar structures, Airblast Assessment and Control The project determined the important variables for controlling the generation and propagation of noise from blasting, developed techniques for minimizing noise levels, and established noise and damage thresholds for use in developing regula- tions. The initial task was a survey of the literature to determine the important variables for controlling airblast. Field tests were designed, using this information, to evaluate the instrumenta- tion available for impulsive noise level measurement, to determine the effects of generation and propagation variables on noise levels, and to establish safe noise level criteria. Evaluation of Current Methodologies for Ground Vibration Measurement Increased interest by all sections of industry and Government in ground vibration problems necessitated a stan- dardized methodology for determining ground vibration levels. The Bureau of Mines, in an unbiased capacity, evaluated existing instrumentation, methods, and measurement criteria to produce a reason- able standardized measurement system. This will permit efficient planning for new mine monitoring systems and help insure compliance with environmental statutes. Collection and Analysis of Ground Vibration Data From Surface Mine Blasting This project determined ground vibration levels for surface coal mine blasting that will permit economical min- ing yet will minimize damage from blast- ing. Experimental work measuring vibra- tions from actual mine blasts was combined with previous blast vibration work to achieve guidelines that will include effects of structural fatigue damage as well as damage from single shots. Evaluation of Noise-Measuring Devices for Airblast Transients This project examined techniques for the measurement of blast noise overpres- sures and evaluated the performance of commercially available impulse precision sound level meters and carrier-type sys- tems designed for sonic boom studies. Using recorded blast signals, measurement methods such as peak, root mean square, linear or flat, and C-weighted were investigated. Recommendations were made on instrumentation and measurement tech- niques for airblast noise measurement at surface mines. Determination of Criteria for Ground Vibration Damage From Surface Mine Blasting Damage caused by ground vibrations from surface coal mine blasting is a serious problem for both mine operators and governmental agencies responsible for regulating these adverse environmental effects. Appropriate permissible levels for blast-produced ground vibrations will be determined, permitting economical min- ing while minimizing damage to nearby residences. Field measurements from coal mine blasts will be combined with previ- ous blast vibration work and response spectra analysis techniques to develop safe levels that will include effects of repeated blasting damage as well as damage from single shots. Control of Blast Noise and Vibration From Contour Mining of Coal in Appalachia Airblast and ground vibration effects on structures from the contour mining of coal in Appalachia will be determined. Many complaints on record for the Appalachian Coal Region indicate that the particular topography and mining method may generate abnormal levels of airblast and ground vibrations. The applicability of blasting criteria devel- oped for midwestern surface coal mining will be evaluated, and if required, specialized criteria will be developed for Appalachian mining. Fatigue and Structural Damage From Repeated Surface Mine Blasting Fatigue damage to structures from repeated blasting is an often-posed prob- lem to the mining industry and the gov- ernmental agencies responsible for reg- ulating these adverse environmental effects. Appropriate criteria will be recommended, incorporating the results of this long-terra single- structure with data from concurrent fatigue model tests and the peak-level criteria developed from previous short- term studies. Application of Abatement Technique to Mine Environmental Noise Problems The objective of this project was to determine and promote the application of noise abatement techniques to the solution of fugitive mine noise problems. Noise emissions were identified, characterized, and quanti- fied, and cost-effective abatement technology was described. Changes necessary in mining systems to provide isolation of noise sources, were identified. Blast Design To Minimize Airblast and Ground Vibration The objective of this project is to develop blast design cri- teria to minimize airblast and ground vibrations and still permit effective blasting programs at surface mines. Past work will be integrated with new data on delay intervals and use of decking. Other blast design param- eters will also be considered for research as needed. Analysis and Technical Clarification of Ground Vibration and Airblast Standards In developing criteria for control of damage and annoyance levels of air- blast and ground vibration and associated measurement methods (descriptors), both the National Academy of Science-sponsored Committee on Hearing and Bioacoustics (CHABA) and the Army Corps of Engineers have supplied support to the Interna- tional Standards Organization, American National Standards Institute, the U.S. Department of Housing and Urban Develop- ment, and U.S. Environmental Protection Agency. Their recommendations will be analyzed and critiqued for applicability to blasting. This will involve partici- pation in working group meetings, an effort that has already been initiated. Although none of the criteria proposed so far include any blasting data, they are often more stringent than the Bureau's well-founded recommendations for airblast and ground vibration. Feasibility of the Development of a Precious Blast Initiation System Current delay blasting systems will be studied, and alternatives to pyro- technic delay caps analyzed. Experi- mental prototypes will be built and tested in the laboratory, and a feasibil- ity and cost analysis will be done. CONTRACT research"^ Control of Vibration and Blast Noise From Surface Coal Mining (JO255022) 2 years work, completed. The contract has been (Wiss, Janney, Elstner and Associates, Inc.) The objective of this work was to determine the extent of adverse environ- mental effects of airblast and ground vibrations from surface coal mine blast- ing and to develop blasting techniques to minimize these effects. The project was divided into three phases covering 'Dates and funding appear in appendix B. Survey of Blast Damage to Water Supplies in Appalachla (JO285029) (Philip R. Berger and Associates) The objective of this contract was to determine possible adverse environ- mental effects of blasting on ground water supplies in close proximity to con- tour coal mining operations in Appalachla. Ground vibrations associated with surface coal mine blasting are a major problem to homeowners near the mine sites. Not only can the vibrations cause damage to the residences, as shown in a number of Bureau studies, but a number of complaints exist in contour strip mining areas concerning loss of, or damage to, water wells caused by blasting. The final report will be available in 1982. Human Response to Blast Noise and Ground Structure Vibrations (JO206009) (Bolt, Beranek and Newman) This study will determine, by field surveys and field tests, levels of surface-mine-blasting-induced ground vi- brations and airblast that are per- ceptible, humans. annoying , or intolerable to coordinating responsibility, specifically in the technical areas of human and structural tolerance and measurement of noise and vibration. Technology for Environmental Noise Control in Surface Mines (JOlOOOOl) (ORI, Inc.) Work under this contract will identify the environmental noise problems associated with mining operations, develop techniques for monitoring such noise, and identify and recommend tech- nology for abatement of noise problems. Technology for Control of Environmental Noise From Off Road Haul Trucks (J0218020) Standards on the Measurement of Human Acceptability of Blast Noise and Ground-Transmitted Vibration and Shock (JO205020) (Acoustical Society of America) This contract provides for adminis- tration of the national and international standards committees for which the Acoustical Society of America holds (Woodward Associates) This contract supports the develop- ment of cost-effective techniques for reducing the sound radiated from large haulage trucks without significantly reducing the efficiency of the trucks. Prototype techniques will be applied to trucks and demonstrated under actual operating conditions. APPENDIX A.— IN-HOUSE BUREAU RESEARCH PROJECTS Research Area: Minerals Environmental Technology Research Program: Noise and Vibration Control From Surface Mine Blasting Research Center: Twin Cities Starting date Expected completion Funding, thousand dollars Project FY 75 fy1 76 FY 77 FY 78 FY 79 FY 80 FY 81 FY 82 Assessment of Damage From Blast-Induced Ground Vibrations. FY 75—7/1/74 Completed 60 175 Airblast Assessment and Control. FY 75—7/1/74 Completed 100 125 120 130 - - - - Evaluation of Current Method- ologies for Ground Vibration Measurement. FY 77—10/1/76 Completed — — 35 ~ ~ ~ ~ ~ Collection and Analysis of Ground Vibration Data From Surface Mine Blasting. FY 77—10/1/76 Completed ~~ 175 — "~ ~" ^ Evaluation of Noise-Measuring Devices for Airblast Transients. FY 77-10/1/76 Completed — — 35 _ ~ ~ — Determination of Criteria for Ground Vibration Damage From Surface Mine Blasting. FY 78—10/1/77 Completed — ~ 100 ~ ~ ~ — Control of Blast Noise and Vibration From Contour Min- ing of Coal in Appalachia. FY 78—10/1/77 Completed ~ " ■ 120 90 130 ' Fatigue and Structural Damage From Repeated Surface Mine Blasting. FY 79—10/1/78 9/30/84 — — — 100 100 75 70 160 Application of Abatement Techniques to Mine Environ- mental Noise Problems. FY 79—10/1/78 9/30/83 _ — ~ ~ 20 30 65 ~ Blast Design To Minimize Air- blast and Ground Vibration. FY 79—10/1/78 9/30/85 - - 50 90 120 130 Analysis and Technical Clarification of Ground Vibration and Airblast Standards. FY 80—10/1/79 9/30/83 20 20 50 Feasibility of the Develop- ment of a Precise Blast Initiation System. FY 81 — 10/1/80 9/30/87 - - - - - - 50 100 Total 160 300 365 330 290 305 455 440 ^Includes transition quarter. APPENDIX B. - CONTRACT BUREAU RESEARCH PROJECTS Research Area: Research Program: Minerals Environmental Technology Noise and Vibration Control From Surface Mine Blasting Starting date Expected completion Funding, thousand dollars Project FY 75 FY1 76 FY 77 FY 78 FY 79 FY 80 FY 81 FY 82 JO255022— Control of Vibration and Blast Noise From Surface Coal Mining. 1975 Completed 535 2 JO285029— Survey of Blast Dam- age to Water Supplies in Appalachia. 1978 1982 •~ "~ ~~ 267 — 31 — — JO206009 — Human Response to Blast Noise and Ground Struc- ture Vibrations. 1980 1982 ^ — — ■" — 202 121 ^ JO205020~Standards on the Measurement of Human Accepta- bility of Blast Noise and Ground Transmitted Vibration and shock. 1980 1982 10 10 J0100001~Technology for En- vironmental Noise Control in Surface Mines. 1980 Completed — — — — — 76 — — J0218020~Technology for Con- trol of Environmental Noise From Off Road Haul Trucks. 1981 1983 - - - - - 103 - - Total - - 535 - - 267 2 422 131 - ^Includes transition quarter. 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