When an explosive charge is detonated, chemical reaction occur which, very rapidly changes the solid or liquid explosive. Airblast and ground vibration are discussed along with methods for evaluation and control. A complete copy of rock blasting and overbreak control is available free of charge in adobe acrobat pdf format by following the internet link. The topic is covered in more detail in the fhwa manual rock blasting and overbreak control. University of rizona mining and geological engineering. Initiations and timing effects as well as patterns are also discussed. Following are the techniques of controlled blasting. The oregon department of transportation is providing the short course rock blasting and overbreak control on october 3rd through 5th at their flanders office in portland, oregon. University of rizona mining and geological engineering rock excavation mne 415 515.
This reference may be obtained free of charge in adobe acrobat pdf format through the fhwa at the following. Limiting of overbreak with good perimeter blasting cautious blasting practices such as presplitting and smooth blasting are well known e. The blasting team was provided with such information to be well equipped for blast control in such areas. This handbook is specifically designed as a guide to highway engineers and blasting practitioners working with highway applications. Tagged blasting, blasting techniques, controlled blasting techniques, mining leave a comment. While stemming is typically put in the top of a blast hole, it can also be. Only the most naively optimistic amongst us would claim that the end of the road has been reached and that the subject has matured into a fully developed applied science. The detailed requirements for design of rock cuts provided in fhwa hi99007 rock slopes reference manual munfakh, et al. Drilling and blasting an overview sciencedirect topics. There is a tendency to consider mine tunnels as temporary access ways, but how many mines are using tunnels that are thirty or.
Line drilling a method of overbreak control which uses a series of closely spaced holes that are not charged. Loading density the weight of explosives per metre of. Mechanism of rock breakage while release of explosives energy upon detonation and other relevant points are discussed below. Emuline is a continuous length of emulsion packaged in tough film cartridges with an. Many of the figures and specification concepts originated from the rock blasting and overbreak control manual. Explosives are energy, and the efficient use of this energy is a major factor in keeping rock blasting costs under control. Rock blasting and overbreak control drilling nature. Pdf rock blasting and control overbreak yuri garcia. A new measure of explosive energy, the perimeter powder factor. Pdf causes, impact and control of overbreak in underground. Predictions of overbreak blocks in tunnels based on the. This class is designed for engineering geologists, geotechnical engineers, and construction inspectors.
In such operations, flyrock control is of high importance especially due to safety issues and the damages it may cause to infrastructures, properties as well as the people who live within and around the blasting site. Causes, impact and control of overbreak in underground excavations article pdf available in tunnelling and underground space technology 201. It was used as a handbook for the fhwa courses of the above title. Blasting is an economical method to break rock, but t he consequence of blasting is damage to the perimeter of the opening. The most important of these is the increased worker and equipment exposure to potential rock fall hazards. Understanding the connection between blasting and highwall. Engineered blasting agents, not dynamite account for 99% of explosive material used. The 5th edition of rock blasting and overbreak control by dr.
A guide for highway engineers and blasting practitioners working with highway applications. The original version of this book was written in 1983 for the federal highway administration. Techniques of controlled blasting linkedin slideshare. Participants at the conclusion of the class will be able to. Blast damage control reduces scaling time and dilution, allows easier. The handbook is specifically designed as a guide to highway engineers and blasting practitioners working with highway applications. Line drilling, trim cushion blasting, smooth contour or perimeter blasting, presplitting, selecting and employing various parameters of blast design, using modern technology, precise and accurate timing delays, muffle blasting at critical and congested areas. This book was updated and launched in 2015 to include the newest information available in the explosives and blasting industry. The primary objectives in rock blasting are to optimize blast performance and ensure the. Investigations at the aquamilpa hydroelectric project in mexico have shown decreased overbreak and increased underbreak as a result of increased rock quality and decreased explosive energy. Highenergy explosives enhance fragmentation, which ultimately produces a positive effect on production. Controlling the adverse effects of blasting this module addresses the control of offsite impacts that result from blasting, namely.
However, there are other issues related to bench stability, and future blast performance based on the amount of overbreak occurring during a blasting operation. Advantages emuline is a continuous length of emulsion packaged in tough. Conventional drifting or tunneling by drilling and blasting method requires a much higher specific charge than ordinary production blasting such as bench blasting. The use of vent holes or vent pits may also be necessary. Report date t i t l e and subtitle december 1991 rock blasting and overbreak control 6. Common question during mining and tunneling operations is whether overbreak has been caused by blasting practice or poor rock mass quality. Rock blasting and overbreak control fhwahi92001 a slideshow presentation has been provided for the participant to. Anfo ammonium nitrate mixed with fuel oil is the most common product. Pound for pound anfo is a more effective explosive. Modification of blasting procedures should include limiting the size and frequency of blasts to limit the production of noxious fumes, and stripping of the overburden prior to blasting and excavating the shot rock immediately after blasting to allow the venting of gases. Blasting damage in rock introduction the development of rock mechanics as a practical engineering tool in both underground and surface mining has followed a rather erratic path. Observations should be aimed at providing insight into. Types of blasting primary type of blasting will be for ditch excavation. To simplify the work, rock blasting is the easiest way.
Overbreak and underbreak in underground openings part 2. Control and reclamation act of 1977, upon which their state surface coalmine. Rock blasting and overbreak control 2006 edition open. A fuzzy rulebased approach to address uncertainty in risk. In addition, for the development of blasting plans for rock cut excavation, the fhwa manual entitled rock blasting and overbreak control,fhwahi92001 konya and walter, 1991 shall be used. In portal area, overbreak was minimized by preexcavation treatment of rockmass through fore. Chapter 19 blast design introduction this chapter is an introduction to blasting techniques based primarily on the explosives and blasting procedures manual dick et al. Toward this aim, a blast design software tool was completed in collaboration with the colorado school of mines and hustrulid mining services.
Geometrical parameters of structural plane are first obtained by field survey. Rock blasting and control overbreak fhwa us department of. Pdf drill and blast system is used in hard rock excavation due to its economics and adaptability to changing rock mass conditions. In this video anthony konya of explains stemming and stemming calculations. Rock blasting and overbreak control national highway institute technical report documentation page 3. The typical method of drifting is to drill and blast. This section only covers the basic concepts of rock blasting. Stemming for blast holes academy blastingacademy blasting. Excessive amounts of overbreak on a rock face can cause several issues. Much of the information in the module is derived from the surface mining control and reclamation act of 1977 smcra.
Blasting will take place along the ruby pipeline project rightofway. Strict control of the environmental impacts of blasting operations needs to be completely in line with the regulatory limits. For example, the specific charge at tunneling is 310 times higher than at bench blasting, depending on borehole deviation, tight holes, lift of the. You are all aware that mining is a major economic sector of any country.
Rock blasting and overbreak control free ebook download as pdf file. The economic analysis of the use of explosives is an important part of blasting operations in mining and construction. The project aim was to provide industry and mine research institutions with detailed information on perimetercontrolled blasting and blast damage models that support perimeter control design. Predicting overbreak blocks is a valid way to protect constructors, safeties in the process of tunnel excavation. Tempat belajar semua engineer teknik sipil indonesia anda bebas untuk mendownload ebook, software dan tutorial tentang teknik sipil anda juga bisa mendapatkan info terbaru tentang lowongan kerja dan ilmu teknik sipil all about civil engineering.
It is anticipated that this may occur anywhere along the rightofway. Zongxian zhang, in rock fracture and blasting, 2016. Image from rock blasting and overbreak control, fhwa, 1992. Federal highway administration national highway institute u. Ruby pipeline, llc plans to blast only in the areas where the rock cannot be economically excavated by conventional means. Several examples are given to help simplify calculations with some stepbystep procedures. Rock and mineral identification for engineers 1991. It was used as a handbook for the fhwa course of the above title. Stemming is a material that is put inside of a blast hole to help prevent gases from escaping. In this paper, a prediction method of the overbreak blocks in tunnels is developed in the frame of the wavelet neural network of geological statistics models. Chapter 12 rock cut design washington state department. The newly developed light sectioning method has been used to investigate some of the causes and costs of overbreak and underbreak.
Reflections on the functionality of presplit blasting for wall control in surface mining rock fragmentation by blasting, fragblast 10, proc. The damage results in overbreak or rock that was not designed to be removed, loose rock to be scaled, and permanent damage to the remaining perimeter. Measurement of blast damage office of surface mining. In order to achieve the optimum blasting results, it is of paramount importance. Balasubramanian centre for advanced studies in earth science university of mysore mysore6 2. Prevention and control measures different measures were adapted to control geological overbreak, in particular, by preventing secondaryoverbreak. In classification and development in grade control blasting for surface mines fragblast, trevor little, director and principal consultant.