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HomeMy WebLinkAboutMiscellaneous APPLICANT 4/20/2004 J . I ,. . , I' Explosive ~ T eChnical~~ Service .~~ BLASTING PLAN, MOUNTAINGATE PROJECT, , SPRINGFIELD, OR ' Portland, Oregon April 20, 2004 -1. -7JYrY oate Received: J L ,,/Ldfl p\anOer. { oJ'1-l'''';o"f&uU ~~cU~A This plan is offered as a practical approach to blasting in a recognized urban area. The intent being to accomplish the reclamation of an abandoned quarry by turning it into home sites with an adjacent neighborhood park. The blasting necessary to gen~erate this task will be highly controlled and done in a safe manner that does not endanger the citizenry or damage the surrounding residences. Critical to this program is the need to communicate and cdoperate with the neighbors residing in the . imniediate surrounding residential neighborhoods! . I , The following conceptual blasting plan has been developed to comply with the following applicable construction blasting statutes; CFR 29, Part I 926,ISubpart "D". In Oregon; OSHA, Chapt. 17, 1910.109 and 1926.900 and OAR Chapt. 437 subdivision D, OAR 480-10 and the the NFPA Explosive Code. The City of Springfield DeveloJment Code, Article 24 for Quarry and Mining operations, while not relevant to the proposed codstruction operation, will be observed to the extent possible The State of Oregon does not have blasting licenses and does not certify blaster competencies. Mr. Kris Jeremiah is certified by the Oregon State Fir~ Marshall to possess explosives, is experienced in urban blasting techniques and will serve as the Blaster-in-Charge for this project. Blasting will be done in the reclamation process where it has beed determined that the presence of solid rock precludes reasonable excavation by mechanical rrieans. . . I This conceptual blasting program is designed to De very cautious and conservative using only the minimum amount of explosives necessary to fragbent and displace the rock while containing it within the designated work area. This plan focusbs on the safe control of the overall drilling and blasting operations as well as careful compliancelwith both the letter and intent of plan and is intended to serve as a guide for subsequent individual blast specific shot plans. Blast hole explosive loading will . be designed an~ calculated to achieve powder factors (pounds per cubic yard) between 0.95 and 1.15. Particular attention will be afforded to; controlling throw rock, . controlling ground motion to below threshold lirriits of damage to residential buildings and controlling blast generated air overpressure and ~ound. Prior to the start of blasting activities, all residenls living within 500 feet ~fthe blasting will be advised by letter of the intent to blast and residerices within 250 feet of the blasting will be offered, at no cost to them, a third party preblast inspecti6n of their homes. The letter will advise the .'. . I (503 )644-7544 12010 NW Lovejoy, Portland, OR 97229 FAX (503) 643-4961 - , . , e-mail etsIOO@comcast.net . . ~ f residents of the programs duration and the contractors practices designed to minimize any adverse effect to their homes from blasting. The letter will give a contact telephone number for residents to call should they have concerns about the blasting. . SCOPE The'bhisting.will be directed toward: . . -.."- '-_~l-'"""u;~,.;" _I',. . ~ I. -The flattening of existing todh:i.1t faces to generate intermediate benchs and create slopes not to exceed r vertical to 1-Id'hCiHzohtal. 2. The creation of a storm water retention basin. Vertical blast holes will be three (3) inches in diameter and will be drilled in depth to the proposed elevation of the cut plus a nominal 2 to 3 foot subdrill depth. For site grading, the holes will be drilled on an offset square pattern with spacings of 5 to T feet. At the perimeter rock cut faces, "a perimeter control blasting method will be used. For utility trenching, the excavation width will be equal to the pipe diameter plus 2 feet. Two reduced size test blasts will made to determine the seismic and physical characteristics of the " "rock. These shots will be thoroughly monitored and will be "used to calculate subsequent blasting parameters. Prior to the commencement of drilling, the City of Spring filed will be advised of the timing and area of the proposed blasting activities. " ROCK / BLAST ABILITY The soil overburden that covered the site in the working area of the old quarry has been largely removed by quarrying operations. The underlying rock appears to be largely composed of fine grained dense basaltic rocks that have been fractured and slightly uplifted. In-s"o-far as blasting characteristics are concerned, the rock will require powder factors (pounds per cubic yard) estimated " to be in the range of 0.95 to 1.15 for bench blasting, depending upon cut depths. Upon blasting, this rock will typically displace on the joints rather than fragment when not in dose contact with the explosive column. This formation is largely unweathered and appears to have tight fractures and joints. Drilled holes can be expected to intersect shallow ground/surface water if drilled during wet seasons. The relatively shallow depths ofrock cuts in this project will increase overall shot rock sizing as the explosives in the rock will be confined to the lower portions of the blast holes. This will be done to control fly rock and noise. RECORDS & REPORTS The blasting activity will be thoroughly documented using industry standard blasting reports. Note attachment. Page 2 of4" J . . " SEISMIC AND SOUND MONITORING Seismic and sound measurements will made by two (2) currently calibrated blast monitors. The results ofthis monitoring will be incorporated into! the blast reports to better'evaluate ground response to blasting. A summary analysis of the blasting covering all shots will be prepared and made available to the city as will all blasting doculnentation. EXPLOSIVE CONTROL No explosives' will be stored at this site. Explosive requirements for each blast will be delivered to the site in a placarded truck that meets all federal imd state regulations for the transportation of explosive materials. The truck will either stand-by during the loading or return to the site to . remove any unused explosives at the end of the shift. . . . . I BLASTING LIMITS The volume of rock blasted any single shot will not exceed 5,000 cubic yards. The weight of explosives detonated in any discrete 8 ms time pehod will be restricted in order comply with contract vibration and noise provisions. The data!obtained from the initial test blasts will be used to make this determination and a scaled distance val~e will be calculated for subsequent shots. I . BLASTING PRACTICE Stemming will consist of dry granular crushed mineral aggregate (+ 1/4, - 1/2) material placed on , top of the explosive charges. Care will be taken iio assure there are no voids in the stemming column and the top of the stemming material extends to the surface of the rock. Through the use of a consistent depth stemming iaterial placed over the explosive column, accurate drilling practices, and consistent hole initiation tiking practices, noise from blasting will be . minimized to an acceptable level. No unconfined detonators or explosives will be pennitted in the , blast. Detonating cord trunk lines or pigtails of down-the-hole detonating cord will be covered by a minimum of 10 inches of granular non organic niaterial to mitigate blast noise. In situations where the Blaster-in-Charge feels hl is unable to control fly rock within acceptable levels, additional material will be brought in to cbver the blast or blasting mats will used. BLASTING SITE CONTROL During the loading of explosives and the subsequent blasting, the number of personnel pennitted on the shot area will be restricted to the absolute mihimum number necessary to accomplish the task. . Non-employees, with the exception of regulatorY personnel connected with the project, will be asked to leave the blast area. Page 3 of4 .- . , Individuals not connected with the project will not be permitted to observe blasting and blasting will only be done after guards have placed on all access points and the Blaster-in-Charge blaster has determined the area is clear of people. No blasts will be made during periods when school busses are scheduled to be passing through the area. The owners of overhead and subsurface utilities that are not within the scope of the work but that might potentially impacted by the blasting will be advised priorto the start of blasting. Every effort will be inade to control blasting operations in orqer not to adversely affect them. Following a blast, the blast site will be thoroughly examined for any unshot explosives and, should any be found, they will be removed from the site before the end of the day. . EXPLOSIVES The primary explosive type used in blasting will be 2" diameter cartridged dynamite, 2" diameter cartridged emulsion explosive supplemented with blasting agerits when appropriate. The nonelectric "Nonel" millisecond delay initiation system will be used exclusively and there will be no exposed detonating cord used in the blasts. dick daniel cc: BJ Equipment Co. Page 4 of4