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1 <br />t Vieria-TECHr <br />f ; '~ ~,' l .~i 7'I! ),~`,C /ur AIIlRL: L~ I' Ot'/i R/'Rli.``'~J '121'~.ti <br />' f!: (;SAM has camcluded in its RI-8485 (Structural Response and Damage Produced by Airblast <br />~~~n!i Suli:ue Mme's), bascxi on a minnnal probahilny of the most superficial qpc of damage in a <br />' r.~i,lrntinl-q~1x structure, any ol'the li,llowing represent safe maximum arrtrlast overpressure Icvels <br />Lower frequency 1-imps of Mcasunn ~ S stem Maximum Level m d6 <br />' 0.1 Ilz high-pass system 131 dli <br />Fiz high-pass system 133 dB <br />r~r (~ hi~~h-1,a+ti st ~trm 129 d[i <br />~-~~+~~ ~i',~rlrt~ n~;l C\~::~:~Iu!;.' .~. v:: ~Ilir:lhon) tU5 dE3 <br />I i~surc I <br />' I h~ ~ ila;,- I r~ h I , rrlen ~~~ ~~ ~~ ~ V ulu~: i, ~ F u~rlcrt ~'c anJ 111 Seismographs have a 2 f-Iz high- <br />I,.r~~ >ystent, thus the recanuncndcd wlc lunn uuhr.ing this system is I? ± dl3 <br />~, !,'l~.;N~/AL UA~41AI ~l': h}~:1IHBl.~I~~T OI`1:721'IUiStif iRf:' <br />structural damage as a result of air overpressure is generally accepted not to t+e lx~ssible without <br />' r\trnsive windo+v breakage, as the glass is the weakest portion of a structure's exterior where <br />Diu. rressure acts. Windowpanes are designed to safely withstand changes of I 0 Ibs~rn` (psi) <br />i 17u dli) when properly Installed, and even in the worst situation u pane should he able w <br />' ,~~thstand 0.1 psi 1150 d13) .4ir overprossures from blasting rarely exceed 0.(11 psi (130 d131, <br />;rppruxlmately one one-hundredth of the overpressure that a window can safety +vithstand. <br />' _ Airblaat Levels _ __ ___ _ Results - - <br />1 15 dR Complaints likely <br />120 JB StnnGng <br />128 dli Bureau of Mines 'safe' level <br />135 dg Bureau o(' Mmes maximum <br />' 150 dB Pcxxly installed windows can break <br />170 dl3 Most windows will break <br />ISO dli Structural damage <br />I,ti~~~~ <br />1 <br />1 <br />