The URL can be used to link to this page

Home My WebLink AboutCUP 9; South Coast Asphalt; Conditional Use Permit (CUP) (31)May 21, 1.976 CALIFORNIA DRILLING 6 BLk,smx COMPANY, rNc. 4 144 N. Arden Drive . El Montc, California 931731 Our Job 76-65 Soirt h Coc?r;t Asphg 1. t Prod.,rcts Csmpsny , Inc. Quarry Blast May 20, i976 Subject: Sei smograpkic Results Very truly yours, wiws COF~AN 6 F.SCCOFJ~ICE ohn J. McCormick -Civil Engineer 16211 Geophysicist 138 ' Geologist 2385 J JM : cm At t a c I1fn.s nt Two copies $ubrnitteed r. .. FOUNDATION BNGINREmG GKOLOGY 0 ENGINE E RING SEWLOGY w i ! f i i I I 1 f I t -- INTRODUCT 1 ON Earthborne vibration emanating from primary blasting in the South Coast Asphalt Products Company, Streuter Quarry, Carlsbad , Califarriia, was seismographically recorded on May 20 and October 6, 1976. Air blast vibrations were also recorded OR October 6. I. This investigation was performed in order to quantita- tively evaluate ground and air blast vibrations in terms of their capability to damage neighboring residential structures and other improvements in the area. This study was performed at the request. of California Drilling 6 Bl.asting Company which conducted the drilling and blast- ing operations. BLAST DATA ' Both quarry blasts were located in the northerly portion of the third quarry bench counted from the highest el.evatj.on in the quarry. Essential blast data are tabulated as follows: Rlas t Date May 20, 1976 October 6, 1976 Time No. of Blast Holes 125 97 Hole diameter, inches 3 3 Hole depth, feet 44 44 . Total Explosives, pounds 15,200 10,825 Milliseconds Delay Periods. 1-14 4-11 blaximum Explosives per Delay Period, pounds * 1,100 450 5:30 P.M. 6:30 P.M. I r i . -- Our Job 76-65 Page 5 INSTRUMENT LOCATIONS The locations of the instrumentation during this in- vestigation are identified as follows: .Description -I_ Location 1 2 .. 3 4 On asphalt paving, adjacent to curb gutter, opposite the southwest corner of the residence at 3661 Esplanade Street, Oceanside. On asphalt paving, at entrance to Shipping-Receiving dock area, Tri City Hospital I Occansj.de. On asplzal. t pavirig, ad.j acent to south- west corner of Seven-Eleven convenience store, 3704 College Boulevard. On concrete patio, adjacent to rear entrance of residence at 3741 Gail Driver Oceansi.de * . Air blast vibration instr~~mentation was yositi,oned at Location 4, opposite from the open quarry bench containing the blast. INSTRUMENTATION RESULTS Seismographic results are tabulated as follows: Seismograph Particle Velocity Blast Location (inch per second) Maximum . ~ May 20 'May 20 October 6 October 6 1 2 3 4 0.14 0.04 0.08 0.02 s. --- c Our Job 76-65 2: Thc peak sound pressure level recordcd, Location 4, was 'r: !, . 126 decibels. This blast overpressure, 0.0074 pounds per square inch, corresponds to a. wind gust vel-ocity of approximately 16 miles per hour. HUMAN RESPOiiSE TO VIBRATION . l__ll..--_l_-- I_ . The human body is sensiti.ve to all forms of vibration. It is not relia.hle, however, as a quantitative measuring device. Personal evaluati.011 of ground 31' buil.ding vibration depends on the displacement the frequency,. t:he direction of the vibraticri, and the activity and the temperarnent of the indivi.dua1. In order to illustrate the relative magnitudes of vi.b-ration in their gen- eral p e 1- s p e c t i. ve as rela.ted to hurnan respnse the following scale is included for ve 1- t i c a I vibration when at. he sub j ec t is s t and i n.g : Perccptible to some Perceptible to most We 1 1 no t i ce a b 1 e Unpleasant Di s turhing Objectionable 4 units 7 units IS units 30 units 50 units 60 units Plaster cracks (contributory) 100 units The eva 1 u a t ion of vibration is influenced what a person hears. Ground vibration accompanied by blast noise is generally judged to be more iniense than ground vibration not accompanied by noise. ._ -... . -- Our Job 76-65 Page 7 coNcI,us ION Ground and air blast vibrations measured during this investigation were well. within safe limits as concer:lls the well- being of all improvements in the area surrounding the Streuter Quarry. Plates 1 through 4 are attached and. complete this report. JJM: cm Respectfully submitted, EVANS, GOFFYA1.I 6 McCORFlICK ... Aohn JI McCormick 1 3 8 Civil Engineer 16211 Ge o phy s i c is t Geologist 2185 I 'F. -.