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6 <br /> E l...i..18!. al <br /> N <br /> f <br /> T <br /> 442.000E •,, <br /> y 542.505N lv t`., 465.000 E <br /> {562.500 N <br /> 6 --- - <br /> 0 400 f17 12i tbf` 14 <br /> Se33.It pd LAI 3 <br /> ? lo. J—I <br /> Scats.m <br /> KEY <br /> • Closest Dta4rndo for oath slot <br /> -� Fonce around tNDWne Aoki <br /> • 111110‘01606132102 <br /> o Oudtne 01 ovaa,rdon asst <br /> o Outline or parting bleat <br /> Figure I. Minnehaba mine pipeline test area and production blasts monitored <br /> Strains <br /> t o , t —I r r r r i r <br /> Figures 6 through 10 show a variety of compar- 4. 0 &Inds <br /> isons of measured strains and surface ground vibra- I. 8- ° 20 C3 - <br /> tions. These are obviously not the only correlations 1 7- 0 - <br /> possible out of 34 total independent channels and, In 11- - <br /> some opinions, not the best choices. The SwRI 11,- <br /> authors calculated stresses from blasting parameters 1 2- 0 • <br /> - <br /> (explosive type, amount,distances, etc)and believe 2L 0 <br /> _ <br /> that particle velocities will not consistently be relit- t- i`� <br /> ed to strains (end stresses). The Fig. 6-10 plots sug- t r L <br /> a 2 4 4 4 10 12 ti If If 20 <br /> gests that rough correlations with velocities or at Gnu.°n°a.T,cr,.atctg.i <br /> Figure 5. Ground and pipeline vibrations <br /> GROUND VIBRATION DATA,.AMPLITUDE 2.0 Ws:1 - <br /> I iy l 1- least maximum envelopes covering all the highest <br /> �,i v'` Surface.von,� measurements are possible. Alternatives could be <br /> direct pipeline vibration response, conversions of <br /> - 1j\flAf\j‘e -- Sumacs,radial velocities to displacements, computations of stress <br /> and strain propagation equations, etc. The authors <br /> anticipate future examinations of alternatives, <br /> PIPELINE STRAIN DATA,AMPLITUDE 50 Az:, Strains are relatively high for the PVC pipeline by <br /> 4 contrast with the steel, consistent with its lower <br /> 1•1 PVC TopbnglttQad stiffness. If the pipelines were all fully coupled and <br /> moving with the ground, this difference should not <br /> 6Inch,Front ion gitudnd exist. This problem will be examined in more detail <br /> in the follow-up comprehensive report. Generally, <br /> eAndt.Top draMa/rttW similar measurements on the steel pipelines gave <br /> &Inch,Top,onot>ud,n,I similar amplitudes (e.g, front Iongitudinal measure- <br /> merits). Circumferential strains were often, although <br /> 12-rxh.Top longhudnd not always, the highest, particularly when measured <br /> 20lnds,Top drevmlenm d on top compared to on the side. <br /> Compared to previous studies, strains were rela- <br /> tively low for given particle velocities. The large <br /> vveich.Toplonpin,oInal blasts involved in this study; produced high particle <br /> velocities at relatively large distance. Hence, the <br /> 00 °'s to to 2'o pipelines experienced high vibration amplitudes at <br /> TtME,sot distances beyond the inelastic zone. In addition, <br /> Figure 4. Vibrations and strain time histories <br /> for blast No. 25 charges are in blastholes, bein2 vertical co]J2 ^.s <br /> , which are long compared to the closest blast to <br /> 35 <br />