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J ~P;TP~UM & RSSOCIRTES TEL ~ 7]i-995-7191 <br />sss <br />O~ <br />TO: Dr. Jesse Crag <br />Jun 06,~ 108 Mo:007 P.03 <br />DATE: June 6.1986 <br />FROM: C. E. f3erity <br />8U'B.iSC1: Tatum house Subsidence <br />Clarification of Some Items of Discussion for the Record / <br />For the reoor+d I would llke to clarify a few items: <br />Today I talked to Michael Karmie of the Department..of Mining and Minerals <br />En Bering, Virginiei Polytechnic Institute and~t3tate University to reconfirm our <br />earlier ooaveraatione. He noted that my reoolleatibn and notes were essentially as <br />he recalled them. This includes the unknown effect of water, and the conservative <br />extreaF3on rate, while using the room and pillar method of the Pra$le F~nation <br />Formulation; the "angle of draw", which he eaid:could reach 90°; and the "angle of <br />influence" a8 defined in the $DP8 Users Manual, which is based on empirical data. <br />Farther discussion on this su4iect iadfoated that there were other "angles of <br />in0ueaoe" which would be ].ens than the "eagle of draw" ,except a hydrologic "angle <br />of influence" which could reach 40° or more, presumably measured on the same <br />basis as the "angle of draw". <br />We, also discussed the appmpriatsnese of using the PrnSle Function Formulation to <br />calolilate the effects of mining, longitudinally to the.mining direction. It wan <br />confirmed that the program is not designed for this purlws'a, but for transverse <br />calcnlationa. <br />During our meeting on May 113, yrou stated that the memos written by Mr: <br />Roeeathal gad Mr. 8aadberg, which clearlq showed that they both used the Profile <br />Function Formulation, were correct, please ezplain this: <br />At the same meeting you stated that nay analyeit: was .wrung; speaficelly the use of <br />the term "angle of influence". There ie apparently eome.oontradictaon in the <br />meaning ae it used on page 4 of ray memo, since it ie.messuzed from a diflbrent <br />r~eferenoe than the "angle of draw', in the seneo of the USBM "limit angle"; however <br />the use of the term on page 6 is exactly ae defined is the software desaript8on. <br />Generally it is not a term that is widely used is western mine studies. Please <br />explain how the potential different use of the .tertr- makes the analysis wrong. <br />,_•. -.. <br />Dr. Kohl, during his site visit, stated that ia; Q;' ` in;od; that the use of the SDPS <br />ly ' ppropriate, yet you;q~e mathematical solutions <br />software was entire inn <br />ertensively. This discrepancy needs to be~.clsrified~: <br />Finally, the SDPS software Users Manual di~ouees at length the fect`that the <br />parameters used were based on eastern oQal~mine data and that it may not be <br />appropriate to use in a western noel miningmodel without checking with empirical <br />data or parameters. <br />PION[tRINO faNi1N[tRINa aCml.T..Alfwn6~ <br />COMiYLr7M0 tNifwtf,ts 1Jx6aq, COdOL?I <br />