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Rebuttal Report to Gerity Expert Report of February 2001 <br />completed. However, it is not true that the access was blocked. Ron Thompson (in his affidavit <br />of February ] 4, 2001, attached) stated that, during his normal duties, he visited the northernmost <br />face of Entry 7 many times between 1990 and the beginning of mine flooding in 1992. <br />6.0 UNPROVEN ASSUMPTION OF PILLAR PUNCHING HYPOTHESIS <br />Mr. Gerity justifies the alleged mine subsidence from 1997 to the present by assuming pillar <br />punching, yet no credible evidence was presented to support that assumption. The term "soft <br />floor" is often used to describe mine vehicles getting stuck in the mud rather than from floor <br />heave from pillaz punching. Communication with and an afEtdavit from Ron Thompson prove <br />that no pillar punching occurred in the 1N panel during the almost four years after the mining <br />ceased there. <br />6.0 SURVEYING PROBLEHIS <br />Mr. Qerity's discussions of the Mincic surveys contain several erroneous statements. Mr. Gerity <br />writes that "...the Basin survey (of 5/26!88) was not completed until after minim work in ]N <br />had akeady proceeded under the monuments. Subsidence could already have occurred before <br />the baseline was established." Although the first sentence may be fire, subsidence could not <br />have occurred then because the mine was kept open and maintained without roof collapse or <br />pillaz punching until at least 1492 (Ron Thompson 2001}. <br />The monitoring points alone the railroad over the 1N panel were surveyed in July 1993. They <br />showed downward movements of IN-] of .360 feet and of IN-2 of .460 feet since 1988- Whereas <br />the survey was conducted with an )<AyI instrument, it was decided to rerun the survey in August <br />1993 using the more accurate spirit level closed loop method. Mr. Gerity's statement that "The <br />results of this survey were identical to the fast in terms of surveying order of accuracy." is <br />disproven by his attached Appendix 7, which shows that in the second survey IN-1 was only <br />down .130 instead of .360 and 1-N-2 was only down .340 instead of .460. Even though the <br />second sun~ey should be the most accurate, Mr. Gerity continues to use the larger subsidence <br />figures as input to his models. <br />Wright Water Ergiaeers, ]nc. -2- 00]-361.OD0 <br />BOO d Scli 08C f0~ 131 (31h.M1 9311':11 i,H`!!1J.P. 9c'~l 1;3,IIIl0.Bi- 03~ <br />