2010-11-12_REVISION - M2009076 - Laserfiche WebLink

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? - C We have presented a design here to adhere to these newly prescribed requirements. Venture Resources has gone far beyond what the Hardrock Rules and statutes require to satisfy the additional requirements asked of us by the DRMS. We feel that these additional requirements are extraordinary, but Venture Resources has elected to meet them inorder to compromise. We are serious about our business venture and reaching a rational engineering solution. Venture Resources has been working carefully with a leading geosynthetics manufacturer, Synteen Technical Fabrics, to develop a design that incorporates geogrid into the Tailings Impoundment to increase stability. Synteen's analysis considered multiple scenarios to model the Tailings Impoundment stability incorporating their SF350 Geogrid product. These scenarios looked at both saturated and un-saturated states in both static and seismic conditions. Multiple levels of Tailings Impoundment buildout were also evaluated: buildout through Bench #2 and buildout through Bench #5. Below is a table summarizing the newly reported factors of safety at these varying conditions (to be found also in Exhibit C, Rev. 2): incorporating S nteen SF350 Factor of Safety Factor of Safety Geo rid Reinforcing Static Analysis Seismic Analysis Un-Saturated Conditions Buildout through Bench #2 Z.10 1.47 Buildout through Bench #5 Z07 1.44 Saturated Conditions Buildout through Bench #2 1.67 1.10 Buildout through Bench #5 1.52 1.02 This clearly illustrates that the proposed design does indeed meet the un-saturated factors of safety prescribed by the DRMS on November 8s', namely: Un-Saturated Tailings, Static Conditions - minimum Factor of Safety = 1.5 Un-Saturated Tailings, Seismic Conditions - minimum Factor of Safety = 1.1 Perhaps more importantly this also illustrates that considering saturated conditions the factors of safety are also largely met. The Synteen SF350 geogrid is to be incorporated incrementally into the Tailings Impoundment in horizontal planes at a vertical spacing of 10' lifts, with the exception of Bench #3 which is to be spaced at 5' lifts. Refer to the attached revised Exhibit E Drawing E 11 for an illustration of this. The incorporation of geosynthetics into this design brings forth applying the latest technology and proven engineering practice to bolster the stability of these types of upstream raised tailings impoundments. Applying this technology should eliminate unfounded fears of failure. Advanced Terra Testing, Inc. (ATT) performed a series of Consolidation Tests to also look at tailings density characteristics during consolidation. ATT utilized ASTM D-2435 standards for this. The Coarse Fraction and Slimes Fraction were prepared to a 30% pulp density to mimic the target tailings discharge from the mill down the tailings pipeline. The results of this are as follows: Page 2 of 5