Greetings Mile High Chapter,
Please join us for our first official meeting as the Mile High Chapter next Thursday, October 13. Our speaker will be Todd Loar with the US Army Corps of Engineers. Todd's topic will be "Harvesting Clay Core Material for a Large Dam from Leach Cap Rock within an Active Mining Operation." Todd's abstract is below. This month's meeting will be in Room 201 of the Colorado School of Mines Geology Museum Building, 1310 Maple Street, Golden CO 80401. Google map. Free parking is available after 5pm in Lot V next to the museum, on Maple Street, and in Lot S across Maple Street.
New website! The meeting information and reservation forms are currently double posted at our old aegrms.org website, and also at our new site at AEGMileHigh.org. If you're feeling adventurous, you can try out the new reservation form here, but the old one still works too. The new site needs a few edits, so please be tolerant of typos and minor inconsistencies. If you have feedback regarding usability and appearance, please email Jill at email@example.com. I am still trying to figure out how to make some of the form text bigger. The (outdated but easily searchable) newsletter archive will continue to live at aegrms.org until I have time to move everything over.
October 2016 meeting details:
Thursday, October 13, 2016
Conference Room 201
Colorado School of Mines Geology Museum Building
1301 Maple Street, Golden, CO 80401
Social hour begins at 5:30 pm
RSVP here -- deadline is noon, Tuesday, October 11, 2016.
(The old RSVP form still works -- here is the link)
Once you have submitted a reservation, please pre-pay here. The meeting cost is an additional $10 if paid at the door.
Meeting sponsors needed! Meeting sponsorships help reduce the meeting cost for all attendees. If you or your company would like to sponsor the October meeting, or any upcoming meeting, please visit our meeting sponsorship page. Meeting sponsors will be recognized in meeting announcement and reminder emails, on the AEGMileHigh.org website, and at the meeting. We will be revamping our sponsorship program very soon, and will probably begin offering chapter sponsorships that include recognition for the entire calendar year or September through May academic year.
Rocky Mountain Geo-Conference November 4, 2016 at the Denver Marriott West. Please join us for the biennial Rocky Mountain Geo-Conference, presented by the Geo-Institute of ASCE Colorado Section, CAGE and AEG. The goal of the conference is to enhance the technical knowledge of local geotechnical engineers and geologists in areas of current regional interest. Each attendee will receive a copy of the proceedings. The proceedings includes all peer-reviewed papers accepted for the Geo-Conference and is published nationally by the Geo-Institute of ASCE as a Geotechnical Practice Publication. Meeting details are available in the conference brochure and here is a link to geoconference information and registration.
Hope to see you on October 13,
The AEG-RMS Board and Editors
Harvesting Clay Core Material for a Large Dam from Leach Cap Rock within an Active Mining Operation
LOAR, Todd N., Senior Geological Engineer, USACE, RMC, Lakewood Colorado, USA, firstname.lastname@example.org
Between 2007 and 2015 a large tailing storage facility (TSF) was in design and construction for one of the largest and most productive copper mines in the world. The design consists of a 165m (541 ft) high rock fill Starter Dam with a central, low-permeability core and filter/transition zones that was completed in 2015. The remainder of the 310m 1,017 ft) high main TSF embankment is continually being constructed of compacted cycloned tailings underflow sand. Critical to the successful construction and operation of the Starter Dam is a central clay core composed of material that meets the engineering design objectives. Locating the required volume of suitable core material was a significant challenge throughout the project because there are little economically viable or suitable clay resources in the region. Ultimately, the core material was derived from hydrothermal argillic alteration zones of the granodiorite porphyry within the leach cap (i.e. over-burden) positioned above the economic ore deposit. The most suitable overburden material from the pit is relatively weak, has a higher clay alteration grade, and breaks down with mechanical energy and hydration into a clayey sand to clayey gravel (SC-GC) with the appropriate engineering properties for the dam core. These alteration zones within the mine are highly variable in their geological and engineering properties as well as spatial distribution throughout the active pit, and typically little geologic assessment is performed by the mine geology department in the leach cap zone since it has little economic value to the operation. Considerable geological characterization was required in addition to coordination with the mine geology, planning, and operations departments to identify and stockpile suitable leach cap rock material for the dam within the constraints and schedule of an active mining operation. This presentation describes the geological and geotechnical evaluation methodology, field procedures implemented, and coordination requirements for successfully harvesting suitable clay core material from the leach cap zone within an active mining operation.