By: Steve Johnson

Steve Johnson — Tue, 19 Mar 2024 04:32:14 +0000

I looked at some of the geotechnical reports prepared for review. The reports provided geometric forms and locations of mine waste. There was no attempt to provide a detailed geotechnical design for the waste pile. My understanding of the administrative replies to the proposed design showed absolutely no sign of an understanding of geotechnical waste pile design. The responses I saw just assumed catastrophic failure of the geometric form. I was actually agast. Hopefully somebody attempted to discuss designs. My concern would be the introduction of internal ice and internally perched water from snowmelt. Usually these things are designed with flat tops and standing water. In the municipal/hazardous waste disposal world such designs would never be allowed because of the chance of slope failure. There are examples where snowmelt did create perched water tables internally and did cause failure of waste piles. I was very critical of Vale’s designs from a soil mechanics standpoint (after the failure) and of course the company and the community paid a price. Indeed, the whole problem swept over the world like the BreX scandal. All sorts of issues appeared and allowable designs were no doubt reconsidered. I can only hope somebody has proposed reasonable geotechnical designs but who knows how far they went. I’m sure Bingham’s waste pile failure did no good re-assuring anyone of the merits of geotechnical design. What can I say…keep the slimes out and don’t let them form. Perched water tables are not to be allowed….I am inclined to think there are ways to address self consolidation and generation of authigenic clays that facilitate the buildup of internal porepressures….one can only hope.

By: Ismail Umar

Ismail Umar — Tue, 19 Mar 2024 04:20:46 +0000

Mining is on going

Comments on: Pebble mine developer sues EPA over Alaska mine veto

By: Steve Johnson

By: Ismail Umar