settlement of decommisioned tailingsdam
settlement of decommisioned tailingsdam
(OP)
Hi All,
I am involved with an interesting project.....
A client wants to build light structures for energy generation on large 40+ hectare area 60m high decommisioned gold tailingsdams (slimesdams).
The dams have only recently been decommisions and although the surface is dry the dam below is still very wet.
How would one go about calculating the settlement over time of the structure?
I first want to determine if the project is feasable before I allow detailed investigation.
Anny and all feedback will be appreciated.
I am involved with an interesting project.....
A client wants to build light structures for energy generation on large 40+ hectare area 60m high decommisioned gold tailingsdams (slimesdams).
The dams have only recently been decommisions and although the surface is dry the dam below is still very wet.
How would one go about calculating the settlement over time of the structure?
I first want to determine if the project is feasable before I allow detailed investigation.
Anny and all feedback will be appreciated.





RE: settlement of decommisioned tailingsdam
I'd also jam CPT and DPT profiles at a few locations.
Then I'd run some numbers.
f-d
¡papá gordo ain't no madre flaca!
RE: settlement of decommisioned tailingsdam
RE: settlement of decommisioned tailingsdam
I'd consider using the DPT and I'd also install a few real piezometers.
f-d
¡papá gordo ain't no madre flaca!
RE: settlement of decommisioned tailingsdam
RE: settlement of decommisioned tailingsdam
RE: settlement of decommisioned tailingsdam
The dam itself should ALWAYS be wet and any settlement must not change this condition. I would be very hesitant to disturb the core of this dam with anything resembling a single pile.
RE: settlement of decommisioned tailingsdam
tailings placement is uncontrolled and not compacted. method of placement (cyclone, spigot, point discharge) can vary, pulp density, water content, specific gravity and gradation of the tails and slimes can vary from time to time. The result is unpredictable variability in the density, gradation, voids and water content of the in-place tailings. I would say there is a high possibility of differential settlement and 8 mm is not much room for error. the end result is that O&M will be required frequently to monitor settlement and adjust / level the structures in order to account for the settlement. This could be a deal killer.
RE: settlement of decommisioned tailingsdam
I'd still have a cone or dilatometer for soundings of soil strength and such.
f-d
¡papá gordo ain't no madre flaca!
RE: settlement of decommisioned tailingsdam
The dam has been decomossiioned and are going into rehabilitation so the only fluids that wil be added to it is rainfall. over time it will settle and compact and the settlement will decrease. This is why I want to determine the settlemant for over say the next 5 years to determine when it will be safe to construct the solar farm on the surface. The client wants to start ASAP but I feel it will have to wait a few years. I just need to work out roughly how long.
This is a LARGE tailings dam ~440 000 sq m. and the generating potential planned for is 40 MWp from PV, so reconstructing a soil raft is not an option.
RE: settlement of decommisioned tailingsdam
Maybe this is not the site for the project?
f-d
¡papá gordo ain't no madre flaca!
RE: settlement of decommisioned tailingsdam
RE: settlement of decommisioned tailingsdam
It will probably be desirable to grade the site to drain the rainfall off rather than maintaining ponds. This will accelerate settlement and facilitate development.
You could consider using a rolling surcharge to hasten settlement, eliminating the large early settlements from consideration.
Be sure the dam and pond are stable before placing a big investment on it.
RE: settlement of decommisioned tailingsdam
RE: settlement of decommisioned tailingsdam
Regards,
DRG