In the construction of containment dams and embankments on waterlogged foundation soils, the key challenge is to increase the bearing capacity of the foundation and reduce the consolidation time.
The core element of the technology is a vertical strip geodrain СТО 56910145-046-2021, consisting of a flexible polymer core enclosed in nonwoven geotextile, which protects the core from soil particles entering it. The geodrain reduces excess pore pressure during embankment placement.
The vertical drainage technology involves several stages.
1. Construction of a working platform from drainage soil with a permeability coefficient Кф ≥ 3.0 m/day and a thickness of 800 mm beneath the dam foundation. The working platform may be reinforced with high-strength woven geotextile; in this case, its thickness can be reduced to 500 mm.
2. Installation of geodrains across the entire foundation area using Stitcher attachment equipment mounted on a tracked excavator, through the working platform, with the drains inserted into the soil to the design elevations by static pressing.
3. Installation of monitoring sensors to determine when the design pore pressure value has been reached.
During the installation of vertical drains, the gradual stabilisation of the foundation soil over time is analysed under the pressure of the structure under construction, as well as the time required for dissipation of the excess pore pressure generated during loading.
The relevance of vertical drainage technology is confirmed by the successful construction by Russian mining companies of containment dams on water-saturated soils in regions with short construction seasons.
The specialists of «ТЕХПОЛИМЕР» are developing this area and propose transferring successful global experience in foundation stabilisation using geodrains to reclamation or decommissioning projects, specifically by using vertical drainage technology to increase the bearing capacity of «tailings» and subsequently construct a dump or cake storage facility on the allocated land of the decommissioned ГТС.
Using software and calculation packages, and based on high-quality engineering-geological and hydrogeological surveys, the specialists of «ТЕХПОЛИМЕР» can forecast the potential height of a future dump (storage facility) in a tailings storage facility cell with a specific geodrain layout.
Storing cake on allocated land within former operating tailings storage facilities will enable increased mineral processing volumes where free space is limited.
Implementation concept:
1) construction of a temporary road by placing overburden material across the cell;
2) installation of vertical drains beneath the cake storage facility;
3) stabilisation of the «tailings» and, consequently, increased foundation stability;
4) gradual placement of cake on the allocated land of the decommissioned ГТС.
The specialists of «ТЕХПОЛИМЕР» are open to dialogue and ready to work with customers to find optimal solutions.
