Download CH-HW-ZA-Van Ryssen Dam construction, Limpopo

CASE HISTORY
ZAF - CH - 030: Eng - Rev. 08, June 2014
VAN RYSSEN DAM
PHALABORWA, LIMPOPO PROVINCE
HYDRAULIC & EROSION CONTROL / DAMS & RESERVOIRS
Product: Terramesh® System
Problem
In order to comply with the National Water Act (Act 36 of 1998),
Foskor Mine wants to collect and contain polluted surface runoff from its tailing dams in the Van Ryssen Dam for re-use in
the mines processing plant.
The Water Management Project incorporating this recycling will
result in reduced raw water requirements, which are currently
sourced from this water scare area at a barrage in the Olifants
River.
The dam will be sealed with an impermeable Bentonite layer
and designed to cater for the 1:50 year flood, further benefiting
the environment by preventing contamination of the
downstream water resource.
Starting Terramesh® Installation
Date: Oct 2003
Packing the front face
Date: Oct 2003
Backfilling
Date: Oct 2003
Solution
As with all earth embankments, the higher the structure the
more fill material is required.
The initial design solution comprised a 22m high rockfill dam
with an upstream earthfill facing only.
However, through a simple adjustment involving reducing the
height of the rockfill structure to 19m and making up the last
2,4m in height with a vertical Terramesh® wall on the upstream
side, the amount of required rock was reduced significantly.
Lack of suitable dam-building material e.g. clay, meant that
recycling of the waste rock dumps to create a rockfill dam was
the most obvious solution.
Client name:
FOSKOR MINE
Main contractor name:
GRINAKER LTA CIVIL ENGINEERING
Consultant:
KNIGHT PIESOLD
Product used:
TERRAMESH® SYSTEM
Construction info:
Construction date:
SEPTEMBER 2003
Completion date:
MARCH 2004
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As part of the ISO 9001 Management Systems, guided research and development
programmes, information contained herein is continuously updated. Please confirm
with Maccaferri SA (Pty) Ltd the latest version of the Product’s Specification
available.
Benefits
The greatest benefit lay in the reduced earth fill quantities and
project costs as tabled below:
Earthfill (m³)
Cost (R million)
Original
290 000
32
Saving
100 000
8
% Saving
30
25
Maccaferri’s MacStars 2000™ software program was used to
design the structure. The program performs a series of stability
checks of the reinforced structure and provides a detailed
calculation report, cross sections and safety factors for the final
design.
Seismic loading together with the RMF flood had to be
accounted for during the design of the wall.
Compaction of material in front of wall
Typical Section
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Date: March 2004