The system is based on the work together of a compacted fill and the reinforcements inside.
The vertical / horizontal deformations are met through the friction occurs between the fill and the reinforcement.
The resulting durable composite material block gives chance to construct retaining structures.
The main components of the system
Concrete facing panels
Back fill material
Concrete facing panels
They are the elements used to cover the front face of the compacted fill layers.
They are produced by c30 concrete, in steel moulds, with vibration
They can be produced plain, patterned or colored.
Type and the dimensions depend on the wall height and geometry.
They are precast on a land near to erection site and stocked for 5 at max, one over another.
A)Galvanised steel strips: They are high adherence strips produced from steel with minimum tensile strength of 510 n/mm2, The source steel is a sertified s355jr type and the ribbed strips are produced with hot rolling method They are hot-dip galvanised with at least 530 g/m2 of cover.
B)Geosynthetic reinforcements: They are produced from polymer materials such as polypropylene, polyethylene or polyester Tensile strength ranges between 25 and 75 kn and have width of 5-9 cm Their type and dimension changes according to wall height, service type and the alkalinity of fill material
Hot-dip galvanized steel lugs and bolts-nuts are used if the steel strips are utilized in the structure
Long strips are obtained by connecting two strips together with hot-dip galvanised steel plates and bolts and nuts.
For polymer strips, the plastic elements are left within the panel during casting.
Relevance of back fill material
A)Gradation / granulometry
The fill material spread over the strips must be granular. The size may range from uniform silty sand to fragmental rocks
The maximum grain size must not exceed 2/3rdof the layer thickness and the percentage passing no 200 sieve must be less than %15.
B)Electrochemical properties (for steel strips)
i.The resistivity must be more than 3.000 ohm.cm
ii.The ph value must vary between 5 and 10
Spread and compaction of back fil
A) Spreading are done with care by the help of greyders, without harming the strips underlying,
B) Compaction is done parallel to wall face, with flat drum vibrating rollers of linear load capacity more than 30 kg/cm.
C) The thickness of compacted fill layers is set to 20 cm (for polimer strips) and 37.5 cm (for steel strips).
D) The number and speed of passes required to get %95 of the standard proctor test value are determined by the help of a “trial pass”
Precast concrete cappings are used as finishing elements at top of the walls
Their dimensions may be of 70x150x9 cm and 80x120x9 cm
Advantages of the system
Application on weak soils
Resistance to seismic activities
Construction rate and economy
No interruption of existing traffic lines
Safe and economic solutions for high walls as compared to conventional ways