Facts of Reinforced Earth Wall

 

Reinforced Earth Wall (RE Wall) is used for sustaining soil laterally, so that it can retained levels properly at both sides of the carriageway. RE Wall is a combination of earth and linear reinforcement in the form of strips, grids etc. that are capable of bearing tensile stress. 

The reinforced earth fill material is essentially borrowed. It includes many geotechnical properties and they are tested in the laboratory. If the test condition satisfies or approved, then only the filling material is used for RE Wall. These materials are specifically got from river beds or sand beds, where fine soil is available. Rock boulders are also used. They are quarried into 10-15 mm aggregates and then they are used. Basically these aggregates are used for drainage media/filter media. 

Components of Reinforced Earth Wall 

A reinforced earth Wall comprises various components that are necessary for the stability and functions of the structure. Each of them are analysed below : 

Geogrid material 

Reinforced Earth fill material is used so that it can restrain the panels. These are belt like shape, which is fitted inside the cavities of the panels. It gives strength and pressure to the panels/blocks, so that the panels doesn't falls to the outward direction. 

And these belts are available in roll shape. Wait let me clarify you. Actually they come in roll form first, of width upto 2.4 - 5.9 meters and length upto 100 meters. After that the Geogrid which is to be cutted, is brought to the site, and then cut's ✂ it according to the required shape and size (or required length). After that piece by piece geogrid is cutted and required number of belts are cut. 

Like this the geogrids are cutted

Use of Geotextile 

Geotextile is use to cover the earth materials or soil filling materials. These are available in white color and are attach beside the walls. There are also some geotextiles which are used for ground improvement. They are basically used for loose soil or soil seepage or where soil bearing capacity (SBC)is low. These are available of length 2-5 meters. 

As you can see here, this geotextile is used on the excavation pit. This done for ground improvement. 

This is the geotextile use to cover the earth materials or soil, so that the soil does not comes out through the gaps of the panel. 

Filter media 

Filter media is laid above the Ground Level and that also at the sides of the panels, inside it. It is done due to the soil pressure or the lateral loads of the vehicles moving on the highway 🛣️. When a heavy vehicle moves on a highway it exerts some hydrostatic pressure. So to prevent that filter media is used to resists it. A drainage media/filter media of around 600mm is given during RE Wall construction.  

Drainage pipe 

This is given to drain out the water entering inside the RE Wall. So filter pipes are used for this work, and after that it is wrapped with non-woven geotextile. 

Levelling pad 

Levelling pad is made to erect the panels. So that it can be placed at proper position. After precast, the panels are used for erection, and like that the work goes on. 

There are also many other things such as, friction slab, crash barrier, abutment Wall/dirt Wall, approach slab etc. All these things are also given for various purposes. 

But the main topic is why RE Wall is given at flyovers. Or what is the main reason of this RE Wall. Well, this is for making the approach road, isn't it? Then also there is something left out, which is .............. 

Sorry, I couldn't get exact word to express it. But remember about the terms and concepts of RE Wall.