**2.1 Tallest geosynthetic reinforced slope**

One of the tallest geogrid reinforced green faced slope 1H:1 V and 74 m high (**Figure 2**) is airport runway extension in Charleston, West Virginia [5]. **Figure 3** depicts a schematic of the reinforced slope.

The high angle of shearing resistance of 36° of onsite soils provided two significant benefits viz., no need to import borrow soil and minimum required embedment length. However, there was a partial failure of this slope which was restored subsequently.

**15**

**Figure 4.**

economical option.

**Figure 3.**

**fills for Sikkim airport**

*Geoysynthetic Reinforced Embankment Slopes DOI: http://dx.doi.org/10.5772/intechopen.95106*

*Reinforced slope Yeager runway extension (after [5]).*

**2.2 Geogrid reinforced embankment with steep side slopes**

**2.3 Composite soil reinforcement system for very high and steep** 

*Schematic of reinforced slope for highway extension (sketch based on [6]).*

For a highway project in Brampton, Ontario, property acquisition costs and other problems necessitated the design of 7 m high embankment with 1H:1 V steep side slopes. Cost–benefit studies showed that steep side slopes reinforced with synthetic tensile elements were considerably cheaper than the other alternatives. Design and construction of 7 m high embankment with slopes using geogrids (**Figure 4**) as an alternative to rock fill embankment with side slopes of 1.25H:1 V requiring additional land has been covered by Devata [6]. Reinforced earth slope was found to be most economical (**Table 1**). The total cost of 1H:1 V reinforced slope is the least among all the alternatives making it the most

For runway construction of airport at Pakyong in north eastern Indian state of Sikkim huge cutting of earth and its filling on the valley side was required to form a level platform to provide runway of 1820 m x 150 m and other related

#### **Figure 2.**

*Schematic of reinforced embankment for Yeager runway extension (redrawn based on [5]).*

*Geoysynthetic Reinforced Embankment Slopes DOI: http://dx.doi.org/10.5772/intechopen.95106*

*Slope Engineering*

**Figure 1.**

even allow use of marginal soil.

**2. Case histories**

subsequently.

use of geosynthetics as reinforcing material.

**2.1 Tallest geosynthetic reinforced slope**

depicts a schematic of the reinforced slope.

Embankments are built with engineered fills. Geosynthetics facilitate reduction of earthwork volume by altering the geometry of the embankment (**Figure 1**) and

*Effect of geosynthetic reinforcement on geometry of embankment: (a) flat and (b) steep slopes.*

In reinforced soil, conventionally free draining material is specified for backfill due to its high strength and draining properties. The cost of fill material is about 40% of the total cost of the structure [4]. If marginal soil is used instead it could be more economical. Apart from economics, technical factors like esthetics, reliability, simple construction techniques, good seismic performance and ability to tolerate large deformations without structural distress have enhanced the acceptance and

One of the tallest geogrid reinforced green faced slope 1H:1 V and 74 m high (**Figure 2**) is airport runway extension in Charleston, West Virginia [5]. **Figure 3**

The high angle of shearing resistance of 36° of onsite soils provided two significant benefits viz., no need to import borrow soil and minimum required embedment length. However, there was a partial failure of this slope which was restored

*Schematic of reinforced embankment for Yeager runway extension (redrawn based on [5]).*

**14**

**Figure 2.**

**Figure 3.** *Reinforced slope Yeager runway extension (after [5]).*
