Q$\mathrm{.}1.$ Answer the followings:

$)=(40$

i$)$ What is the basic difference between 'Reinforced Earth' and 'Earth Retaining Structure'? Why earth retaining system is popular?

ii$)$ Classify the following reinforced earth systems. Among these which one is most suitable for stabilizing hill slope and why?

$($a$)$ Secant Pile

$($b$)$ Cofferdam

$($c$)$ Anchored Earth

$($d$)$ Soil Nailing

iii$)$ List the properties of 'Reinforcement' and 'Soil' that affect the performance of earth retaining structures.

iv$)$ How the design strength of reinforcing materials are decided?

v$)$ Briefly describe the soil reinforcing mechanisms in embankment foundation.

vi$)$ List the factors affecting tensile behviour of flexible reinforcement.

vii$)$ List the mechanical and serviceability properties for designing earth retaining system.

viii$)$ Compare the functions of geotextile and geogrid.

ix$)$ Draw a typical section of a reinforced soil embankment. Describe the function$($s$)$ of reinforcement in the embankment.

x$)$ Describe the beneficial effect of vegetation in preventing soil erosion. Write two points on the potential of bioengineered slope protection in Bangladesh.