Dear Mann<br>
<br>
I think you're asking a little too much in one question. The selection of a type of retaining wall does not solely depend on the height of material to be retained. There are a multitude of reasons why certain types of wall are selected over others. For example:<br>
<br>
a) Have you sufficient room to construct an in-situ wall before placing fill behind it?<br>
b) Is the formation able to carry the base loads for this type of wall or should a sheet piled alternative be considered?<br>
c) Do ground conditions dictate that only certain methos can be used for construction?<br>
d) Can sufficient passive resistance at the toe of the wall be generated or is a deeper piled toe required?<br>
e) Do you have the appropriate plant, materials and skilled labour on the project to construct a wall of this type, or another.<br>
f) Does your client want a finish best produced by a proprietary precast system?<br>
g) What is the design life of the wall? This may preclude sheet piles for example.<br>
h) Can ties be incorporated to reduce bending moments, or are buttresses required.<br>
<br>
Theses are just a few samples elements that are involved in choosing the appropriate wall type. In some cases, one factor may sufficiently override all other problems or benefits. I'm afraid it is down to the expertise of the engineer (in view of safety, client requirements and cost)as to which type is best for your particular case.<br>
<br>
Regards <p>Andy Machon<br><a href=mailto:Andy@machona.freeserve.co.uk>Andy@machona.freeserve.co.uk</a><br><a href= > </a><br>