It is very important to select the suitable type of retaining wall depending on the nature of the earth retaining system. The following factors to be considered selecting the suitable type of retaining wall.
- Durability requirements
- Height of the retaining wall
- Ground conditions
- Material availability
- Cost of construction
Durability Requirements
The durability of the structure is very important especially when the retaining walls are connected with the permanent structures.
As we all know, rubble retaining walls are built with cement sand mix which could deteriorate with the bad environmental conditions.
Continuous wetting and drying, exposure to aggressive chemical environments, etc. could deteriorate the bond or the cement sand paste.
On the other hand, concrete is comparatively more durable, and it has the capacity to withstand aggressive environmental conditions.
Heigh of the Retaining Wall
It is very important in determining the type of material to be used for the construction. When the retaining walls tend to be tall, we use select concrete retaining walls.
Generally, we considered rubble retaining walls to build retaining structures up to about 6m. Beyond this limit, we shall make special attention when rubble retaining walls are constructed.
Concrete can be used to construct any height retaining walls. However, the cost factor and the durability requirements could be taken into account when selecting the type of material.
Material Availability
When rubble retaining walls are constructed, we need lots of rubble volume as it is a gravity-type retaining wall. The gravity structures maintain their stability from their own weight. We need lots of materials.
On the other hand, reinforced concrete retaining walls required fairly thinner sections.
Cost of Construction
In general, rubble retaining walls are low cost. However, it may vary with the height of the retaining wall.
Labor rates, material rates, etc. have higher influence on the cost of the construction.
Mostly, the rubble retaining walls up to 6m could be low cost compared to the reinforced concrete retaining walls. However, we have to consider other factors such as durability when selecting the type of retinting wall.
Summary of Comparison
- When the retaining walls are connected to a permanent structure, it is always advisable to construct reinforced concrete retaining walls.
- If the exposure conditions are adverse and there are chemicals that could lead to the deterioration of the cement sand paste, it is always advisable to go with reinforced concrete walls.
- If the height of the retaining walls is more than 6m, it is suggested to consider reinforced concrete retaining walls.
- When the height of the retaining wall is less than 6m, depending on the condition, type of retaining wall could be selected.
