The question of "can a retaining wall be sloped?" is most commonly asked by architects when erecting retaining walls. Historically, the only answer to this question was no, because no technological development had yet been developed to allow the building industry to build walls that would allow for an improved slope or to eliminate the need for a slope altogether.
Recently, the building industry has begun to address this problem and a new type of wall which eliminates the need for a slope is now available in the market. This solution allows the building industry to once again build retaining walls which are virtually impervious to a variety of natural conditions and thus eliminate the need for them. These walls are also very cost effective.
Slopes are very difficult to build retaining walls around because they completely compromise the strength and durability of the wall. In most cases, a two-foot slope presents the biggest problem. Even a 1-foot slope is at risk of collapse due the weight of the walls and poor slope design. The weight of the walls not only puts stress on the foundation, but also increases the cost of the project.
A significant amount of soil pressure can be brought to bear on any wall which is placed on a slope. Generally speaking, the stronger the wall, the more pressure will be directed onto the wall, causing it to flex and crumble under the weight. Additionally, the longer the wall is placed on the slope, the greater the soil pressure will be. Of course, this increases the risk of structural failure in that the wall becomes brittle and can easily succumb to external pressure. Furthermore, a wall which is placed on a slope can lead to increased water infiltration into the building causing further stresses in the walls and the overall structure.
When a building company is asked "what can a retaining wall be sloped?" in terms of cost, the first and foremost question that would often come up is "why would I need to do so"? The simple answer is that if the retaining wall was not put in, the building would have to be relocated, which costs money. Furthermore, relocating the building can often mean additional expenses such as removal of debris, disruption of work, and more.
There are a number of ways in which walls can be constructed which will keep out the soil, but may require slopes of at least three degrees. These walls are commonly referred to as retaining walls, escarpments, or hillocks. The purpose of a wall is to create a hill which helps to retain and filter rainwater runoff. It is not uncommon for a flat to slope slightly towards a building in order to aid drainage, but many buildings do not need this and it does not help in retaining soil.
Sloping the retaining wall can reduce the amount of concrete that must be used, as well as the amount of steel needed to reinforce the wall. The first question to ask yourself when asking "what can a retaining wall be sloped?" is whether or not the retaining wall can be supported by vegetation. If you are working with a natural incline such as hillside or mountain top, then you may have the option of using the natural topography to your advantage. For instance, if you are planning on building a retaining wall along a river, then you can build the wall with the hillside or mountain top in mind. If you are planning on building on an industrial site, then this may not be possible.
When you ask "What can a retaining walls be sloped?", the second question is: The slope should not affect the wall's structural integrity. Your retaining wall should not sag due to changes in ground. You should also ensure that your soil is resistant to flooding and soil erosion from ground fluctuations.