When you have land that is sloping and uneven, it quite often renders it unusable for many activities. You can contour the land easily by building a retaining wall and changing levels so that the ground becomes more amenable to leisure and other activities.
Retaining walls can also be used to create terraces, each of which can be put to a different use. Sloping land also leads to faster runoff of rainwater and can cause soil erosion, which can be reduced by building a series of retaining walls on such land. The building of a retaining wall holds back stones, rocks, and earth and keeps them from getting into more public areas that are in use. A retaining wall acts like a small dam that retains soil and earth instead of water. The creation of terraces through building retaining walls can also allow for better landscaping as then the soil is supported and prevented from getting eroded.
You can build retaining walls with a number of materials, like brick, stone, timber steel and almost any material that can resist the forces that the retained earth will exert on them.The strength of the materials used will determine the width of the retaining wall. Building a retaining wall requires the type of soil and its water content also to be assessed before any design is attempted. Soil acts in a way like water and imposes a horizontal force on retaining walls, which the design of the wall has to be able to resist.
The capacity of the soil to retain itself, often called the angle of repose is determined by engineers in laboratories before any retaining wall is taken up for design. Often this is a standard for various geographical areas having similar kinds of soil.This angle of repose is also affected by the moisture content of the soil and can tend towards zero, and act like water, in soils that have a large water content. It is customary to provide drainage for soil to allow the trapped water to escape from soils retained by walls. In most cases of design, the horizontal force that can be imposed by the retained soil is estimated. This force will come from all the soil that is at an angle greater than the angle of repose and will vary from zero to the maximum at the top of the wall. The design of the wall will in most cases rely on the weight of the wall to resist this force, and factors of safety of 2 or more are assumed to give the required static load to resist the overturning force of the retained soil. Where a steel or reinforced concrete structure is used, the structure will be designed to resist this overturning force.
Building a retaining wall also requires the wall to have foundations that are deep enough to provide a firm base for the wall and prevent it from being eroded by rain or water. The soil below the foundation must also be firm and strong enough to take the weight of the retaining wall that is built on it. It is possible to build cheap retaining walls by using stone masonry without any cement, as the weight of the stone itself enables the structure to remain in place. This sort of dry rubble masonry retaining walls is very common for farm and land terracing, as it often uses the material found on the land itself.
You can also build a retaining wall by driving wooden members or steel piles into the ground so that they go deep enough to resist the overturning moment of the earth that is retained. It is customary for all retaining walls to have some form of drainage outlets that will allow water that is in the soil to find an outlet. Weep holes are often left within the walls to facilitate such drainage, that can be in the form of pipes or just openings.It is important to also provide for adequate drainage for this water, as if it accumulates at the base of the wall it can damage its foundation.
Landscape artists often use retaining walls to accentuate levels and may also use the walls themselves as support for plants or creepers. This utilization also helps to disguise the starkness of stone or masonry that can often be quite intimidating. It is not unknown for weep holes in walls to be used as areas where plants are allowed to grow and this can greatly improve the aesthetics of a retaining wall.
The building of retaining walls on property lines will require the permission from adjacent property owners and also often from local authorities, as well.It is important that they are properly designed and executed in such a way that they do not cause any disputes at a later date. Large retaining walls where heights are more than three of four feet will require proper attention to design and may involve the use of machinery and other construction equipment during their building. Reinforced concrete retaining walls are the best for such areas, as they require less width and will not take away more area from either property.
Maintenance of a retaining wall has to be constant, as otherwise, this can lead to their failure, which can then be quite disastrous. Weep holes must always be fully functional and allowed to bleed constantly. Any cracks or structural problems must be attended to immediately if the wall has to give the service that is required from building it.