Good Soil For Building Foundation

            One of the most important things to consider upon building a structure is the kind of soil to be used. According to Robert M. Felton (2010), recognizing the soil where a foundation rests on is part of the foundation system itself. In building strong foundations, good soils must be used. Examples of these are expansive clay soil, sandy loam soil and rock soil. First, expansive clay soil contain minerals such as smectite clays that absorb water. Though some people may say that this is dangerous to buildings, they do not know that damages are done slowly because of this soil. Second, sandy Loam or sometimes called select fill is a very stable soil that shows little change with the increase or decrease of moisture or temperature. This soil can easily support a slab foundation without heaving too much. Lastly, rock soil is good in providing great stability to buildings. Soil needs to be solid if it is to support a wall, buildings or steps. According to Immamura, A. (1937), If the quality of soil is hard and unyielding, the threat of earthquakes is minimal.

            It is also important to know the different types of soils as to know which are efficient for building strong foundations. Based on the Unified Soil Classification System, soils can be classified as coarse grained, fine grained and highly organic. According to Jonathan S. Goode (2006), coarse grained soils are those least affected by moisture-content changes as most surface becomes gravitational water. Examples of these are sands and gravels. On the other hand, fine grained soils like silts and clays are good in providing plasticity and compressibility upon force exertion. Lastly, highly organic soil is rich in minerals and nutrients necessary for strength and stability.

            Knowing the characteristics of a good soil is important in deciding which soil to use. According to Wallis B. (2001), these properties are strength, cohesion and consolidation. The strength of soil exhibits the magnitude of shear stress that it can sustain. It is important to assess the soil strength in order to provide stability to the building. Next cohesion is one of the measurement indexes of soil resistance. Cohesive soils are generally dense and tightly bound together. This cohesion increases as the particle size of the soil decreases. Lastly, according to Kshitija Nadgouda (2006) consolidation is the removal of water from soil. In other words, it is the squeezing out of water from the soil to make it more dense. This way, soils can provide greater foundation to buildings.