What type of foundation is known as a floating foundation

As the base of the entire structure of your home, thereвЂ™s a reason why your foundation is the most important aspect of your residence. Of course, for basement foundation companies, the term has a much more literal meaning. To prevent the heave formation in the side walls of excavated trench, lateral supports should be provided.When you hear the term вЂњfoundation,вЂќ what do you think of? ItвЂ™s undeniable that the word has crept into popular culture as a way of describing character, morals, and core values, at both the individual and institutional level. By lowering water table also, it can be minimized. Installing friction piles before excavation or after the completion of half excavation can also prevents the formation of heave. We cannot prevent the formation of heave but there are some methods to minimize the formation of heave.Д®xcavating narrow trenches and filling them with concrete soon after the excavation minimizes the heave formation. The formed heave causes settlement to the structure or foundation. When the soil is excavated up to some depth, the pressure of the soil below this depth is lowered which results the formation of heave. Where N c = SkemptonвЂ™s bearing capacity factor.Д«y using any one the above two equations, the critical depth or maximum depth of excavation can be determined. There are two equations are available to determine critical depth of excavation given by Terzaghi and Skempton respectively.ДЎ) Terzaghi equation for the critical depth is:Д« = width of foundation (if width is less than length of foundation вЂњLвЂќ)Дў) SkemptonвЂ™s equation for critical depth is If the soil is of low shear strength as specified above, there is a limit to the depth of excavation which is known as critical depth. Dewatering should be done cautiously otherwise it may cause lowering of water table which disturbs the adjoining structures. It is better to examine the water table level prior to the excavation. If the depth of the excavation is below the water table then dewatering is essential. The walls of excavated part should be supported using sheet piles or timber piles or soldier piles etc. The excavation for floating foundation should be done carefully.

Here also, floating foundation helps to reduce the shear stresses to satisfactory level and hence settlement is prevented.Дifficulties in Construction of Floating FoundationДuring the construction of floating foundation some problems may arise which can be prevented by taking proper care. Soils which are having low shear strength and there is no hard layer of soil at reasonable depth.In which case, floating foundation can reduce the settlement values to greater extent. Soils which are having good shear strength but having a problem of large settlements and differential settlements under heavy loads.So, this type of foundations can also be called as partly compensated foundations instead of fully floating or compensated foundations.ДЇloating foundations are desirable for the following types of soils: But here one point is to be noted that we cannot build a structure immediately after the excavation.Дuring the time of construction, the effective vertical pressure under the depth of excavation may slightly increase because of unbalancing weight. Now in the next step, a building is constructed which is as same weight as of the removed soil and water.Д®ven the depth of excavation is below the table the total vertical pressure in the soil below the foundation is unchanged because of its balancing weight. The ground is excavated up to certain depth which is below water table.

LetвЂ™s consider a ground with water table at the top as shown in the above picture. So, this foundation is also called as balancing raft foundation.

The main principle of floating foundation is to balance the weight of removed soil by a structure of same weight which causes zero settlement to the structure. Floating foundation is also called balancing raft and causes zero settlement to the structure.

Difficulties in Construction of Floating FoundationДЄ floating foundation is a type of foundation constructed by excavating the soil in such a way that the weight of structure built on the soil is nearly equal to the total weight of the soil excavated from the ground including the weight water in the soil before the construction of structure.

What type of foundation is known as a floating foundation