What is Grillage Foundation And Types of Grillage Foundation
The grillage foundation is used at the base of columns. These tiers are encased in concrete and are at right angles to each other.
Though both foundation and grillage look ta like they are different. Where as the foundation transfers load from the structure to the ground, grillage distribute heavy loads over large areas.
Types of Grillage Foundation
The categories of grillage foundation is a per the materials used in construction, Grillage foundation is of two types:
Timber grillage foundation
Timber type foundation is provided for heavily loaded masonry wall of timber columns. The foundation is usually useful in waterlogged areas and where the bearing capacity of the soil is quite low and again, where the loading on the soil limit to 50-60 KN/SQM. Timber beams and timber planks are used instead of steel joists. There no concrete poured surrounded between the timber points.
Steel Grillage foundation
Steel grillage foundation has steel joints or beams provided in double or single tiers. The smallest cover of 10 cm is kept on the outer area of the external beams and above it.
The depth of concrete in Steel Grillage Foundation should be more than 15 cm. After leveling the base and pouring the concrete, ensure you check to ensure compaction is done properly and formed an impervious layer of a thickness of at least 15 cm. This shields steel joist from water, that can cause corrosion corrosion then we lay the first layer over the concrete bed at a distance of 100 mm to 300mm, with the help of pile separators.
Pour the concrete between and around the beams of the first tier. After that, placing the second tier of the beam at the 90 degrees angle to the first tiers with the help of the separator.