BULDING CONSTRUCTION (2130607) TOPIC:- TYPES OF FOUNDATIONS

SUBJECT:- TYPES OF FOUNDATIONS NAME OF STUDENTS :- 1) DHARAK KARELIYA (131130106013) 2) ANIL THAKKAR (131130106055) 3) YASH PATEL (131130106038) 4) PARTH DHANDHALKA (131130106009) 5) HAFIJ MULTANI (131130106021) 6) DHRUMIL SONI (131130106054)

TYPES OF FOUNDATION :- (1) SHALLOW FOUNDATION i) spread footing ii) Combined footing iii) Raft footing iv) Grillage foundation (2) DEEP FOUNDATION i) pile foundation ii) cassions or well foundation iii) coffer dams

Shallow foundations:- The guidelines for a shallow foundation are : They are founded near to the finished ground surface. The depth is generally less than the width of the footing and less than 3m. They are used when the surface soils are strong enough to support the load imposed upon it.

i) Spread Footings Square or rectangular shaped blocks of reinforced concrete that typically support a single column or wall of a building. The allowable bearing pressure on the soil determines the size of the spread footing.

ii) combined footing Whenever two or more columns in a straight line are carried on a single spread footing, it is called a combined footing. Isolated footings for each column are generally the economical. Combined footings are provided only when it is absolutely necessary, as 1) When two columns are close together, causing overlap of adjacent isolated footings 2) Where soil bearing capacity is low, causing overlap of adjacent isolated footings 3) Proximity of building line or existing building or sewer, adjacent to a building column

iii) Raft foundation These are used to spread the load from a structure over a large area. This would normally be the entire area of the structure. Raft foundations are often needed on soft or loose soils which have a low load bearing capacity.

iv) Grillage founadation Grillage foundation is used to transfer heavy structural loads from steel columns to a soil having low bearing capacity. There are many advantages of grillage foundation. the major advantage is it is economical and it is light. Grillage foundations does not require deep cutting because the required base area with required pressure intensity is obtained at a shallow depth.

Deep foundations Shallow foundations are unsuitable in weak or highly compressible soils. DEEP foundations include piles, pile walls and piers. Deep foundations are usually at depths deeper than 3m. Deep foundations are used to transmit the loading to a deeper, more competent strata

i) Pile founadtion A pile is a slender structural member made of steel, concrete or timber. In pile foundation, a pile is either driven into the soil and or formed in-situ by excavating a hole and filling it with concrete.

ii) Coffer dams A cofferdam is a temporary dam or barrier used to divert a stream or to enclose an area during construction. The design of an adequate cofferdam involves the problem of construction economics. When the construction is timed so that the foundation work can be executed during the low- water season, the use of cofferdams can be held to a minimum. However, where the stream flow characteristics are such that this is not practical, the cofferdam must be so designed that it is not only safe, but also of the optimum height.