Component or parts of a building Building Construction

Component or parts of a building Building Construction I Sofia Sebastian 1 1

Construction of foundation Foundation is a very important part of a building Different types of foundations are Shallow Foundations 1. Strip Foundation 2. Footing foundation 3. Raft foundation Deep foundation 1. Pile foundation 2. Pier foundation Building Construction I Sofia Sebastian In Framed construction, we use footings as the foundation for the column The brick work for walls starts from grade beams connecting 2 columns 2

Construction of plinth Plinth is the dividing line between the substructure and the superstructure. The projecting part of the wall above the ground level to the floor level is the plinth. It is capped by a beam called the plinth beam Provision of a plinth beam and damp proof course at plinth level are very important Plinth is usually 45 cm above the ground level Building Construction I Sofia Sebastian 3 3

Construction of walls and columns Walls are mostly made of masonry. – brick, block work, stone work, etc Load bearing walls, Partition walls Framed structure with columns and footings and then in-filled. Most of the Flats and high rise buildings are built this way. Arches and lintels are also used in masonry walls Building Construction I Sofia Sebastian 4 4

Construction of floors Ground floors constructed on the ground Top floors are made of reinforced concrete Load bearing walls, Partition walls Concrete work, formwork and placing of steel reinforcement Floor finishes Building Construction I Sofia Sebastian 5 5

Construction of Roofs must be water proof, heat proof or weather roof Overview- Roofing assemblies consist of two parts: 1. the substrate (structural frame and deck), that provides a surface for the. . . 2. roofing (the actual water barrier that protects the substrate, and everything beneath it). There are two main categories of roofing: steep-slope (based on a water shedding, overlapping principle); low-slope (often incorrectly called "flat; " although it is possible, but unusual, to design Building Construction I a roof that is literally Sofia Sebastian flat: 6 6

Construction of Doors and windows Openings are necessary for passages inside and outside the building Windows for lighting and ventilation Cost of doors and windows – 10 -20% of the total cost of civil works Windows – woodwork, steel and aluminium Construction of Stairs and lifts Most buildings are more than one storey high. Study of staircase is very important Electrical lifts is necessary for more than 4 floors (G+3) Construction of Building finishes Plastering, pointing Painting of walls, wood work, grill work, etc Building Construction I Sofia Sebastian 7 7

Foundation Building Construction I Sofia Sebastian 8 8

Foundation – Loads on foundation • • Foundation is the part of the construction where the base of the building meets the ground. Foundations are usually placed below ground level because the surrounding ground provides 1. Stability 2. Protection against impact 3. Protection from the extremes of weather such as excessive rain or drought Depth of the foundation varies according to the site, but the best load bearing ground is 90 cm below the surface Two types of foundations • • Building Construction I Natural foundation – Ground underneath the base of the building after the excavations are completed Artificial foundation – structure that lie between the building and the natural foundation Sofia Sebastian 9 9

Foundation – Loads on foundation Building Construction I • An artificial foundation carries the building loads • Dead loads- weight of all the fixed parts of the building such as the walls, floors, ceilings and services such as sanitary fittings and plumbing • Superimposed loads/ live loads – weight of the people, furniture and machines that will occupy the building after completion • Wind loads – pressures on the walls and roofs from the wind. Wind load is very important in tall building’s foundation Sofia Sebastian 10 10

Foundation – Loads on foundation Lateral loads Sliding Overturning uplift Soil & Water Pressure Anchoring against lateral loads Horizontal Movement Earthquake Building Construction I Sofia Sebastian 11 11

Conditions that affect foundations 1. The load bearing capacity of the ground 2. The depth where you will suitable load bearing soil 3. The distance from trees which can affect the stability of the soil 4. The level of the water table 5. The normal variation in the water table 6. The total weight of the building. If the building is heavier than the soil that was removed, then there will be some settlement as the soil adjust to the new load Building Construction I Sofia Sebastian 12 12

Settlement in foundation • Settlement is the gradual sinking of a structure as the soil below its foundation consolidates after loading. – On dense, granular soils, such as coarse sand gravel, this consolidation is usually slight and occurs quickly as loads are applied. – When the foundation soil is a moist, cohesive clay, which has a relatively large percentage of voids, consolidation can be quite large and occur slowly over a longer period of time. Building Construction I Sofia Sebastian 13 13

Differential Settlement in foundation • Differential settlement is the relative movement of different parts of a structure caused by uneven consolidation of the foundation soil. • This can cause a building to shift out of plumb • and cracks to occur in its foundation, structure, or finishes. Building Construction I Sofia Sebastian 14 14

Foundation systems Foundations Shallow Spread footing Deep Raft foundation Isolated footing Strip footing Stepped footing Combined footing Cantilever or strap footing Continuous footing Building Construction I Pile & Caisson Sofia Sebastian 15 15

Foundation systems Shallow foundation Deep foundation Used where the soil is strong with good bearing capacity. Used when the soil under a foundation is unstable or of lesser bearing capacity. Placed directly below the superstructure. Extend down through unsuitable soil to a more stronger soil stratum. Loads are transferred directly to the supporting soil. Transfer building loads to a the strong stratum well below the superstructure. Building Construction I Sofia Sebastian 16 16

Types of Foundation 1. Concrete strip foundation 2. Deep strip foundation 3. Raft foundation 4. Pad foundation 5. Stepped strip foundation 6. Pile foundation Building Construction I Sofia Sebastian 17 17

Types of Foundation Concrete strip foundation 1. Used frequently 2. Consist of continuous mass concrete strips poured in the bottom of trenches 3. This foundation supports load bearing walls which are centered. 4. This concrete strip is of uniform width and depth 5. Must be deep enough to avoid soil movement 6. Depending on soil depth – the maximum depth – 90 cm Building Construction I Sofia Sebastian 18 18

Types of Foundation Deep strip foundation 1. Variation of strip foundation 2. Usually dug with a mechanical excavator 3. Cuts a narrow trench that is filled with concrete upto ground level 4. Use more concrete 5. Reduce the cost of masonry walls Building Construction I Sofia Sebastian 19 19

Types of Foundation Raft foundation 1. For soil which has poor bearing capacity 2. When the building loads are quite small and the cost of digging separate foundation is eliminated 3. The over-site concrete slab becomes the raft foundation 4. Slag can be thickened at the edges with an edge beam and thickened underneath internal load bearing walls 5. Mesh reinforcement increases the strength of the raft foundation and distributes the pressures of the building loads evenly Building Construction I Sofia Sebastian 20 20

Types of Foundation Pad foundation 1. Isolated foundations 2. To support concrete columns 3. Square concrete pad foundation distributes the load evenly on the ground Building Construction I Sofia Sebastian 21 21

1. Built on sloping sites 2. Reduce the cost of foundation along the perimeter of the building 3. The higher level foundation should extend over and meet with the lower one for a distance not less than its thickness 4. Not less than 30 cm Types of Foundation Stepped foundation Building Construction I Sofia Sebastian 22 22

Types of Foundation 1. Soil conditions are poor at the surface, then we use pile foundations 2. Trial holes indicate the depth of suitable load bearing soil 3. As deep as 2 or 3 m 1. Two types of pile foundation 2. Bored or replacement piles 3. Driven dispalcement piles Building Construction I Sofia Sebastian 23 23

Pile foundation Load bearing walls Tie beams integrated with pile caps Pile caps Friction piles End bearing piles Building Construction I • Piles are usually driven in clusters of two or more. • Pile cap joins the heads of a cluster of piles to distribute the load from a column or grade beam equally among the piles. • Steel H-sections, concrete-filled pipes, or precast reinforced or pre-stressed concrete are common pile materials. Sofia Sebastian 24 24

Types of Foundation Bored or replacement piles Building Construction I Sofia Sebastian 25 25

Types of Foundation Driven or displacement piles Building Construction I Sofia Sebastian 26 26