CE 420 COMPUTER AIDED DESIGN6TH SEMESTER UG-01

FoundationFoundation is the lower most part of a structure which forms a base

for super structure. Before designing foundation, a designer should get all information regarding the nature and type of foundation. The basic purpose of this information gives help in fixing the bearing capacity of soil, selecting economical and safe type of foundation and fixing the depth of foundation.

The lowest part of structure which transmits all loads and is in direct contact with ground is called a foundation.

Term, foundation, includes the structure below the ground level. Artificial arrangement provided to transmit loads to the soil below are also included in this term e.g., piles, raft. Grillage concrete blocks etc.

FoundationThe purpose of foundation is:- To spread or distribute the weight of the structure over a large area. To avoid unequal settlement of the soil below. To provide a level surface the building. To increase the stability of the structure and prevent it from over turning.

Classification of foundations: Foundations can be broadly classified as under:-

Deep Foundation: The foundation of structure when taken deep to attain a bearing stratum suitable in all respects is called a Deep Foundation. Piles, cofferdams, caissons come under the deep foundation.

Shallow Foundation: A foundation placed immediately between the lowest part of the super structure is called Shallow Foundation. Shallow Foundation distributes the structural loads over a large area at shallow depth below the ground level.

Types of Shallow Foundation Spread footing foundation.

Raft foundation.

Grillage foundation

Eccentrically loaded footings.

Combined footings.

Spread Footing FoundationThe base of a foundation transmitting load to the soil and made

wider to distribute the load over a larger area is called Spread Footing Foundation.

Different examples of spread footing foundation are as under:

Wall footings. Reinforced concrete footings. Column footing.

It may be noted that all types of foundation come under spread footing foundations but they are traded separately due to design and construction point of view.

Raft Foundation A foundation under which a reinforced cement concrete base is

spread over whole area of the bottom of a structure or a building is called Raft or Mat Foundation.

The walls are constructed over an R.C.C base Raft foundation is used where heavy loads are to be distributed over a larger area or where soil conditions are very poor.

Grillage Foundation A foundation consisting of two or more steel beams, in single or

double tier grillage, embedded in cement concrete is called Grillage Foundation.

In case of double tier grillage, top tier is laid at right angles to the lower tier.

Pile Foundation Pile foundation is used where it is not possible simple spread

foundation at a suitable depth because the stratum of required bearing capacity is at a greater depth or where there are steep slopes. A Pile foundation has a base of cement concrete or steel grillage foundation supported by piles. Piles are classified as:

Timber Piles, Concrete Piles, Composite or Steel Piles.

Well Foundation A foundation in the form of masonry or concrete well sunk in the

ground is called WELL FOUNDATION.

Such a foundation is provided where the soil is softy and sandy.

In well foundation each well is provided with a curb of wood, mild steel or R.C.C. at bottom

Stepped or Benched or Slipped Foundation The foundation provided on a sloping ground in the form of steps

is called Stepped Foundation.

Selection of Building PlotThe following points be in fully be kept in mid while selecting a plot for

residential building:- The plot should be in fully developed locality or fast developing locality

with availability of roads, water supply, electricity, drainage, etc. and preferably with other utilities like school, post and telegraph office, dispensary etc.

An are where by laws of local authorities enforce restrictions regarding open area, proportion of plot to be built, steel widths, house line, etc.

The plot should be rectangular, preferably, but should not be irregular in shape and with sharp corners.

The plot should be fairly high and leveled with uniform slope for quick drainage of rain water.

Selection of Building Plot Soil should be light loamy on surface without any newly filled earth. Newly

filled earth in a plot requires deep and expensive foundation. There should be firm soil, rock or sand below 600mm to 1200mm layer of light soil.

The plot should have unobstructed breeze and sun.

Plot near unhealthy, noisy or crowed localities and slums. Factories, water logged areas, badly maintained drains and nallahs should be avoided.

Legal and financial aspects are worthy of careful considerations. Title of plot should be clear.

Cost of plot should not exceed 35% of total amount to be invested in the house property.

It is advisable to consult a lawyer before purchasing a plot.

Principles of PlanningThe planning of a building is based on following principles1. Orientation

Placing of rooms with respect to North is called Orientation. Room are kept in proper direction and also proper disposition of doors and windows in the exterior walls of different rooms so that the inmates of the house enjoy the gifts of nature such as fresh air, warmth, health giving morning sun rays and landscape. Fig. 17-1 shows the placing of different rooms with respect to North.

Principles of Planning2. Privacy. Privacy is of two types:

Privacy of whole house from highways and minor roads. It can be accomplished by providing walls, tall trees, hedges, creepers and screens etc.

Privacy inside the house can be accomplished by providing passages and lobbies, skilful placement of doors and opening, curtains and blinds in windows etc.

3. Grouping of rooms: Placement of rooms in respect to their utility is called Grouping of

Rooms. For example dining should be close to kitchen, sanitary services close to and easily accessible from each bed room and away from kitchen and dining etc.

Principles of Planning4. Circulation:

Free movement of inmates of a house is called Circulation. Circulation is of two types:- Horizontal Circulation: Circulation on same floor is called Horizontal

Circulation. It can be accomplished by providing direct well lighted passage. Independent passage should to living, common room, lobby and staircase.

Vertical Circulation: Circulation between different floors is called Vertical Circulation. For vertical circulation between two different floors, staircase is only a thoroughfare. It should be well lighted, ventilated, easy to climb and broad. For public buildings ramp and lift are also provided.

5. Sanitation: For preservation of perfect health, sanitation is must. Building should be on an elevate site so that the rain water flows away easily. It should also be away from stagnant ponds, quarry (excavations) and other objectionable nuisance. Room should be well ventilated.

Principles of Planning6. Flexibility: Provision of some space to be sued for some other overlapping

activities. For example a drawing room or dining with flexibility portion in lounge can accommodate more guests on festive gatherings small parties. There are a number of such overlapping activities which require large space occasionally for which provision should made and provided.

7. Economy: An economical structure be planned and designed. And estimate of

quantities should be prepared along with abstract of cost.

General Design of House Design of a house depends on numerous conditions as a whether

it is designed to meet the climatic conditions or with regard to availability of space.

Requirements of a house vary from person to person because styles and tastes have always differed. Everyone wants a different styles to the extent that it should look exceptionally different from the others. A house reflects the taste and styles of those who live in it.

Climatic conditions also play a major role in design. In hilly areas, roof is sloping and a fire chimney is provided as a safeguard snowfall and cold respectively. Design of a house is more elaborate and sophisticated in plains where climate is generally dry.

Style of ArchitectureStyle of architecture is most important while planning a house.

Following are the styles of architecture: Geometric Style: A geometric house is composed of arches and

cylinders. All the doors and windows are covered with round projections along with small hut type slabs. Arches also give a good height to the structure. While designing such house, designer should be careful about composition of arches, circles, cylinders and hut type slopes.

Box Style: Box style architecture is economical and easily planned. It is a combination of balconies, chajjas and canopies. Such house, if properly designed, givens a compact and neat look.

Villa Styles: such architecture is like old villa.

Internal PlanningInternal Planning:There are generally four types of internal planning of a house. Single Unit: Single unit is only for one family. It consists of ground floor,

mezzanine and first floor with barsati. It can also have a basement.

Duplex: Two vertical units are made, instead of a single, on a corner, rectangular length and such arrangement is called Duplex. In duplex one can enjoy the comforts of a single unit and at the same time other unit can be rented out.

Typical Vertical Unit: In vertical unit, ground floor and mezzanine are converted into single unit and separate independent stair case is provided for first floor. First floor can be rented out independently.

Flats: In flats whole unit is built on ground floor and further unit is added on first floor. In this way maximum number of units can be added on each floor for rental purpose. This system is actually a business or rental style.

Basic Elements of Planning a Residential BuildingA residential building has the following living requirements:

Living Area

Sleeping Area

Service Area

Other areas or circulation area.

Preparing a Line PlanThe plan drawn with single line showing different positions of rooms

with dimensions excluding the thickness of walls is called Line Plan.

After determining the plinth area and shape of building, draw the North line is a corner to facilitate the orientation of different rooms. The line plan should be started either with a kitchen or with bed rooms. After kitchen, dining should be provided adjacent to it. Bath and W.C. should have at least one side exposed to sunlight and air. They should be approachable and provided with each bed room independently (preferably). Now provide drawing room or living room and lounge, staircase should be provided in the lounge or separately when upper floor is to rented out. Provide store with master bed room. After this position of doors and windows be determined. They should be arranged that they do not come in the way of beds of furniture etc.

Projection of Plan Top view of lower part of a building projected on a horizontal

plane, by assuming it to be cut by horizontal cutting plane at a height of 1.5m from plinth level is called a plan.

Projection of Elevation & SectionProjection of Elevation: The front view projected on a vertical plane is called front

elevation. When the object is looked at from side then it is called side view.

Projection of Section: A view obtained on a vertical plane when the building is assumed

to be cut by it is called a section.

Detailed DrawingA drawing showing a detailed plan section and elevation

along with other necessary data is called a detailed drawing. While drawing detailed drawing, following should be drawn:

North lineReferencesScaleDimension and heights of rooms.Lintels over doors and windows and other openings.

CAD UG01

LAYOUT TABS

This lesson will show you the preferred way of plotting your drawings. In AutoCAD there are two different workspaces:

model space and Layout / Paper Space.What is a Layout?

A layout is a page that allows you to set up a plot or printout of your drawing. Below is a sample of what a layout looks like (a really simple one).

LAYOUT TABSThe floor plan and dimensions (above) were

created in MODEL SPACE at a 1:1 scale. The walls were drawn to be 30' or more long.

The title block and viewport were created in a LAYOUT TAB / PAPER SPACE at a 1:1 scale. The title block is 8-1/2 x 11 inches.

The viewport is a window into "model space". In the image below, the viewport is the black rectangle and the contents of the viewport are displayed inside it. The contents of the viewport are scaled to either fit the viewport or (preferably) to conform to a specific drafting scale (ie: 1"=1')

View Port

This conceptual image shows the relationship between model space and a Layout.

LAYOUT TABSTo see through 'into' model space, you have to

create a viewport (Make Viewport MV command). Think of a viewport as a window.

As soon as you create the viewport, the window is closed and the extents of your drawing are displayed. You can see through it, but you can not 'touch' anything in model space.

To have access to your objects in model space from paper space, you have to enter the viewport by typing MS <ENTER>. This 'opens the window' for access. Type in PS <ENTER> to 'close the window'.