Excavation and Timbering of trenches
1. Sketch the following
i. Typical timbering in firm soil (Depth up to 1000mm)
ii. Typical timbering in loose wet soil (Depth up to 1000mm)
2. Write down 20 or more technical terms used in connection with excavation work and timbering of trenches.
3. Write down10 or more tools and machineries used in connection with excavation work and timbering of trenches
4. What are the safety precautions which should be used in connection with excavation work and timbering of trenches
Typical Timbering In Firm Soil Up To 1000mm
When earth has been excavated to a considerable depth the vertical faces of the excavations need supporting by means of timber, to prevent the soil from falling in and injuring the workmen or the work upon which they are engaged.
The strength of the timbering used for this purpose necessarily depends upon the nature of the soil, the depth of the excavations, and the length of time it is likely to be kept open.
The struts should not be closer together than 6 feet, otherwise they will prove a considerable inconvenience to the workmen in the trenches.
Typical Timbering In Loose Wet Soil Up To 1000mm
Should the looseness of the soil necessitate supports being fixed at closer intervals than 6 feet the system of timbering shown in Fig. 02 should be used. In this case it will be noted that the poling boards are supported by long horizontal members about 6 by 4 inches, called Wailings or Wailing Pieces, which in turn are supported by struts at intervals of 6 feet.
If the trenches are deep the timbering is inserted in tiers until the required depth is reached, the struts being placed vertically under one another, and at a distance of about 6 feet apart, so that stages may be supported upon them for the disposition of the excavated soil - 6 feet being the limit of depth from which an excavator can comfortably throw soil out of a trench.
Technical Terms Used In Connection With Excavation And Timbering Of
Trenches
Cohesive soil Hard soil Firm soil
Moderately soil Loose soil Loose and water logged
Iron shoe Puncheons Folding wedges
Uprooting Struts Sole plate
Ron strap Polling board Lacing boards
Dead load Vertical sheeting Planks
Non cohesive soil Peat
Live load Excavation
Tools And Machinery Used in Connection With Excavation Work.
Plumb rule Excavator Crow bar Level
Wheel barrow Mamoty Wacker Compactor
Case Dozers Wheel Loaders Bobcat Skid Steer Loaders
Safety Precautions Which Should Be Adapted In Excavation And Timbering Of Trenches
Ø Provide timbering or other supports where necessary
Ø Men erecting supports should be in a protected position
Ø When should only work within the supported section and should be prohibited from entering unsupported sections.
Ø Notices should be posted to this effect.
Ø Men should not walk or clamber about on the timbering as this weakness it.
Ø Don’t place the excavated spoil or other materials or plant close to edges of excavations.
Ø Do not allow plant to move close to the edges of excavations
Ø Creaks in timbering can indicate a danger or collaps.
Ø The sides of large, open excavations should be bettered or adequately supported where soil conditions require it and when men have to work in close proximity to the face.
Module number B.M. 123
Foundations
1. Sketch the following and name the parts
i. Strip foundation using Random Rubble masonry
ii. Strip foundation using brick masonry
iii. Strip foundation using R.C.C. Base
iv. Pad foundation
2. Write down 20 or more technical terms used in connection with foundation work
3. i. Ground Materials may consist of five groups. Name them with examples
ii. Name four types of foundations
Strip Foundation Using Random Rubble Mesonry
Strip Foundation Using Brick Masonry
Strip Foundation Using RCC Base 
Terms used in connection with foundation work
Rocks Cohesive Non cohesive Peat Made up ground
Gneiss Sand Granite Sandstone Limestone
Slope Bearing capacity Retaining wall Wetland Raft foundation
Bore holes Stratum Excavation Ramming Strip foundation Trial pits Laterite Pad foundation Cut and fill Pile foundation
Gravel Reinforcement
A broad classifications of the ground material may consist of five groups.
Ø Rocks
Ø Cohesive
Ø Non-cohesive
Ø Peat
Ø Made up ground
Rocks: These includes gneiss, granite, sandstone, limestone and laterite.
Cohesive Soils: The main cohesive soil is clay.
Non Cohesive soil: These include gravel and Sand.
Peat: Peat is black or dark in colour and very often smelly.
Made up ground or fill: These are low lying areas and depression are sometimes filled with various materials such as house refuse, industrial refuse, industrial refuse, building debris, excess earth from other sites, etc.
Types Of Foundations
1. Strip foundations
2. Pad foundations
3. Raft foundations
4. Pile foundations
Module number B.M. 124
Walls
1. Sketch the following
i. Alternate plan (two courses) of a right angle quoin (90° corner) of a 9" thick brick wall in English bond
ii. Alternate plan of a right angle Tee junction of a 9" thick brick wall in English bond
iii. Alternate plan of a right angle stopped end of a 9" thick brick wall in English bond
2.
i. Sketch the following
Elevation and cross section of a Random Rubble wall, 7΄-0" high from ground level (coursed or uncoursed) and name the parts.
ii. Name five types of rubble walls and give their advantages
3. Write down the terms, machineries and tools used in connection with the construction of walls.
Alternates Plans (two cources) Of A Right Angle Qoin (900 corners) Of A
9” Thick Brick Wall In English Bond
Alternates Plans (two courses) Of A Tee Junction Of A
9” Thick Brick Wall In English Bond
Alternates Plans (two cources) Of A Stop End Of A
9” Thick Brick Wall In English Bond
Elevation And Cross Section Of A Random Rubble Wall
Random Rubble Masonry (Uncoursed)
The stones are used as they are received from the quarry. The stones are not in same height. They are levelled at every 300 to 500mm. height. Stone chips and spalls are used to fill the empty spaces. The joints are about 12mm. Though stones are used to full width of the wall if the width of the wall is less tha 600 mm, for width more than 600mm 2 stones of lap joint is used. This masonry is useed for the construction of godowns, labour quarters, compound walls.
Suitability: Used for construction of walls of low height in case of ordinary buildings.
Random Rubble Built To Courses
The random rubble masonry in which stones are laid in layers of equal height is called random rubble masonry. In this masonry, the stones are laid in somewhat level courses. Headers of one coursed height are placed at certain intervals. The stones are hammer dressed.
Suitability: Used for construction of residential buildings, go downs, boundary walls etc.
Un coursed square rubble masonry: The squared rubble in masonry which hammer dressed stones are laid without making courses is called un coursed square rubble masonry. It consists of stones which are squared on all joints and beds by hammer dressing. All the stones to be laid are of different sizes.
Suitability: Used for construction of ordinary buildings in hilly areas where a good variety of stones are cheaply available.
Squared Rubble Built To Coursed
Coursed Square rubble masonry: The square rubble masonry in which chisel dressed stones laid in courses is called coarse square rubble masonry. This is a superior variety of rubble masonry. It consists of stones, which are squared on all joints and laid in courses. The stones are to be laid in courses of equal layers. and the joints should also be uniform.
Suitability: Used for construction of public buildings, hospitals, schools, markets, modern residential buildings etc and in hilly areas where good quality of stone is easily available.
The stone masonry in which finely dressed stones are laid in cement or lime mortar is known as ashlars masonry. In this masonry are the courses are of uniform height, all the joints are regular, thin and have uniform thickness. This type of masonry is much costly as it requires dressing of stones.
Suitability: This masonry is used for heavy structures, architectural buildings, high piers and abutments of bridges.
Terms Or More Used In Connection With The
External wall Internal wall Solid wall Frame wall
Load bearing wall Non Load bearing wall Arris Bed
Header Stretcher Face Frog or Kick
Bed joints Course Quoin Perpends
Racking back Tooting Bat Closer
Bull nose Splay Dogleg
Tools And Machinery With The
Spall hammer Mallet Iron hammer Scabbing hammer
Line and pins Plumb rule & bob Square Trowel Drag
Spirit Level Pick-axe Crow bar Pitching tool
Gauge Punch Chisel Nicke
Point Jumper Hand saw Wedge & Feather
Level Frame saw Cross-cut saw
Module number B.M. 125
Doors & Windows
1. Sketch the following and name the parts
i. Ledged, braced and battened door
ii. A framed and paneled door
iii. A paneled and glazed doo
2. Sketch a typical timber window with three slashes including slats on top and name them
3. List out 20 or more terms used in connection with the construction and fixing of doors and windows.
Ledged Braced And Battened Door
Technical Terms Used In Doors And Window
Door Rail Sill Mullion
Post Head Horns Door frame
Spur stone Door slashes Wrought iron traps Wrought iron dowel
Flush doors Nose Hanging edge Edge lipping
Bottom rails Glazed panels Intermediate rails Slide Hung
Module number B.M. 126
Stairs
1. Sketch the plan and cross section of a R.C.C. stair case and name the parts. Also give the proposed dimensions.
2. What are the types of stairs? Select two out of them and show them with sketches.
3. List out 20 or more terms used in connection with the construction of stairs.
Types Of Stairs
Basically there are three types of stares.
1. A strait flight stair
2. A quarter turn stair
3. A half turn stair
A strait flight stair rises from floor to floor in one direction with or without an intermediate landing, hence the name straight flight.
A quarter turn stair rises to a landing between two floors, turn through 900 then rises to the floor above, hence “Quarter turn”.
Cross Section Of A RCC Stair Case
Technical terms used in construction of stairs
Landing Rise Tread Nosing Hand rail
Yield steel Flight Steps Pitch Head room
Doe leg Balustrade Half turn Quarter turn Cast stone
Stair well Mild steel Rails Steep Stair Going
Thread Shallow stairs
Module number B.M. 127-A
Wall and floor finishes
1. What are the common types of plastering used in building works? Including the following details.
- Materials used
- Proportions
- Thickness & finish
2. What are the types of floor finishes and their advantages?
3. Write down 20 or more technical terms used in connection with the work in carrying out wall and floor finishes.
Common types of plastering used in building
| Description | Material | Proportion | Thickness | Finish |
| External Plastering | Cement: Lime: Sand: | 1:1:5 | 5/8" | Rough/Semi rough |
| Internal Plastering | Lime: Sand | 1:5 1:2 | 1/2", 5/8" | Finished smooth with lime putty. |
| Cement: Lime: Sand: | 1:1:5 | 5/8" | Finished smooth with lime putty. | |
| Soffit plastering | Cement: Sand | 1:2 , 1:3 | 3/8" | Finished smooth with lime putty. |
| Plinth plastering | Cement: Sand | 1:2 , 1:3 | 1/2", 3/4" | Finished smooth with cement putty. |
| Cement rendering | Cement: Sand | 1:2 | 1/2", 3/4" | Finished smooth with cement putty. |
| Skirting | Cement: Sand | 1:2 | 1/2", 5/8" | Finished smooth with cement putty. |
Types Of Floor Finishes
Ø Brick paved and cement rendered
Ø Concrete paving and cement rendered
Ø Asphalt
Ø Pressed tiles
Ø Glazed tiles
Ø Clay tiles
Ø Granite
Ø Terrazzo
Ø Rubber tiles
Ø Parquet flooring
Technical Terms Used In Connection With The Floor And Wall Finishes
Exterior wall Interior wall Lime plaster Cement plaster
Salt carbon Scaffolding Gauges Mortar
Smooth finish Coping Damp proof course Soffit
Parapet top Skirting Curling Moldings
Brick paved Concrete paved Rough finish Proportions
Cement, lime, sand plaster
Module number B.M. 127-B
Painting
1. List out the various stages of painting in respect of the following new surfaces.
- Wood/Timber
- Iron/Steel
- Concrete/plastered surfaces
2. Names 20 or more types of paints commonly used in building works and their advantages.
3. Write down 20 or more technical terms used in connection with painting work.
4.
Ø Applying sand and paper to the surface along the grain
Ø Clean the surface with a dry brush or piece of rag
Ø Apply two coats of Aluminum primer
Ø Fill the cavities, cracks, etc with stopping
Ø Apply first coat of paint (Under coat)
Ø Apply second coat of paint (Finishing coat)
Iron/Steel
Ø If there is rust, removing them with chopping, scrapping or wire brushing
Ø Clean the surface. If there is oil or grease on the surface, wipe this off with clean rag and paint thinner
Ø As soon as finished the cleaning apply a coat of primer
Ø Apply first coat of paint (Under coat)
Ø Apply second coat of paint (Finishing coat)
Iron/Steel
Ø Brush down to remove the dust, loose sand and efflorescence and scrape off any splashes of plaster mortar or cement
Ø Stop up cracks and holes with plaster or one of the patent fillers mixed with water
Ø Then if a primer is needed apply a one coat of Alkali Resisting Primer
Ø Apply first coat of paint (Under coat)
Ø Apply second coat of paint (Finishing coat)
Types Of Paints Commonly Used On Building
Enamel paints Snocem
Weather shield paints Whitewash
Emulsion paints Samara wash
Anticorrosion paints Wood primer
Distemper Anti-corrosive
Cement paints Filler
Gloss paints Luminous Paint
Filler Aluminous filler
Bituminous paints Water paints
Elastic paints Varnishes
Technical Terms Used In Connection With The Work In Carrying Out Painting
Corrosion Wear Decay Alkali resisting primer Efflorescence Adherent Entrained pain skins Distemper
Bituminous conspicuous Blemishes Tackiness
Wrinkling Fat edges Blistering Peeling
Obscure Brushing Spraying Dipping
Absorbent surfaces Porous glass paper Sand paper
Grain Knots Rust Rag
Putty Discoloration Scale
Shrink Elastic paints
