Estimate Of Other Structures | Civil Engineering SSC JE (Technical) - Civil Engineering (CE) PDF Download

Example 1: What are factors to be considered in design of septic tank? The following factors should be taken into consideration:

• Material should be water proof and corrosion resistant.
• Natural ventilation provided should be adequate A manhole should be provided to permit inspection and cleaning.
• Baffles should be limited to one at the inlet and one at the outlet.
• The escape of gas and sludge to effluent pipe should be avoided.

• Define lead
  Lead is the crow flying horizontal distance from the centre of borrow pit to the centre  of the earthwork at site, i.e centre of the area of excavation to the centre of placed earth.
• Define lift
  Lift is the distance through which the excavated soil is lifted beyond a certain specified depth.

Example 1: The actual expenditure incurred in the construction of a school building which have a total length of main walls 140m is Rs.4.97lakhs.Estimate the approximate cost of a similar school building which will have 180m length of main walls.

Total expenditure = Rs.4,97,000
Total length of main walls = 140m
Rate per m length of main wall = 4,96,000/140 = Rs.3550/- Length of main walls in the proposed building = 180m Approximate cost = 180 x 3550 = Rs.6,39,000/-

• Define estimate
  An estimate is a computation or calculation of the quantities required and expenditure likely to be incurred in the construction of a work. The estimate is the probable cost of a work and is determined theoretically by mathematical calculation based on the plans and drawing and current rates.

Example 1: Write the recommendation for degree of accuracy in measurements.

Dimensions of works shall be measured to an accuracy of 0.01 m 

Thickness of R.C works shall be measured to an accuracy of 0.0005 m 

Areas of works shall be calculated to the nearest 0.01 m² 

Volumes of work shall be calculated to the nearest 0.01 m³ 

Volumes of wood shall be calculated to the nearest 0.001 m³

Example 2: Briefly explain about revised estimate

The estimate, which is prepared When any major change or alteration is made in the plan / structural arrangement, with or without affecting the estimate cost, and
When the estimated cost is likely to exceed by more than 5% during execution, due to increase in the cost of materials and labour or due to increase in the cost of materials and labour or due to alterations in the items of works to get the revised quantities /rates/ amount is called a revised estimate

Example 3: Calculate the quality of brickwork in an arch over a 1.80m span opening. The arch is 40cm.thick and the breath of a wall is 40 cm.

Radius of the arch = 1.8m Thickness  of arch =  40  cm
The  breath of wall  = 40cm Mean dia  =  3.60+0.40  =  4 m Mean  length of the  arch given = 1/6 *(22/7)* 4 = 2.1m Quantity of brickwork = 2.1*0.40*0.4 = 0.34 cu.m
No of bricks required = 0..34cu.m @ 550 bricks per cu.m = 187

• Define Floor area
  It defined as covered area i.e plinth area excluding area of walls (generally 10% -15 %) sills of the doors are not included in floor area. The floor area of very storey shall be measured separately.
• Define Carpet area
  his means area in a building which is useful one i.e area of drawing room, dining room bedroom etc. Areas of kitchens, staircase, stores, verandahs, entrance hall, bathroom, basement etc. are excluded. It is generally 50% to 60% of the plinth area.
• Define Plinth area
  It is defined area of a building measured at floor level. It is measured by taking external dimensions excluding plinth offset if any.

Example 1: What are the methods of taking out estimates?

• Centre line method 
• Crossing method 
• Out to Out and in to in method 
• Bay method 
• Service unit method

Briefly explain about Out to Out and in to in method.
This method is most practicable under all  circumstances  and is generally followed in the P.W.D for computing the quantities of various items.

Briefly explain about bay method.
This method is useful and is generally followed in case of buildings having several bays. The cost of the typical bay is worked out and is then multiplied by the number of bays in that building. The extra cost for the end walls and difference in framing, if there is any, should be made, so as to arrive at the correct cost.

Example 1: Workout the quality of stone metal required for 2Km.Length for wearing coat of a 4m wide road. The thickness of the metal road required is 12cm loose.

Quality of metal = 1 X 2 X 1000 X 4 X 0.12 = 960.00cu.m

Example 2: An approach road 2Km.long is to be constructed. Work  out  the  quantity  of materials required i.e. stone metal and bricks. Data is given below.
Length = 2 Km
Metalled width = 3.60m
Soiling of bricks = 10cm
Wearing coat of stone metal = 12 cm

Quantity of bricks = 1 x 2 x 1000 x 3.60 x 0.10 = 720 cu.m
No of bricks = 720.0 x 3.60 x 0.12 = 3,60,000
Stone metal = 1 x 2000 x 3.60 x 0.12 = 864 cu.m
Bricks = 3,60,000 Nos 

Example 3: Cement concrete road (1:2:3) is to be constructed over the existing water bound macadam road. The thickness of slab = 10cm. The length of the road is one km and the width 3.60m. Calculate the quality of cement concrete and the material required,

Quality of cement concrete = 1 x 1000 x 3.60 x 0.10 = 360 cu.m

Example 4: Calculate the quality of earthwork for the construction of an approach road Length = 1Km
Width of formation = 10 m Height of embankment = 60 cm Side slope = 1:2

 Quantity of earth work = L (Bd+Sd2) B=10cm ; d =0.60m ;S = 2  

Quantity of earth work = 1000 x (10 x 0.60) +2 x 0.60 x 0.60 = 6720 cu.m 

Example 5: What are the methods of measurements of earthwork?

The work shall be measured as given below 

Each dimension shall measured nearest to 0.01 

Area shall be worked out nearest to 0.01 m² 

Volume shall be worked out nearest to 0.01 m³