1. While designing a hill road with a ruling gradient of 6%, if a sharp horizontal curve of 50 m radius is encountered, the compensated gradient at the curve as per the Indian Roads Congress specifications should be

1. 1. 4.4%

   
   
   

   2. 4.75%

   
   
   

   3. 5.0%

   
   
   

   4. 5.25%

   
   
   

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1. View Hint View Answer Discuss in Forum

   Compensation for ruling gradient =	30 + R	= 1.6%
   	R

   
   

   Max. value =	75	= 1.5 %
   	R

   
   ∴ Take 1.5% But as per question, take 1.6%
   ∴ Compensated gradient = 6 – 1.6 = 4.4%

   Correct Option: A

   Compensation for ruling gradient =	30 + R	= 1.6%
   	R

   
   

   Max. value =	75	= 1.5 %
   	R

   
   ∴ Take 1.5% But as per question, take 1.6%
   ∴ Compensated gradient = 6 – 1.6 = 4.4%

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2. A vehicle moving at 60 kmph on an ascending gradient of a highway has to come to stop position to avoid collision with a stationary object.The ratio of lag to brake distance is 6: 5. Considering total reaction time of the driver as 2.5 seconds and the coefficient of longitudinal friction as 0.36, the value of ascending gradient (%) is

1. 1. 3.3

   
   
   

   2. 4.8

   
   
   

   3. 5.3

   
   
   

   4. 6.8

   
   
   

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1. View Hint View Answer Discuss in Forum

   Lag distance = 60 ×	5	× 2.5 = 41.67 m
   	18

   
   

   	Lag distance	=	6
   	Brake distance		5

   
   

   ∴ Brake distance(s) = 41.67 ×	5	= 34.725 m
   	6

   
   

   S =	v²
   	2gƒ + g sin θ

   
   

   ∴ 2ƒ + sinθ =	v²
   	Sg

   
   

   ∴ sinθ =	v²	- 2ƒ
   	Sg

   
   

   =	16.672	- 2 × 0.36 = 34.75
   	34.75 × 9.81

   
   ∴ θ = 4.8%

   Correct Option: B

   Lag distance = 60 ×	5	× 2.5 = 41.67 m
   	18

   
   

   	Lag distance	=	6
   	Brake distance		5

   
   

   ∴ Brake distance(s) = 41.67 ×	5	= 34.725 m
   	6

   
   

   S =	v²
   	2gƒ + g sin θ

   
   

   ∴ 2ƒ + sinθ =	v²
   	Sg

   
   

   ∴ sinθ =	v²	- 2ƒ
   	Sg

   
   

   =	16.672	- 2 × 0.36 = 34.75
   	34.75 × 9.81

   
   ∴ θ = 4.8%

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3. Using IRC: 37-1984 “Guidelines for the Design of Flexible Pavements” and the following data, choose the total thickness of the pavement.
   No. of commercial vehicles when construction is completed = 2723 veh/day
   Annual growth rate of the traffic = 5.0%
   Design life of the pavement = 10 years
   Vehicle damage factor = 2.4
   CBR value of the subgrade soil = 5%
   Data for 5% CBR value
   

1. 1. 620 mm

   
   
   

   2. 640 mm

   
   
   

   3. 670 mm

   
   
   

   4. 700 mm

   
   
   

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1. View Hint View Answer Discuss in Forum

   Axle load =	365 × A × [(1 + r)n - 1]	× F
   	Y

   
   

   =	365 × 2723 × [(1 + 0.05)10 - 1]	× F
   	0.05

   
   = 30 × 10⁶axle load = 30 msa
   For 30 msa, thickness = 670 mm

   Correct Option: C

   Axle load =	365 × A × [(1 + r)n - 1]	× F
   	Y

   
   

   =	365 × 2723 × [(1 + 0.05)10 - 1]	× F
   	0.05

   
   = 30 × 10⁶axle load = 30 msa
   For 30 msa, thickness = 670 mm

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4. The extra widening required for a two-lane national highway at a horizontal curve of 300 m radius, considering a wheel base of 8 m and a design speed of 100 kmph is

1. 1. 0.42 m

   
   
   

   2. 0.62 m

   
   
   

   3. 0.82 m

   
   
   

   4. 0.92 m

   
   
   

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1. View Hint View Answer Discuss in Forum

   Extra widening =	nL²	+	V
   	2R		9.5√R

   
   

   =	2 × 8²	+	100
   	2 × 300		9.5√300

   
   = 0.82 m

   Correct Option: C

   Extra widening =	nL²	+	V
   	2R		9.5√R

   
   

   =	2 × 8²	+	100
   	2 × 300		9.5√300

   
   = 0.82 m

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5. The specific gravity of paving bitumen as per IS:73-1992 lies between

1. 1. 1.10 and 1.06

   
   
   

   2. 1.06 and 1.02

   
   
   

   3. 1.02 and 0.97

   
   
   

   4. 0.97 and 0.92

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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