Civil Engineering - Highway Engineering - Discussion

Discussion Forum : Highway Engineering - Section 1 (Q.No. 1)
1.
A district road with a bituminous pavement has a horizontal curve of 1000 m for a design speed of 75 km ph. The super-elevation is
1 in 40
1 in 50
1 in 60
1 in 70
none of these.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
95 comments Page 3 of 10.

Happy singh said:   4 years ago
Given data,

Speed = 75 kmp = 75*5/18 m/s = 20.83333333 m/s.
75% speed is the designed speed. So, 75% speed=20.83333333*0.75 m/s =15.625 m/s
Radius of curvature = 1000m.

Here 'g' is the gravitational acceleration and the value of 'g' is 9.8 m/s.

Formula of super elevation is (V2/gR) =(15.625*15.625/(9.8*1000)) =0.024912309%
0.024912309% of Super elevation means 1 in 40.1408.
So, the answer is 1 in 40 is correct.
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Jahidul Islam said:   4 years ago
V^2\225R is correct.

Dr. ANUJ said:   4 years ago
This will as per the design steps given by IRC for heterogeneous traffic. Step one is, you have to find the value of e (superelevation) neglecting friction for 75% of design speed.

If the value so obtained is less than 0.07, the design is over and that value is taken as the designed value of superelevation.

Elavarasy R said:   4 years ago
v^2/225R.
= 75 x 75/227 x 1000.
= 0.025.
=1in40.
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Umesh said:   5 years ago
as per IRC e=v^/225.R.

Here, In question, it should be 1000m radius

Sushil said:   5 years ago
Super elevation = V^2 / 225 R.
= 75x75 / 225x1000.
= 0.025 = 1 in 40.

Pramit Samanta said:   5 years ago
If mixed traffic or maximum value was mentioned then it has to be e + f = V2/225R. Otherwise for design purpose e + f = V2/127R.
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Just said:   6 years ago
75*75/(225*1000) = 75/(3*1000) = 25/1000 = 5/200 = 1/40.
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Jeet said:   6 years ago
Super elevation = V^2 / 225 R.

= 75x75 / 225x1000.

= 0.025 = 1 in 40.

Ramkishor Sahu said:   6 years ago
Superelevation is always.

e+f=v^2/127R.

But for the design of the superelevation we take,

e=V^2/225R.

So, Here velocity 75 kmph and horizontal curve 1000 meter given.

That means it is the radius of the horizontal curve.

Note:- Horizontal curve always given in the form of the radius.

Put these values to find the horizontal curve,

e = 75^2 / (225*1000).

e = 1/40.

Thank you.
(1)


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