Highway Engineeering

1. HILL ROAD
Presented by,
Prof. P.G. Shinde

2. TYPES OF CURVE
1. Salient curve
2. Re-entrant Curve
3. Hairpin curve

3. Hairpin Curve / Hairpin Bend
• These are curves in a hill road which change
direction through an angle of 180◦
• look like shape of hairpin so called hairpin
curve .

7. Selection Criteria
1. straight length between two successive hairpin
bend should be =min 60m
2.Radius of inner curve = min 14 m
3.Length of transition = min 15m
4. Design Speed =20KMPH
5.Superelevation =1in10
6.Gradient = not steeper than 5% for 40m

8. Salient Curve
• Convexity on outer edges of road
• Occurs in road length constructed on bridge of
hill.
• Curves are very dangerous for fast moving
vehicle traffic
• The bend so formed at the salient curve in hill
road is known as corner bend.

10. Re-entrant curve
• The curves having their convexity on the inner
edge of a hill road are called re-entrant curve.
• The center of curvature of a re-entrant curve lies
away from the hill side. This type of curve occurs
in the road length constructed in the valley of a
hill.
• These curves are less dangerous as they provided
adequate visibility to the fast-moving traffic. At
such curves, the parapet wall is provided only for
safety of fast-moving traffic.

12. Drainage Structure on Hill Road
Drainage System
1. Surface Drainage
A)Side Drain
B)Catch Water Drain
2. Controlling seepage flow
3. Cross Drainage

13. Surface Drainage
A) Side Drain
- To carry rainwater from the carriageway
surface and sloping side of hill .
- Provided on both side of roadway only in
cutting
Forms of Side Drain - Angle Drain
- Saucer Drain
- Kerb & Channel Drain

14. B) Catch Water drain / Intercepting drain
Are provided higher upon the hill slope side,
parallel to the road.
Function
-To intercept the rain water from the hill slope .
-To divert the rain water into a nearby cross
drainage work.

15. Cross Drainage
• CD system is essential for disposing off the
surface water controlled by catch water drain
and side drain across hill road.
• It prevents side drains from overflowing and
flooding the road surface.

16. Land slide
• The movement of the soil, rocks on the land
caused by the finite shear failure.
Classification
1. Slide- is the movement of the rocks caused by
the finite shear failure along one or the
several surfaces which either visible or whose
presence can be imagined.

17. 2.Falls- It includes the free fall and rolling of rocks and
debris without interaction of one pieces with another.
3.Flows-It is movement within the dispatched
mass such that the moving material resembles
with the viscous fluid whose slip whose slip
surface is difficult to locate.
4.Complex slide- Movement is caused by the
combination of two or more of the type of
failures above

18. Causes of Land slide
• Increase in the water content of the soil.
• Increase in weight due to accumulation of
snow.
• Vibration and shocks caused by blasting or
earthquakes.
• Hair Cracking due to alternate swelling and
shrinkage of the soil mass.

19. Thank You