Necessity for road drainage - road drainage, Civil Engineering

Necessity for Road Drainage:

Poor drainage can cause damage to the various components of a road in the following manner:

(a) Water can enter the various pavement layers through cracks and potholes in a pavement and the pavement edges. When this water reaches the sub-grade, the soil becomes moist and saturated and loses its supporting power. As a result, the pavement sinks and settles, the cracks widen and more potholes develop (Figure 1).

733_Necessity for Road Drainage - Road Drainage.png

Figure: Rain Water entering Sub-grade through Cracks

(b) The water reaching the sub-grade has no outlet if the material below the shoulders is not drainable. Thus a "bathtub" situation develops, with the pavement surrounded by water on all its three sides (Figure 2). This causes the pavement to sink and settle.

1396_Necessity for Road Drainage - Road Drainage1.png

Figure: Pavement Surrounded by Water on all Three Sides

(c) If the earthen shoulders are not trimmed and graded regularly, the shoulders often become higher than the pavement, and the surface water cannot get drained. The water accumulates on the road, gets into the pavement layers and damages the road (Figure 3).

277_Necessity for Road Drainage - Road Drainage2.png

Figure: Higher Shoulders Result in Accumulation of Rain Water

(d) In hill roads, landslides are often caused by lack of drainage in the hill slopes (Figure).

1670_Necessity for Road Drainage - Road Drainage3.png

Figure : Landslide Caused by Lack of Drainage in Hill Roads

(e) Water can travel upwards due to capillary rise in a clayey soil sub-grade, saturate the pavement supporting layer and decrease its bearing power. As a result, the pavement sinks and settles (Figure 5).

698_Necessity for Road Drainage - Road Drainage4.png

Figure : Capillary Rise of Water Causes Saturation and Softening of Pavement Support

(f) In high embankments, the water entering the soil increases its weight and reduces its shear strength, thus causing slips (Figure 6).

796_Necessity for Road Drainage - Road Drainage5.png

Figure : Slip Caused in Embankment Slope due to Lack of Drainage

Posted Date: 1/22/2013 5:12:16 AM | Location : United States







Related Discussions:- Necessity for road drainage - road drainage, Assignment Help, Ask Question on Necessity for road drainage - road drainage, Get Answer, Expert's Help, Necessity for road drainage - road drainage Discussions

Write discussion on Necessity for road drainage - road drainage
Your posts are moderated
Related Questions
what are the basic assumption of traffic flow model and capacity model used in signal timing design ? discuss

Q. Fire resistance of steelwork Because of the high thermal conductivity of steel, temperature of unprotected steel is almost the same as temperature of fire. Because the yiel


in plane table surveying which activity is done first whether centering or levelling?

My team has to construct a swimming pool at the back of the house. It’s interior dimensions are 10M x 3M and 1M at the shallow end and 2.5M at the deep end. The walls and the bas

The most probable value of the following observations on the same angle (35º 17' 42" ; 35º 17' 38" ; 35º 18' 00" ; 35º 17'; 22"; 35º 17' 42");  is most nearly:   35º 17' 40.8

Define the pre-tensioned concrete construction We understand that in the pre-tensioned concrete construction, stretched tendons are provided in the concrete moulds at the time

tack rivet figures with connections

The Figure 1 below shows a section through a stairway for a garage in a new proposed dwelling. The stairway is 3 meters wide with 300 mm wide treads(7 treads) and 170 mm high riser

Question What is reason of skin reinforcement for deep beams ? Answer In BS8110, it declares that secondary reinforcement have to be provided for beams greater than 750mm deep