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
Question In search reclamation, what are considerations in choosing between trailer suction hopper dredgers and grab dredgers ? Answer Trailer suction hopper dred

Question For rigid pavement, what is recompense of using lean concrete sub-base instead of traditional granular sub-base? Answer There are some shortcomings of using

An oven-dry soil sample of volume 225 cm3 weighs 3.90 N. If the grain specific gravity is 2.72, determine the void-ratio and shrinkage limit. What will be the water content which w

Define Rotation - Actions in POT Bearings? POT bearings are associated with large rotations which are accommodated by the deformation of elastomeric pad. Large cyclic rotations

Define Reactivity - Hazardous Waste - Undergoes violent Change w/o detonating - reacts violently with water - Forms potentially explosive mixtures with water - generat



Q. What do you mean by Ozone Test? Some research and studies determined that the ozone test was unnecessary as this affects only the surface layer.  In un-stretched rubber, ozo

Describe the various steps in embankment construction.

Ask question #MiniThe base of an isosceles triangle and the altitude drawn from one of the congruent sides are equal to 18cm and 15cm, respectively. Find the lengths of the sides o