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

Keywords related to Modern Trends in Transportation: Exclusive Bus Lane :           A lane reserved exclusively for buses. High Capacity Bus System            :

how to remove dampness in mud houses?

Develop a simple urban constructed wetland design guidelines and drawings. Your report should include the following: I. Data required for the design II. Types of constructed

please discuss about trenches

Q. State different types of chlorination processes available in Railway & market for disinfect ion of water. What type of chlorine used in the above different process. What do you

Q. Principle of airlifting for cleaning pile bores? Airlifting is generally carried out before concreting to remove debris and clean the base of pile bores. It basically acts a

For the project work points (x,y) shown in the figure the bearing of point R is due West. The coordinate for point R is most nearly:    Solution: Determine the length o

Explain Brake and Electrical Horsepower Brake horsepower (bhp) = whp/pump efficiency Electrical or motor horsepower (ehp) or (mhp) = bhp/motor efficiency Friction of heat