Rural Road Ppt

7/21/2019 Rural Road Ppt

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Site No. 1

Chainage: 3+300Location: Noopu

Sailent features:

Road 1 :Road width: 3.5mGrade:

Road 2:Road width: 3.5mGrade:

Road 3:Road width: 4.0mRadius of road: 16m

Road 4:Road width: 4.8mGrade:

The main road is black topped and other roads connecting to mainroad are still under construction phase


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Defects: Hume pipe is placed intersecting the flow of water Large rocks and chunks of construction materials is interrupting

the flow of water Possible erosion in agricultural land and below the outlet of

hume pipe Pot holes formation Inappropriate design at intersections

Solutions: If Hume pipe is placed along the flow of water, the flow would be smooth Large rocks and chunks of construction materials could be deposited on

banks of gully so that they would protect from erosion towards roadsembankments and agricultural lands

The pot hole formation may be due to falling of heavy stones duringconstruction of other roads nearby main road. So proper spoil disposal is

very necessary. Small hume pipe could be used instead of bigger one and flushed atleast

60cm below the ground level so that road would act as causeways tooduring rainy season and there would not be the problem of soil erosionbelow outlet of humepipe.


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Site No:2Chainage: 9+00

Salient feature Construction of side drain is not complete. Minimum cutting has been done. This meets the

Green Road Approach. Slope is stable as the beddings are dipping in

opposite direction from the road. Syncline and Anticline beddings. Labour based construction is motivated as local

people are involved. This Road construction was started in 2046 B.S. and

has not completed yet. Road width: 5.5 m


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Defects: This road is free of technical defects. Construction period which has been very long is the

only defect at this site.si


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Site No: 3Chainage: 9+800Sailent features: Road width: 3.75m

This road is in the second stage of construction Loop size decreases towards the lower gradient which is useful design for

surface water management. The road is aligned along the side of agricultural land but agricultural

land is kept intact.

Defects: Building is obstructing sight distance. Road has been constructed in the weak unstable ridge and curve has

been set behind the house at some place. If landslide occurs itdamages the road and in turn the road will damage the house.

There is no place for further widening of road as in one side of roadis the building and in the other side there is agricultural land.

Solutions: Proper alignment selection is necessary to control the above problems. Bio-engineering has to be done in the slopes to protect from erosion.


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Site No: 4Chainage: 19+100Location: Sukaura Khola

Structure: Check damConstruction material: carved rocks and wire nets

Present condition: Damaged Condition

Causes of failure: Under cutting and side cutting by river water.

Suggestions: Provide V or U shaped notch at middle of dam. Gabionstructures should be built from foundation at certain depth below bedlevel, not from the surface of bed level. If there is scouring problem due tohigh velocity of water at upstream side then large rocks or stones can be

placed staggered that will function as rip-rap. Vertical joints should beprovided in such a way that they do not fall in straight line.


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Site No: 5Chainage: 21+000

Sailent features:

The road alignment is selected in the valley side of slopes. The road is in the final stage of rural road construction i.e. the road is black

topped and the better provision of improving retaining walls is continued. Road width: 3.5m Material type: alluvial deposit in the slopes.

Why road alignment is selected in the valley side? The main reason is to conserve agricultural land. One of the main

objectives of rural road construction is to enhance the economic status of localpeople. If their agricultural land is destroyed in the name of road construction,there is no meaning of construction of road or providing access to remote areas.Thus, the agricultural land was given utmost priority and instead alignment

was diverted to valley side.

The other reason is there is alluvial deposit in the ridges and theyare most susceptible to landslides.


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Problems: Because of alluvial deposit in ridges there is higher probability

of landslide occurrence. Very dry and harsh condition of slope material.

Implemented solutions:

check dams/ gabion walls are constructed across the slope.

Suggestions:Bio-engineering can be the most economical and effective one.


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Sailent features: An example of result of improper selection of road alignment. Box cutting has been done which should be avoided as far as possible. Radius of curve provided is 5 to 6m which is inadequate. Long Steep gradient.

Why box cutting should be avoided in road construction in Hilly areas? Box cuts require removal of material where the adjacent grade is higher on both

sides of the route. There is a problem of mass balancing. In this case "little or no material can be

excavated by sidecasting", i.e., removed material cannot be dumped alongsidethe route.

Daylighting a tunnel becomes necessary to improve vertical or horizontalclearance and this increases additional cost.

Water management problem arises as box cut acts as channel for water flow andfurther problem of toe erosion of side slopes is added.

If box cut has to be made at curves the extra widening problem may arise. If it isnot solved problem of sight distance may arise.


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Problems:

Turning radius is not sufficient for vehicles.

Mass movement is continuous.

Surface water may cause problem. Sight distance is not sufficient for inspection.

Solutions: To prevent the happening of above problems proper alignment

selection is very necessary. In our case the new alignment should

had to be selected at level higher than existing level. This newalignment would also avoid box cutting and would also solve theproblem of long steep gradient.


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Sailent features: This road is in the final stage of construction i.e. it is black topped. An example of disposal of excavated materials from upper hill sides to

lower hill sides. It is the road constructed in between the agricultural land and forest

area. The agricultural land is located in the upper hill side and there is

forest area in lower hill sides. Road width: 3.75 m Roads are with normal gradient and in some places roads are with

steep gradients.


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Site No: 8Chainage:0+000Location: Dakshinkali Temple

Sailent features: A temple of Kali known as Dakshinkali Temple is located. An example to show how alignment selection is affected by no

of rivers or kholas. There are two rivers meeting at Dakshinkali temple and

culverts are constructed across each river.

Conclusion: If there are two or more than two rivers or similar features where

culvert or bridge is necessary and alignment of road has to be fixed

then the alignment has to be passed downstream of Dhovan as far aspossible. This is because the no of culvert or bridge structures to beconstructed is reduced and the cost of construction becomes low.

Rural Road Ppt

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