Road Profiles

Question 1

What is the most common scale used for plan view?

what elements are included in plan view?

Answer 1

1: 5000 is the standard
1: 2000 for detailed roads

Includes streams, legal boundaries, stream crossing, Reference points, curves, culverts, right of way width.

Question 2

What is the difference between a P-line and an L-line

Answer 2

P-line (preliminary line) first traversed line.

L-Line (final road location after design correction.

On easy roads there are no changes

Question 3

What is Profile View?

Answer 3

• A vertical representation of the ground profile
• Designed road scale
• Exaggerated vert. alignment (1:200 vert, 1:2000 horiz.)

Question 4

Why is vert allignment exaggerated in profile view?

Answer 4

To bring attention to even minor changes in grade

Question 5

What does profile view show?

Answer 5

• Ground line from survey
• Designed grade of L line
• Culvert location and specs
• Terrain features and existing structures

Question 6

What does ground line above or ground line below grade line imply?

Answer 6

Above: cut
Below: fill

Question 7

What does full cut imply?

Answer 7

Road below ground line

Question 8

What does cut and fill imply?

Answer 8

Part of road cut to grade line and part of road filled to gradeline

Question 9

What does fill section imply?

Answer 9

Road is above ground level

Question 10

What is site preparation?

Answer 10

• Clearing woody debris and overburden out of the way

- 3m clearance from top of cut slopes and toe of fill

Question 11

What is excavation?

Answer 11

• movement of material after site prep

- Solid rock or (OM) Other material

Question 12

List the materials

Answer 12

• No organics
• Rock (requires blasting or ripping)
• OM: Includes gravel and sand

Question 13

What is grading?

Answer 13

Rough excavation to form the roadbed to the gradeline

Question 14

What is sidecast?

Answer 14

Material used to build up the lower side of a road on a slope.

Question 15

What is it called when material is excavated from one spot and filled into nearby gullies or dips?

What about when it needs to be moved a long distance?

Answer 15

Short distance: “longitudinal movement”

long distance: end hauling

Question 16

What does wasted refer to?

Answer 16

Excess Material that is discarded. Generally frowned upon.

Question 17

What is a rule of thumb with slopes when roadbuilding?

Answer 17

If sideslope over 60%, hire a geotech to sign off on plans.

Question 18

What are some uses for rock that is too big to be used in surfacing?

Answer 18

Use as sidecast or

Use to stabilize culverts

Question 19

What is ballasting?

Answer 19

Also called surfacing. ballasting is when suitable blasted material is used to improve the running surface of a road.

Question 20

What are the road standards of a class 5 road

Answer 20

• Stabilized subgrade 5m
• Ditches 1m deep
• 50% Slope to ditch from road
• 20m clearing width

Question 21

What is important about cut and fill slopes

Answer 21

• The more erodable the material the lower the slope

Question 22

What does a “balanced design” imply

Answer 22

Cut and Fill should be near equal to acheive balance and minimal waste

Question 23

What is “expansion and Compaction?”

What does it imply

Answer 23

Materials get bigger when they are dug up and smaller when they are packed into a hole.

Correction factors must be applied to calculate their equivalant fill volume.

Question 24

What are compaction factors?

Answer 24

• Excavated OM compacts to 75% of its original volume

Question 25

What are the expansion and overbreak factors for rock?

Answer 25

Factors applied to solid rock volumes to estimate their expanded volume

Question 26

What is the accuracy of grades on a profile

Answer 26

To the nearest 10th of a percent

Question 27

In a designed gradeline, what does cut or fill at center line imply

Answer 27

difference between original groundline and subgrade elevation to the nearest decimeter.

Question 28

What is the rule of thumb for grade changes?

Answer 28

No more than 3% per 10m

Question 29

Why do we draw profiles?

Answer 29

• Allows engineers to catch mistakes before building roads

- Create accurate instructions for the road crew

Question 30

At is important about cut and fill slopes w.r.t materials

Answer 30

The more erodable the material, the lower the slope should be or it will just fill up your ditches.