1. E4014 Construction Surveying
Pavement Setout

2. Road Construction Consists of a number of sequential steps clearing
earthworks
drainage works
pavement construction
road furniture

3. Road Construction - Clearing
When
occurs prior to commencement of earthworks
Where
1.5metres outside road formation
How
remove all trees and other vegetation

4. Road Construction - Clearing
Surveyor’s Role
mark limits of road formation
batter points + 1.5metres
stakes with flagging or flag trees
use plans and tables

5. Road Construction - Clearing
Existing Survey Control
baseline survey marks and offsets
permanent marks & bench marks
Accuracy of Setout
probably ±0.5metre horizontal

6. Road Construction - Drainage
When
before major earthworks
keep construction site dry
after major earthworks
to keep subgrade dry

7. Road Construction - Drainage Surface Drains
Where
catch drains
catch surface water flow over adjacent natural surface and divert it into the drainage system
2metres from edge of cutting
maybe construct bank rather than cut surface drains
When
before major earthworks

8. Road Construction - Drainage Surface Drains
Where
Table Drains
collect surface water draining off the road pavement
wide and deep enough to collect and hold all surface water
deep enough to intercept any subsoil moisture close to the surface
discharge onto natural surface or into culverts every 100 metres
When
after major earthworks - before subgrade construction

9. Road Construction - Drainage Surface Drains
Where
Levy Drains
used on hills to collect run-off from pavement area and direct it into flumes which carry the water down the embankment
prevents scouring of the batters in fill
When
before and after major earthworks

10. Road Construction - Drainage Surface Drains
Where
kerb & Gutter
urban form of table drain
also used in rural road cuttings
normally constructed by an extrusion machine
When
after major earthworks and pavement construction

11. Road Construction - Drainage Subsoil Drains
Where
constructed to prevent damage by underground water from
water seeping down through the pavement
water rising in springs
water flowing downhill in the upper soil layers
control is achieved by
intercepting ground water before it reaches the roadway
lowering the water table by providing outlets for reservoirs surrounded by impervious barriers
subsoil pipes are usually located
in the shoulder between the pavement and the table drain
under the edge of pavement

12. Road Construction - Drainage Subsoil Drains
Where
Culverts
carry water from one side of the road formation to the other
pre-cast concrete pipes, pre-cast concrete boxes, insitu concrete boxes, corrugated steel pipes and arches
When
after construction of sub-grade, before placing the sub-base

13. Road Construction - Earthworks
Proper construction involves
clearing
stripping of topsoil
drainage of swampy areas
removal of poor materials
compaction of natural surfaces
benching of steep slopes
spreading and compaction of fill materials

14. Road Construction - Earthworks
Preparation of site
clear all timber
utilities
re-location of existing utilities
conduits for future utilities will save cost and damage to road formation at a later time

15. Road Construction - Earthworks
Preparation of site, cont
access through the site for current traffic
away from construction site
in rugged country locate the side-track in the position of the final catch drain on the up-hill side of cuttings

16. Road Construction - Earthworks
Preparation of site, cont
Removal of topsoil
valuable commodity to be conserved for later landscaping
wasted in fills and destroyed by having fills placed over it
removal of top soil ensures firmer foundation of fills
stockpiled in heaps of less than 1 metre in height
if buried for long periods fertility is lossed

17. Road Construction - Earthworks
Preparation of site, cont
Removal of material too weak to support fill
highly organic clays, saturated clays in swamps, silt and mud
compact the natural surface of fill sites by rolling

18. Road Construction - Earthworks
Preparation of site, cont
Cuttings and Fills
eventual aim of all fill work is to position the the subgrade underlying the pavement layers in the right location and at the correct level and to provide drainage to maintain its condition

19. Road Construction - Earthworks
Preparation of site, cont
earthworks operation comprises the following operations
formation of cutting by excavating through the high ground
formation of embankments by filling over the low ground
shaping the ground or finished surface to true formation levels
excavation for drainage works

20. Road Construction - Earthworks
Preparation of site, cont
earthworks operation will involve
excavating or loosening natural material
loading the material into haulage units
transporting the material from cuttings or borrow pits to fill sites
dumping the material
compacting the material

21. Road Construction - Earthworks
Preparation of site, cont
Cuttings
Through Cuts
may be through a small hill or over the top of a large hill to lower the grade of a road
prior to construction the material type must be identified and the angle of repose estimated
Side Hill Cuts
part of the road in cut and part in fill
enables balancing of earthworks
embankment portion tends to move downhill, better to be full cut

22. Road Construction - Earthworks
Preparation of site, cont
Fills
material should be obtained from as near to the embankment site as possible
material should be stable, high bearing strength and a free draining nature
sand gravel mix, sand clay mix and sand silt mix are suitable fill materials when correctly placed

23. Road Construction - Earthworks
Preparation of site, cont
Cut & Fills
often the largest task in road works
often the most costly operation in terms of total sums of money involved
speed and efficiency depends largely on the quantity and types of earthmoving plant available
initial plant selection for a site will effect the its overall progress

24. Road Construction - Earthworks
Preparation of site, cont
Cut & Fills, cont
in most materials except rock the factor governing the speed of work is likely to be transporting of the material and not the excavation itself
capacity of the haulage system must equal the maximum digging output
it follows that the haul should be kept as short as possible

25. Road Construction - Earthworks
Preparation of site, cont
Sequence of operations in CUT
excavate to reach formation level or to remove alll unsuitable material
transport away from site the undesirable soils
organic top soil, heavy highly plastic water-logged clays, loose sand
haul suitable material from cuts to fill areas

26. Road Construction - Earthworks
Preparation of site, cont
Sequence of operations in FILL
drain water from hollows and holes, dispose of sludge before filling is begun
spread the fill material into horizontal layers not more than 250mm deep
thoroughly compact these layers to maximum density

27. Road Construction - Bases and Sub-Bases
After the earthworks and compaction of fills, subgrade is brought tp the correct formation and trimmed
Road Pavement
sub-base layer, maybe
base course layer

28. Road Construction - Bases and Sub-Bases
Road Pavement
sub-base layer, maybe
stronger than the underlying subgrade
base course layer
stronger than the sub-base
surface course
stronger than the base course
wheel loads which are most intense near the surface are taken by materials which are able to accept the load without significant deformation

29. Road Construction - Bases and Sub-Bases
Base Course
Rigid
cement concrete with or without the addition of a separate wearing course
used in roads effected by flooding or subjected to heavy traffic loads

30. Road Construction - Bases and Sub-Bases
Base Course, cont
Flexible bases
natural materials which deflect slightly under loads
common in Qld are soil aggregate, crushed rock and uncrushed stone
level control required as the material is placed in layers deep enough to ensure required compaction can be achieved
if tests have not been done on the material the loose layer should be placed 25% thicker than the desired final compacted layer

31. Road Construction - Bases and Sub-Bases
Base Course, cont
Flexible bases
natural materials which deflect slightly under loads
common in Qld are soil aggregate, crushed rock and uncrushed stone
level control required as the material is placed in layers deep enough to ensure required compaction can be achieved
if tests have not been done on the material the loose layer should be placed 25% thicker than the desired final compacted layer 1