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| Date post: | 12-Jan-2016 |
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Learning outcome
• Basic techniques of road construction• Plant and equipment selection• Types of pavements• Construction sequences• Mass haul diagram
PLANT & EQUIPMENTEARTHMOVING MACHINERY• DOZERS• SCRAPERS• EXCAVATORS • TIP TRUCKS
COMPACTION EQUIPMENT• SHEEPSFOOT ROLLERS• TAMPING ROLLERS• SMOOTH-DRUM VIBRATORY SOIL COMPACTORS• PAD-DRUM VIBRATORY SOIL COMPACTORS• PNEUMATIC TIRED ROLLERS
PLANT & EQUIPMENT (CONT.)
OTHER PLANT & EQUIPMENT
• WATER DISTRIBUTOR• DRILL & BLAST EQUIPMENT • PAVING MACHINES• BITUMEN SPRAYERS & EQUIPMENT• DE-WATERING EQUIPMENT
100101
101102
102
103
106
105
104
No cut / no fill line
CUTTING FILL
Elevation
Plan
ROAD DESIGNNatural surface
Road gradeline
Cross SectionExcavation (Cut)
ROAD DESIGN
Cross SectionEmbankment (Fill)
Subgrade
Cross SectionFlexible Pavements (Typical)
Wearing CourseAsphalt / Bitumen Seal)
Base course
Sub-base course
Lower Sub-base course
Subgrade
Batter
Subgrade strength
• Removing poor material in cutting and replacing with selected fill.
• Ensure compaction to a high dry density.• Providing adequate subsoil drainage.
Why we need Subsoil Drainage
Drainage pipe
Sub soil drain
Subsoil drainage location
Soil stabilisation
• Stabilisation refers to any treatment of the soil that increases its strength.
• Stabilisation may be achieved by various agents, which include cement, lime, bitumen.
California bearing ratio
C.B.R. = Test load/Standard load
Types of pavements
Flexible pavement
• Flexible pavement
Consists of several layers of materials Flexible pavement distributes loads over a
smaller area. It relies on a combination of layers for
transmitting load to the subgrade
Rigid pavement
Rigid Pavement Consists of a concrete slab resting on subbase
material Distribute the load over a relatively wide area of
subgrade
Contraction joints
A contraction joint is provided to controlcracking in rigid pavementsTransverse contraction joints can be cut at
right angles or skewed to the direction oftraffic flow to help with load transferDowel bars are used to transfer loads
across the joints.
Expansion joints
• Expansion joints are constructed to allow pavements to expand and contract without damage to adjacent pavements or structures
Construction joints
• A construction joint is a joint between slabs that results when concrete is placed at different times.
• This type of joint can be further broken down into transverse and longitudinal construction joints
CONSTRUCTION SEQUENCEESTABLISHMENT• COMPOUNDS AND OFFICES
ROADWORKS• SURVEY• INVESTIGATION WORKS • ENVIRONMENTAL WORKS• CLEARING / STRIP VEGETATION & STOCKPILE
TOPSOIL• INSTALL MAJOR DRAINAGE STRUCTURES• BULK EARTHWORKS (CUTS AND FILLS)• INCLUDE IMPORT FILL (SHORTFALL FROM CUTS)• BOX FOR PAVEMENTS
CONSTRUCTION SEQUENCE (CONT.)ROADWORKS (CONT.)
• INSTALL SUB-BASE PAVEMENTS • INSTALL BASE COURSE PAVEMENTS
(ALTERNATIVES ASPHALT OR CONCRETE PAVEMENTS)
• INSTALL PAVEMENT DRAINAGE• INSTALL WEARING SURFACE
(ASPHALT OR SPRAYED BITUMEN / AGGREGATE)• BATTER SLOPE PROTECTION (TOSOIL RE-
SPREAD & LANDSCAPING WORKS)• INSTALL ROAD HARDWARE / FURNITURE• LINE MARKING & ROAD SIGNS
SURVEY
• SET OUT HORIZONTAL AND VERTICAL CURVES
• SET OUT SUPER ELEVATIONS (CROSSFALLS)
• MONITOR EARTHWORKS DURING CONSTRUCTION
• PREPARE “AS CONSTRUCTED” DRAWINGS
EXISTING SUBSTRATE
PREPARING SUBSTRATE BENEATH FILLS(GROUND SURFACE TREATMENT)
150
PROOF ROLL EXISTING GROUND SURFACE
EXPOSE SOFT SPOTS
EXCAVATE SOFT SPOTS
FILL AND COMPACT SOFT SPOTS
REMOVE TOP SOIL & VEGETATION
TOP SOIL
CONSTRUCTION PROCEDURES
EXCAVATIONS (CUTS) IN OTHERTHAN ROCK (OTR) AND IN ROCK
CONSTRUCTION PROCEDURES
DRILL AND BLAST
OTR EXCAVATION
REMOVED BY SCRAPERSDOZERS, EXCAVATORS
ROCK EXCAVATION
REMOVED BY DRILLINGAND BLASTING, RIPPING,LOADING OUT BY TRUCKS
PREPARED SUBSTRATE
WIN FILL MATERIAL (FROM CUTS OR IMPORTED)
TRANSPORT FILL TO SITE
SPREAD FILL ON PREPARED SUBSTRATE
COMPACT FILL WHILE CONTROLLING MOISTURE
EMBANKMENTS (FILLS)
TRIM TO PROFILE
CONSTRUCTION PROCEDURES
CUT OUT BOX
PREPARED SUBSTRATE
PLACE AND COMPACT GRAVEL SUB-BASE
GRAVEL PAVEMENTS
ROLL BOX / PREPARE SUBGRADE
PLACE & COMPACT GRAVEL BASE
FINAL TRIM TO GRAVEL PAVEMENTS
CONSTRUCTION PROCEDURES
COMPACTED EMBANKMENT
CONSTRUCTION PROCEDURES
GUARD RAILS
DELINEATOR POSTS(GUIDE POSTS)
MULCHING OR GRASSING TOSTABLISE BATTERS
COMPACT ASPHALTPLACE ASPHALT WEARING COURSE
WEARING SURFACE AND ROAD FURNITURE
COMPLETED EMBANKMENT& GRAVEL PAVEMENTS
SLOPE PAVING / PROTECTION
SURFACE DRAINS
PLACE & COMPACT PAVEMENTS & WEARING COURSE
CONSTRUCTION PROCEDURESIN EXCAVATIONS (CUTS)
ROLL BOX / PREPARE SUBGRADEROAD FURNITURE
SUB-SURFACE DRAINS
CATCH DRAINS
REINFORCED CONCRETE BASE
BOX CULVERTWING WALLS
POROUSBACKFILL
HIGHLY COMPACTEDBACKFILL
COMPACTED BACKFILL
EMBANKMENT FORMATION
Plan
Section(Through Watercourse)
STREAM
BOX CULVERTS
Box culvert
Mass haul diagram
• The mass haul diagram is an excellent method of analysing linear earthmoving operation.
MASS HAUL• CALCULATE QUANTITIES FOR CUT AND FILL FOR
SEGMENTS TYPICALLY AT REGULAR INTERVALS (EVERY 50m OR 100m)
• FOR EACH SEGMENT CALCULATE QUANTITY CUT TO FILL WITHIN SEGMENT
• FOR EACH SEGMENT CALCULATE QUANTITY EXCESS CUT OR SHORTFALL FILL
• DETERMINE MOST EFFICIENT HAULS FOR CUT TO FILL OPERATION
• TYPES OF EQUIPMENT SHOULD BE CONSIDERED FOR ACCOMPLISHING THE WORK.
MASS HAUL DIAGRAM
Chainage (m)
0-100
100-200
200-300
300-400
400-500
500-600
600-700
700-800
Totals
Cut (m3) 200 1000 3000 2000 0 100 1000 0 7300 m3
Fill (compacted Vol m3)
500 300 0 500 3500 3500 500 500 9300 m3
Fill (m3) 575 345 0 575 4025 4025 575 575 10695 m3
Cut to Fill<100m
200 345 0 575 0 100 575 0 1795 m3
Cut less Fill i.e Excess Cut +ve shortfall Fill -ve
-375 280 3280 4705 680 -3245 -2820 -3395
MASS HAUL DIAGRAM (CONT.)
Balanced line
• A balanced line is a horizontal line of specific length that intersects the mass diagram in two places.
• The balance line can be constructed so that its length is the maximum haul distance for different types of equipment.
