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FINAL PRESENTATION OF SIX MONTHS INTERNSHIP
SUBMITTED BY
Anshul Soni
B100030025
UNDER GUIDANCE OF
Mr. Bidyut Panda Mr. Dinesh Kumar
(Faculty Coordinator) (AGM)
ABOUT OMAXE
25 years old
Having its footprints in 9 states across 30 cities in India
Working on more than 1000 projects in India
DETAILS OF WORK
Clearing and Grubbing
Earthwork
Granular sub base
Water bound Macadam
Wet Mix Macdam
Lab work
Construction of Pavement Structures
Evaluation of Pavement Structures
Maintenance Programs of Pavement Structures
Design of Pavement Materials
Aggregates Asphalt
Laboratory Exp.
ROAD CONSTRUCTION
EARTHWORKS
The eventual aim of the earthworks phase of the construction is to position the subgrade underlying the pavement layers in the right location and at the correct level, and to provide drainage. The operations to be performed are:
•formation of cuttings by excavating through high ground,
•formation of embankments by filling over low ground, formation of embankments by filling over low ground, shaping the finished surface to design levels, and excavating for drainage works.
SEQUENCE OF OPERATIONSFOR EARTHWORK
The normal sequence of operations in cut and fill work is: –
In Cut :-
excavate to the depth necessary to reach formation level, py,
transport away from the site undesirable material such as organic soils
SEQUENCE OF OPERATIONSFOR EARTHWORK
In Fill :-
drain water from depressions and dispose of any unsuitable underlying material,
spread fill material in horizontal layers not more than 250 mm
Compacted properly
COMPONENTS OF FLEXIBLE PAVEMENT
SUB GRADE
Sub grade is normally formed with natural earth
Compacted to 97% of dry density .
Materials used for sub grade construction should have the dry density of not less than 1.75 gm/cc - Wherever necessary, the original ground shall be leveled to facilitate placement of first layer of embankment, scarified, mixed with water and then compacted by rolling so as to achieve minimum dry density.
SUB GRADE
As far as possible a non expansive soil should not be used for the sub grade.
The sub grade strength is assessed in terms of the CBR (California Bearing Ratio).
The design should be based on the CBR value of the weakest soil type proposed to be used for subgrade construction or encountered extensively at subgrade level over a given section of the road.
SUB BASE
Material comprise natural sand, gravel, metal, laterite crushed stone etc. and
Should have liquid limit and plasticity index of not more than 25 and 6 respectively
for drainage consideration the granular sub base should be extended over entire formation width in case of the sub grade soil is of relatively low permeability.
SUB BASE
In our project a GSB(granular sub base) of thickness 260mm is provided
BASE COURSE
Granular base comprises wet mix macadam (WMM) or other equivalent granular construction
In our project WMM of thickness 250mm is provided
BINDER COURSE
DBM(Dense Bitumen Macadam) of thickness 95mm is used in our project
BITUMINOUS SURFACING
Comprise of either a wearing course or a binder course with wearing course depending on traffic intensity and structural requirements
DBM( Dense bitumen macadam )is recommended
BC(Asphalt) of thickness 40mm is provided
DESIGN APPROACH AND CRITERIA AS PER IRC-SP
2002
The following three types of pavement distress resulting from repeated application of traffic are considered: (i)Horizontal tensile strain at the bottom of the bituminous layer (ii)Vertical compressive strain at the top of the subgrade (iii)Pavement deformation with in the bituminous layer
The deformation with in the bituminous layer is assumed to be controlled by meeting the mix design requirements
F A I L U R E C R I T E R I A
Fatigue Cracking
-Is due to the build up of tensile strain at the bottom of Asphaltic Concrete Layer
-Pavement is considered failed if 20% of the surface has cracked
Rutting Failure
-Is due to the build up of excessive compressive strain at the top of subgrade layer
-Pavement is considered failed if it exhibits a rut depth of 20 mm
TRAFFIC
Traffic is considered in terms of the cumulative number of standard axles (8160 kg) to be carried by the pavement during the design life
For estimating the design traffic, the following Information is needed:
-Initial traffic after construction (CVPD)
-Traffic growth rate during the design life ,By studying the past trends of traffic growth .
COMPUTATION OF DESIGN TRAFFIC
365 x A[(1+r)n – 1]N = --------------------------- x D x F
r
N = Cumulative No. of standard axles to be catered for the design in terms of msaD = Lane distribution factor A = Initial traffic, in the year of completion of construction, in terms of number of commercial vehicles per day F = Vehicle Damage Factorn = Design life in years r = Annual growth rate of commercial vehicles
EXAMPLE OF PAVEMENT DESIGN FOR A NEW BYPASS
DATA:Two-lane single carriageway = 400 CV/day (sum of both directions)Initial traffic in a year of completion of construction
Traffic growth rate per annum = 7.5 percent Design life = 15 years
Vehicle damage factor = 2.5 (standard axles per commercial vehicle)
Design CBR value of sub-grade soil = 4 %
Distribution factor = 0.75Cumulative number of standard axles to to be catered for in the design
365 x [(1+0.075)15 –1]N = ----------------------------- x 400 x 0.75 x 2.5
.0075
= 7200000 = 7.2 msa
Total pavement thickness for = 660 mm CBR 4% and Traffic 7.2 msa
Pavement Composition interpolatedFrom Plate 1, CBR 4% (IRC37-2001)Bituminous surfacing = 25 mm SDBC +
70 mm DBM Road base, WBM = 250 mm Sub-base = 315 mm
EXAMPLE OF PAVEMENT DESIGN FOR WIDENING AN EXISTING 2-LANE
NH TO 4-LANE DIVIDED ROAD
Data:i) 4-lane divided carriageway
Initial traffic in each directions in the year of = 5600cv / day
Completion of constructioniii) Design life = 10/15yrs
iv) Design CBR of sub-grade soil = 5 % v) Traffic growth rate = 8 % vi) Vehicle damage factor = 4.5 (Found
out from axle road survey axles per CV on existing road)
Distribution factor = 0.75VDF = 4.5CSA for 10 Years = 100 msa(million standard axle) CSA for 15 years = 185 msaPavement thickness for CBR 5% and 100 msa for 10 Years = 745 mmFor 185 msa for 15 years = 760 mm
Provide 300 mm GSB + 250 mm WMM + 150 mm DBM + 50 mm BC (10 years)
Provide 300 mm GSB + 250 mm WMM + 170 mm DBM + 50 mm BC (15 years)
EQUAL SINGLE WHEEL LOAD (ESWL)
(Boyd & Foster - 1950)
PROCEDURE
Traffic intensity is calculated for next 15 years by GMADA
GMADA has given those values to the Omaxe
On the basic of that values and geological profile made by survey
Design engineer designed the road as per the recommendation given by the IRC
PROCEDURE
Life of road is considered as 15 years so taking that a design of road was prepared
PROCEDURE
After getting the design the site engineer started construction
Clearing and grubbing were done keeping in mind that all the existing line road and sewer lines and water supply pipes may not get any type of loss.
All the instruments used in earthwork were mentioned by site engineer for safety of water supply and sewer pipe
PROCEDURE
After earthwork, subgrade layer for flexible pavement was compacted at omc up to 97%.
Levelling was done properly ,so that in lateral stages all the problem of drainage may not be faced.
One subgrade layer get prepared ,construction of sub base layer was started.
PROCEDURE
After the completion of sub base layer , its compaction is done
After the sub base completion tack coat is done for better bond between two layers
And construction base layer is started
PROCEDURE
After the base layer again tack coat is done and final surface layer is constructed in two layers
TEST ON SOIL
CBRDetermining Water Content In SoilDetermine Free Swell Index Of SoilDetermine The Plastic Limit Of SoilDetermine The Liquid Limit Of SoilDetermine Particle Size Distribution Of Soil
DETERMINING WATER CONTENT IN SOIL – OVEN DRYING METHOD
FREE SWELL INDEX OF SOIL
Free swell index = [Vd - Vk] / Vk x 100%
PLASTIC LIMIT OF SOIL
Take about 8g of the soil and roll it with fingers on a glass plate. The rate of rolling should be between 80 to 90 strokes per minute to form a 3mm dia.
The plastic limit should be determined for at least three portions of the soil passing through 425µm IS Sieve. The average water content to the nearest whole number should be reported.
DETERMINE THE LIQUID LIMIT OF SOIL
DETERMINE PARTICLE SIZE DISTRIBUTION OF SOIL
C B R
to determine the California bearing ratio by conducting a load penetration test in the lab
C.B.R. = (Test load/Standard load )X100
TEST ON BITUMIN
Determining Penetration of BitumenDetermining Specific Gravity of Bitumen
PENETRATION OF BITUMEN
Bitumen should be just sufficient to fill the container to a depth of at least 15mm in excess of the expected penetration.
SPECIFIC GRAVITY OF BITUMEN
i) Specific gravity (Solids and semi-solids) = (C-A )/[ ( B-A) - (D-C)]ii) Specific gravity (Liquids) = (E-A)/(B-A)The average of the two results should be reported.
TEST ON AGGREGATES
Water Absorption of AggregatesAggregate Impact ValueAggregate Abrasion ValueAggregate Crushing Value
WATER ABSORPTION OF AGGREGATES
Formula used is Water absorption = [(A - B)/B] x 100%.
AGGREGATE IMPACT VALUE
AGGREGATE ABRASION VALUE
AGGREGATE CRUSHING VALUE