Selection of the road Path
Road Dimension
Horizontal alignment
Vertical alignment
Intersection Calculation
Structure Design
Bill of Quantities
Road Dimension
Surface Flow=2000*v/c*fw*fHv*fp*fE*N
Surface Flow=DHV at 15 year
DHV15=DHV0 *(1+i)^n
DHV0=DHV(max volume from given)/Peak Hour Factor
i=3% n= 15year PHF=0.9
from table(2-1)
v=120kph , L.O.S=D →V/C=0.87
from table(2-2)
fw=1.0 (Lane width=3.75m Shoulder=2m)
from table(2-3)
at rolling terrain
Et=4.0
Eb=3.0
1
Fhv= =0.80 1+Pt(Et-1)+Pb(Eb-1)
1
Fhv= =0.80 1+0.15(4-1)+0.05(3-1)
fp=0.8 table (2-11) New road
from table (2-10)
fE=1.0 → Rural,divided
N≈2
CHARTS
Horizontal alignment
New Road
vd=120kph=75mph
From table(5-1) & page(5-6)→f=0.11,e=0.06
e+f=v²/127R
0.06+0.11=120²/127R →Rmin=666.97
Take R=800m → e=0.032=3.2%
For Spiral:
V=120kph →Amin=350m
A²=Ls*Rc→Ls=(350)²/800=153.13m
Check:
Lrun off=50ew/r=50*0.06*3.75*4/0.38=118.42m
Ls>Lrunoff OK
For curve(A)
Length=
Radius=
Delta angle=
Tangent=
Beginnig of curve Station=
End of curve Station=
Superelevation=
For curve(B)
Length=
Radius=
Delta angle=
Tangent=
Beginnig of curve Station=
End of curve Station=
Superelevation=
CHARTS
Vertical alignment
Vertical alignment
New road
1)crest vertical curves[on stopping sight distance]
vd=75mph→Kmin=325ft=100(table 6-2)
For A=|2.29-0.95|=1.34
L=K.A=100*1.34=134m
2)Sag vertical curves[on stopping sight distance]
V=75mph →Kmin=160ft≈50m
CHARTS
Intersection of the New rood with the existing rood
Weaving section:
Type A No of lanes =1
L.O.S=C
Quality of Flow= II - III
Weaving Length
(w1+w2)future=457+572=1029vph
For figure (10-13)
At II L=152.4mAt III L=277.6mTake Lweaving =250m
CHART
Intersection design elements
Turning Radius:
Vloop rump=(0.5→0.6)Vd=(0.5→0.6)*75
=37.5mph=60kph
e+f=v²/127R
take e=0.06 , f=0.17 (at v=37.5mph)
0.06+0.17=(60)²/127R
→ R=123.2m=125m
Or Take R=135m (From Tables)
And calculate equivalent e.
Width of pavements for turning rood ways
from table page(8-11)
at R=445ft ,(case III-B)→ Two lanes
w=28ft=8.5m
Two lanes 4.25 each
1)acc. And dec. lane from new rood(table page 8-14)
a)acc. Lane
va=75mph vtur=37.5mph
→ Ltaper=100 m
Llane= 200 m
b)decc.lane
vd=75mph vtur=37.5mph
→ Ltaper= 100 m
Llane= 50 m
CHARTS
Length of pavement narrowing at the entrance of a turning rood way
F=0.278*v*t
=0.278*60*4sec=66~70m
Nose taper
C=0.5lane→lane
Take c=3m=10ft →t=3sec
Vav=90kph=56.25mph
L=1.47vt=1.47*56.25*3=248.06ft=75.61m
→ L=80m
Bill of Quantities:
Rural Road:
Asphalt =Area of road= Length *width(2+1+7.5) = m2
Base= Area of road= Length *width(2+1+7.5) = m2
Subbase =Area of road= Length *width(2+1+7.5) = m2
Tackcoat= Area of road= Length *width(2+1+7.5) = m2
Primecoat= Area of road= Length *width(2+1+7.5) = m2
Total Volume of Cut= m3
Total Volume of Fill= m3
Urban Road:
Asphalt =Area of roads= m2
Base= Area of roads= m2
Subbase =Area of roads= m2
Tackcoat= Area of roads= m2
Primecoat= Area of roads= m2
Curbs = Lengths of sidewalk *2 = m
Interlock= Area of side walks = m2
Sand under Interlock= Area of side walks *5cm depth= m2
Total Volume of Cut= m3
Total Volume of Fill= m3
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