Post on 03-Sep-2019
Horizontal Alignment
Vertical Alignment
Bad Combinations of Bad Combinations of Horizontal and Vertical CurvatureHorizontal and Vertical Curvature
Good Combinations of Good Combinations of Horizontal and Vertical CurvatureHorizontal and Vertical Curvature
Bad Combinations of Bad Combinations of Horizontal and Vertical CurvatureHorizontal and Vertical Curvature
Vertical AlignmentVertical Alignment
• Maximum Grade• Critical Length of Climbing Lane• Property of Simple Parabolic Curve• Vertical Curve
• Crest • Sag
• Minimum Length of Vertical Curve
Typical MassTypical Mass--Haul DiagramHaul Diagram
STA.4+200 STA.4+300 STA.4+400 STA.4+500 STA.4+600 STA.4+700
20,00
25,00
30,00
35,00
40,00
45,00
20,00
25,00
30,00
35,00
40,00
45,00
Gambar 2 Profil Elevasi Tanah
Existing Ground ProfileExisting Ground Profile
STA.4+200 STA.4+300 STA.4+400 STA.4+500 STA.4+600 STA.4+700
20,00
25,00
30,00
35,00
40,00
45,00
20,00
25,00
30,00
35,00
40,00
45,00
Gambar 2 Profil Elevasi Tanah
Existing Ground ProfileExisting Ground Profile
STA.4+200 STA.4+300 STA.4+400 STA.4+500 STA.4+600 STA.4+700
20,00
25,00
30,00
35,00
40,00
45,00
20,00
25,00
30,00
35,00
40,00
45,00
Gambar 2 Profil Elevasi Tanah
Existing Ground ProfileExisting Ground Profile MAXIMUM GRADE (G)MAXIMUM GRADE (G)
Grade (%) = ( H / L )Grade (%) = ( H / L ) x 100x 100Slope Ratio = H : LSlope Ratio = H : L
Tan Tan α α ((oo) = H / L) = H / L
ααGG
LL
HH
850
760
670
680
590
5100
Maximum Grade (%)
Design Speed (km/h)
RSNI 2004 Table 19 p. 41 MAXIMUM CRITICAL LENGTH OF MAXIMUM CRITICAL LENGTH OF GRADE WITHOUT CLIMBING LANEGRADE WITHOUT CLIMBING LANE
Critical Length of Up Grade Slope
G %
Properties of ParabolaProperties of Parabola
1. The line joining the midpoint C of a chord AB of a parabola with the intersection D of the tangents at the ends of the chords is bisected by the parabola it self at E. Thus DE = EC.
2. Offsets from the tangent to the parabola vary as the square of the distance from the point of tangency.
3. The rate of change of curvature of the parabola varies directly as the distance.
Source: Barry, B. Austin (1988)
11STST Property of ParabolaProperty of Parabola
Source: Barry, B. Austin (1988)
D E C
B
A
D
E
CA
B
22ndnd Property of ParabolaProperty of Parabola
Tangent to ParabolaParabola
(2/3)2 10.00 = 4.44
(1/3)2 10.00 = 1.11
10.00
1/3 T2/3 T
T
33rdrd Property of ParabolaProperty of Parabola
The initial gradient changes uniformly with the distance: the rate of change of gradient in percent per station (r) is constant between the initial gradient (g1) and the final gradient (g2):
Lggr 12 −
=
33rdrd Property of Parabola Property of Parabola (cont(cont’’d)d)
For,g1 = -2.00%g2 = +4.00%L = 6 Sta.
r = (-2.00% - (+4.00%))/6 Sta.= -1.00%/Sta.
33rdrd Property of Parabola Property of Parabola (cont(cont’’d)d)
The initial gradient = + 4.00% will run out to 0% at this constant rate in four stations, thus giving the high point at Sta. 61:
g1 + r(n’) = 0%;n’ = -g1/r
= -4.00%/-1.00% = 4.00 Sta. From PVC
A Simple Computation of Parabolic A Simple Computation of Parabolic Vertical CurveVertical Curve
80
84
88
92
96
100
55 56 57 58 59 60 61 62 63 64 65
STATIONING OF ROUTE
ELE
VA
TIO
N O
F R
OU
TE
Tangent Elevation Curve Elevation Chord Elevation
PV
C
PV
I
PV
T
g1 = + 4.00%
g2 = - 2.00%
El. 100.00D
E
C
A
B
El. 88.00
El. 94.00
Parabolic Vertical Curve
Forward Tangent
Following Tangent
El. = 1/2 (100+91) = 95.50
El. = 1/2 (94+88) = 91.00
Finding offsets at any point Finding offsets at any point for a vertical parabolic curvefor a vertical parabolic curve
Offset at Sta. 58 = offset at Sta. 62= (1/3)2 4.50 = 0.50
Offset at Sta. 59 = offset at Sta. 61= (2/3)2 4.50 = 2.00
L = ( A x SL = ( A x S22 ) / 658 ) / 658 S < LS < LL = 2S L = 2S –– ( 658 / A )( 658 / A ) S > LS > L
L crest curve length (m)A algebraic difference in grade (%)S stopping sight distance (m)
Standard Minimum Crest Vertical Curve Standard Minimum Crest Vertical Curve Length for Stopping Sight DistanceLength for Stopping Sight Distance
RSNI 2004 p.41 & Table 20 p.42
Z = AS / 800Z = AS / 800
A algebraic difference in grade (%)S stopping sight distance (m)
Z > h1 Z > h1 S < LS < LZ < h1 Z < h1 S > LS > L
S < L or S > L ?S < L or S > L ? Standard Minimum Crest Vertical Curve Standard Minimum Crest Vertical Curve Length for Stopping Sight DistanceLength for Stopping Sight Distance
Standard Minimum Crest Vertical Curve Standard Minimum Crest Vertical Curve Length for Stopping Sight DistanceLength for Stopping Sight Distance
Standard Minimum Crest Vertical Curve Standard Minimum Crest Vertical Curve Length for Stopping Sight DistanceLength for Stopping Sight Distance
L = ( A x SL = ( A x S22 ) / (120 + 3,5S)) / (120 + 3,5S) S < LS < LL = 2S L = 2S –– [ (120 + 3,5S) / A ][ (120 + 3,5S) / A ] S > LS > L
L sag curve length (m)A algebraic difference in grade (%)S stopping sight distance (m)
Standard Minimum Sag Vertical Curve Length Standard Minimum Sag Vertical Curve Length for Stopping Sight Distancefor Stopping Sight Distance
RSNI 2004 p.42 & Table 21 p.43
Standard Minimum Sag Vertical Standard Minimum Sag Vertical Curve Length for Stopping Sight Curve Length for Stopping Sight
DistanceDistance
STOPPING SIGHT DISTANCESTOPPING SIGHT DISTANCE
( )gfVVDSSD ±
+=254
7,02
PASSING SIGHT DISTANCEPASSING SIGHT DISTANCE
4321 ddddDPSD +++= 432min 32 dddDPSD ++=
[SSGDUR 1992 p.33 or p.123-125]
Calculated Stopping Sight DistanceCalculated Stopping Sight Distance
Source:Standar Specification for Geometric Design of Urban Roads, 1992
( )gfVVSSD+
+=2
00394.0694.0
V = running speed (kph)f = friction coefficientg = grade (%)
Calculated Stopping Sight Distance Calculated Stopping Sight Distance (cont(cont’’d)d)
0.440.44202020200.440.44303030300.380.38363640400.350.35454550500.330.33545460600.310.31686880800.300.3085851001000.290.29102102120120
Friction Friction CoefficientCoefficient
Running SpeedRunning Speed((kphkph))
Design Speed Design Speed ((kphkph))
Source:Standar Specification for Geometric Design of Urban Roads, 1992
STOPPING SIGHT DISTANCE CHART FOR DESIGN SPEED 20 - 50 kph
10
20
30
40
50
60
70
10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10
Grade (%)
Stop
ping
Sig
ht D
ista
nce
(m)
V=50kph
V=40kph
V=30kph
V=20kph
( )gfVVSSD+
+=2
00394.0694.0
V = running speed (kph)f = friction coefficientg = grade
STOPPING SIGHT DISTANCE CHART FOR DESIGN SPEED 60 - 100 kph
50
100
150
200
250
300
10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10
Grade (%)St
oppi
ng S
ight
Dis
tanc
e (m
)
V=120kph
V=100kph
V=80kph
V=60kph
( )gfVVSSD+
+=2
00394.0694.0
V = running speed (kph)f = friction coefficientg = grade
L = ( A x SL = ( A x S22 ) / [ 800 (C) / [ 800 (C--1,5) ] 1,5) ] S < LS < LL = 2S L = 2S –– [ 800 (C[ 800 (C--1,5) / A ] 1,5) / A ] S > LS > L
L sag curve length (m)A algebraic difference in grade (%)S stopping sight distance (m)C vertical clearance (m)
Standard Minimum Sag Vertical Curve Standard Minimum Sag Vertical Curve Length for Underpass Sight DistanceLength for Underpass Sight Distance
RSNI 2004 p.43 & Table 21 p.43
Standard Minimum Sag Vertical Standard Minimum Sag Vertical Curve Length for Underpass Sight Curve Length for Underpass Sight
DistanceDistance
L = K x A L = K x A
K Crest Curve Table 20 page 42Sag Curve Table 21 page 43
L crest curve length (m)A algebraic difference in grade (%)
Standard Minimum Vertical Curve Length Standard Minimum Vertical Curve Length for Kfor K--ValueValue
RSNI 2004 Table 20 p.42 & Table 21 p.43