design of proposed highway
TRANSCRIPT
GEOMETRIC DESIGN OF PROPOSED HIGHWAY
PROJECT REPORT
Submitted by
AHMED TOWFEEQULLAH SIDDIQUI
(247935)
&
MOHAMMED SHOAIB
(248509)
DEPARTMENT OF CIVIL ENGINEERING & CONSTRUCTION
BRADLEY UNIVERSITY
PEORIA, IL
TABLE OF CONTENTS
LOCATION MAP
BACKGROUND AND SPECIFICATIONS
ALTERNATIVE ROUTES
SCREENING OF ALTERNATIVE ROUTES
HORIZONTAL ALIGNMENT
HORIZONTAL CURVE COMPUTATIONS
PROFILE (VERTICAL ALIGNMENT)
VERTICAL CURVE COMPUTATIONS
CROSS SECTIONS
LOCATION MAP
The location map indicates the topographic features in the area of the route and selected end points where connections with the existing roads are to be made. Obviously, the route cannot be indicated until the preliminary design has been completed.
In addition, it is usually important that the location map be properly identified with regard to state, country, municipal, and other jurisdictional boundaries, (including federal) agencies and other interests. In practice, it would also be usual to relate the proposed highway to the regional highway network.
8 1 9
9 0 0
100
0
950
900
850
8 5 2
E
A
B
11 0 1 1
9 4 0
850
E n d p o in t
E
B E G I N N I N G P O I N T
810
810B
19 9 5
1 0 0 0
850
840
9 7 0
830
840A
BO
ND
ON
ED
RO
AD
800
800
790
790
780780
Specified end points of proposed highway
Beginning point – B
End point ‐ 1
DRAWING NO: Figure Title: LOCATION OF PROPOSED HIGHWAY SCALE (S) : As shown
BACKGROUND AND SPECIFICATIONS
This section provides the basic information which the designer relies upon to select the routes and undertake the design. The information should be clearly stated also because it informs others about the base guidelines and assumptions that have affected the outcome. These guidelines and assumptions may be the subject of future policy changes resulting from the review of the preliminary design but typically do not change during the preliminary design process.
In this project the background and specifications are presented in the following pages:
Introduction and Background:
The preliminary route selection and design of the proposed highway is intended to exist in
exploring the cost and land use implications of connecting North road with Southwest Road at
points B and 1 respectively, shown on the location map. Tentative analysis of future traffic
levels has been made, including consideration of potential use of the state reservation as an
environmental research area, with possible public access.
Objectives:
In accordance with above background, it is required to conduct a preliminary route selection
and design for a 2 lane highway in accordance with AASHTO “Rural collector” highway design
standards. Two alternative routes initially investigated. However, only one Route is to be
selected for the design process, immediately following a brief screening of both routes.
Design policy:
In addition to Using the AASHTO policy on geometric design for “rural collector” highway as
basic design guidelines, several more specific guidelines has been defined within the IDOT and
general policy, resulting from examination or the environs of highway and its likely uses. The
traffic control devices should be provided in accordance with the latest version of MUTCD and
local regulations.
Design designation:
Classification =Rural Collector
Design speed =40mph
ADT (current year) =0
ADT (future year) =4000
K =10%
D =60%
T =2%
Design Controls:
Design speed, V =40mph
Super elevation rate, e(max) =6%
Minimum Radius for above V and E =485 ft
(Also satisfies stopping sight dist. Requirements for horizontal curves)
Maximum grade, except at intersections =6%
Minimum grade (All locations) =0.5%
Maximum Vertical curve K value, drainage criteria =167
Design vehicle =WB‐50
Intersection Geometrics: Horizontal intersection of proposed route with existing highway should be a minimum
of 100ft tangent segment as close to 90°as possible to the existing highway, but within
the range of 75° to 105°.
Maximum grade (+ or ‐) within 100ft of intersection
Lane Requirements: Two lanes are minimum number of lanes for an adequate design. Therefore, the
highway will comprise 2‐12ft lanes with 8ft shoulders.
ALTERNATIVE ROUTE
From the examination of the contours and terrain, two possible routes, A and
B, were defined, as shown in the figure. In the plan view of these routes, the
curves have been shown to conform with the minimum required radius. In the
profiles shown in figure, both alternatives comply with the required controls, and
Route A is approximately 403ft longer than B. (fig)
819
900
1000
950
900
850
852
E
A
B
11011
940
850
E n d p oin t
E
B E G IN N IN G P O IN T
810
810B
1995
1000
850
840
970
830
840A
BO
ND
ON
ED
RO
AD
800
800
790
790
780780
ROUTE B
ROUT
E A
DRAWING NO: Figure Title: ALTERNATIVE ROUTES A & B SCALE (S) : As shown
ROUTE‐A
Elevations Cummulative Distance
845 0
840 255.73
830 389.33
820 539.11
810 677.67
800 852
790 1104.8
780 1258.79
770 1444.2
780 1545.45
790 1629.51
800 1724.94
810 1900.14
820 2048.71
830 2116.51
840 2539.42
850 2645.84
860 2970.87
870 3126.49
880 3299.36
890 3409.6
900 3708.97
910 3846.4
920 4032.08
930 4219.95
940 4407.03
950 4559.27
960 4689.71
970 4826.07
980 4930.36
990 5068.12
995 5322.29
ROUTE A
ROUTE‐B
(DESIGN ROUTE)
Elevations Cummulative Distance
845 0
840 336.49
830 529.73
820 727.16
810 938.87
810 1121.88
820 1233.39
830 1781.54
830 2312.28
820 2417.28
830 2510.67
840 2588.7
850 2717.04
860 2816.56
870 2907.1
880 3111.91
890 3255.83
900 3295.93
910 3423.04
920 3599.98
930 3749.73
940 3869.29
950 3952.76
960 4116.65
970 4350.79
980 4528.06
990 4735.71
1000 4919.92
SCREENING OF ALTERNATIVES
Examination of the profiles of Routes A and B, shown in figure , indicates that
both Routes A and B could provide a vertical profile which would conform with
the gradient and depth of cut and fill but that Route A requires excessive uphill
haul. For this and other reasons indicated in the summary screening process
shown in the figure, Route B is the one selected for technical feasibility.
SCREEN EVALUATION
S No. CRITERIA
ROUTE A ROUTE B
1 Length of Route 5322.29 ft 4919 FT
2
Conformance with design controls
Full conformance
3 Cut and fill balance There is an even balance
Excessive cutting is required
4
Need for bridges or special structures
None None
5 Environmental impacts No obvious Environmental impacts
Excessive cut & fill will lead to
environmental impacts.
6
Potential high cost items
None Excessive hauling & digging costs
involved
7 Haul direction Satisfactory
Excessive uphill hauling.
CONCLUSIONS: Route‐A is longer than Route‐B, but Route B requires excessive
uphill haul and need to dispose of considerable earthwork off the site.
PROCEEDING WITH THE ROUTE‐A FOR ANALYSIS PURPOSES.
HORIZONTAL ALIGNMENT
The horizontal alignment can be developed for alternative B and the relevant dimensions and angles computed and checked. The development of tangent and curve distances may then be converted to stations and an estimate of the traverse closure made to ensure that no gross errors have been made in the scaling of distances and angles. As well as the dimensions of each of the tangent and curve segments of the proposed highway, the stations are computed for points along the centerline of the route.
Care must be taken to define clearly the location of the beginning and end points of the proposed route, in this case assumed to be the centerlines of the existing highways. Each curve radius is checked for compliance with the minimum allowable radius of 485ft (According to BDE manual).
During this preliminary design stage for this class of highway, no attempt has been made to illustrate the use of transition curves, however, the superelevation curve has been designed and calculated and shown on drawings.
STA 1+00
STA 2+00
STA 3+00
STA 4+00
STA 5+00
STA 6+00
STA 7+00
STA 8+00
STA 9 +00
ST A 1 0+00
ST A 1 1+00
STA 12+00
STA 13+00
STA 14+00
STA 15+00
ST A 16 +00
STA 17+00
STA 18+00
STA 19+00STA 20+00
STA 21+00STA 22+00
STA 23+00STA 24+00
STA 25+00STA 26+00
STA 27+00STA 28+00
STA 29+00
STA 30+00
STA 31+00
STA 32+00
STA 33+00
STA 34+00
STA 35+00
STA 36+00
STA 37+00
STA 38+00
STA 39+00
STA 40+00
STA 41+00
STA 42+00
STA 43+00
STA 44+00
STA 45+00
STA 46+00
STA 47+00
STA 48+00
STA 49+00
STA 50+00
STA 51+00
STA 53+22.29STA 53+00
STA 52+00
434.7621
849.4409
660.
7152
STA 0+00
CURVE #1
CURVE #2
CURV
E #
3
81.1156°
41.5167°
63.0
936°
DRAWING NO: Figure Title: HORIZONTAL ALIGNMENT PROPOSED CENTRELINE SCALE (S) : As shown
DRAWING NO: Figure Title: HORIZONTAL TOPO SCALE (S) : As shown
DRAWING NO: Figure Title: HORIZONTAL CURVE 1 SCALE (S) : As shown
DRAWING NO: Figure Title: HORIZONTAL CURVE 2 SCALE (S) : NA
DRAWING NO: Figure Title: HORIZONTAL CURVE 3 SCALE (S) : NA
CURVE#1 CURVE#2 CURVE#3
PC= 6+12.13 PC= 13+42.15 PC= 42+61.18 PT= 10+46.89 PT= 21+91.59 PT= 49+21.89 R=600 R=600 R=600 Rmin= v^2 15(e+fs) Rmin= 40^2 =485ft 15(0.06+fs)
Rmin= v^2 15(e+fs) Rmin= 40^2 =485ft 15(0.06+fs)
Rmin= v^2 15(e+fs) Rmin= 40^2 =485ft 15(0.06+fs)
D= 5729.58 = 9.54° 600
D= 5729.58 = 9.54° 600
D= 5729.58 = 9.54° 600
Δ=L*D 100 Δ=434.76*9.54 =41.47° 100
Δ=L*D 100 Δ=849.44*9.54 =81.036° 100
Δ=L*D 100 Δ=660.71*9.54 =63.03° 100
T= Rtan (Δ/2) T= 600tan (41.47/2) = 230.31’
T= Rtan (Δ/2) T= 600tan (81.03/2) = 512.44’
T= Rtan (Δ/2) T= 600tan (63.03/2) = 367.68’
M= R (1‐cos (Δ/2)) M= 600(1‐cos (41.47/2)) M=22.84’
M= R (1‐cos (Δ/2)) M= 600(1‐cos (81.03/2)) M=22.91’
M= R (1‐cos (Δ/2)) M=600(1‐cos (63.03/2)) M=22.68’
E=R (sec (Δ/2)) E=600(sec (41.47/2)) E=42.68’
E=R (sec (Δ/2)) E=600(sec (81.03/2)) E=189.05’
E=R (sec (Δ/2)) E=600(sec (63.03/2)) E=103.69’
C=2RSin (Δ/2) C=2*600Sin (41.47/2) C=424.85’
C=2RSin (Δ/2) C=2*600Sin (81.036/2) C=779.624’
C=2RSin (Δ/2) C=2*600Sin (63.03/2) C=627.26’
Station Chord Cummulative Angle PC = 6+12.13 0 0 7+00 88.72 4.24° 8+00 101.04 9.07° 9+00 101.04 13.9° 10+00 101.04 18.73° PT= 10+46.89 46.89 20.99° (D/2=21°)
DRAWING NO. : Title : HORIZONTAL CURVE 1,2 & 3 CALCULATION
SUPER ELEVATION TRANSITION LENGTH (SETL)
Curve 1
SUPER ELEVATION TRANSITION LENGTH (SETL):‐
Lr = (w*n1)ed*bw
Δ
ed = 5.8%
Lr = (12*1)5.8*1 = 120’
0.58
Lr = 120’
Nc = 1.5
Lt = (Nc/ ed)* Lr
Lt = (1.5/ 5.8)* 120 =31.03’
Lt = 31.03’
SETL=151.03
I. Start of Tangent Runout:
12+30.72
II. Start of Super elevation Runoff:
12+61.75
III. Point at which Design Super elevation is attained:
13+81.75
IV. Last Point of Full Design Super elevation:
21+51.4
V. End of Super elevation Runoff:
22+71.99
VI. End of Tangent Runout:
23+03.02
VERTICAL ALIGNMENT
Based upon the horizontal alignment established earlier and incorporating any modifications to it, the profile at the centerline of the proposed highway is plotted shown in the figure. The location and length of all vertical curves and of positive gradients are clearly shown. All the controls (maximum grades, maximum and minimum length of curve, maximum vertical cut and fill dimensions, and approximate balance of cut and fill) have been compiled with. The following summarizes the curve selection process:
The minimum length of the curve is based upon stopping sight distance criterion.
The maximum length of the curve for this project is based upon the maximum K (=167) value established for the drainage criteria.
Select a curve length that is equal to or greater than the minimum length for stopping sight distance criteria and equal to or less than the maximum for the drainage criteria.
If the selected length of curve based upon the above considerations is not acceptable when the overall profile is considered, the profile must be examined and adjusted, and the process repeated until all criteria are met.
VERTICAL CUVE #1 COMPUTATIONS(CREST)
1.1% ‐5.72%
Vertical Curve Computations
Sag(1) Curve ‐Input
ITEM SOURCE VALUE
G1 Profile 1%
G2 Profile 5.7%
PVC Profile 100
PVT Profile 490
L Profile 401
PVI PVC + L/2 300.5
A G2‐G1 6.7
E LA/800 3.35
PVI EI Profile 874.39
PVC EI (PVI EI)‐((G1/100)*(L/2)) 841.34
PVT EI EL of PVC + (G1/100)*L )+ 4E(X/L)2 831.5
XTP G1*L/G2‐G1 59.85
X: Station PVC +X 159.85
XELEV EL of PVC + (G1/100)*X )+ 4E(X/L)2 841.67
DRAWING NO.: TITLE: Vertical Curve 1 computations
VERTICAL CURVE #2 COMPUTATIONS (SAG)
‐5.7% 5.8%
Vertical Curve Computations
CREST(1) Curve ‐Input
ITEM SOURCE VALUE
G1 Profile 5.7%
G2 Profile 5.8%
PVC Profile 780
PVT Profile 2020
L Profile 1248.07
PVI PVC + L/2 2644.03
A G2‐G1 11.5
E LA/800 17.94
PVI EI Profile 782.43
PVC EI (PVI EI)‐((G1/100)*(L/2)) 818.00
PVT EI EL of PVC + (G1/100)*L )+ 4E(X/L)2 816.00
XTP G1*L/G1‐G2 618.57
X: Station PVC +X 1398.57
XELEV EL of PVC + (G1/100)*X )+ 4E(X/L)2 800.24
DRAWING NO : TITLE: Vertical Curve# 2 Computations
OMMENTS:
The Horizontal# 2 and Vertical Sag Curve#2 coincides at PVI = 2600+44.03
DRAWING NO : TITLE: Horizontal & Vertical
CROSS SECTIONS
The cross sections are based upon the selected design elements shown in figure that are consistent with the cross section design dimensions described in the background and specifications. Note that the cross section elevations for earthmoving are not the same as the pavement elevations because the pavement thickness must be allowed for. For this highway, we are assuming the total pavement thickness (surface, base, sub base) of 1.5 ft.
The cross‐sections are taken at 500‐ft intervals instead of the usual 100‐ft intervals. The 500‐ft intervals are been used to illustrate the process only. In certain instances of preliminary design, this will provide an indication of the extent of the balance between cut and fill but may not always not provide an adequate indication of haul lengths. This latter consideration is not investigated further in this project.
DRAWING NO : TITLE: TYPICAL CROSS SECTIONS
DRAWING NO : TITLE: CROSS SECTIONS
CRITICAL LENGTH OF GRADE
Critical length of grade:
= 401 + 275 + 1248.07 = 787.51’ 4 4
From length of grade chart for 5.6% grade 10 mph curve ; L = 800 Safe