1 the proposed alternatives and choosing the

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1  Introduction
:

                This chapter will include an introduction to the
project

ü Transportation system is one of the important aspects of
civil eng. deals with considering the road design, lying out and modes of transportation
in order to get the most acceptable results for road users and pedestrians. And
it’s known that the transportation system starting from the road design is an
important face of civilization around the world.

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ü Before the beginning of the design of a high-way a certain
studies must be considered, one of these studies is the corridor studies which
are required for new high way and the major relocations of improvements of
existing high ways planned by MOPW and under taken to select and recommend.

 

ü The objective of this project is to design an alternative
road for Jordan Street connecting Amman-Irbid road with center of amman

 

 

 

 

 

 

ü
 Design location studies must consider the
following:

1.  Alignment and profile design.

2.  All drainage facilities to develop horizontal and vertical
curve.

3.  Investigation of geological char.

4.  Typical sections.

5.  Traffic data.

ü One of the most important information we must consider is: 

–        
AADT
expansion for 20 yrs from the estimated construction time.

–        
Topographic
maps.

–        
Transportation
studies reports.

–        
  The ultimate objective of geometric design is
to provide for a safe, economical, and efficient highway system consistent with
traffic volume, speed, and density and characteristics of vehicles, drivers,
and pedestrian to minimize the adverse socioeconomic and environmental impact
upon the nonuser sector.

 

ü For design purposes, highways are divided into classes
according to road function: freeways, primary, secondary, major arterials,
collector, and local streets in urban areas

 

ü
  Highway geometric design deals with
horizontal and vertical alignments, cross sections, sight distance,
intersections and interchanges, etc.

 

ü Before design any highway project, we must study the
following:

1.    
Topography
of the area.

2.    
Population
centers.

3.    
existing
valleys.

4.    
Alternatives
properties .

 

2  Choosing
the alternatives:

                This chapter will discuss the comparison between the
proposed alternatives and choosing the best one

 

   2.1  The
alternatives for this project were assigned taking into consideration the
following factors:

 

 

–        
Avoiding
steep valleys or high mountains.

–        
Serving
the maximum possible population centers.

–        
Reducing
the length of the road as possible.

–        
Making
the route as straight as possible.

–        
Ensuring
smooth curves.

–        
Balancing
the amount of cut and fill.

 

 

 

2.2 Properties of alternatives:

2.2.1 ALTERNATIVE 1:

–        
 Cut Area = 60031.25 m2

–        
 Fill Area = 200937.5 m2

–        
 Borrowed Area = 140906.25 m2

–        
 Length = 16.75 km

–        
 Maximum grade = 7 %

–        
 Number of horizontal curves = 4

–        
 Number of vertical curves = 9

–        
 Number of crossed steep valleys = 5

–        
 Marsa’a, Marj
AL-Faras, AL-Mo’amar,
Al-Medan, AL-Nasryeh,
Dahret AL-Meqathah, Esmer, Om Romanah, and Al-Azmah can use this road.

 

2.2.2 ALTERNATIVE 2:

 

–        
Cut Area
= 63281.25 m2

–        
Fill
Area = 117968 m2

–        
Borrowed
Area = 54687.5 m2

–        
  Length = 18.85 km

–        
 Maximum grade = 7 %

–        
 Number of horizontal curves = 11

–        
 Number of vertical curves = 13

–        
 Number of crossed steep valleys = 7

–        
 Salhob, Hay Al- Masajreh, Maqam Issa, Shafa
Badran, and Yajooz can use this road.

 

2.2.3 ALTERNATIVE 3:

–        
Cut Area
= 81250 m2

–        
Fill
Area = 128906.25 m2

–        
Borrowed
Area = 47656.25 m2

–        
  Length = 21.05 km

–        
 Maximum grade = 6.4 %

–        
 Number of horizontal curves = 16

–        
 Number of vertical curves = 13

–        
 Number of crossed steep valleys = 7

–        
 Salhob, Hay Al- Masajreh, Mobes, Abu Hamed,
Eskan Abu Nussair, and Eskan Al-Jam’a can use this road.

 

 

 

 

 

After comparing the
properties of the three alternatives I’ve chosen alternative 1.

 

 

2.3 Main advantages of
alternative 1:

 

–        
It
serves more population centers than 2 & 3.

–        
It
crosses 5 steep valleys while both of 2&3 cross 7 steep valleys which
increases the cost of the project and makes the construction of the road more
difficult.

–        
It has
less horizontal curves than 2&3.

–        
It has
less vertical curves than 2&3.

–        
It has
the smoothest curves among the 3 alternatives.

–        
Alternative
1 has a maximum grade of 7% which is acceptable in design process and does not
make any difficulties while driving on it.

–        
It has
no sag vertical curves at cut areas.

–        
It has
neither broken back nor reverse curves.

 

 

 

 

 

3  Capacity Analysis :

                                     The capacity of a highway is the max
number of vehicles which have a reasonable expectation of passing over a given
section of a roadway in one direction or in both direction in two lane highway
during a given time period under prevailing roadway conditions ( physical
features ) and traffic conditions ( nature of traffic ) .

 

3.1 Ideal conditions for
capacity analysis:

1.    
Lane
widths greater than or equal to 3.6 m.

2.    
Clear
shoulders wider than or equal to 1.8 m.

3.    
No
no-passing zone.

4.    
All
passenger cars.

5.    
No
impediments to through traffic.

6.    
Level
terrain

 

 

3.2 LEVEL OF SERVICE (LOS)

 

     
The level of service of a highway of expressing the operating 

conditions and the riding quality on the
highway. The main factor affecting the level of service of a highway is the
traffic volume, but

there are other factors that can
significantly have impacts on the level

of service of the highway. These factors are
briefly discussed in the following points:

 

1.    
Lane
width: if the traffic lane is less than 12ft (3.6m) in width, the traffic tends
to be more restricted due to the motorist’s discomfort.

2.    
Lateral
obstruction: objects that are located at the edge of the highway cause a
decrease in the traffic flow, because the driver tries to avoid this
obstruction by lowering the speed and driving a way from it.

3.    
Traffic
composition: the presence of large vehicles such as trucks, busses, and
recreational vehicles tend to lower the level of service of the highway due to
their operating characteristics and there large volumes.

4.    
Grade:
the effect of the grade on the road level of service depends on both the slope
and length of the grade.

5.    
Speed:
space mean speed is considered.

 

 

We Will Consider LOS B in the
design process of this project 

 

3.3 Calculations:

 

      

N: Number of lanes.
PHF : Peak Hour Factor (take
it = 0.90)
Vp   : 15 min passenger
car equivalent flow rate

            For: – V = 100 km/h

                    – And
LOS = B

                       
Vp = 1100 pc/h/ln

Fhv: Adjustment factor of heavy vehicles.
Fp: Driver
population factor. ( take it = 1 )

 

PT: Percent of Trucks (Assumed
= 10%)

ET: Passenger car
Equivalent factor for Trucks and buses.

PR: Percent of
Recreational Vehicles. (Assumed = 0%)

ER: Passenger car
Equivalent factor for Recreational Vehicles.

Max grade = 7%

 

       DDHV =
AADT × K × D

DDHV: Directional Design Hourly
Volume.

AADT: Annual Average
Daily Traffic.

K        : Percent of
AADT in the peak hour (take it = 0.12)

D       : Directional distribution of the peak direction (take it = 0.55)


AADT = 20,000 vpd


DDHV = 20,000 * 0.12 * 0.55 = 1320

      Use 2 lanes in each direction

Downgrade:


ET = 1.5                  

     Use 2 lanes in each direction.

 

4  Pavement
Design :

This chapter will discuss the design
of the flexible pavement

3.1 Pavement Design
Objectives: 

 

1.    
Ensure
that the deflection in subgrade layer does not exceed the allowable values.

2.    
Ensure
that the tensile strain at the bottom of asphalt layer does not exceed the
allowable values.

3.    
Ensure
that shear stress in the middle of asphalt layer does not exceed the allowable
values.

 

3.2 Design procedure:

 

1.    
Convert
all traffic loads into the 18-kip equivalent single-axle load.

2.    
Determine
the soil support values for all materials considered in the design of the
flexible pavement.

3.    
Determine
the regional factor R and the terminal serviceability index (Pt).

4.    
Using
the graphs provided by the AASHTO design method Find the values of the
structural numbers (SN’s) for each layer.

5.    
Using
the graphs provided by the AASHTO design method Determine the layer
coefficients (a1, a2, a3) for all layers.

6.    
Determine
the drainage coefficients (m2, m3) according to previous background information
about rainfall values in the area considered in the project.

7.    
Determine
the thicknesses for the flexible pavement layers using the equation provided by
the AASHTO design method.

 

3.3 ESAL’S Calculations:

 

Ø   Passenger car (2000
Ib per axial ) = 90 %     Trucks = 10%

Ø   2-axial single unit
= 60 % of trucks

Ø   3-axial single unit
= 20 % of trucks

Ø   3-axial semi-trailer
= 10 % of trucks

Ø   4-axial semi-trailer
= 5 % of trucks

Ø   5-axial semi-trailer
= 5 % of trucks

 

Ø AADT = 20,000 vpd 

Ø Fd ( design lane factor ) = 0.45 , table 20.7

 

Ø G ( growth factor ) = 33.06 , table 20.6 
where growth rate = 5% and design period = 20 years.

 

 

Ø
ESAL’s =
AADT * % in traffic * 365 * fd *G * N * FE

Vehicle

%
in traffic

N

FE

EASL’s

Pc

90

2

0.0003

58645.134

2- axial single unit

6

2

0.005

65161.26

3- axial single unit

2

3

0.0196

127250.37

3-semi trailer

1

3

0.47

1531289.61

4-semi trailer

0.5

4

0.83

1796221.26

5-semi trailer

0.5

5

0.98

2651049.45

Total

6229617.084

 

 

 

 

o   CBR base coarse = 100 

o   CBR sub-base     =
22 

o   CBR sub-grade   = 6

o  
Reliability           = 99
%  , table 20.16

o  
Standard
deviation = 0.5   ,   range
:  0.4 – 0.5

o   Pi = 4.5   

o   Pt =2.5 

o   ?P.S.I = 4.5-2.5 = 2.0 

o   MR asphalt = 450 ksi

o   MR sub-grade = 9 ksi

o   MR base = 31 ksi

o   MR sub-base = 13.5 ksi 

From charts:

o  
SN1 = 4.4

o  
SN2 = 5.7

o  
SN3 = 6.2                                          

o  
a1    = 0.44

o  
a2    = 0.14

o   a3    = 0.10 

o  
Drainage quality
is fair then m = 0.8

 

ü
D1 = ( SN1 / a1
) = 4.4 / 0.44 = 10 inch

ü
D2 = ( SN2 – SN1 ) / (
a2 * m ) = 11.61                     use
D2 = 12 inch

ü
D3 = ( SN3 – SN2 ) / (
a3 * m ) = 6.25                       use D3 = 7 inch

 

 

 

5  Earth
Work Calculation :

This chapter will discuss the
calculation of cross-sections areas and the volumes fill and cut and mass haul
diagram

4.1 Introduction :

During the construction of long engineering projects such as
roads, railways, pipelines and canals there may be a considerable quantity of
earth required to be brought on the sight to form embankment and to be removed
from site during formation of cutting.

The earth brought to form embankment may come from another
section of the site such as a tip formed from excavated materials (known as
spoil heap) or may be imported on the site from a nearby quarry. Any earth
brought on to the site is said to have been borrowed.

The earth excavated to form cutting may be deposited in tips
at regular intervals along the project to form spoil heap for later use in
embankment formation or may be wasted either by spreading the earth at right
angles to the center line to form verges or by carting it away from the site
area and depositing it in suitable local areas.  

This amount of earth through out the site can be very
expensive and since the majority of the cost of such projects is usually given
over to the earth moving, it is essential that considerable should taken when
planning the way in which material is handled during the construction.

The mass haul diagram is a graph of volume against Chainage,
which greatly helps in planning such moving; the mass haul diagram only considers
earth moved in a direction longitudinal to the direction of the centerline of
the project.

 

5.2 Calculation and shapes of areas:

 Type a) The ground is level through the
cross section:

                

A= h (w + nh)

ü h:
depth of cut or fill at center line.

ü W:
road width.

ü (1:
n): side slope.

Type b)
The ground is not level through the cross section:

WL =s (b+nh) / (s+n)

WG=s (b+nh) / (s-n)

A = 0.5 * (h + b/h) * (WL+WG) –
b2/n 

ü WL: lesser side width.

ü WG: greater side width.

ü h: depth of cut or fill at center line.

ü (1: n): side slope.  

ü S: ground or transverse slope.

Type c) mix of cut and fill:

ACut = Afill = b2/{2(s-n)}

ü (1: n): side slope.  

ü S: ground or transverse slope.

ü Ac: area of cut 

ü Af: area of fill.

 

 

 

 

5.3 Calculation of volume:

 

1.    
Volume between two fill sections, or two cut sections.

 

V= 0.5 (A1+A2)D

ü V: volume between two sections.

ü A1: cross section at area1.

ü A2: cross section at area2.

ü D: distance between the two areas.(=250m ).

 

2.   volume between fill section and cut section :

Vfill =

Vcut
=

ü F: fill area.

ü C: cut area.

ü D: distance between the two areas. (250m).

 

3.    
volume between mix section and other mix section:

 

Vfill = 0.5 (F1+F2) D

Vcut = 0.5 (C1+C2) D

 

4.    
volume between mix section and cut section:

Vfill =0.33 FD

Vcut = 0.5 (C1+C2) D

5.   volume between mixed section and fill
section:

Vfill = 0.5 (F1+F2) D

Vcut = 0.33 CD

 

 

 

5.4 Side slope ( 1 : n ) :

 

We can find it from the following table:

 

Side Slope

Height of fill or cut
(m)

6:1

< 1 4:1 1 – 3 3:1 3 – 4.5 2:1 4.5 – 6 1:1½ > 6

 

 

 

 

 

 

 

 

 

 

 

5.5 Mass-Haul Diagram:

The mass haul diagram is a graph of volume
against chainage which greatly helps in planning such earth moving.

The x-axis represents the chainage along the
project from the position of zero chainage.

The y-axes represents the volumes of
material up to any Chainage from the position of zero Chainage .

Borrow material: volume of material, which must be imported into a section
of the site due to deficiency of suitable material.

Waste material: it is that volume of
material, which must be exported from a section of the site due to a surplus.

Free haul distance: is that distance which is usually specified in the
contract, over which a chainage is leveled only for the volume of earth
excavation and not its movement.

Over haul distance: is the distance in excess of the free haul distance over
which it may be necessary to transport materials.

5.6 Earthwork costs: –

Excavation cost = 1.1 JD/m3

Overhaul cost = 0.2 JD/m3

Borrow cost = 1.4 JD/m3

Free-Haul distance = 250m

 

 

 

5.7 Ground Level and Floor Level :

chainage

G.L

F.L

chainage

G.L

F.L

0

560

560

8500

877

883

250

570

570

8750

842.5

867

500

580

577.5

9000

805

850

750

580

587

9250

825

845

1000

600

595

9500

873

855

1250

600

605

9750

880

857

1500

600

625

10000

827.5

850

1750

605

640

10250

780

845

2000

620

660

10500

810

860

2250

647

677

10750

840

877

2500

668

695

11000

875

895

2750

720

715

11250

903

912.5

3000

742.5

732

11500

955

930

3250

742.5

750

11750

952

935

3500

743

767

12000

912

927

3750

745

785

12250

912

918

4000

765

802

12500

918

909

4250

800

820

12750

898

900

4500

845

837.5

13000

900

890

4750

865

855

13250

886

881

5000

896

873

13500

880

873

5250

917

890

13750

880

863

5500

917.5

910

14000

856

855

5750

917.5

925

14250

838

847

6000

923

943

14500

820

837

6250

980

960

14750

838

845

6500

981

968

15000

838

853

6750

968

965

15250

861

861

7000

920

962.5

15500

860

870

7250

980

960

15750

870

877

7500

967

950

16000

889

862.5

7750

915

935

16250

870

842

8000

900

925

16500

823

823

8250

880

900

16750

803

803

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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