design traffic
DESCRIPTION
traTRANSCRIPT
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1Babak Shahbodagh KhanCE 507, School of Civil & Environmental [email protected]
CVEN3031: CIVIL ENGINEERING PRACTICE
CVEN3731: ENVIRONMENTAL ENGINEERING PRACTICE
Semester 2, 2014
PROJECT 2
Design Traffic
Content
2
Introduction
Traffic Parameters
Examples
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2Fork lift zone
New Container Terminal
Fork lift & Truck zone
Straddle carrier zone
Rigid pavement zoneFlexible pavement zone
Container rows (3315 m)
Reclaimed soil zoneExisting natural soil zone
New realigned road
300 mProject 2
1. Subgrade Evaluation
2. Design Traffic
3. Design Flexible
Pavement
4. Design Concrete Pavement
4
Main Reference
Austroads Pavement Design Guide
https://www.onlinepublications.austroads.com.au/items/AGPT02-12
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35
Design Traffic
Austroads Pavement Design Guide(Chapter 7)
6
Introduction
Figure 8.4 Design chart for granular pavements with thin bituminous surfacing
AUSTROADS Pavement Design Guide
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47
Introduction
Design Traffic:
Convert loads of various magnitudes and repetitions (mixed traffic) to an equivalent number of standard loads.
Design Traffic is the function of number and types of vehicle loads that a particular pavement will be subject to, over its design life.
1) Vehicles Loads Different
2) Load Repetitions Pavement Design Life
Vehicles
Load distribution
TypesLoads
Survey data
Equivalent Standard Load
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Design Traffic:
1) Vehicles Loads DifferentVehicles
Load distributionEquivalent Standard Load
TypesLoads
The damage caused to a pavement by the passage of one heavy vehicle depends on The number of axles on the vehicle; The manner in which these axles are grouped together into axle groups The loading applied to the pavement through each of these axle groups.
Traffic Parameters
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Traffic Parameters
- Wide range of loads- Strong enough to cater the heaviest vehicle
1) Vehicles Loads DifferentVehicles
Load distributionEquivalent Standard Load
TypesLoads
Pavement Pavement applications
10AUSTROADS
Pavement Design Guide
Types of Vehicles for Road Pavements:
light vehicles Contribute very little to structural deterioration
Traffic Parameters
1) Vehicles Loads DifferentVehicles
Load distributionEquivalent Standard Load
TypesLoads
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611
AUSTROADS Pavement Design
GuideClasses 3-12: Heavy vehicles
Traffic Parameters
Types of Vehicles for Road Pavements:
Only heavy vehicles are considered in pavement design.
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Traffic Parameters
The axle configuration
1) Vehicles Loads DifferentVehicles
Load distributionEquivalent Standard Load
TypesLoads
The damage caused to a pavement by the passage of a heavy vehicle depends on the number of axles on the vehicle; the manner in which these axles are grouped together into axle groups The loading applied to the pavement through each of these axle groups.
Axle group: A set of closely spaced axles acting as a unit (adjacent axles are less than 2.1 m apart)
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Single Axle Single Tyre - SAST Single Axle Dual Tyre - SADT
Tandem Axle Single Tyre - TAST Tandem Axle Dual Tyre - TADT
Traffic Parameters
Tri-Axle Dual Tyre - TRDT
Quad-Axle Dual Tyre - TRDT
Traffic Parameters
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2
3 3
15
Numbers of heavy vehicle axle groups per heavy vehicle (NHVAG):
Traffic Parameters
3 4
5 7
Traffic Parameters
16
Numbers of heavy vehicle axle groups per heavy vehicle (NHVAG):
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917
Design Traffic:
1) Vehicles Loads DifferentVehicles
Load distributionEquivalent Standard Load
TypesLoads
The damage caused to a pavement by the passage of a heavy vehicle depends on The number of axles on the vehicle; The manner in which these axles are grouped together into axle groups The loading applied to the pavement through each of these axle groups.
Traffic Parameters
Austroads Philosophy: Convert the number of repetitions of each Heavy Vehicle Axle Group into the number of Standard Axle repetitions that cause the equivalent amount of damage.
8.2t
Single Axle Dual Tyre - SADT
Standard Axle & Standard Axle Load
SADT carrying a load of 80 kN, with a width between the dual tyres of 1800 mm.
Traffic Parameters
Austroads Philosophy: Convert the number of repetitions of each Heavy Vehicle Axle Group into the number of Standard Axle repetitions that cause the equivalent amount of damage.
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Standard Axle & Standard Axle Load
Traffic Parameters
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Circular (radius = 92.1 mm)Load on tyre = 80 kN / 4 = 20 kN
Tyre-pavement contact stress = 750 kPa
Contact surface:
Tyre-pavement contact stress assumed to be uniform and equal to tyre pressure - 750kPa
SADT carrying a load of 80 kN, with a width between the dual tyres of 1800 mm.
Loads on axle groups that cause the same amount of damage (deflection) as the standard axle:
20
90kN 135kN
181kN
53kN
Single axle with single tyres (SAST)
80kN
Single axle with dual tyres (SADT)
Tandem axle with single tyres (TAST)
Tandem axle with dual tyres (TADT)
Tri-axle with dual tyres (TRDT):
Traffic Parameters
Above loads are all equal to 1 standard axle
Standard Axle
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Example 1
53kN 135kN 135kN181kN 181kN
Double road train (Class 11)
For one pass of the vehicle shown above, calculate:
1) Numbers of heavy vehicle axle groups (NHVAG):
2) Equivalent standard axles (ESA):
(per heavy vehicle)
1 ESA 1 ESA 1 ESA 1 ESA 1 ESA
5
5 ESA
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Example 2
Double road train (Class 11)
For one pass of the vehicle shown above, calculate:
1) Numbers of heavy vehicle axle groups (NHVAG):
2) Equivalent standard axles (ESA):
(per heavy vehicle)
55kN 150kN 150kN190kN 190kN
5
???
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Standard Axle Repetitions
Traffic Parameters
Standard axle repetitions are dependent on pavement type and damage exponent m
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Traffic Parameters
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55kN 150kN 150kN190kN 190kN
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Example 2
53kN 135kN 135kN181kN 181kN(Standard)
Granular base
Subgrade
Granular pavement with thin bituminous surfacing
4 4 4 4 455 150 190 150 190ESA= 6.6253 135 181 135 181
Once above truck traversing the granular pavement
Equivalent to 6.62standard axle
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Traffic Parameters
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Designation Standard Load (kN)
Standard Load
(tonnes)
Legal Limit (tonnes)
SAST 53 5.4 6.0
SADT 80 8.2 11.0
TAST 90 9.2 10.0
TADT 135 13.8 17.0
TRDT 181 18.5 21.5
QADT 221 22.5 27.0
Traffic Parameters
- Legal Load Limit
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Design Traffic:
Damage Index
Traffic Parameters
1) Vehicles Loads Different
2) Load Repetitions Pavement Design Life
Vehicles
Load distributionEquivalent Standard Load
Number of heavy vehicle axle groups (HVAG) passing the design lane during design period (NDT)
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Traffic ParametersLoad Repetitions
(Annual Average Daily Traffic)
NDT
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Design Period (P)
Time span considered for the road pavement to function without major rehabilitation or reconstruction.
It is not the period until the next resurfacing!!
The considerations in selecting the design period:
Available funds The importance of the road
AUSTROADS Pavement Design Guide
Traffic Parameters
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Annual Average Daily Traffic (AADT)
Average daily number of (Light + Heavy) vehicles in the 1st year of service.
Obtained from the actual traffic survey on the existing roadway where the pavement is to be constructed, or on nearby roads with similar travel patterns.
The traffic survey data should be Recent Obtained without interruption of the traffic stream.
Traffic Parameters
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Annual Average Daily Traffic (AADT)
"A WIM, Weigh-In-Motion" system is a type ofvehicle detection system(VDS) that can measurethe traffic parameters such as the moving carsweight, speed, and type.
Traffic Parameters
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Heavy Vehicle Factor (%HV)
Only heavy vehicles are considered in pavement design.
Heavy Vehicle factor %HV, which is the average percentage of all traffic comprising heavy vehicles, can be determined based on the traffic survey.
Average daily number of Heavy vehicles in the 1st year of service.
AADT %HV/100
Traffic Parameters
Traffic Loads
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Directional Distribution Factor (DF)
Annual average daily traffic (AADT) is historically for traffic in both directions of a road. The directional distribution factor (DF) is multiplied with the AADT (usually = 0.5) to obtain
the daily traffic in one direction.
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Traffic Loads
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Lane Distribution Factor (LDF)
Location Lanes Each Direction
Lane Distribution Factor (LDF)
Left Lane Centre Lane Right Lane
Rural2 lane 1.00 N/A 0.50
3 lane 0.95 0.65 0.30
Urban2 lane 1.00 N/A 0.50
3 lane 0.65 0.65 0.50
Lane Distribution Factor (LDF): Proportion of traffic assigned to a specific lane. It is obtained from traffic survey data. The same pavement configuration is usually adopted for all lanes. It is determined for the WORST CASE (The most heavily-trafficked lane).
Outside lane
Traffic Loads
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Cumulative Growth Factor (CGF)
During the design period, the daily volume of traffic is likely to change. The growth is estimated base on growths experienced by similar roads in vicinity R% : Annual Growth Rate
P2 P-1 (1 0.01R) 11 (1 0.01R) (1 0.01R) ... (1 0.01R) for R 0CGF 0
esign Period:Year.01R
P (D for R 0s)
AUSTROADS Pavement Design Guide
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Traffic Loads
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Axle Groups per Heavy Vechicle (NHVAG)
Axle Groups per Heavy Vehicle:
In the absence of survey data, a presumptive value need to be selected.
NHVAG
Rural Areas 2.8
Urban Areas 2.5
HVAGNumber ofN
Number of axel groups
heavy vehicles
Traffic Loads
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Cumulative Heavy Vehicle Axle Groups (NDT)
Number of heavy vehicle axle groups (HVAG) passing the design lane during design period
NDT = 365 AADT DF %HV/100 LDF CGF NHVAG
AADT = Annual Average Daily Traffic in vehicles per day in the first year
DF = Directional distribution factor
%HV = average percentage of all traffic comprising Heavy Vehicles
NHVAG = average Number of Axle Groups per Heavy Vehicle
LDF = Lane Distribution FactorCGF = Cumulative Growth Factor
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Assume: Rural road Annual Average Daily Traffic (AADT) = 20,000 %HV = 12% Annual growth = 3% No. lanes = 4 (2 in each direction) Design period = 30 years
Determine design traffic for : a) Thin asphalt on unbound granular b) Structural (thick) asphalt on cemented base.
Note: No details of heavy vehicle types known
Example 1
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Step 1. Calculate Cumulative Growth Factor CGF
CGF = (1 + 0.01R)P 10.01R
where R = 3 = annual growth rate (%)P = 30 = design period (years)
CGF = (1 + 0.01x3)30 1 = 47.50.01x 3
Example 1
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Step 2. Determine Direction Factor DF DF = 0.5 (2 way traffic)
Determine Lane Distribution Factor LDF LDF = 1 (select heaviest lane)
Example 1
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Location Lanes Each Direction
Lane Distribution Factor (LDF)
Left Lane Centre Lane Right Lane
Rural2 lane 1.00 N/A 0.50
3 lane 0.95 0.65 0.30
Urban2 lane 1.00 N/A 0.50
3 lane 0.65 0.65 0.50
Step 3.
Determine NHVAG = 2.8
Step 4. Calculate Design Traffic NDT
NDT = 365 (AADT DF) %HV/100 NHVAG LDF CGF
= 365 (20,000x0.5) 12/100 2.5 1.0 47.5
= 5.8 107 HVAG
Example 1
NHVAGRural Areas 2.8
Urban Areas 2.5
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Step 5. Determine ESA/HVAG Calculate Design Traffic DESA
DESA = ESA/HVAG NDT (Austroads 7.4)= 0.9 ESA/HVAG 5.8 107 HVAG= 5.24 107 ESA
(This is the design traffic for a granular pavement with thin surfacing)
Example 1
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= 0.9
Step 6. For alternative stabilised pavement with structural asphalt surface: Calculate Design Traffic DSARm
DSARm = SARm/ESA DESA (Austroads 7.5)
DSAR5 = 1.1 5.24 107 ESA = 5.77 107
DSAR7 = 1.6 5.24 107 ESA = 8.39 107
DSAR12 = 12 5.24 107 ESA = 6.29 108
Example 1
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Design Traffic Using WIM Data
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Steps: Determine numbers of each vehicle type Determine total numbers of each axle group Apply distribution of loads on axle groups Calculate equivalent damage factor for each load increment for each axle type SARijm
Basic equation:DSARm= NDT x Pi x Pij x (Lij/SLi)m
DSARm = design no. Standard Axle RepititionsNDT = Total no axle groups on design lanePi = Proportion axle groups type iPij = Proportion all type i axle groups with loads ijLij = jth load magnitude carried on type i axleSLi = standard axle loading for type i axle m = damage exponent for damage type m
If the designer has access to project-specific WIM data, the relevant design traffic values are then determined as follows:
Example 2
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Calculation of ESAs and DSARm by Average Daily Axle Types
Class 3300 units
Class 4 120 units
Class 5 60 units
Class 890 units
Class 960 units
Class 1020 units
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Example 2
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Calculate number of each axle type (per day):
Truck Class
Number Units
Axle Load GroupSAST SADT TAST TADT TRDT
3 300 300 3004 120 120 1205 60 60 608 90 90 1809 60 60 60 60
10 20 20 40 20
Example 2
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Assuming:- Design period 20 years, - Growth 4 %, - 2 lane dual carriageway, - Single direction count.
CGF = 29.8 LDF = 1.0
Calculate number of each axle type (for the whole design life)
Truck ClassNumber
UnitsAxle Load Group
SAST SADT TAST TADT TRDT3 3260700 3260700 32607004 1304280 1304280 13042805 652140 652140 6521408 978210 978210 19564209 652140 652140 652140 652140
10 217380 217380 434760 217380
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Example 2Axle Group
LoadAxle Group Type
SAST SADT TAST TADT TRDT(kN) % % % % %10 0.2804 3.4730 0.0354 0.1444 0.005020 7.8270 8.6960 0.2377 0.5755 0.156830 15.4600 23.4600 0.2763 0.6242 0.329040 15.7100 21.9300 0.5755 1.9770 1.317050 29.9400 16.8000 2.8890 6.4960 4.167060 23.2900 9.6060 10.2700 9.5110 7.419070 6.5020 6.5000 16.8100 10.9400 9.777080 0.7943 4.6230 16.6100 9.7690 8.338090 0.1087 2.9690 15.9500 7.6110 6.1500100 0.0354 1.3930 14.4200 7.2420 5.0290110 0.0174 0.4098 9.7740 6.2670 3.7010120 0.0174 0.1158 5.9030 5.9520 3.2980130 0.0174 0.0244 2.9430 5.8780 3.1470140 1.5390 6.5340 3.3610150 0.8439 8.0300 4.0080160 0.4279 5.7170 4.1150170 0.2308 3.5540 4.8190180 0.1367 1.8630 6.0970190 0.0723 0.8535 7.7330200 0.0555 0.3331 8.4330210 0.0801 5.1360220 0.0322 2.3390230 0.0160 0.7764240 0.2503250 0.0905260 0.0080
TOTAL 100.0 100.0 100.0 100.0 100.0
E.g. 6.5% of all single axle dual tyre loads carry
approx 70kN
Presumptive Traffic Load Distribution for urban road
Example 2
(6.5% of 300 single axle dual tyre loads in 70kN) GF 365
= 6.5/100 300 29.78 365 = 211,945
- Multiply Number of axles of each type by load proportion
Axle Group Load
No Axles in Load GroupSAST SADT TAST TADT TRDT
(kN) [NAj] [NBj] [NCj] [NDj] [NEj]10 17981 113244 231 7220 4320 501923 283550 1550 28774 136330 991405 764960 1802 31208 286140 1007437 715071 3753 98845 1145250 1919965 547798 18840 324783 3623360 1493520 313223 66975 475525 6451070 416954 211945 109625 546971 8501380 50936 150742 108320 488425 7250190 6971 96810 104016 380530 53475100 2270 45422 94039 362081 43728110 1116 13362 63740 313334 32181120 1116 3776 38496 297584 28677130 1116 796 19192 293885 27364140 0 0 10036 326683 29225150 0 0 5503 401479 34850160 0 0 2791 285835 35781170 0 0 1505 177691 41902180 0 0 891 93145 53015190 0 0 471 42673 67240200 0 0 362 16654 73327210 0 0 0 4005 44659220 0 0 0 1610 20338230 0 0 0 800 6751240 0 0 0 0 2176250 0 0 0 0 787260 0 0 0 0 70
TOTAL 6412709 3260700 652140 4999739 869520
HVAG's = 1.62E+07
NHVAG 2.3
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Example 2
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Damage Exponents:
Design Method
Pavement Type Damage Type Damage unit Damage exponent (m)
Emperical granular with thin bituminous surfacing
Overall pavement damage
ESA 4
Mechanistic Pavement contains one or more bound
layers
Fatigue of asphalt
SAR5 5
Rutting & shape loss
SAR7 7
Fatigue of cemented
layers
SAR12 12
Example 2Axle Group
LoadDesign ESA for overall pavement damage
SAST SADT TAST TADT TRDT
(kN) [NAj(L/53)4] [NBj(L/80)4] [NCj(L/90)4] [NDj(L/135)4] [NEj(L/181)4]10 23 28 0 0 020 10178 1108 4 14 030 101773 15127 22 76 240 326854 44692 146 762 2750 1520792 83587 1795 6111 21160 2453085 99106 13230 18554 77970 1268753 124239 40117 39539 190280 264413 150742 67624 60231 276790 57961 155071 104016 75166 3269100 28770 110892 143330 109011 4074110 20704 47763 142237 138116 4390120 29323 19115 121666 185781 5540130 40389 5548 83548 252706 7282140 0 0 58765 377836 10460150 0 0 42465 611918 16438160 0 0 27874 563976 21848170 0 0 19160 446813 32608180 0 0 14264 294385 51853190 0 0 9365 167429 81645200 0 0 8826 80224 109312210 0 0 0 23449 80922220 0 0 0 11354 44390230 0 0 0 6740 17602240 0 0 0 0 6728250 0 0 0 0 2864260 0 0 0 0 296
TOTAL 6123019 857018 898454 3470190 507209DESA = 1.19E+07
ESA/HVAG = 0.73
211,945 axles (Lij/Pij)mLij = 70kN (load bin)Pij = 80kN (for SADT)m = 4 (for overall pavement damage)DESA = 211,945 (70/80)4
= 124,239
- Multiply no. axles (load/standard load)m
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Example 2
211,945 axles (Lij/Pij)mLij = 70kN (load bin)Pij = 80kN (for SADT)m = 5 (for asphalt fatigue)
DESA = 211,945 (70/80)5= 108,709
- Multiply no. axles (load/standard load)m
Axle Group Load
Design Std Axles Repetitions for Asphalt Distress SAST SADT TAST TADT TRDT
(kN) [NAj(L/53)5] [NBj(L/80)5] [NCj(L/90)5] [NDj(L/135)5] [NEj(L/181)5]10 4 3 0 0 020 3841 277 1 2 030 57607 5673 7 17 040 246683 22346 65 226 650 1434710 52242 997 2263 5860 2777077 74329 8820 8246 25870 1675712 108709 31202 20502 73580 399114 150742 60110 35693 122390 98425 174455 104016 50111 1625100 54283 138616 159255 80749 2251110 42971 65674 173846 112539 2668120 66392 28673 162221 165138 3673130 99067 9015 120680 243346 5230140 0 0 91413 391830 8091150 0 0 70774 679908 13623160 0 0 49553 668416 19313170 0 0 36192 562653 30626180 0 0 28527 392513 51566190 0 0 19771 235641 85704200 0 0 19614 118851 120787210 0 0 0 36476 93888220 0 0 0 18503 53955230 0 0 0 11483 22367240 0 0 0 0 8921250 0 0 0 0 3956260 0 0 0 0 425
TOTAL 6955885 830755 1137065 3835105 530951
DSAR5 = 1.33E+07
Example 2
211,945 axles (Lij/Pij)mLij = 70kN (load bin)Pij = 80kN (for SADT)m = 12 (for cemented fatigue)
DESA = 211,945 (70/80)12= 42,689
- Multiply no. axles (load/standard load)m
Axle Group Load
Design Std Axles Repetitions for Cemented Layer Distress SAST SADT TAST TADT TRDT
(kN) [NAj(L/53)12] [NBj(L/80)12] [NCj(L/90)12] [NDj(L/135)12] [NEj(L/181)12]10 0 0 0 0 020 4 0 0 0 030 1072 6 0 0 040 34405 175 0 0 050 954164 1946 16 2 060 6617830 9922 516 28 070 11747746 42689 5372 207 180 7125175 150742 26356 916 490 4007475 397879 104016 2933 12100 4620983 660970 332963 9881 35110 7128409 610260 708297 26836 82120 20251412 489908 1215286 72407 207130 52917655 269737 1583220 186850 516140 0 0 2014678 505426 1340150 0 0 2528231 1421519 3657160 0 0 2781075 2195584 8146170 0 0 3104942 2825183 19746180 0 0 3651483 2940526 49605190 0 0 3694981 2577442 120373200 0 0 5249085 1861559 242929210 0 0 0 803908 265701220 0 0 0 564768 211465230 0 0 0 478405 119662240 0 0 0 0 64288250 0 0 0 0 37937260 0 0 0 0 5369
TOTAL 115406330 2634235 27000517 16474380 1151075
DSAR12 = 1.36E+08
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Example 2
211,945 axles (Lij/Pij)mLij = 70kN (load bin)Pij = 80kN (for SADT)m = 7 (for deformation)
DESA = 211,945 (70/80)7= 83,230
- Multiply no. axles (load/standard load)m
Axle Group Load
Design Std Axles Repetitions for DeformationSAST SADT TAST TADT TRDT
(kN) [NAj(L/53)7] [NBj(L/80)7] [NCj(L/90)7] [NDj(L/135)7] [NEj(L/181)7]10 0 0 0 0 020 547 17 0 0 030 18457 798 1 1 040 140510 5586 13 20 050 1276886 20407 308 310 460 3559088 41810 3920 1629 2870 2923100 83230 18875 5512 11080 909337 150742 47494 12534 23990 283816 220795 104016 22272 402100 193247 216587 196611 44307 687110 185101 124166 259695 74717 985120 340352 64515 288393 130480 1615130 596023 23805 251789 225655 2698140 0 0 221196 421392 4841150 0 0 196595 839393 9356160 0 0 156612 938899 15092170 0 0 129128 892218 27016180 0 0 114109 697801 50998190 0 0 88116 466756 94439200 0 0 96860 260853 147476210 0 0 0 88263 126383220 0 0 0 49139 79711230 0 0 0 33329 36117240 0 0 0 0 15684250 0 0 0 0 7547260 0 0 0 0 878
TOTAL 10426466 952458 2173731 5205478 622307DSAR7 = 1.72E+07
Project 2
Input Traffic Data
- Existing traffic on the access road:
- Road Traffic Counts- Presumptive Traffic Load Distribution (Urban Area)
- Additional traffic generated by the port development:
- Container Load Distribution- Types of Trucks used to transport Containers
Existing traffic + Additional traffic DSARm
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