ENGINEERING SCIENCE AND TECHNOLOGY INTERNATIONAL RESEARCH JOURNAL, VOL.1, NO.3, SEP, 2017

Corresponding author Email address: jam_shahzaib@hotmail.com

Jam Shahzaib Khan1, Tauha Hussain Ali

2, Arshad Ali Memon

3, Salim Khoso

4, Manthar Ali Keerio

5 and

Samiullah Sohu6

1,4,5,6Department of Civil Engineering Quaid-e-Awam University College of Engineering Sciences and Technology,

Larkana 2,3

Department of Civil Engineering, MUET, Jamshoro

Keywords: KENLAYER, GAMES, Elastic Analysis, Deflection, Model

1. Introduction

he rapid growth in the transport system of the world

has enhanced the acceleration in the research and

development of the sustainable transport system, which

also introduced and familiarized many tools to design a

pavement within very quick time and analyze the physical

response with impact on the design life of the pavement

[1]. It is also illustrated that it results in optimizing the

impacts analysis of the pavements such as loads, and

material properties, which physically impacts at every

stage of the pavement performance. For such type of

findings, many classical methodologies involve in-situ and

laboratory tests, with significant time and cost

consumption.

In this modern world of technology, the new emerging

trend has revolutionized and introduced simple procedures

for obtaining same the result without such type of

traditional classical methods [2]. Using the modeling and

simulation of pavements behavior specialized computer

programs, which results can be verified experimentally for

the calibration of models and for their validation [3].

2. Research Flow In the previous years, pavement design has been done

through traditional methods of analysis, which typically

treats wheel loads as static and use unreasonable boundary

conditions these analyses create impracticable results [4].

By broadening pavement design and analysis to the

computer programs (GAMES and KENLAYER) implicates

more realistic approach and results to allow further

analysis of the pavement [5].

2.1 Aim and Objectives

The aim of this analysis is to figure out the major

difference in their results and to analyze their limitations,

and output of these programs. Following are the objectives

of this research:

To illustrate the input procedure of the GAMES

and KENLAYER programs.

To analyze and compare the results of both

software.

To estimate design traffic load application from

both program and access design application.

2.2 Scope of the research

Following the objectives, this research illustrates the input

procedure of the GAMES and KENLAYER programs and

review limitations of the two pavement analysis programs

in designing pavement. Also compare the results of both

programs their design, and analysis capabilities. Then

compare these two types of programs and their

applications. The scope of this project is to estimate design

traffic load application (ESAL) [1].

2.3 KENLAYER Computer Program

T

Modeling Analysis of GAMES and

KENLAYER for Highway Pavement and

Management

Abstract: Innovated trend of the mechanistic approach of flexible pavement design is used to explore the design life of the

pavements. The mechanistic approach defines the phenomena by identifying the physical causes. The research explores and

examines the comparison of General Analysis of Multi-layered Elastic Systems (GAMES) and KENLAYER Layered Elastic

Analysis Computer Programs for asphalt highway pavement analysis and design. The programs are identical to analyze any flexible

pavement; the GAMES program has an ability to model multiple pavement layers and loads with layer interface slip and higher

accuracy near to the surface of the flexible pavement, whereas, KENLAYER program is used to identify the responses of the

pavement. Research evaluated the capabilities of both traditional pavement structural response programs. Data used in both

computer programs GAMES and KENLAYER produced the same results of deflection and showed that placing the different

vertical coordinates of points in KENLAYER programs does not show zero stresses and deflection at any point. Therefore, both the

programs are vital sources to analyze any flexible pavement. However, KENLAYER program has an ability to determine vertical

stresses under one point but at different vertical coordinates which will be helpful in understanding from top to bottom multilayered

elastic pavement. This research also estimated design traffic load applications from both the programs and access design application

(ESAL) for the future research.

ISSN (e) 2520-7393

ISSN (p) 2521-5027

Received on 21st Aug, 2017

Revised on 22nd Sept, 2017

www.estirj.com

J.SHAHZAIB.KHAN et.al: MODELING ANALYSIS OF GAMES AND KENLAYER FOR HIGHWAY PAVEMENT……..

Copyright ©2017 ESTIRJ-VOL.1, NO.3 (28-32)

The computer program KENLAYER is applied to the

flexible pavements having no joints or rigid layers in it.

The KENLAYER program works under the circular loaded

area of an elastic multilayer system. It has an ability to be

applied to a layered system under single, dual, dual-

tandem, or dual tridem wheels with different layer

optimizing different behaviors, either linear, nonlinear or

visco-elastic behavior [6]. In this KENLAYER program,

the damage analysis can be made by dividing each layer

into a maximum of 12 periods, having a set of material

properties. These damages are caused by fatigue, cracking,

and permanent deformation in each period and then for the

evaluation of the design life all the periods are summed up

[6] [7].

The application of the KENLAYER programs is:

Applied to 19 layers.

Output at 10 different radial coordinates.

19 different vertical coordinates.

Solutions can be obtained at a total of 25 points

by specifying the x and y coordinates of each

point.

Creep compliance at a maximum of 15-time

durations.

Maximum of 12 periods.

Each with a maximum of 12 loads groups.

Although a large number of input parameters appears

overwhelming and default values are provided to many of

them, so only a limited number of inputs will be required.

2.4 GAMES Computer program

GAMES (General Analysis of Multi-layered Elastic

Systems), is the computer program which has been

developed based on the assumption that the pavements are

modeled as multi-layered elastic systems. In this program,

vertical loads and horizontal loads are assumed, which are

wheel loads and brakes loads acting on the surface of the

pavement. In the form of shear spring, GAMES program

allows interface slip. The principle of superposition is

being utilized in this program by summing both the

vertical as well as the horizontal loads. GAMES program

is capable of computing stresses, strains, and deflections at

any point in the pavement system. The GAMES program

has a viability of accommodating currently a maximum of

100 loads, 100 pavements layers, and 1000 points of

interest [6].

In the pavement, design traffic is considered to be the

foremost element. The traffic consideration includes both

the magnitude of the loading and number of the load

repetitions in which different types of the procedures occur

such as:

Fixed traffic

Fixed vehicles

Variable traffic

Variable vehicle

These four procedures categorized on the design

criteria of the pavement, where it is designed according to

the need and accumulative usage of the surroundings [7].

3. Methodology

3.1 Model Development

The data in this project is used from the one of the

published paper [8]. Following is the core consideration

for the data:

Thickness data are taken from Pavement Structure

model of LTPP section 28-2807, construction.

Back-calculated Young’s Modulus Results.

Traffic Volume and ESAL on the LTPP section

28-2807.

3.2 Calculations and Results:

It is usually known that Loaded area= P/p, whereas (P) is a

load on wheels and (p) is the tire pressure. As in the

research paper, there is 5,000lb wheel load and 100psi tire

pressure given. Therefore, this research assumed same

values and used in the equation:

Loaded Area = 5,000/100 = 50 (1)

Hence “50=πa^2”. Therefore, a= √50/ 3.14= 2.251 in.

which is 5.717 cm.

Table.1. Statistical data

Thickness of

layer (in)

Back-calculated

Young’s Modulus

(psi)

Assumed

Poison’s ratio

Base 5.5 9,89,800 0.35

Sub base 5.1 1,093,300 0.35

Sub grade 6.6 1,19,100 0.20

Semi-infinite

layer 28,200 0.45

The following figure shows the results from the data

analyzed through the KENLAYER program, in the above

table, vertical coordinates at three different layers are

given and the pavement is analyzed at three different

points, showing vertical displacement at three different

coordinates along with the vertical compressive stresses,

vertical compressive strains, tensile stresses and tensile

strains.

The vertical compressive stress as shown in figure 1

below and vertical compressive strain as it is given in

figure 2 below are on the top of the subgrade. These two

elastic responses are directly related to the subgrade

rutting, which might have been the most important reason

of the pavement failure. For the asphalt pavement surface

rutting, the main parameters are vertical compressive

stresses and the surface deflection, which have caused

damage to the pavement [1].

J.SHAHZAIB.KHAN et.al: MODELING ANALYSIS OF GAMES AND KENLAYER FOR HIGHWAY PAVEMENT……..

Copyright ©2017 ESTIRJ-VOL.1, NO.3 (28-32)

Figure.1. Computational Vertical displacement through KENLAYER

Figure.2. Computational Vertical Stress from KENLAYER

Tensile stresses and Tensile Strains at the bottom of

the asphalt layer are responsive results; while contribute to

fatigue cracking within the asphalt layers. These types of

the damages are caused by the heavy truck traffic load

repetitions over the pavement. “The maximum number of

the Load repetitions that an asphalt pavement carries

without cracking is called as the fatigue life” [3]

4. Results and Discussion

The below-given figure shows that the deflection found

through KENLAYER program is 0.00089 inches. Which is

more realistic damage to the pavement, the deflection

found on the edge of the tire, in this program is usually

observed through a graph that the tire load is at the edge of

the pavement. However, GAMES program has given out

of the deflection as 0.00278 inches. The GAMES program

0.00089

0.00083

0.00075

0.00065

0.0007

0.00075

0.0008

0.00085

0.0009

0.00095

5.499 10.599 17.199

Ver

tica

l D

isp

lace

men

t (i

n)

Verticle Coordinate (in)

vertical Displacement

18.71

1.8910.601

0

4

8

12

16

20

5.499 10.599 17.199

Ver

tica

l S

tres

s (i

n)

Vertical Coordinate (in)

Vertical Stress

J.SHAHZAIB.KHAN et.al: MODELING ANALYSIS OF GAMES AND KENLAYER FOR HIGHWAY PAVEMENT……..

Copyright ©2017 ESTIRJ-VOL.1, NO.3 (28-32)

has the capability to define many layers as discussed above

so it assumes less damage in comparison. However, the

difference of the results was 0.00189 inches more in

GAMES as compared to KENLAYER program and 68%

deflection value increased as a percent of GAMES results.

Figure.3. Shows Comparison of the Deflection Data

Indeed these programs have different output values due

to the fact that GAMES program analyzes pavement at the

z-axis, whereas KENLAYER program analyzes up to three

layers, in which KENLAYER analyzes all the layers and

gives an output of all three coordinates which are given to

the computer program (KENLAYER) [9].

4.1 Design Traffic Load Application

As the data are shown in the paper, the design is based

on the equivalent 18-kip (80-KN) for the count of truck

collectively that is 783,236 per year. Using this data, the

following calculations are made and section area is taken

as two lanes.

Count of truck= 783,236 per year (2)

783,236/365= 2146 per day (3)

Growth rate = 10%

Mr= 10,000 psi

Referring to the table given for the distribution of the

trucks in different classes of the United States, estimates

ESAL for 20 years using ESAL equation [7].

ESAL= (ADT)o(T)(Tf)(G)(D)(L)(365)(Y)

The growth factor found theoretically is 57.28 at 20

years, for 2 lanes gives values 50%= 0.50, the truck

percent calculated as 43%. The TF truck factor is

calculated as 0.52. By putting values if ESAL equation

theoretically.

ESAL = (2146)(0.52)(0.50)(57.28)(365) (4)

ESAL= 1.167x107 (5)

The design traffic is considered as the most important

factor in the pavement. In addition, two basic components

are considered (Traffic factor and Growth factor) the

directional lanes distribution is also considered based on

these factors. Unless the traffic loading or volume is

heavier in one direction than in the other due to some

special reason, a directional distribution of 0.5 is assumed.

The lane distribution factor varies with the number of

lanes and the ADT (Average Daily Traffic), when the

design is based on the equivalent 18-kip (80-KN) single-

axle load, the use of a truck factor is very convenient. The

method for computing truck factors based on the number

of axles, trucks weighed, number of trucks counted, and

then the AASHTO equivalent factors are illustrated.

Damage analyses by KENLAYER indicate that the

passage of set (tandem or tridem) axles may be considered

as one repetition in some cases, not in all cases, depending

on pavement thickness and subgrade support. The problem

is complex so it is best to analyze each load group, either

tandem or tridem directly instead of applying a fixed

number of repetitions.

5. Conclusion

In the design of the pavement, the major causes are

stresses, strains, and deflections within the infrastructure of

the pavements, the impacts of the physical causes are loads

and material properties of the pavement structure. Many

models have been introduced to idealize design of the

flexible pavements, the most common method which is

known as a layered elastic model. With the emerging

trends in transportation and pavement design, it is possible

to evaluate the stress and strain distribution of the

multilayered pavements within very less time and resource

utilization. The analysis of a fore mentioned comparisons

shows that the GAMES computer program model provides

vertical deflection results more than KENLAYER program

that the 68% deflection value increased as a percent of

GAMES results.

Pavement deflection data analysis in this project shows

that the modulus values have been decreased, as given

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

KENLAYER GAMES

Def

lect

ion

(In

ches

)68% deflection value increased

as a percent of GAMES results.

0.00278 in.

0.00089 in.

J.SHAHZAIB.KHAN et.al: MODELING ANALYSIS OF GAMES AND KENLAYER FOR HIGHWAY PAVEMENT……..

Copyright ©2017 ESTIRJ-VOL.1, NO.3 (28-32)

above. This indicates the decrease in the capacity and

capability of the pavement. In fact, both the programs have

viability for the analysis and design of an asphalt

pavement. The design traffic load application also

elaborated its accumulative applicable application for the

design of traffic load, using some theoretical analysis.

However, for three-layered elastic pavement, KENLAYER

program idealizes the more realistic approach in finding

and resulting different results (output) used for Layered

elastic analysis.

References

[1] D. S. Gedafa, “Comparison of Flexible Pavement

Performance Using Kenlayer and Hdm-4,” Midwest Transp.

Consort., vol. 1, no. 785, pp. 1–14, 2006.

[2] D. K. B. Salim Khoso, Manthar Ali Keerio, Abdul Aziz

Ansari, Jam Shahzeb khan, “Effects of rice husk ash and

fiber on mechanical properties of pervious concrete

pavement,” Constr. Build. Mater., vol. 8, no. 3, pp. 1832–

1835, 2017.

[3] X. Wang, Z. Su, A. Xu, A. Zhou, and H. Zhang, “Shear

fatigue between asphalt pavement layers and its application

in design,” Constr. Build. Mater., vol. 135, pp. 297–305,

2017.

[4] P. Tian, A. Shukla, L. Nie, G. Zhan, and S. Liu,

“Characteristics relation model of asphalt pavement

performance based on factor analysis,” Int. J. Pavement Res.

Technol., 2017.

[5] J. W. Maina, E. Denneman, and M. de Beer, “Introduction

of New Road Pavement Response Modelling Software By

Means of Benchmarking,” South African Transp. Conf., no.

1951, 2008.

[6] H. Yin, “Integrating Instrumentation Data In Probabilistic

Performance Prediction Of Flexible Pavements,” 2007.

[7] Y. H. (Yang H. Huang, Pavement analysis, and design.

Pearson/Prentice Hall, 2004.

[8] Z. Jaafar, M. Ahlan, and W. Uddin, “Modeling of pavement

roughness performance using the LTPP database for

southern region in the U.S.,” in Bituminous Mixtures and

Pavements VI, CRC Press, 2015, pp. 713–722.

[9] E. F. H. W. Engr. Salim Khoso, Engr. Abdul Aziz Ansari,

Engr. Jam Shahzaib Khan, “Experimental Study on

Recycled Concrete Using dismantled Road Aggregate and

Baggase Ash,” Inst. Eng. Pakistan, vol. Vol. 63, no. 1, pp.

15–19, 2016.

About Authors

Jam Shahzaib Khan is an Assistant Professor at

Department of Civil Engineering, QUCEST Larkana. Mr.

Khan has enormous teaching and research experience in

Construction Management; Green Buildings; Sustainable

Development/Sustainability; Infrastructure Management,

and Facilities Management etc.

Prof. Dr. Tauha Hussain Ali is Professor at Department

of Civil Engineering, MUET, Jamshoro. Prof. Dr. Tauha

has tremendous research and academic experience. The

research interest includes Construction Management,

Construction Engineering, and Sustainable Infrastructure

Management. Prof. Dr. Tauha Ali has been involved in

arranging and attending national and international

conferences, seminars and symposiums throughout the

world.

Eng. Arshad Ali Memon is an Assistant Professor at

Department of Civil Engineering, MUET Jamshoro. Engr.

Arshad Ali has been researching on a wide variety of

topics including Construction Engineering, Pavements and

Structure Management etc.

Engr. Salim Khoso is an Assistant Professor at

Department of Civil Engineering, QUCEST Larkana. His

research interests are Steel Structures, Earthquake

Engineering, Cement Replacement Materials, and Fiber

Reinforced Concrete etc.

Dr. Manthar Ali Keerio is an Assistant Professor at

Department of Civil Engineering, QUCEST Larkana.

Recently Engr. Mathar has completed Ph.D. in Civil

Engineering from QUEST, Nawabshah. His research

interests are Cement Replacement Materials, Fiber

Reinforced Concrete, Polymer Modified Concrete, and

Self Compacted Concrete etc.

Engr. Samiullah Sohu is an Assistant Professor at

Department of Civil Engineering, QUCEST Larkana. His

research interests are Building Construction, Waste

Minimization in Buildings, and Construction Contracts and

Disputes etc.