0927 Runway SDR.pdf

7/25/2019 0927 Runway SDR.pdf

1/175


2/175


3/175

Larsen & Toubro Limited

CSIA Expansion & Renovation Program i 10/06/2009

Scheme Design Report Runway 09/27 Upgrade Pavement Structural Design Rev B

MUMBAI INTERNATIONALAIRPORT PRIVATE LIMITEDCSIA EXPANSION & RENOVATION PROGRAM

Scheme Design Report Runway 09/27Upgrade Pavement Structural DesignRev B

10 June 2009

Prepared by:

Larsen & Toubro Limited, ECC Division

Regional Office

5th Floor, North Block II, Gate No.1,

Saki Vihar Road, Powai

Mumbai 400072


4/175


CSIA Expansion & Renovation Program ii 10/06/2009


Document Control

Project Title:

CSIA Expansion & Renovation Program

Runway 09/27 Upgrade Project No: N044

Document Title: Scheme Design Report Runway 09/27 Upgrade Pavement Structural Design

Document Number: MIAL-LT-O-N044-CV11-SD-001

Revision Date Designed by Checked by Approved by Descripti on

A 13 April 2009 Manoj Tipnis Paul McCullagh Larry Mujaj Issued for MIAL review

B 10 June 2009 Manoj Tipnis Paul McCullagh Larry Mujaj Issued for MIAL review

Document Change History

Revision Reason for Change Date

A Preliminary Issue 13 April 2009

B Revised as per client recommendations 10 June 2009


5/175


CSIA Expansion & Renovation Program 1-1 10/06/2009


TABLEOFCONTENTS

1. INTRODUCTION .................................................................................................................. 1-2

1.1 GENERAL ................................................................................................................... 1-2

1.2 SCHEME DESIGN REPORT OBJECTIVES ............................................................... 1-2

2. AIRCRAFT TRAFFIC ANALYSIS ........................................................................................ 2-3

3. AIRCRAFT OPERATING WEIGHTS ................................................................................... 3-4

4. NON-DESTRUCTIVE TESTING ........................................................................................... 4-5

4.1 DEFLECTION DATA ANALYSIS................................................................................. 4-5

4.2 PAVEMENT STRUCTURE MODELLING ................................................................... 4-5

5. GEOTECHNICAL INVESTIGATIONS .................................................................................. 5-8

5.1

TESTING REGIME ...................................................................................................... 5-8

5.2 SUBGRADE DESCRIPTION ....................................................................................... 5-8

5.3 SUBGRADE STRENGTH............................................................................................ 5-8

5.4 EXISTING PAVEMENT STRUCTURE ........................................................................ 5-9

6. PAVEMENT THICKNESS DESIGN ................................................................................... 6-10

6.1 FAARFIELD RESULTS ............................................................................................. 6-10

6.1.1 FAARFIELD Design Methodology ............................................................... 6-10

6.1.2 Runway Elements ........................................................................................ 6-12

6.1.3 Runway Shoulders ...................................................................................... 6-14

6.2

COMFAA CHECK ..................................................................................................... 6-15

6.3 COMPARISON OF DESIGN RESULTS .................................................................... 6-16

6.4 RUNWAY OVERLAY DESIGN AT TAXIWAY LOCATIONS ..................................... 6-18

6.5 DESIGNED PAVEMENT STRUCTURES ................................................................. 6-19

6.6 RUNWAY STRIP & RESA ......................................................................................... 6-21

6.7 PCN ASSIGNMENT .................................................................................................. 6-22

7. CONCLUSION AND RECOMMENDATIONS .................................................................... 7-24

8. LIST OF CODES ................................................................................................................ 8-26

9. APPENDICES & SKETCHES ............................................................................................ 9-27


6/175




1. INTRODUCTION

1.1 GENERAL

This report includes the scheme design of pavement structure for Runway 09/27 Upgrade Project

(N044), at Chhatrapati Shivaji International Airport (CSIA), Mumbai which mainly comprisesasphalt overlay. The asphalt overlay is essentially required for structural strengthening and runway

profile correction, both longitudinal and transverse. The scheme for the structural design is thesubject of this report.

1.2 SCHEME DESIGN REPORT OBJECTIVES

This Scheme Design Report is intended to establish the design of the structural overlay for the

preparation of detailed design construction drawings.


7/175




2. AIRCRAFT TRAFFIC ANALYSIS

The aircraft traffic analysis for Runway 09/27 is detailed in the document titled Scheme Design

Report Aircraft Traffic for Airport Pavements, which has already been submitted. The same traffic

is being utilised for the Runway re-strengthening design except for Runway chainage -153m to -30m(09 Runway).

The aircraft design traffic for Runway 09/27 as extracted from above report is given in Appendix A.

For design of the section from chainage -153m to -30m (09 Runway), 100% Runway 09 departures

and 20% of Runway 27 arrivals are considered. This is because the majority of Runway 27 arrivals

will have exited on the preceding RETs. Runway 27 departures have been ignored since mostdeparting aircraft would have attained lift off before reaching this section of runway pavement. The

design traffic is presented in Appendix A.

For design of existing inner 7.5m wide shoulder upgrade to runway outer pavement specifications,

the design traffic considered is 1% departures of the total aircraft traffic on Runway 09/27, inaccordance with FAA Advisory Circular 150-5320-6E.

For design of overlay requirement over existing 7.5m wide outer shoulder, design traffic considered

is 10 passes of the critical aircraft, B777-300ER, in accordance with FAA Advisory Circular150-5320-6E.


8/175




3. AIRCRAFT OPERATING WEIGHTS

The aircraft traffic analysis details the various aircraft arriving and departing on the runway.

Accordingly we have adopted Maximum Take-off Weight (MTOW) in respect of departing aircraft

traffic and Maximum Landing Weight (MLW) in respect of arriving aircraft traffic for the pavementthickness design. The MTOW and MLW figures for each aircraft type are listed in Table 3.1 below:

Table 3.1 Aircraft Operating Mass

Code C D

Aircraft A320 A321 B737-800 A300 B767-400

MTOM

(Tonnes)77 89 79 171 204

MLM

(Tonnes)64.5 75.5 71 140 159

Code E

Aircraft A330 A340-300 A340-600 B747-400 B777-300 B777-300ER MD-11

MTOM(Tonnes)

230 275 368 397 300 353 285

MLM

(Tonnes)185 200 259 274 252 252 200

Code F

Aircraft A380 B747-8

MTOM(Tonnes)

560 441.4

MLM

(Tonnes)386 340


9/175




4. NON-DESTRUCTIVE TESTING

4.1 DEFLECTION DATA ANALYSIS

Non-destructive testing of the runway pavement using Heavy Falling Weight Deflectometer

(HFWD) was undertaken by MIAL (through Mott Mac Donald Ooms Avenhorn Pvt Ltd- EMSUnihorn bv infrastructure consultants Pvt Ltd). The deflection data as presented in report titled

CSI Airport Mumbai Runway Pavement Testing Runway 09-27 dated April 2007, was

re-analysed by L&T using PAVERS software with an aim to identify the pavement structure and

layer strength parameters so as to define the existing pavement structure for overlay design.

The HFWD generated deflection data analysis report is attached atAppendix B.

4.2 PAVEMENT STRUCTURE MODELLING

On basis of the recommendations of the deflection data analysis report, the existing runway

pavement structure as modelled for design is given in Table 4.1 below. The various sections pertain

to the different homogeneous runway pavement sections identified, as elaborated in the report. Thelayer thicknesses have been adopted from borehole data and the E moduli from the back-calculationresults. The E moduli are within the realistic range of material characterisation for each of the

identified pavement layers. The same back-calculated E moduli are assumed in respect of theshoulder pavement layers. The existing runway shoulder pavement structure as modelled for design

is given in Table 4.2.

Table 4.1: Runway Pavement Structure Model

SectionPavementmodel

Layer Thickness(mm) Evalue(MPa)

Chainagefrom09

153to78

PCC 500 16000

subgrade 20.68

Chainagefrom

09

78to30

Surface 600 1091

PCC/Base 300 350

subbase 800 67

subgrade 20.68

LeftofCentreLine

Chainagefrom09

30to1000

Surface 600 1653

PCC 300 20000

subbase 850 200

subgrade 20.68

LeftofCentreLine

Chainagefrom09

1000to

1785

Surface 600 1111

PCC

300

21000

subbase 950 300

subgrade 20.68

LeftofCentreLine

Chainagefrom09

2100to2250

Surface 600 859

PCC 300 20000

subbase 1160 223

subgrade 20.68


10/175






LeftofCentreLine

Chainage

from

09

2250to3222

Surface 600 959

PCC

300

22000

subbase 1400 293

subgrade 20.68

RightofCentreLine

Chainagefrom09

30to1785

Surface 600 1025

PCC 300 23000

subbase 1000 266

subgrade 20.68

RightofCentreLine

Chainagefrom09

2100to2250

Surface 600 595

PCC 300 20500

subbase 1200 300

subgrade 20.68

RightofCentreLine

Chainagefrom09

2250to3222

Surface 600 1091

PCC 300 20500

subbase 1000 266

subgrade 20.68

Chainagefrom09

3222to3297

PCC 420 16400

Base 450 3200

subgrade 20.68

Table 4.2: Runway Shoulder Pavement Structure Model



Chainagefrom09

78 to30

Surface 300 1091

PCC/base 150 350

subbase 800 67

subgrade 20.68

LeftofCentreLine

Chainagefrom09

30to1785

Surface 300 1111

PCC 150 20000

subbase 850 200

subgrade

20.68

LeftofCentreLine

Chainagefrom09

2100to3222

Surface 300 859

PCC 150 20000

subbase 1160 223

subgrade 20.68


11/175




Section Layer Thickness(mm) Evalue(MPa)

RightofCentreLine

Chainagefrom09

30to1785

Surface 300 1025

PCC 150 23000

subbase

1000

266

subgrade 20.68

RightofCentreLine

Chainagefrom09

2100to2250

Surface 300 595

PCC 150 20500

subbase 1000 266

subgrade 20.68


12/175




5. GEOTECHNICAL INVESTIGATIONS

5.1 TESTING REGIME

Geotechnical investigations comprising of Standard Penetration Tests & laboratory testing have been

undertaken for design purposes. The purpose of the Geotechnical investigation was to log thepavement profile, collect pavement cores, undertake laboratory testing and conduct SPT tests

through the bore/core holes for identification of the soil type and estimation of field CBR from N

value. The details of Geotechnical investigation were incorporated in Addendum-I to Technical

Report - Soil Investigations and Geotechnical Recommendations for Airside Work at CSIA,Mumbai.

5.2 SUBGRADE DESCRIPTION

The soil forming the natural subgrade in CSIA, Mumbai predominantly comprises of Black Cotton

soil and on the basis of Particle Size Distribution and Plasticity Index, is classified under the Unified

Soil Classification System (USCS) as high plasticity clay (CH). The adjoining bore logs on 09 sideof the runway intersection indicate the presence of weathered/hard rock at a depth of 1.9m and on the27 side of the runway intersection indicate the presence of weathered/hard rock at a depth of 2.1m

under the existing runway surface level. The depth to rock increases further away from the runway

intersection, with the maximum recorded depth to rock being 5.35m.

5.3 SUBGRADE STRENGTH

FAA Advisory Circular AC 150/5320-6D - Airport Pavement Design and Evaluation states that thedesign CBR value should be conservatively selected, and that common paving engineering practice

is to select a value which is one standard deviation below the mean (85th percentile).

The soil type and E value is correlated from the N values obtained from SPT tests conducted in field.

Subgrade CBR values are further correlated from the E values in accordance with relation given inMori Chart,1965, 6thinternational conference on soil mechanics and foundation engineering Vol. III.

The evaluated subgrade CBR is 2.1% as per SPT values. The soil classification as per USCS derived

from the grain size analysis is CH type (Highly Plastic Clay).

Considering all of the above data, the design subgrade CBR adopted is 2%. However, between

chainage 1785m and chainage 2100m from 09 Runway, presence of weathered/hard rock strata isreported under the existing pavement structure at a depth of 1.9m to 2.1m. Runway 14/32 also

crosses 09/27 Runway in this area and hence it is assumed that here, pavement strengthening is notrequired and that the runway overlay thickness will be determined based on geometric shape

correction of the both runways.


13/175




5.4 EXISTING PAVEMENT STRUCTURE

The existing runway pavement structure was logged during the field investigations on Runway

09/27. The geotechnical sub-surface profile for the pavement structure is attached at Appendix C.

As indicated in the Bore Logs, the runway pavement is essentially a composite construction in whichflexible overlays have been constructed over the original rigid pavement. The present structurecomprises of approximately 600mm of structurally stable Asphalt surface course. The layer under

the surface course is a PCC layer with an approximate thickness of 300 mm. Under the PCC layer is

a subbase course of granular material / WBM with a thickness varying from 800mm to 1400 mm.

From chainage -78m to -30m, the PCC layer was found to be in a disintegrated state. The subgrade

under the subbase course as described in Para 5.3 above, is Black Cotton soil.

The western 75m Runway 27 end and eastern 75m Runway 09 end of the pavement are both rigid

construction. The western 75m pavement comprises of 500mm PCC over 800mm filled up soil. This

pavement has been recently overlaid with approximately 50mm Asphalt Concrete. The eastern

Runway 09 end 75m pavement comprises of 420mm PQC, 450mm DLC / CTB base. A number of

slabs have developed cracks and most of the pavement is old with edge spalls and surfacedeterioration. Asphalt Concrete has been used as filling in some slabs after removal of AGL insetlights.

The section of runway pavement extending approximately 200m ahead of Rapid Exit Taxiway C, is

reported to be under frequent maintenance. This maintainance being undertaken, involves patchrepairs upto a depth of 100mm. The same is attributable to damage of the surface course of the

runway pavement due to shear stresses generated by braking aircraft arriving onto Taxiway C. A

number of slabs on Taxiway C adjoining the runway pavement are also cracked.

There are no bore logs to confirm the existing pavement structure at the runway intersection.

However, the adjoining bore logs on either side of the intersection confirm a composite pavementstructure resting on weathered/hard rock.

As indicated in the Bore Logs, the shoulder pavement structure is also a composite construction inwhich flexible overlays have been constructed over the original rigid pavement. The present

structure comprises of approximately 300mm of structurally stable Asphalt surface course. The layerunder the surface course is a PCC layer of approximate thickness of 150 mm. Under the PCC layer is

the subbase course of granular material / WBM of thickness varying from 800mm to 1100 mm. Thesubgrade under the subbase course as described in Para 5.3 above, is Black Cotton soil.

The identified approximate structure of the existing pavement has been modelled for structuralanalysis on basis of the deflection data as described in Para 4.2 above.

The design of the runway overlay has therefore been progressed based on this pavement model. The

pavement layer moduli, being realistic, are assumed to be representative of the homogeneouspavement sections identified.


14/175




6. PAVEMENT THICKNESS DESIGN

The existing pavement structure has been defined on the basis of the Geotechnical investigations and

the analysis of deflection data collected by non-destructive testing. FAARFIELD has been used for

thickness designs of the flexible pavement overlay and PQC over existing base. Design life ofre-strengthened flexible runway pavement is taken as 20 years and for rigid pavement 30 years.

LEDFAA software gives the same results for flexible pavement designs. A gross check of thickness

designs has been performed using COMFAA software. The COMFAA checks are for ascertaining

general correctness of designs.

6.1 FAARFIELD RESULTS

6.1.1 FAARFIELD Design Methodology

The design methodology adopted for the FAARFIELD analysis is as follows:

For Flexible Overlay

Input traffic data, including aircraft type, operating weights and number of annualmovements;

Set design life equal to 20 years;

Define pavement structure (as per Table 4.1 for runway and as per Table 4.2 for runwayshoulder);

Design overlay thickness. For flexible overlay we have adopted P-401 AC Overlay andP-401 Asphalt stabilised base.

For New Rigid Pavement construction over existing subbase. (Chainage 3222 to 3297m)

Input traffic data, including aircraft type, operating weights and number of annualmovements;


Define pavement structure.

For Design, we have adopted PCC Surface, Existing cementatious base (CTB/DLC) withE modulus = 3200 MPa, and K= 34 MN/m2/m on top of existing subbase.

Define existing pavement base layer thickness = 450mm and design PCC surface thickness.


15/175




For New Expedient Pavement (for Existing Runway Shoulder Pavement Upgrade to Outer Runway

Pavement)

Input traffic data, including aircraft type, operating weights and number of annual

movements;


For Expedient shoulder pavement we have adopted AC Surface, P-306 Econocrete andSubgrade K=11 MN/m

2/m

For Expedient pavements set P401- AC surface thickness to 200mm and design thickness ofEconocrete layer.

FAARFIELD uses properties for pavement materials from FAA construction specifications, detailedin FAA AC 150/5370-10C Standards For Specifying Construction of Airports (Sept 2007). All

pavement materials used for the construction of aircraft pavements for this project will meet the

minimum strength requirements of the FAA standard materials, however the material specificationsfor this project have been written around Indian Standards and local construction methods.


16/175




6.1.2 Runway Elements

A summary of the FAARFIELD generated pavement flexible thicknesses are presented in Tables 6.1to 6.3 below. The overlay thicknesses are also shown on Sketch P. Prints of the FAARFIELD

software runs are presented in Appendix D, Annexure I to III.

Table 6.1 FAARFIELD Generated Overlay Thicknesses for Existing Runway Pavement

Upgrade

Design Life 20 years

Section

FlexibleOverlay

P401ACSurface

(mm)

P401AC Stabilized Base

(mm)

TotalDesign Overlay

Thickness

(mm)

LEFT&RIGHT:

153 to7850.8 50

LEFT&RIGHT:

78to30101.6 327.8 430

LEFT:30

to

1000

86.3

85

LEFT:1000to1785 96.7 100

LEFT:2100to2250 120.8 120

LEFT:2250to3222 50.8 50

RIGHT:30to1785 103.6 100

RIGHT:2100to2250 99.7 100

RIGHT:2250to3222 103.3 100

Table 6.2 FAARFIELD Generated Overlay Thicknesses for Existing Runway Shoulder

Pavement Upgrade to Outer Runway Pavement specifications.

Design Life 20 years, Design Traffic 1% of total departure traffic, in accordance with FAA AC150-5320-6E

Section

FlexibleOverlay

P401ACSurface

(mm)

P401AC Stabilized Base

(mm)

TotalDesign Overlay

Thickness

(mm)

LEFT&RIGHT:

153 to7850.8 50

LEFT&RIGHT:

78to30101.6 292.4 395

LEFT:30to1785 101.6 126.5 230

LEFT:2100to3222 146.3 145

RIGHT:30to1785 101.6 53.8 155

RIGHT:2100to3222 101.6 80.4 180

From the FAARFIELD software runs it is observed that B747-400 and A380-800 majorly contribute

to the CDF for the pavement structure. The pavement design thickness would therefore remain

sensitive to the number of passes of these critical design aircraft. Therefore any further increase in

operations of these aircraft will have a corresponding impact on pavement life.


17/175




Table 6.3 FAARFIELD Generated New Expedient Pavement Thickness for Existing Runway

Shoulder Pavement Upgrade to Outer Runway Pavement specifications.Design Life 20 years

PavementLayer

RequiredDesign

Thickness

(mm)

AdoptedDesign

Thickness

(mm)

P401ACSurface 200 200

Econocrete 604.6 600

Subgrade(CBR=2%)

For upgradation of the existing shoulder to outer runway specifications of FAA AC 150-5320-6E

ie. 1% of total departure traffic, the adequacy of overlay provided consequent to adopting 1.25%cross slope for the runway vertical profile was checked. The computed pavement life for these

existing shoulder sections after providing the shape correction overlay (not full structural overlay) is

given in Sketch Q. For this purpose the overlay thickness considered was Average 1 SD (ie. the

85thpercentile) over the given chainages. The computed results indicate that the overlay thickness is

inadequate over majority of the existing shoulder sections ie. between chinages 30 to 1785 andbetween 2100 to 3222.

Therefore for upgradation of the existing shoulder to outer runway specifications, the existingrunway shoulder will be divided in sections capable of receiving full structural overlay and those

which cannot accommodate the overlay thickness, on the basis of vertical geometric design /grading. The sections which can accomodate the respective design overlay as per Table 6.2 will be

provided with the same. Sections where the depth between designed and existing levels is not

sufficient to accommodate the respective designed overlay, will be reconstructed as per newexpedient pavement design given in Table 6.3. Alternatively MIAL may seek dispensation from

DGCA to adopt a reduced thickness and accordingly a reduced life in terms of aircraft passes.

A summary of the FAARFIELD generated rigid pavement thickness is presented in Table 6.4 below.Print of the FAARFIELD software run is presented in Appendix D, Annexure IV.

Table 6.4 FAARFIELD Generated Rigid Pavement Thickness over Existing Base (chainage

3222m to 3297m)

Design Life 30 years

Pavement LayerRequired Design

Thickness (mm)

Adopted Design

Thickness (mm)

PQC 471.6 475

Existing Base 450 450

Existing Subbase (K=34MN/m3) - -


18/175




6.1.3 Runway Shoulders

Shoulders to runways are required by ICAO Annex 14 to be structurally capable of accommodatingan occasional pass of an aircraft and to be structurally capable of supporting maintenance vehicles

and emergency vehicles. The shoulders are designed for 10 passes of the critical aircraft

B777-300ER, over a life of 20 years.

The FAARFIELD generated pavement overlay thicknesses are 0mm over the entire stretch of therunway shoulder, except for chainage -78m to -30m where an overlay of 155mm is required. For this

project the existing outer shoulders will be provided with a minimum functional overlay of 50mmAsphalt Concrete after requisite milling for shape correction.

It should be noted that this thickness is often exceeded due to the need to correct transverse slopes to

meet ICAO grading requirements.

Prints of the FAARFIELD software runs are presented in Appendix D, Annexure V.


19/175




6.2 COMFAA CHECK

A check of the derived pavement thicknesses has been conducted using COMFAA. The procedure

for calculating pavement thicknesses using COMFAA is as follows:

Annotate with the number of departures of each aircraft;

Determine the critical design aircraft.

Considering the gear factors and weight factors, convert all traffic of various aircraft in thedesign fleet mix to equivalent departures of the design aircraft, individually.

Determine the Pass to Coverage Ratio (PCR) for each aircraft;

Calculate the number of coverages for each aircraft (Coverages = Departures / PCR) interms of equivalent coverages of the critical design aircraft;

Sum the total number of equivalent coverages of the critical aircraft;

Determine the S77-1 pavement thickness required for the total number of equivalentcoverages of the critical aircraft. Alpha factors as per 2006 revision are incorporated in thepavement thickness design in order to account for the coverages of various multiple wheel

gear assemblies. Using published material equivalency factors, convert the existing structure with

FAARFIELD generated overlays into S77-1 pavement thickness.

Compare the COMFAA and FAARFIELD S77-1 derived pavement thicknesses.

The determination of the pavement structure equivalent to the standard S77-1 pavement structurerelies on the use of published material equivalency factors, which are typically expressed within a

range. We have calculated the equivalent pavement thicknesses using appropriate / average values

within the range for comparison with the FAARFIELD derived pavement thicknesses. The detailed

calculations for COMFAA check are included in Appendix E.

As per the COMFAA procedure the critical design aircraft is to be slected based on maximum

pavement thickness requirement for the given aircraft traffic. Therefore, for the flexible overlaydesign, the B777-300ER at 353 Tonnes (MTOW) has been selected as the critical aircraft. However,

FAARFIELD assigns a greater damage factor(CDF) to B747-400 and A380-800, but due to lesserpavement thickness requirement, they do not qualify to be the critical aircraft as per the COMFAA

design procedure. The following is a summary of the COMFAA results presented in Appendix E.

For chainage -153m to -30m, The total number of coverages of the total aircraft fleet mix isequivalent to 41647 coverages of the B777-300ER at 353 Tonne. The S77-1 pavement thickness

required is 2547mm and for chainage -30m to 3222m, The total number of coverages of the aircraft

fleet mix is equivalent to 380964 coverages of the B777-300ER at 353 Tonne. The S77-1 pavement

thickness required is 2663.9mm.

For rigid pavement over existing subbase (chainage 3222m to 3297m), the modulus of subgrade

reaction (k) of the subgrade underneath rigid pavement section is 11 MN/m2

/m, over which a900mm of existing subbase is available which gives an effecive k = 34 MN/m2/m on top of the

existing subbase. Over that, 450mm of existing cementatious base (CTB / DLC) is available. From

ICAO Aerodrome Design Manual Part 3, Figure 4-55 and FAA AC 150/5320-6D, Figure 3-16, aneffective k value on top of the base course layer is derived as 109 MN/m2/m by extrapolation of the

chart.


20/175




6.3 COMPARISON OF DESIGN RESULTS

The next step in the design check is the comparison of the equivalent flexible pavement thicknesses

computed using FAARFIELD and COMFAA. To do this, the pavement thickness derived from

FAARFIELD is converted to an equivalent S77-1 structure. Here a constant Asphalt Concrete and

WMM layer thickness is assumed and GSB layer thickness is calculated based on layer equivalencyfactors. Table 6.5 below details the results for comparison:

Table 6.5 Comparison of FAARFIELD and COMFAA computed Flexible Pavement

Thicknesses

FAARFIELD computed Structure

(Converted to Equivalent S77-1 Structure)

COMFAA

computed

StructureChainagefrom 09

(m)

-78to

-30

L: -30to

1000

L: 1000to

1785

L:2100to

2250

L: 2250to

3222

R: -30to

1785

R: 2100to

2250

R: 2250to

3222

-78to

-30

-30to

3222

AC (mm) 75 75 75 75 75 75 75 75 75 75

WMM

(mm)150 150 150 150 150 150 150 150 150 150

GSB

(mm)2487 2469 2595 2832 2880 2640 2820 2640 2322 2469

Subgrade(CBR 2%)

- - - - - - - - - -

Total

(mm)2712 2694 2820 3057 3105 2865 3045 2865 2547 2664

As can be seen from Table 6.5 above, the COMFAA derived pavement thicknesses for flexible

pavements are comparable with the FAARFIELD generated pavement thickness. Accordingly, the

FAARFIELD design results are considered to be accurate, and the adopted pavement structuresdetailed in Table 6.1 are adequate for construction.

For existing rigid pavements on the western end of the runway, the comparison of FAARFIELD and

COMFAA computed thicknesses is given in Table 6.6 below.

Table 6.6 Comparison of FAARFIELD and COMFAA computed Rigid Pavement

Thicknesses over existing subbase (Chainage 3222 to 3297m)

Design Life- 30years

FAARFIELD COMFAA

PQC (mm) 475 501

From above results for Rigid pavements, it is observed that the FAARFIELD design thicknesses are

not adequate in comparison with the COMFAA design requirement.

The western end existing rigid pavement (chainage 3222 to 3297) , has a remaining life of 15 years

as computed with FAARFIELD, which would be in respect of intact slabs in the pavement extent.As reported in the geotechnical investigations, a number of slabs have developed cracks and most of

the pavement is old with edge spalls and surface deterioration. Based on visual inspection, it is

considered that the existing pavement would probably have a life of at least 5 years subject to urgent

maintenance being undertaken. It is noted from the geometric design that this section is required to


21/175




be regraded. Hence in consideration of the regrading pavement and the poor surface condition andopportunity for renewal, it is recommended that the existing PQC pavement be reconstructed over

the existing subbase. As per FAARFIELD design given in Table 6.4 the required PQC thickness is475mm as against the COMFAA design requirement of 500mm as in Table 6.6. The design as per

FAARFIELD of 475mm PQC is being adopted for construction over the existing subbase .

For the eastern rigid end of the runway (chainage -153m to -78m), the vertical geometry designindicates that the pavement surface will have to be raised by a minimum of 600mm (already

provided with 50mm overlay). Therefore the geometric overlay will satisfy the structural needs of

the pavement. Thus only the Asphalt overlay alternative was evalauated for this runway end. Inconsideration of the same and equivalent S77-1 thicknesses were computed for the existing structure

with overlay. The adopted design section is given below in Table 6.7.

Table 6.7 Adopted Structure for eastern Rigid end (-153m to -78m)

Layer Thickness(mm)

OverlayAC 200

CTB 400 (min)

Existing structurePCC 500

Subgrade (CBR 2%) -

The adequacy of the adopted section was checked with COMFAA. The details are given below in

Table 6.8.

Table 6.8 Comparison of Adopted Structure and COMFAA computed Thicknesses for

Pavement (Chainage -153m to -78m)

Overlay based on

Geometric Requirement

(Converted to EquivalentS77-1 Structure)

COMFAA computed

Structure

AC (mm) 75 75

WMM (mm) 150 150

GSB (mm) 2410 2322

Subgrade (CBR 2%) - -

Total (mm) 2635 2547


22/175




6.4 RUNWAY OVERLAY DESIGN AT TAXIWAY LOCATIONS

The design runway pavement sections based on estimated runway aircraft traffic as detailed in

preceding paragraphs also need to be checked for structural adequacy at the connecting

taxiway/ runway locations. The runway overlay design in these locations is then based on estimated

aircraft traffic on each of the exit taxiways. The higher of the two overlay designs viz; overlaythickness based on runway traffic and overlay based on connecting taxiway traffic, then becomes the

ruling overlay requirement for the particular location on the runway. For the present case, the

structural overlay required for runway traffic is analysed as the ruling overlay for the central 20m

full strength width of the runway. Beyond the middle third runway width, a reduced strength keelsection (as per ICAO Aerodrome Design Manual Part 3 Clause 4.4.14 and FAA AC 150/5320-6E

clause 305) is to be provided. The structural thickness is designed for 1% of the total runway

departure traffic, for the outer section of the runway for upgradation of existing shoulders. However,the reduced thickness over the outer section will not be provided at Taxiway connections. Instead,

full strength taxiway pavement sections will be provided here.

Further, the runway design thickness is checked for adequacy at taxiway connection locations. The

structural adequacy is checked by comparing the computed structural runway overlay with that

required for connecting taxiway traffic. In case the CDF is lesser than 1, the designed structuralsection is adequate for Life of minimum 20 years. At sections where the existing structure is

computed as adequate, a minimum 50mm functional overlay will still be provided, incorporating aminimum 15mm milling of the existing runway surface.

A summary of the FAARFIELD generated runway pavement overlay thicknesses for 20 year designlife at connecting taxiway locations are presented in Table 6.9. It can be seen that no overlay is

required on the runway when considering the connecting taxiway traffic, except for connection toTaxiway N where a minimum 50mm overlay is required, where a 600mm (minimum) overlay is

being provided due to grading requirements. Prints of the FAARFIELD software runs are presented

in Appendix D, Annexure VI.

Table 6.9 FAARFIELD Generated Overlay Thicknesses at Taxiway Connection Locations

Taxiway

Connection

Chainage

from09

FlexibleOverlay

P401ACSurface

(mm)

P401AC Stabilized

Base(mm)

TotalOverlayThickness

(mm)

TWYN L:92 50.8 50

TWYW1 L:1676 0 0

RETN5 L:2133 0 0

TWYN4 L:2649 0 0

TWYN3 L:3023 0 0

TWYN1 L:3243 NotApplicable* NotApplicable*

TWYS R:0 0 0

RETS8

R:609

0

0

RETS7 R:1112 0 0

TWYW1 R:1676 0 0

TWYS4 R:2649 0 0

TWYS3 R:3023 0 0

*NOTE: Taxiway N1 (A4) is an existing rigid pavement and the runway connection is also rigid, sono overlay is required. The recommended structure of 475mm PQC on existing subbase is adequate

for the taxiway N1 traffic.


23/175




6.5 DESIGNED PAVEMENT STRUCTURES

A summary of the thicknesses adopted for flexible overlay, New Expedient pavement and Rigid

Pavement over existing subbase are presented in Tables 6.10 to 6.13.

Table 6.10 Designed Flexible Overlay Thicknesses for Existing Runway Pavement UpgradeDesign Life 20years

Section(m)

Designed Structural

OverlayThickness

(mm)

LEFT&RIGHT: 153to78 200Asphalt+400CTB

LEFT&RIGHT: 78to30 430Asphalt

LEFT:30to1000 85 Asphalt

LEFT:1000to1785 100Asphalt


LEFT:2250to3222 50 Asphalt

RIGHT:30to1785 100Asphalt



Table 6.11 Designed Flexible Overlay Thicknesses for Existing Runway Shoulder Pavement

Upgrade to Outer Runway Pavement specifications.

Design Life 20years

Section(m)

DesignedStructural

OverlayThickness

(mm)

LEFT&RIGHT: 153to78 200Asphalt+120CTB

LEFT&RIGHT: 78to30 395Asphalt





Table 6.12 Designed Structure of New Expedient Pavement Thickness for Outer Runway

Pavement specifications.

Design Life 20years

PavementLayerDesignedThickness

(mm)

P401ACSurface 200

Econocrete 600

Subgrade(CBR=2%)


24/175




Table 6.13 Designed Rigid Pavement Thickness over Existing Base (chainage 3222 to 3297m)

Design Life 30years

Pavement LayerDesigned

Thickness (mm)

PQC 475

Existing Base 450

Existing Subbase (K=34MN/m2/m) -


25/175




6.6 RUNWAY STRIP & RESA

Clause 3.4.16 of the DGCA CARS statesthat:

The portion of a strip of an instrument runway within a distance of at least:

75 m where the code number is 3 or 4; and

40 m where the code number is 1 or 2;

From the centre line of the runway and its extended centre line shall be so prepared or constructed

as to minimize hazards arising from differences in load bearing capacity to aeroplanes which the

runway is intended to serve in the event of an aeroplane running off the runway.

Clause 3.5.11 of the DGCA CARs states that:

A runway end safety area shall be so prepared or constructed as to reduce the risk of damage to an

aeroplane undershooting or overrunning the runway, enhance aeroplane deceleration and facilitate

the movement of rescue and fire fighting vehicles.

In order to comply with the above clause, the bearing capacity of Runway strip area and RESA willbe improved if required in specific areas as identified by MIAL.


26/175




6.7 PCN ASSIGNMENT

The ICAO ACN/PCN system is used by airport operators as a pavement management tool, whereby

aircraft that operate at Aircraft Classification Numbers (ACN) less than the Pavement Classification

Number (PCN) for a particular pavement can do so without weight restriction without undue damage

occurring to the pavement. Aircraft that wish to operate with an ACN greater than the publishedPCN must apply to the airport operator for a Pavement Concession.

FAA Advisory Circular AC 150/5335-5A, Standardized Method of Reporting Airport Pavement

Strength PCN, Paragraph 6 states The ACN-PCN system is only intended as a method ofreporting relative pavement strength so airport operators can evaluate acceptable operations of

airplanes. It is not intended as a pavement design or pavement evaluation procedure, nor does it

restrict the methodology used to design or evaluate a pavement structure. A similar philosophy isalso expressed in ICAO Aerodrome Design Manual Part 3, Clause 1.1.2.1.

The airport operator is free to select any value of PCN, and the decision as to which value to select is

often a balance between commercial considerations and the actual strength of the pavement. An

airport operator may choose to increase the PCN without strengthening a pavement, in order to

attract larger aircraft and thereby gaining increased revenue. The airport operator would make thisdecision consciously knowing that the overloaded operations of the larger aircraft would reduce the

life of the pavement, and would result in the need for early maintenance of the pavement.

The aircraft pavements for this project have been designed based on a rigorous analysis of the actual

number of aircraft that are likely to utilise the runway pavement within the design period. The PCN

analysis is attached at Appendix F.

Since the basis of design for the aircraft pavements are published in this report, it is anticipated that

the airport operator will track usage of the airport pavements throughout the design period, and will

use the aircraft traffic included in Appendix A (analysis submitted separately as SDR-Aircraft

Traffic for Aircraft Pavements), as a baseline in which to manage aircraft operations at the airport.

L&T therefore recommend that highest ACN value of all aircraft in the fleet mix be adopted as thePCN for the airport. ACNs for various aircraft in the fleet mix, based on a flexible pavement and

subgrade category C, are summarised in Table 6.14.

From Table 6.14, the highest ACN is 89, corresponding to B777-300ER operating at a MTOW of

353 Tonne.

The minimum ACN computed for various design sections, corresponding to B777-300ER operatingweight of 359 T is 92.

The recommended PCN assignment of the Runway 09/27 for publication is 89/F/C/W/T.


27/175




Table 6.14 Aircraft Classification Number for Various Aircraft

(Using 2006 Alpha factors)

Code C D

Aircraft A320 A321 B737-800 A300 B767-400

MTOM

(Tonnes)77 89 79 171 204

ACN 46.8 57.3 50.1 65.6 78.3

Code E

Aircraft A330 A340-300 A340-600 B747-400 B777-300 B777-300ER MD-11

MTOM

(Tonnes)230 275 368 397 300 353 285

ACN 71.2 71.5 83.2 72.4 72.4 89 80.5

Code F

Aircraft A380 B747-8

MTOM(Tonnes)

560 441.4

ACN 75 85.8


28/175




7. CONCLUSION AND RECOMMENDATIONS

Runway 09/27 is required to be strengthened in order to cater for the projected aircraft traffic. For

the purpose of design of the structural overlay, the existing runway pavement structure was analysed

based on geotechnical investigations and non-destructive testing.

The major length of the runway comprises of an intact asphalt thickness of 600mm, over a PCC

layer of 300mm thickness. Under the PCC layer exists a granular subbase layer of average thickness

800mm.

The flexible overlay design has been carried out with software FAARFIELD, which provides for

identical design thicknesses as LEDFAA. A gross check has been carried out with COMFAA.

Overlay design solutions have been provided for a design life of 20 years.

For the overlay design, the runway has been divided in ten sections based on the deflectionprofiles obtained by non-destructive testing with HFWD. The E moduli of the existing pavement

layers have been back-calculated from the deflection data. The values have been found to be within a

realistic range and hence adopted for the overlay design. The asphalt structural overlay design

thickness varies from 50mm to 120mm, for a design life of 20 years. However, the overlay thicknesswill be increased over respective sections in keeping with the designed vertical geometry of the

runway. In case, the vertical geometry design dictates adoption of a lesser overlay thickness over a

particular section, the pavement over this runway section will require regular / periodic maintenance.Between chainage -78m and -30m Asphalt overlay requirement of 430mm is computed. Providing

for 200mm Asphalt overlay the CTB requirement is computed as 220mm totalling to 420mm

overlay. As the geometric profiling of the runway to meet the ICAO requirement already results in a

thickness of 430mm, no additional strengthening is required. Similarly, over the existing rigidpavement between chainage -153m to -78m overlay of 200mm Asphalt and minimum 400mm CTB

is being provided in consideration of the vertical profiling of the runway at that location against

minimum overlay requirement of 50mm.

The overlay adequacy has also been confirmed for taxiway traffic at locations where the runway

connects to taxiways. The geo-technical data as interpreted for the cross runway design assumes thatthe runway intersection from chainage 1785m to 2100m has weathered/hard rock strata under the

pavement structure. Based on the same, only a minimum functional overlay of 50mm is necessary

for this section from chainage 1785m to 2100m. Thicker layers however result from the need to meet

the ICAO geometric requirements.

The existing flexible pavement between chainage 537m and 1017m is reported to be requiringfrequent patch repairs. The same is attributed to accentuated braking of the arriving aircraft at this

location. At this location it is recommended to provide a deep lift patch extending 150mm deep into

the existing pavement so as to provide for an average 350mm of new pavement (considering also,the vertical profile design). Also, existing cracked slabs on Rapid Exit Taxiway C adjoining the

runway are recommended to be replaced.

The existing rigid pavement between chainage 3222m and 3297m has a low design life and also

since regrading is required in this area, it is recommended to reconstruct the PQC pavement to a

thickness of 475mm on top of the existing base course.

The inner existing runway shoulder of 7.5m width is being upgraded to outer runway specifications.The shoulder upgradation will be achieved by overlaying existing asphalt shoulder surface, where

possible in consideration of the runway cross profile, or else, will be reconstructed with expedient

paving. The design overlay and new expedient pavement are computed to satisfy strength

requirements of outer runway as per FAA AC 150-5320-6E.


29/175




The outer existing shoulder satisfies the structural requirement of runway shoulder specified in thesame advisory circular. The existing outer shoulder will hence be provided with only 50mm of

Functional overlay.

The existing shoulder pavements will be reconstructed with taxiway design pavement sections at all

new taxiway connections.

As reported by MIAL a subsurface drainage system had been incorporated in the existing runway

pavement structure. The longitudinal drains along both sides of the runway pavement are considered

integral to the subsurface drainage system and are therefore recommended to be retained.

The PCN assignment of the Runway 09-27 after overlay is recommended as 89/F/C/W/T,

corresponding to the highest ACN of aircraft included in the projected traffic levels (B777-300ER).

The design also indicates that B747-400 and A380-800 aircraft contribute significantly to pavementdamage. It is therefore recommended that operations of these three aircraft be restricted to within the

projected traffic level as considered for design.


30/175




8. LIST OF CODES

1. ICAO, Doc 9157-AN/901, Aerodrome Design Manual Part 3, Second Edition, 1983.

2. ICAO Annex 14 Aerodromes , Vol. 1, Aerodrome Design and Operations, Fouth Edition,2004.

3. FAA Advisory Circular AC 150/5335-5A Standardized Method of Reporting AirportPavement Strength PCN

4. FAA Advisory Circular AC 150/5320-6D Airport Pavement Design and Evaluation.

5. FAA Advisory Circular AC 150/5320-6E Airport Pavement Design and Evaluation.

6. FAA Advisory Circular AC 150/5370-10B Standards For Specifying Construction of Airports(April 2005).

7. DGCA Civil Aviation Regulations


31/175




9. APPENDICES & SKETCHES

APPENDICES

A. Runway 09/27 Design Aircraft Traffic

B. Report - Analysis of HFWD Deflection Data

C. Geotechnical subsurface profile

D. FAARFIELD Software Runs

E. COMFAA Results

F. PCN Analysis

SKECTHES

P. 09/27 Runway Structural Overlay Thicknesses

Q. Runway 09/27 Life calculation for outer Runway with overlay provided by adoptingcross slope of 1. 25%


32/175

Appendix A

RUNWAY 09/27 DESIGN AIRCRAFTTRAFFIC


33/175

Annual

Arrivals

Annual

Departures

Annual

Arrivals

Annual

Departures

A320 4803 3431 27448 34310

A321 613 475 3504 4745

A300 1840 1314 10512 13140

A330 1840 1314 10512 13140

A340-300 715 511 4088 5110

A340-600 715 511 4088 5110

A380 51 37 292 365

B737-800 7256 5293 41464 52925

B767-400 1022 694 5840 6935

B747-400 971 730 5548 7300

B747-8 51 37 292 365

B777-300 1446 1007 8264 10074

B777-300ER 598 416 3416 4161

MD11 358 219 2044 2190

Annual

Arrivals

Annual

Departures

Annual

Arrivals

Annual

Departures

A320 4803 34 27448 343

A321 613 5 3504 47

A300 1840 13 10512 131

A330 1840 13 10512 131

A340-300 715 5 4088 51

A340-600 715 5 4088 51

A380 51 1 292 4

B737-800 7256 53 41464 529

B767-400 1022 7 5840 69

B747-400 971 7.3 5548 73

B747-8 51 1 292 4

B777-300 1446 10 8264 101

B777-300ER 598 4 3416 42

MD11 358 2 2044 22

09/27RUNWAYDESIGNAIRCRAFTTRAFFIC

APPENDIXA

09/27RUNWAYOUTERPAVEMENTDESIGNAIRCRAFTTRAFFIC

Aircraft

Chainage:153mTO30m Chainage:30mTO3297m

Aircraft

Chainage:153mTO30m Chainage:30mTO3297m


34/175

Appendix B

ANNEXURE I: ANALYSIS OF HFWD DEFLECTION

DATA


35/175


CSIA Expansion & Renovation Program i 10/06/2009

Analysis of FWD Deflection Data for Runway 09-27

APPENDIX B

ANNEXURE I

Analysis of FWD Deflection

Data for Runway 09-27


36/175


CSIA Expansion & Renovation Program ii 10/06/2009


TABLE OF CONTENTS

1. INTRODUCTION .................................................................................................................. 1-1

1.1 GENERAL ................................................................................................................... 1-1

1.2 DEFLECTION DATA RECORDING ............................................................................ 1-1

2.

DEFLECTION DATA ANALYSIS ......................................................................................... 2-2

3.

FLEXIBLE AIRFIELD PAVEMENT ANALYSIS ................................................................... 3-3

3.1 GENERAL ................................................................................................................... 3-3

3.2 EXISTING PAVEMENT STRUCTURE ........................................................................ 3-4

3.2.1 Reported Structure ........................................................................................ 3-4

3.2.2 Identified Structure ........................................................................................ 3-4

3.3 PAVEMENT STRUCTURE MODELLING ................................................................... 3-5

4.

RIGID AIRFIELD PAVEMENT ANALYSIS .......................................................................... 4-6

5.

RESULTS ............................................................................................................................. 5-7

5.1 SECTION: -153 TO -78 ............................................................................................... 5-7

5.2 SECTION: -78 TO -30 ................................................................................................. 5-8

5.3 SECTION: LEFT (-30 TO 1000) ................................................................................ 5-10

5.4 SECTION: LEFT (1000 TO 1785) ............................................................................. 5-11

5.5 SECTION: LEFT (2100 TO 2250) ............................................................................. 5-12

5.6

SECTION: LEFT (2250 TO 3222) ............................................................................. 5-13

5.7 SECTION: RIGHT (-30 TO 1785) .............................................................................. 5-14

5.8

SECTION: RIGHT (2100 TO 2250) ........................................................................... 5-15

5.9

SECTION: RIGHT (2250 TO 3222) ........................................................................... 5-16

5.10

SECTION: 3222 TO 3297 ......................................................................................... 5-17

6. RECOMMENDATIONS ...................................................................................................... 6-18


37/175




1. INTRODUCTION

1.1 GENERAL

For determination of PCN values of existing runways at Chhatrapati Shivaji International Airport,Mumbai Mott MacDonald had carried out non-destructive testing through Ooms Avenhorn

Holding India Private Limited. A Heavy Falling Weight Deflectometer (HFWD) was used by

Ooms Avenhorn for collection of deflection data from 09-27 Runway of CSI Airport, Mumbai. The

data had been analysed by Ooms using PAVERS software for reporting the PCN value.Accordingly the pavement structure had been modeled as suitable for PCN evaluation. However,

the report did not explain the basis for adopting the specific structural model and E values asreported could not be correlated with the pavement layer materials. Therefore it is not practical to

assess the overlay design section on basis of the reported analysis. The deflection data collected by

Ooms has hence been re-analyzed by L&T using PAVERS software for arriving at realisticmodeling of the existing pavement to be utilised for overlay design by FAARFIELD software.

1.2 DEFLECTION DATA RECORDING

The HFWD generated deflection measurements were recorded in period 24 to 26 Nov 2006. Theload level was kept at approximately 200KN for recording the pavement deflections using 06

geophones at varied distances from the load centre. The deflection data has been recorded along 5

longitudinal lines along either side of the runway centreline at lateral spacing of 3m, 4m, 6m, 7m

and 8m from centreline and longitudinal spacing of 100m along each run (staggered by 25mbetween the runs). The deflections have been recorded at average pavement surface temperature of

37C. The deflections have been recorded for 2000m from Runway 09 end and for 1200m from

Runway 27 end. Approximately 300 m of runway intersection section has not been in recorded,possibly due to operational constraints.


38/175




2. DEFLECTION DATA ANALYSIS

The deflection data recorded at varying loads in range of 154 KN to 234 KN was normalized touniform load of 272 KN, simulating dynamic A330 aircraft wheel loading. The normalized

deflection data was then utilized for identification of pavement sections with similar deflectionprofiles, termed as homogeneous sections for analysis. Since deflection data had been collected for

longitudinal pavement sections left and right of runway centreline separately, the pavementbehaviour patterns based on the deflection profiles could also be established separately for

longitudinal runway sections on left and right of runway centreline. Accordingly the sections withsimilar deflection pattern were identified on either side of runway centreline. Once the pavement

sections were identified the deflection bowl representing the homogeneous sections were selected

on basis of rigorous statistical analysis for further analysis of the pavement structural parameters by

PAVERS software. The bowl nearest to 85th percentile of individual deflections was selected as

representative for each pavement section for further analysis. The sections identified based on the

deflection profiles are tabulated below.

Table 1: Pavement Sections (East to West 09-27)

SECTION ChainageLEFT of Centre Line

1 -153 to -78

2 -78 to -30

3 -30 to 1000

4 1000 to 1785

5 2100 to 2250

6 2250 to 3222

7 3222 to 3297

RIGHT of Centre Line1 -153 to -78

2 -78 to -30

3 -30 to 1785

4 2100 to 2250

5 2250 to 3222

6 3222 to 3297


39/175




3. FLEXIBLE AIRFIELD PAVEMENT ANALYSIS

3.1 GENERAL

The deflection data along with pavement cross-sectional details were utilized as input for thePAVERS analysis. The pavement is modelled as linear elastic multilayered structure with the

assumptions that the layers are infinitely long in horizontal direction, layers are of uniform

thickness and that the layer materials are homogeneous, isotropic and linear elastic in nature. These

assumptions are made in all softwares using layered elastic theory. For back-calculation of materialproperties of pavement layers, following input parameters were required by the program for

analysis:-

(i) Range of Elastic Moduli Values for each pavement layer Realistic range of ElasticModuli comparable with characteristic values was adopted.

(ii) Poissons ratio values for each pavement layer - Characteristic value of 0.35 adopted

for the asphalt layer, the granular base/subbase course and the subgrade.

(iii) Pavement Layer thickness Layer thickness were adopted as per pavementstructural models explained subsequently.

(iv) Friction between the layers Full friction mobilization between pavement layerswas adopted.


40/175




3.2 EXISTING PAVEMENT STRUCTURE

3.2.1 Reported Structure

The existing pavement structure reported in PCN evaluation report by Ooms is as under:-

50mm DAC

75mm SDAC

50mm DAC

50mm SDAC

40mm DAC50mm SDAC

60mm Crack Relief Layer50mm DAC

50mm SDAC

100mm AC

200mm Murrum230mm Murrum

300mm Lime Stabilized soil

3.2.2 Identified Structure

The existing structure indentified as per geotechnical investigations conducted by L&T is as under:

Chainage -153 to -78m from 09: 500mm PCC

800mm WBM

Chainage -78 to -30m from 09: 600mm AC+DBM/BM

300mm Disintegrated PCC800mm WBM/GSB Fill

Chainage -30 to 3222m from 09: 600mm AC+DBM/BM300mm PCC

850-1400mm WBM/GSB Fill

Chainage 3222 to 3297m from 09: 420mm PCC

150mm CTB

300mm PCC

930mm WBM


41/175




3.3 PAVEMENT STRUCTURE MODELLING

For analysis purpose the pavement modelling was based on the actual pavement structure

identified through geotechnical investigations.

Accordingly the flexible pavement sections are modelled as under:-

Pavement

Section (m)Asphalt Layer PCC Layer Subbase Layer Subgrade

-78 to -30

600 mm

(All top 600mm

Asphalt layers)

300mm

(Disintegrated

Existing PCC)

800mm (ExistingWBM/GSB Fill)

As existing

Left :

-30 to 1000

600 mm

(All top 600mm

Asphalt layers)

300mm

(Existing PCC)

850mm (Existing

WBM/GSB Fill)

As existing

Left :

1000 to 1785

600 mm

(All top 600mm

Asphalt layers)

300mm

(Existing PCC)

950mm (Existing

WBM/GSB Fill)As existing

Left :2100 to 2250

600 mm

(All top 600mmAsphalt layers)

300mm(Existing PCC)


As existing

Left :

2250 to 3222

600 mm(All top 600mm

Asphalt layers)

300mm

(Existing PCC)

1400mm (Existing


Right :-30 to 1785

600 mm

(All top 600mm

Asphalt layers)

300mm(Existing PCC)


As existing

Right :

2100 to 2250

600 mm

(All top 600mm

Asphalt layers)

300mm

(Existing PCC)

1200mm (Existing


Right :

2250 to 3222

600 mm

(All top 600mm

Asphalt layers)

300mm

(Existing PCC)

1000mm (Existing


The back-calculation process for modelling the pavement layers was continued till the deflectionsmeasured with FWD equipment matched closely with the theoretically calculated deflections within

an acceptable range of error ( 10% Lack of Fit). The elastic modulus values of the pavement layerswere re-adjusted so as to obtain a computed deflection bowl matching with the normalized

deflection bowl.

The deflections were measured at a certain ambient pavement temperature with the weighed mean

temperature of 37 C. The PAVERS version 2.50 however limits the same to a maximum of 30 C.The back-calculated elastic moduli of the asphalt layers were therefore corrected to 33 C, utilising

the temperature correction suite of the software.


42/175




4. RIGID AIRFIELD PAVEMENT ANALYSIS

The deflection data along with following input parameters required for back-calculation of elasticmodulus of the slab were input in PAVERS software.

(i) Range of Elastic Moduli values for the slab Realistic range of Elastic Modulicomparable with characteristic values was adopted.

(ii) Poissons Ratio value Characteristic value of 0.15 was adopted for PCC layer and0.35 for the asphalt layer, the granular base/subbase course and the subgrade. Forcombined PCC and CTB layer a characteristic value of 0.18 was adopted.

Since the PCN evaluation report by Ooms did not report a Rigid structure. The identified rigid slabthickness over subbase-subgrade combine of infinite thickness was modelled for the Rigid end

sections of the runway pavement for purpose of analysis.

Accordingly the Rigid pavement sections are modelled as under:-

Pavement

Section (m)PCC Layer Base Layer Subgrade

-153 to -78500 mm

(Existing PCC)-

Existing WBM/ GSBFill/clay soil considered

as part of subgrade

3222 to 3297420 mm

(Existing PCC)

150 mm (ExistingCTB) and 300 mm

(Existing PCC)

Existing WBM/ GSBFill/clay soil considered

as part of subgrade

The Back-calculation process was continued till the deflections measured with HWD equipment

matched with the theoretically calculated deflections within an acceptable range of error(10% Lack of Fit).


43/175




5. RESULTS

5.1 SECTION: -153 TO -78

Rigid Pavement Composition

Layer

NoMaterial Type

Elastic Modulus

MPa

(Back-calculated)

Poissons

Ratio

Thickness

(mm)

1 PCC Layer 26000 0.15 500

2Modulus of Subgrade

Reaction (K)0.044N/mm

2

Lack of Fit - 42.3%


44/175




5.2 SECTION: -78 TO -30

Pavement Composition (Option-1)

LayerNo Material Type

Elastic Modulus

MPa(Back-calculated)

PoissonsRatio Thickness(mm)

1 Bituminous Layer 1091 0.35 600

2 PCC/Base Layer 300 0.15 300

3 Subbase Layer 200 0.35 800

4 Sub grade 350 0.35

Lack of Fit 9.8% Back calculated E=1650=>1091MPa corrected to 33o

C


45/175




Pavement Composition (Option-2)

Layer

NoMaterial Type

Elastic Modulus

MPa

(Back-calculated)

Poissons

Ratio

Thickness

(mm)


2 PCC/Base Layer 350 0.35 300




C


46/175




5.3 SECTION: LEFT (-30 TO 1000)

Pavement Composition

Layer

NoMaterial Type

Elastic ModulusMPa

(Back-calculated)

Poissons

Ratio

Thickness

(mm)


2 PCC Layer 20000 0.15 300




C


47/175




5.4 SECTION: LEFT (1000 TO 1785)



Elastic Modulus




2 PCC Layer 21000 0.15 300



Lack of Fit 9.5% Back calculated E= 1680=>1111MPa corrected to 33oC


48/175







Elastic Modulus




2 PCC Layer 20000 0.15 300



Lack of Fit 9.2% Back calculated E= 1300=>859MPa corrected to 33o

C


49/175






Layer

No Material TypeElastic Modulus MPa

(Back-calculated)

Poissons

Ratio

Thickness

(mm)


2 PCC Layer 22000 0.15 300



Lack of Fit 14.5%Back calculated E= 1450=>959MPa corrected to 33o

C


50/175




5.7 SECTION: RIGHT (-30 TO 1785)



Elastic Modulus




2 PCC Layer 23000 0.15 300



Lack of Fit 6.3% Back calculated E= 1550=>1025MPa corrected to 33oC


51/175




5.8 SECTION: RIGHT (2100 TO 2250)


Layer

No Material TypeElastic Modulus MPa

(Back-calculated)

Poissons

Ratio

Thickness

(mm)


2 PCC Layer 20500 0.15 300



Lack of Fit 7.8% Back calculated E=900 =>595MPa corrected to 33o

C


52/175




5.9 SECTION: RIGHT (2250 TO 3222)



Elastic Modulus




2 PCC Layer 20500 0.15 300




C


53/175




5.10 SECTION: 3222 TO 3297

Rigid Pavement Composition

Layer

No Material Type

Elastic Modulus MPa

(Back-calculated)

Poissons

Ratio

Thickness

(mm)

1 PCC Layer 16400 0.15 420

2 Base Layer 3200 0.18 450

2 Sub grade 0.0490 N/mm2

Lack of Fit 10.1 %


54/175




6. RECOMMENDATIONS

On the basis of the analysis of deflection data by PAVERS software, following recommendations are

made:-

(a) The rigid pavement from chainage 3222 to 3297m is rigid and exhibits a low deflectionprofile. However, visual inspection has revealed that a number of slabs are distressed and

cracked. It is assumed therefore that the deflection measurements for the rigid pavement

section would have been recorded for intact slabs. Therefore an assessment of the overallcondition with respect to percentage cracking would dictate adoption of rehabilitation

strategy.

(b) Save the above discussed pavement sections, the runway pavement is structurally amenablefor an overlay construction for re-strengthening or up-gradation.

(c) The back calculation results based on the pavement model are found to be quite realistic andthus can be adopted for overlay design.

(d) The rigid pavement from chainage -153 to -78m exhibits a low deflection profile. The backcalculated E value for PQC is 26000 MPa. The error in back calculation results is high.

However, the lab evaluated E value is 16000 MPa, which is considered realistic when

compared to other back-calculated PCC values. The same is therefore recommended to be

adopted for overlay design.

(e) The pavement from chainage -78 to -30m exhibits high deflection values due to the reporteddisintegrated PCC layer instead of sound PCC. The layer Modulus is very low and

comparable to granular layer Modulus. The analysis has therefore been re-done based on

flexible layer properties. The pavement section would require a thick overlay or alternatively

the pavement may be re-constructed.

(f) Further, for overlay design, the elastic modulus values for the subbase / fill materialcombined should be reduced to a maximum of 30% of the back calculated values as isrecommended by AASHTO, to cater for dry season deflection measurements and assumed

linear elasticity & isotropic properties of the granular materials. The corrected value shouldbe adopted as design modulus for the granular subbase course.

(g) The design subgrade strength should be as per the geotechnical investigations.


55/175

Appendix B

ANNEXURE II: HFWD RESULTS


56/175


57/175


58/175


59/175


60/175


61/175


62/175


63/175


64/175


65/175


66/175


67/175


68/175


69/175


70/175


71/175


72/175


73/175


74/175


75/175


76/175


77/175


78/175


79/175


80/175


81/175


82/175


83/175


84/175


85/175


86/175


87/175


88/175


89/175


90/175


91/175


92/175


93/175


94/175


95/175


96/175


97/175


98/175

Appendix C

GEOTECHNICAL SUBSURFACE PROFILE


99/175


100/175


101/175

Appendix D

ANNEXURE I: FAARFIELD SOFTWARE RUNS

FOR RUNWAY FLEXIBLE OVERLAY


102/175

AppendixD

AnnexureI

DesignLife 20years

Section:153to78m

The structure is AC Overlay on Flexible.

Design Life = 20 years.

A design has not been completed for this section.

Pavement Structure Information by Layer, Top First

Thickness Modulus Poisson's Strength

mm MPa Ratio R,MPa

1

P-401/ P-403 HMA

Overlay 50.8 1,378.95 0.35 0

2 Undefined 500 16,000.00 0.35 0

3 Subgrade 0 20.68 0.35 0

Total thickness to the top of the subgrade = 550.8 mm

Airp lane In for mati on

Gross Wt. Annual % Annual

tonnes Departures Growth

1 A320-200 Twin std 77 3,431 0

2 A320-200 Twin std 64.5 4,803 0

3 A321-200 std 89 475 0

4 A321-200 std 75.5 613 0

5 A300-B4 std 171 1,314 0

6 A300-B4 std 140 1,840 0

7 A330-200 std 230 1,314 0

8 A330-200 std 185 1,840 0

9 A340-300 std 275 511 0

10 A340-300 std Belly 275 511 0

11 A340-300 std 200 715 0

12 A340-300 std Belly 200 715 013 A340-600 std 368 511 0

14 A340-600 std Belly 368 511 0

15 A340-600 std 259 715 0

16 A340-600 std Belly 259 715 0

17 A380-800 560 37 0

18 A380-800 386 51 0

19 B737-800 79 5,293 0

20 B737-800 71 7,256 0

21 B767-400 ER 204 694 0

22 B767-400 ER 159 1,022 0

23 B747-400 397 730 0

24 B747-400 274 971 0

25 B747-400ER 441.4 37 0

26 B747-400ER 340 51 0

27 B777-300 Baseline 300 1,007 0

28 B777-300 Baseline 252 1,446 0

29 B777-300 ER 353 416 0

30 B777-300 ER 252 598 0

31 MD11ER 285 219 0

32 MD11ER Belly 285 219 0

33 MD11ER 200 358 0

34 MD11ER Belly 200 358 0

FAARFIELDSOFTWARERUNSFORRUNWAYFLEXIBLEOVERLAY

No. Type

No. Name


103/175

Add iti onal Air plane Info rmat ion

CDF CDF Max P/C

Contribution for Airplane Ratio

1 A320-200 Twin std 0 0 1.38

2 A320-200 Twin std 0 0 1.38

3 A321-200 std 0 0 1.35

4 A321-200 std 0 0 1.35

5 A300-B4 std 0 0 0.69

6 A300-B4 std 0 0 0.69

7 A330-200 std 0 0 0.79

8 A330-200 std 0 0 0.79

9 A340-300 std 0 0 0.79

10 A340-300 std Belly 0 0 1.27

11 A340-300 std 0 0 0.79

12 A340-300 std Belly 0 0 1.27

13 A340-600 std 0 0 0.79

14 A340-600 std Belly 0 0 0.81

15 A340-600 std 0 0 0.81

16 A340-600 std Belly 0 0 0.78

17 A380-800 0.22 0.23 0.56

18 A380-800 0 0 0.56

19 B737-800 0 0 1.35

20 B737-800 0 0 1.35

21 B767-400 ER 0 0 0.73

22 B767-400 ER 0 0 0.73

23 B747-400 0.52 0.52 0.71

24 B747-400 0 0 0.71

25 B747-400ER 0.1 0.1 0.72

26 B747-400ER 0 0 0.72

27 B777-300 Baseline 0 0.11 0.54

28 B777-300 Baseline 0 0.01 0.54

29 B777-300 ER 0 0.43 0.53

30 B777-300 ER 0 0.01 0.53

31 MD11ER 0 0 0.77

32 MD11ER Belly 0 0 1.29

33 MD11ER 0 0 0.77

34 MD11ER Belly 0 0 1.29

No. Name


104/175

Section:78to30m(200mmAsphaltoverCTB)

The structure is New Flexible. Asphalt CDF was not computed.

Design Life = 20 years.

A design for this section was completed on 04/13/09 at 17:49:14.

Pavement Structure Information by Layer, Top First

Thickness Modulus Poisson's Strength

mm MPa Ratio R,MPa

1

P-401/ P-403 HMA

Surface 101.6 1,378.95 0.35 0

2 Undefined 100 2,500.00 0.35 0

3 P-304 CTB 219.9 3,447.38 0.2 0

4 Undefined 600 1,091.00 0.35 0

5 Undefined 300 350 0.35 0

6 Undefined 800 67 0.35 0

7 Subgrade 0 20.68 0.35 0

Total thickness to the top of the subgrade = 2,121.5 mm

Airp lane In for mati on

Gross Wt. Annual % Annual

tonnes Departures Growth

1 A320-200 Twin std 77 3,431 0

2 A320-200 Twin std 64.5 4,803 0

3 A321-200 std 89 475 0

4 A321-200 std 75.5 613 0

5 A300-B4 std 171 1,314 0

6 A300-B4 std 140 1,840 0

7 A330-200 std 230 1,314 0

8 A330-200 std 185 1,840 0

9 A340-300 std 275 511 0

10 A340-300 std Belly 275 511 0

11 A340-300 std 200 715 0

12 A340-300 std Belly 200 715 0

13 A340-600 std 368 511 0

14 A340-600 std Belly 368 511 015 A340-600 std 259 715 0

16 A340-600 std Belly 259 715 0

17 A380-800 560 37 0

18 A380-800 386 51 0

19 B737-800 79 5,293 0

20 B737-800 71 7,256 0

21 B767-400 ER 204 694 0

22 B767-400 ER 159 1,022 0

23 B747-400 397 730 0

24 B747-400 274 971 0

25 B747-400ER 441.4 37 0

26 B747-400ER 340 51 0

27 B777-300 Baseline 300 1,007 0

28 B777-300 Baseline 252 1,446 0

29 B777-300 ER 353 416 0

30 B777-300 ER 252 598 0

31 MD11ER 285 219 0

32 MD11ER Belly 285 219 0

33 MD11ER 200 358 0

34 MD11ER Belly 200 358 0

No. Type

No. Name


105/175

Add iti onal Air plane Info rmat ion

CDF CDF Max P/C

Contribution for Airplane Ratio

1 A320-200 Twin std 0 0 1.03

2 A320-200 Twin std 0 0 1.03

3 A321-200 std 0 0 1.03

4 A321-200 std 0 0 1.03

5 A300-B4 std 0 0 1.03

6 A300-B4 std 0 0 1.03

7 A330-200 std 0 0.01 0.7

8 A330-200 std 0 0 0.7

9 A340-300 std 0 0 0.7

10 A340-300 std Belly 0 0 1.02

11 A340-300 std 0 0 0.7

12 A340-300 std Belly 0 0 1.02

13 A340-600 std 0 0.02 0.7

14 A340-600 std Belly 0 0 0.62

Documents

0927 Runway SDR.pdf