Report on Airport Visit of Shahjalal International Airport (DHAKA)

Introduction:Air transportation is the most prominent and technologically advanced transportation system in the world. Since the invention of aircraft by Wright brothers in 1903, aircrafts had gone under major changes along with significant changes in airports and its facilities.

The main airport of Bangladesh is Hajrat Shahjalal International Airport. Being a major airport in the country; it is a very busy airport and is classified as KPI (Key Point Installation) with maximum security.

The main objective of visiting the airport is to get acquainted with airport transportation system, components of airport, observing reconstruction of runway and taxiway pavement.

Visit to the airport was arranged by Professor Dr. Md. Mazharul Hoque with association from Abdul Monem Group, Contractor Company appointed for upgrading the runway pavement.

Airport: Main components of an airport a) Terminalsb) Runwayc) Taxiwayd) Apron

Runway Terminals Apron

Shahjalal International Airport: Fig: Hajrat Shahjalal International Airport.

This airport has single runway. It consists of four taxiways. For boarding, alighting of passengers and freight, terminal building is used.

Evaluation of airport site selection: There are several criteria for selecting airport site. They are discussed below

(1) Type of development of the surrounding area: Significant noise at airport cause disturbance to people. Residential areas and schools not avoided. No buffer zones between runways, taxiways, aprons and boundary(2) Atmospheric conditions: Flat Topography. Land-use pattern does not reduce capacity of airport.(3) Accessibility to ground transport: No good public transport. Poor accessibility to ground transport. But adequate parking facilities are provided. (4) There are some available lands for future expansion. (5) Height restriction is imposed on surrounding tall structures. (6) Utilities (Electricity, water etc.) are available.

Considering above options for the airport, it can be said that this airport has the potential to be the Hub of south Asian countries if proper planning and implementation is done.

Observation of Hajrat Shahjalal International Airport:

Aircraft GearConfiguration: We have seen several gear configurations. These are :-

Fig: Aircraft I

The major generic gear configurations is following

2 Duals in Tandem, 2D

Fig: Aircraft II

All gear configurations are Dual D

Fig: Aircraft III

The generic gear configurations are following

3 Duals in Tandem, 3D

Fig: Aircraft II/

The main generic gear configurations is following

2 Duals in Tandem, 2D

RUNWAY: Length of runway is 3200 meters Runway designation 14/32 Single runway

ABDUL MONEM LTD :Abdul Monem Limited-Contractor Company appointed for upgrading the runway pavement, guides us regarding the pavement reconstruction process, technical and engineering issues, challenges, method applied to overcome the challenges etc.

Abdul Monem Limited is one of the leading diversified business conglomerates of Bangladesh which was established in 1956. They began as a construction contractor soon became a trusted name and ultimately a synonym of quality, reliability and commitment. For 56 years Abdul Monem Ltd. Has successfully accomplished numerous projects including those aided by World Bank, Japan Bank, Asian Development Bank, Islamic Development Bank etc.

Among the ongoing Projects the Mymensing 4-lane Highway project, Padma Bridge Project are mentionable. They have one of the best construction equipment here in Bangladesh.

The Authority In-Charge brief us about the reconstruction and improvement of the runway project. From him we learned a lot regarding the construction process.

Fig: Authority In-charge of Abdul Monem Ltd briefing us about Airfield Pavement construction

RUNWAY PAVEMENTRECONSTRUCTION :

Two asphalt plants were used for the runway pavement overlay. These plants were used for mass construction of asphalt within a short period of time. In order to meet the specification, these plants were used. Setup for this plant took around one month. A single plant costs around 7 to 10 core taka. This type of plants was introduced for the very first time in Bangladesh by one of the most prominent construction companies in Bangladesh ABDUL MONEM LTD. This plant is developed by German company named AMMANN.

Fig: Asphalt mixing plant

Theoretically, capacity of a single plant is 160 ton/hour. But practically about 135 ton/hour asphalt mix can be manufactured. After the setting of plant, trial and error of batch mix was done to achieve the accurate batch mix. This process is computer based and can be operated by a single operator. This plant is run by Ferrari engine

Fig: Some of the components of asphalt mixing plant

Grooving: In the runway grooving was provided transversely from 150 m to 3050 m of runway. Thickness of grooving is 6 mm and spacing is 5 inch. Grooving is done in order to

Provide optimum friction Provide easy drainage Increase asphalt pavement life

As 6 mm thick grooving acts as top surface for runway that ensures not only safety of aircraft but also safety of runway. This grooving exists 5 to 7 years

Fig: Grooving was checked before applying on runway

Taxiway : Length of taxiway 6 Kilometers Four taxiways (South , High speed/rapid exit ,Center ,North) We observed the construction of North taxiway

The taxiway pavement reconstruction was going on funded by Denmark Govt. We have got an opportunity to familiarize with the several features of the taxiway pavement re-construction by talking with a pavement Engineer from Palestine appointed by the Denmark contractor company.

Fig: Pavement Engineer informing us regarding the taxiway pavement re-construction process.

Reconstruction and ImprovementOf taxiway pavement:

Reconstruction of taxiways is funded by Denmark government. The equipment and the contractor are from Denmark. The project commenced from Feb 2013. Initially taxiways were rigid pavement but now they are making it flexible pavement. With a view of constructing the flexible pavement:-

Existing soil was modified CBR value was improved for soil layers until the required value was obtained Different soil tests include CBR test, Plate load test for modulus of subgrade reaction (k) were done The soil layer was extracted and improved soil layer was provided Base CBR = min 80 , sub-base CBR = min 30 was attained

Key features :

The thickness of the pavement was 480 mm. It consists of five layers. The base layer and binder layer has maximum aggregate size of 37 mm or 1.5 Top surface has maximum aggregate size of or 12.25 mm

Fig : Taxiway Pavement

For the first time in Bangladesh improved asphalt is used. Chemical is used in the asphalt Bitumen was made more harder by adding special type of rubber. For binder around 7 kg of rubber was used for each ton of asphalt Resulting bitumen with rubber becomes more strong , more tough One of the major challenges of overlaying bitumen during warm and hot weather is the melting of bitumen. This improved asphalt is used for the first time in Bangladesh as well as in South Asia

Fig: Overlay of asphalt in the North taxiway Pavement

Various tests for bitumen was done in Denmark and the quality control was maintained by doing various test

Fig: Quality Control is maintained by doing tests on cylinder specimen

Base layer is improved to provide adequate support to bitumen layer. Another key feature is that recycled asphalt is used. Recycled asphalt was melted and mixed with new asphalt. As a result improved and environmental friendly construction process was attained In the current construction 15 % to 20 % recycled asphalt was used. But in European countries around 50% recycled asphalt was applied. Plastic sheets were provided in order to prevent cracks from propagating to the upper layer.

Fig: Plastic sheets

At the intersection of runway and taxiway, rigid pavement is provided in order to prevent the undulation of pavement during load is applied

Fig: At intersection rigid pavement is provided

Compaction was done by number of modern rollers. Grease was provided on the wheels of roller so that the hot asphalt does not cling to the wheels

Fig : Compaction done by RollersLighting System :

PAPI ( Precision Approach Path Indicator) is provided. Previously this airport was Category I .After upgrading lighting system now it is Category II In Category II pilot is assisted with more lighting facilities. Previously lights were spaced 30 m apart, now the spacing is halved that is 15 m Illumination of approach light is raised Touch down zone lights as well as center lights are increased

Fig: Threshold and approach lighting system