DEVELOPMENT OF DATA BASE FOR FLEXIBLE PAVEMENTS LAYERS ON SOILS USING GIS TECHNIQUE

The design and evaluation of pavement structures require a significant amount of supporting data such as subgrade material properties density and cohesion. The present study is undertaken to prepare thematic maps in order to predict the important parameters used in highway pavement design, geometric design, feasibility and other construction projects taking advantage of the ability of GIS tools by using soil investigation reports as a database. Also, these maps are useful in determining the unsuitable soil materials’ position for subgrade in order to avoid or treat any problem. The GIS system has many benefits such as the data are more easily stored, managed, edited, and transmitted. However, GIS also provides the ability to quickly analyze these data (soil and pavements properties and their tests) in a variety of ways, often in ways that are not feasible with paper maps.
The analytical functions of GIS are at least as important as the map storage and distribution functions this software will be a reference for highway engineers to take right decision in management and maintenance. Also, the GIS techniques are used to manage the database and to develop thematic maps for soil description like the undrained shear strength at 3m below natural ground to help the highway engineers predict the pavement
layers thickness. The results of the study show that the subgrade soils of Baghdad city
are different from region to another according to the data that is obtained. More than 197 km of pavement roads have been tested by Mayoralty of Baghdad according to Iraqi Standards Specifications for Roads and Bridges SCRB (State Committee of Roads and Bridges) R9/2003 in six municipalities (9 Nissan, Al-sha'ab, Karada and New Baghdad) in Al-Rusafa side and (AlII doura and Rasheed) on Al-karkh side. The layer name, thickness and its related test are added directly to the program as a database which is stored in
attribute table, Just click the identify tools on the street map then all data of that street will appear. To achieve the objective of this research, extensive air temperature data for a period of 11 years are collected from (2001) to (2012) for Eighteen Iraqi cities (Anbar, Babylon Baghdad, Basrah, Dahuk, Diyala, Erbil, Kerbala, Missan, Muthanna, Najaf, Ninewa, Qadissiya, Sulaymaniyah, Salah al-Din, Karkok, Thi-Qar and Wassit).Then, the required Performance Graded (PG) is founded for all Iraq, which is classified in four PG groups: PG(64-16), PG(64-10), PG(70-10) and PG(76-10)