The design and calculation of flexible pavement involved in access,internal and side road for the proposed QSTec POLYSILICON Project, Phase-I at Qatar.
1.1
Scope
Design calculation for flexible pavement of access, internal and side road of the above mentioned project.
1.2
Standard and Document
The following standards and documents have been followed for preparation of this document •
Qatar Highway Design Manual (QHDM)
•
Qatar Construction Specification 2007 (QCS 2007)
•
Specification for Road (Doc. No. PS1053-G0000-11-SSP-A4-0001
Pavement design basically aims at determining the total thickness of the pavement structure as also the thickness of the individual layers required for good performance and for effectively standing against the expected traffic loading and prevailing environmental conditions over the design period. For flexible pavement design, the procedure given in the Qatar Highway Design Manual is adopted. 2.2
Parameters for Pavement Design
2.2.1
Design Life
Pavement (Flexible) is designed for a design life of 20 years.
2.2.2
Traffic loading Axle Load
For design traffic loading calculation, axle load is considered as 13 ton. Standard Axles
The standard axles against 13 ton axle loading is adopted as 6.45 Cumulative Equivalent Standard Axle Load
Design traffic loading is calculated to 1.88 million equivalent standard axle after calculation for a design period of 20 years. So the design traffic is under traffic class T2 (1-2 MSA). 2.2.3
Sub grade Class
Soil samples at different test pit locations of the project area were tested, and the minimum soaked CBR found 18.9 percent. So the design subgrade class is adopted as S1(CBR greater than 15% and less than 25%).
2.3
Pavement Design By QHDM
The pavement composition with asphalt concrete road base against traffic class T2 and subgrade class S1,can be adopted from figure 9.2 of QHDM as below :
