Presently Mayor Mohammad Hanif Flyover is the longest Elevated corridor in Bangladesh. This flyover was built in the congested part of the Old Dhaka City namely Sonir Akhra - Jatrabari - Gulistan - Polashi Area of Bangladesh connecting with the main highway bound to Chittagaong Port. The total length of the flyover was 10.6 km including 11 numbers of UP/Down ramps and related infrastructure. The entire flyover including all the ramps are supported by cast-in-situ RCC Bored Pile foundation of 1.20 m diameter and of varying length from 16.25 m to 37.25 m. The alignment of the flyover passes through the old Dhaka city having numbers of different types of underground utilities namely water pipe line, electric cable line, sewerage pipe lines, gas pipe lines and T& T lines. It was a great challenge to finalize the details of pile group and its cap for the foundation of entire flyover by keeping most of the major different utilities in its own position without relocating the same. As a result, separate design for all the 315 numbers of pile group of different regular and irregular shapes comprising of total 2366 numbers of pile shaft was done for the entire flyover. The LRFD method of AASHTO 4th Edition 2007 was adopted for the design of pile foundation of the flyover. Hydraulic Drilling Rig was used for pile boring and plant made ready mix concrete (RMC) through "Tremie" was used to do the pile concerting. This paper presents the detailed design philosophy and construction methodology of pile foundations of the flyover.
Subjects: Flyover, Ramp, Geotechnical Investigation, Pile Foundation, Underground Utilities, Pile Load Tests
Author: Avik Kumar Mandal, Chief General Manager, S. Sailesh, Associate General Manager, Pradyot Biswas, Associate Director, J. P. Das, Sr. Consultant and Dinakar Mandal, Chief General Manager
Publisher: DFI