Deep Marine Foundations with Pipe Pile Cells to Protect Bridge Piers from Seasonal Flooding and Major Earthquakes-PPT Presentation

PPT Presentation

Pdf Summary

The project widened Bangladesh’s National Highway N1 between Dhaka and Chittagong by constructing new bridges beside the existing Kanchpur, Meghna-Gumti, and Gumti bridges. Funded by a Japanese ODA loan, the work ran from January 2016 to January 2020 and included new bridge foundations, piers and superstructures, repairs to existing bridges, and associated roadwork.<br /><br />The new piers were built close to the existing structures, whose foundations had suffered scour. Pipe pile cell foundations were used to support the new piers and integrate the new and existing foundations. Construction presented challenges including low overhead clearance, seasonal river-level changes, and dense sand and silt. These conditions required pile splicing and an installation method that could work in restricted spaces while limiting disturbance to the existing bridges.<br /><br />The contractor used press-in piling, which applies hydraulic force to push piles into the ground and produces little vibration or noise. High-pressure, high-volume water jetting helped install piles in dense soils. Across the three bridges, crews installed 460 permanent and 72 temporary piles, each 1,000 mm in diameter. Permanent piles ranged from 27 to 56 metres long, with multiple splices required.<br /><br />The project demonstrates that pipe pile cells can provide reliable foundations for in-water bridge piers, and that press-in piling with water jetting can install piles efficiently in dense soils. Its low-vibration operation and suitability for low-headroom work made the method appropriate for construction beside operating bridges.

Keywords

Bangladesh

National Highway N1

Kanchpur Bridge

Meghna-Gumti Bridge

Gumti Bridge

Japanese ODA loan

bridge widening

pipe pile cell foundations

press-in piling

water jetting