Title: Optimized Structural Design of Concrete Pile Plug in Steel Pipe Piles

Author(s): Lin Wan-Wendner, Ioan Pop, and Werner Vits

Publication: Structural Journal

Volume: 119

Issue: 6

Appears on pages(s): 153-163

Keywords: asymmetric reinforcement; concrete plug; structural design; sustainability

DOI: 10.14359/51734802

Date: 11/1/2022

Abstract:
Concrete pile plugs are generally used in marine structures to transfer loads between steel piles and top concrete structures. This paper looks at the key aspects for structural analysis of concrete plugs including bond stress with steel pile, plug length, reinforcement design, and with prestressed strands. It is proposed to use an asymmetric reinforcement layout based on the loading conditions to reduce material use and subsequent green gas emissions. This may be combined with the strut-and-tie method for local analysis when prestressed strands or tie rods are present. The design methods are carried out in a typical quay wall project and the consequent economic and environmental impact is analyzed. The optimized strategy ensures a safe and sustainable pile plug design. For the investigated quay wall project, it is found that using asymmetric reinforcement leads to an overall 50% reduction on steel quantity, associated cost, and CO2 emissions. Quantitatively, the saved steel corresponds to $380,000 effective material costs as of 2021, and consequently 515 tonnes (268 US tons) of CO2 emission for equivalent steel production.