• Hussein Shaia

Student thesis: Phd


Fibre reinforced polymer (FRP) composites represent an alternative construction material for deep foundations that have the potential to eliminate most of the durability concerns associated with traditional piling materials. Research studies and database related to the use FRP composite material as piling foundation is very limited. This research project was undertaken to investigate the structural and geotechnical behaviour of FRP composite piles. The originality of this study rests on the following pillars:• Presenting a new understanding for the factors controlling the compressive strength of FRP tube confined concrete. • Introducing the concept of constitutive interface surface which considers the effect of surface hardness and relative roughness on the interface shear coefficient. • Studying the evolution of FRP pile surface roughness during the driving process. • Investigating the effect of harsh environments on the shear behaviour of FRP-granular interface. • Conducting an extensive experimental and numerical study to characterize the FRPs and soil parameters that control the behaviour of axially and laterally loaded FRP composite pile. Experimental testing program was conducted in this study to examine the behaviour of two different FRPs tubes confined concrete under axial compression, and flexural load. Based on the experimental results of this study and test results available in the literature, a new design chart was proposed to predict the strength enhancement based on concrete strength and FRP lateral confinement. An extensive laboratory study was conducted to evaluate the interface friction behaviour between granular materials and two different FRP materials. The interface test results obtained from experiment were used to examine a number of parameters known to have an effect on the interface friction coefficient. Furthermore, to investigate the evolution of FRP pile surface roughness during the driving process laboratory tests were also conducted to quantify the interface shear induced surface roughness changes under increased normal stress levels. Moreover, interface tests were also conducted using three more counterface materials to define schematically the constitutive interface shear surface (CISS) in the three dimensional domain of surface roughness, surface hardness, and interface shear coefficient.The long-term experimental program was also conducted in this study to assess the effect of different ageing environment conditions on FRP-granular interface shear coefficient. Acidic and alkaline aging environments were adopted in this study. The experimental program involved assessing the ageing effect on the testing FRP materials in terms of the changes in their hardness and surface roughness properties. Furthermore, the interface shear tests were conducted, using the unaged and aged FRP materials, to evaluate the effect of aging environments on FRP-granular interface shear coefficient. A small-scale laboratory pile loading tests were carried out to assess the FRP pile behaviour under axial and lateral loads. The laboratory test results were used to verify/validate a numerical model developed by the commercial finite element package ABAQUS (6.11). Additional numerical analyses using the verified model were conducted to investigate the effect of different the FRPs and soil parameters on the engineering behaviour of FRP pile.
Date of Award31 Dec 2013
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorHossam Aboel-Naga (Supervisor) & Jack Wu (Supervisor)


  • FRP Pile
  • Constitutive Interface Shear Surface
  • Lon-Term Interface Shear

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