Innovative Geotechnical Design, Smart Construction and Optic Fibre Sensing

The future of built infrastructure including geotechnical structures relies on smarter use of information to make better engineering decisions leading to a reduction in risk, costs and carbon footprint and enhanced resilience and integrity. The rich information obtained from emerging sensor technologies can act as a catalyst for innovative geotechnical design, smarter construction planning and more cost-effective and energy efficient construction processes. Design of geotechnical structures requires consideration of risks associated with variable geology, which can be managed by having high spatial resolution data to understand the effects of varying soil-structure interaction. At present, there is a mismatch between the data needed and what current sensing systems can collect, which makes data-driven decision hard to achieve in real-time. Fibre optic sensing (FOS) is capable of obtaining high spatial resolution data in geotechnical engineering projects, allowing real-time acquisition of large volumes of data that can be analysed and fed back to designers and constructors to improve construction performance. This paper presents a review of the role of data in driving smart, cost-effective and energy-efficient design and construction and in particular discusses how optic fibre sensing can facilitate this in geotechnical engineering projects. Three local case studies are presented to demonstrate the capability of fibre optic monitoring. The first case describes the use of FOS in developing a full picture of soil-structure interaction on driven mini-piles during pile load tests, enabling the development of new analytical solutions for this footing system. The second case presents monitoring of a pipe-jacking project in Melbourne where a Glass-fibre Reinforced Plastic pipe was instrumented with FOS to capture its behaviour during the drive. The measured longitudinal and circumferential strains led to better understanding of the effects of the process on the pipes, providing a foundation for design improvement. The third case demonstrates the capability of FOS in long-term monitoring of elastic and permanent deformations in pavements constructed with recovered waste tyres.