"Conventional ground improvement techniques are highly invasive, frequently energy intensive and may require the introduction of environmentally damaging chemicals or carbon-intensive materials into the subsurface (e.g. chemical grouts, cement). The construction sector is responsible for 7% of carbon emissions in the UK. The UK target for 80% reduction in carbon emissions by 2050 (against the 1990 baseline) presents both challenges and tremendous opportunities for the UK construction sector in the transition towards a low-carbon economy. The use of cementitious materials is pervasive in conventional ground improvement techniques, and with cement production contributing 5-7% of total global CO2 emissions there is a clear need for the development of new ground improvement technologies.
Over the last ten years the geotechnical engineering research community has witnessed the creation of a new subdiscipline: biogeotechnics a multi-disciplinary field at the interface of biology, geochemistry, soil mechanics, and geotechnical engineering. This represents a paradigm shift in geotechnical engineering- until now the accepted view has been to consider the ground as sterile and inert; now engineers are exploring the potential for use of biological and biochemical processes in ground engineering applications. This proposal represents the first steps towards the development of a novel low-carbon, minimal intervention, biologically based technology using engineered fungal networks.
Biological soil crusts in nature (consisting of fungi, bacteria and other organisms) are known to withstand erosion due to water or wind action. This project will investigate filamentous fungi, i.e. fungi which grow hyphae (tube-like structures). It is thought that fungal hyphae behave similar to plant roots - penetrating between soil particles and entangling them -helping to bind soil particles together, but on a smaller scale. Furthermore, fungi can secrete biochemical products, which may also contribute to binding of soil particles. This project will systematically quantify the mechanical benefit of fungal treatment in soils by investigating three different types of fungi and their ability to enhance the behaviour of different soil types. The project will determine the conditions required for rapid fungal network growth to occur and optimise the orientation of hyphal development to give maximum mechanical benefit. The dataset arising from the proposed experimental campaign will act as a springboard for the development of a new range of nature inspired ground improvement technologies.
The research proposed could transform how we consider the design of, development and deployment of ground improvement technologies. Rather than subject the ground to different energy intensive or invasive techniques, this research proposes to 'grow' the required level of treatment through the use of fungal networks. The process could be engineered using external stimuli to orient the hyphal networks as required for site-specific applications. This project will investigate the feasibility of the deployment of fungal networks as a ground improvement technology."