## 1 Introduction  
To address the construction challenges posed by weak or problematic soils, the implementation of ground improvement methods becomes imperative, aiming to augment the soil's strength and stiffness. Conventional soil improvement techniques, such as chemical grouting or mixing methods [1, 2, 3], have not only resulted in a high carbon footprint but can also lead to environmental problems and ecosystem disturbance [4, 5]. Consequently, Microbially Induced Calcium Carbonate Precipitation (MICP) is emerging as an innovative and sustainable ground improvement method, characterised by its lesser pollution and relatively cost-effective nature [6, 7]. This technique improves soil properties by filling void spaces and forming bonds at interparticle contacts with calcium carbonate precipitation catalysed by ureolytic bacteria. Numerous laboratory investigations have demonstrated the efficacy of MICP in enhancing soil strength, stiffness, and reducing permeability [8, 9, 10, 11, 12, 13, 14, 15, 16]. Furthermore, field applications have validated its practical feasibility [17, 18, 19]. To optimise the MICP process further, numerical models have also been produced, which include aspects such as reaction rates, fluid flow, bacteria cell concentrations, and the resulting concentration of calcium carbonate, alongside the reduction in soil permeability [20; 21; 22; 23; 24]. Despite the evident advantages of MICP, the difficulty in using it as a ground improvement method is in achieving uniform CaCO\({}_{3}\) formation and associated mechanical strength [25; 26]. Some investigations have proposed innovative grouting methods to address this issue [27; 28]; however, these solutions have been primarily evaluated at the laboratory scale. An alternative approach to solve this problem is to use synthetic biology [29] to engineer a biological system capable of controlled precipitation as needed. Recent advancements in the realm of synthetic biology, as reported by [30], have spurred the hypothesis that it could pave the way for the creation of a system wherein soil could be inoculated with genetically engineered bacteria. These bacteria, in response to increased pressure, could catalyse the formation of calcium carbonate crystals, binding soil particles and thereby enhancing soil strength in areas subjected to external loads. Such a system holds the potential to transform soils into a significant smart Engineered Living Material (ELM) type. The system is based on the idea that bacteria can detect and react to alterations in water pressure as the soil is loaded. These changes can act as input stimuli to a gene circuit which triggers the genetic element responsible for inducing calcium carbonate. Previously, prospective mechanisms for genetic responses to heightened pressure have been identified in two'model' organisms, namely Escherichia coli [31] and Bacillus subtilis. The latter, a common soil-dwelling bacterium, although displaying limited natural Microbiology Induced Calcium Carbonate Precipitation (MICP) capabilities, holds promise as a potential chassis organism, serving as a platform for engineering an MICP process. In the experiments, it has also been shown that there is no straightforward genetic response to elevated load. Instead, different genetic sensitivities to environmental stresses have been observed. In this study, by engineering the bacteria with pressure-sensing capabilities, it is anticipated that they can be tuned to respond to various pressures and environmental conditions. This tuning could enable the programmed production of diverse distributions of calcium carbonate precipitation. Designing such a smart system requires the development of a computational model which can bridge the gap between geotechnical models describing load and water pressures through the soil and the genetic responses of our selected bacterium and help design new hypothetical engineered material responses.