Sustainable Methods and Techniques in Special Foundation Engineering
摘要
The construction industry is a major contributor to carbon emissions and is working to optimize construction processes using adapted equipment, methods, materials, and transport, thereby minimizing the environmental impact. The use of soil mixing methods for the construction of cutoff walls for dikes and dams as well as retaining walls for excavation pits but also for foundation elements. In these techniques, properties of in situ soil like the deformation modulus and undrained shear strength are increased by multifold due strengthening by mixing or blending with cement or other binding materials. By mixing the natural soil with cement slurry, the transport of excavated material is largely avoided compared to conventional methods such as pile and diaphragm wall construction. Industry uses several sustainable techniques for increasing the strength of the soils or decreasing the permeability by mixing techniques, such as Cutter Soil Mixing (CSM) with hydro cutter wheels and Mixed-in-Place (MIP) with a triple auger system or mixing with single augers Deep Soil Mixing (DSM). Depending on the objective, performance, service lifetime, and boundary conditions of the specialist foundation element, the process is selected and the dosage of cement in slurry can be adjusted to avoid excess material. The best results can be achieved when soils such as sands and gravels are mixed with cement slurry. However, the technique is not limited to purely granular soils, as some percentage of fines may still be acceptable to achieve good results. The paper addresses the technical details, identifies design approaches, and establishes the criteria for projects that can be undertaken using the aforementioned sustainable construction methods. These techniques help in reduction of carbon emissions by 30% or more and, in addition, these techniques require less transportation and noise emissions can be minimized. A more livable environment can be maintained.