Sustainable approach to urban pile removal through evaluation of innovative circulating mixing for urban infrastructure renewal

This study presents an in-depth evaluation of an innovative circulating mixing method for backfilling boreholes after the removal of existing piles, particularly in urban construction projects where geotechnical stability is critical. Uniform backfill is essential to ensure the structural integrity and long-term performance of newly constructed infrastructure, especially in areas prone to seismic activity. The circulating mixing method involves injecting and circulating backfill material within the boreholes to achieve improved homogeneity throughout the borehole depth. This method was rigorously evaluated through model tests, field experiments, and advanced numerical simulations using the Moving Particle Semi-Implicit (MPS) method within a Computer-Aided Engineering (CAE) framework. The MPS-CAE analysis successfully simulated the complex mixing process, and the results showed strong agreement with the empirical data obtained from the field tests. These results demonstrated a significant improvement in backfill uniformity and a notable reduction in strength variation throughout the borehole depth, addressing critical geotechnical challenges such as surface settlement and structural tilting while promoting sustainable urban development. The field tests confirmed the method’s ability to optimize backfill distribution, providing practical and environmentally responsible solutions for real-world geotechnical applications. In addition, the MPS-CAE simulations provided valuable insights for optimizing process parameters and improving geotechnical quality control, contributing to more sustainable construction practices. The integration of numerical simulation and innovative engineering techniques presented in this research contributes to improving the efficiency, safety, durability, and sustainability of urban redevelopment projects, especially in disaster-prone regions. By providing a robust and sustainable approach to borehole backfilling, this study lays the foundation for further development of more effective, reliable, and environmentally friendly backfilling methods. The research outcomes have the potential to shape the future of sustainable geotechnical engineering, promoting resource efficiency, reducing waste, and minimizing the carbon footprint of urban construction projects. This innovative method offers a pathway to improved geotechnical performance in urban infrastructure development.