Empirical equations for wall movement and surface settlement resulting from deep excavations in asian megacities

Abstract

The lack of space in densely populated urban areas presents a significant challenge to urban development, requiring deep excavations. Advanced engineering techniques are increasingly being adopted to construct high-rise buildings, tunnels, underground parking facilities, and other complex structures. However, deep excavation processes can result in ground settlement or damage to adjacent buildings due to soil removal. To ensure the safety and stability of structures in rapidly changing cities, it is essential to predict ground settlements and wall movements caused by excavation activities. In geotechnical engineering design, a finite element method (FEM) is crucial but often complicated and time-consuming. Therefore, empirical prediction during the preliminary design stage becomes important. This research aims to propose empirical formulas to investigate surface settlement and wall movement induced by deep excavations in Asian countries. The study focuses on understanding soil-structure interactions in deep excavations adjacent to soft soils, particularly clay and sand subsoil conditions. Firstly, the work reanalyzes simulations for seven case studies from Cambodia, Indonesia, Malaysia, Taiwan, Thailand, and Vietnam focusing wall movements and ground surface settlements. The numerical analysis employs both the Mohr-Coulomb (MC) and Hardening Soil Model (HSM). Next, using Zhang’s empirical equations, the empirical curves for both wall deflection and surface settlement were optimized to closely match the numerical results, resulting in new empirical coefficients that provide the best fit curve. Overall, this study highlights the importance of empirical approach for predicting wall movements and ground surface settlements in Asian countries, ultimately contributing to safer and more resilient urban infrastructure by enhancing the accuracy and efficiency of geotechnical design.