ABSTRACT
Urban tunneling is increasingly prevalent due to the expansion of cities and the necessity for efficient transportation and utility systems. The complex geological conditions typical of urban areas, combined with the trend of constructing deeper tunnels, necessitate meticulous planning and safety measures in tunnel boring machine (TBM) operations. Continuous advancements in tunneling technology have enhanced construction safety and efficiency, while improved design approaches have benefited the industry. A critical aspect of these designs is the management of tunnel face pressure to control ground settlement and minimize structural damage.
However, current design practices lack a reliable method to determine the limiting ground settlement resulting from variations in face pressure, particularly in deeper tunnels where maintaining hydrostatic pressure is challenging. This paper presents a modeling approach using PLAXIS 3D to simulate the effects of lowering face pressure at deep tunneling depths below the hydrostatic pressure in full face soil or mixed face excavation. The model aims to identify the impact of adopting different methodologies in simulating face pressure during cutter head intervention (CHI) on surface ground settlement.
Through detailed simulation incorporating geological data, tunnel depth, and construction parameters, this study seeks to provide design engineers with a robust tool to optimize face pressure settings, balancing safety and cost-efficiency. The proposed methodology promises to enhance current design practices, leading to safer and more cost-effective tunnel construction, ultimately benefiting urban development and infrastructure.
