Thiết kế đường hầm NATM bằng phương pháp mô phỏng 3D và phân tích

Tóm tắt

NATM (New Austrian Tunneling Method) has been widely used in Vietnam for road tunnel construction through the mountains. The main feature of NATM is to utilize all available means to develop the maximum self-supporting capacity of the surrounding rock or soil itself and to undertake investigation and monitoring during construction to provide stability to the tunnel. Tunnel excavation adopting the NATM is usually divided into sub-sections to be excavated in sequential steps. The application of temporary reinforcements then follows the whole of each subsection. Different unsupported span lengths in the longitudinal direction at each step considerably affect stress redistribution in the ground, soil deformation, and stress-induced tunnel support systems. This study simulates a mountain road tunnel using finite element analyses. The numerical calculations will be obtained and discussed to predict ground deformation stress changes around the tunnel opening and final displacements in each construction stage.

Keywords: NATM; self-supporting capacity; finite element analyses; stress; soil deformation; numerical modeling; final displacements.