CU Hyperloop - Tunnel Boring Machine

Volunteering group project - The Boring Company's Tunnel Boring Competition

March 2024

Bastrop, Texas

Designed and analyzed the excavation subsystem of a Tunnel Boring Machine (TBM), focusing on translating uncertain soil interaction forces into a reliable mechanical design that ensures structural integrity and effective material removal.

The project began with first-principles modeling of soil–tool interaction to estimate cutting forces under varying operating conditions. These force estimates were used to define torque requirements and guide the sizing of the drivetrain, including motor selection, gear reduction, and rotational speed to achieve consistent excavation performance.

A key aspect of the design involved understanding how loads propagate through the system. Load paths were mapped from the cutting interface through the drivetrain and supporting structure, enabling identification of critical components subjected to peak stresses. This system-level understanding informed decisions on component geometry, material selection, and structural reinforcement.

Finite Element Analysis (ANSYS) was performed on critical drivetrain and structural components to evaluate stress distribution and deformation under expected loading conditions. Iterative design modifications were implemented to reduce stress concentrations, improve stiffness, and maintain an overall factor of safety of 1.5 while avoiding unnecessary material addition.

The design required balancing multiple competing constraints, including structural strength, weight, manufacturability, and integration with actuation systems. Special attention was given to ensuring that the design remained feasible for fabrication while meeting performance requirements.

Through this work, a strong understanding was developed of how mechanical design, load estimation, and simulation-driven iteration come together to create robust systems operating under uncertain and high-load environments.