Abstract
Trenchless excavation has advantages for pipeline deployment in many aspects compared to conventionalmethods, including the minimal surface disruption, less traffic interruption, long-term reliability,
acceleration of the construction process and the concomitant potential cost savings from the features
above. However, existing trenchless excavation method are mostly designed for long-distance and largediameter (>2m) constructions, such as road and railway tunnels, which is not suitable for either the pipe
dimensions or construction locations associated with applications such as communication and water pipe
deployment. This dissertation focuses on a novel trenchless soil excavation method as part of the design
of an underground robot for rapid optical fibre to the premises in collaboration with British Telecom.
The research begins from the analysis and demonstration of the causes of failure in the design of the
previous prototypes designed at the University of Bristol. A screw conveying system design is inherited
from a preceding research project at Bristol and some key refinements are made to the design. This
includes the introduction of a motor driven rotation mechanism that allows the auger to be rotated
independently of the supporting channel and new shafted and shaftless auger designs. Due to the lack of
work in the literature regarding the design of small-diameter (<0.2m) screw conveyors, a discrete element
method simulation and related experiments are conducted to investigate the relations between the screw
conveyor performance and two vital design parameters, auger pitch and auger speed.
A compact design of the prototype is proposed afterwards based on the findings and was examined in a
simulated soil bed, demonstrating the tunnelling function and illustrating significant improvements
compared to the previous designs.
| Date of Award | 10 Dec 2024 |
|---|---|
| Original language | English |
| Awarding Institution |
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| Supervisor | Andrew T Conn (Supervisor) |