Definition - What does Curved Drive mean?
A curved drive can be defined as a microtunnel drive that has a curved path rather than the commonly used straight drive. The trenchless microtunneling technique has been able to successfully incorporate curved alignments in different directions.
Curved drives impart flexibility to the project and also benefits in terms of cost-saving. However, curved drives are more complicated than straight drives and require a special guidance system to correctly steer the cutter head.
Trenchlesspedia explains Curved Drive
Curved drives are incorporated for a variety of reasons, such as when it is not possible to reroute the project, when short straight drives cannot negotiate a curve, or due to environmental concerns. The microtunneling process has evolved over time to allow curved alignments that allow extended drive lengths by avoiding obstacles and intermediate shafts.
To complete a curved microtunnel successfully, the guidance and navigation system should be able to communicate without a glitch. The guidance system required for a curved tunnel can be a Laser Total Station System or a Gyro Navigation System.
This method has successfully completed horizontal as well as vertical curves. Horizontal curves allow pipeline projects to follow curved public rights-of-way without too many manholes, and short straight segments. Vertical curves allow for shallow launch and reception shafts for installing non-gravity pipelines.