Microtunneling is a method in construction where a borehole is excavated and piles are laid simultaneously with the use of pipe jacking, remote guidance, and continuous support. The microtunneling boring machine (MTBM) is utilized from a control panel which is often located on the surface.
Remote pipe jacking is another term for microtunneling. Due to being expensive, microtunneling is often used for pipes that require an advanced degree of precision over long distances.
During the boring phase, water jetting is used for the cutting head and is administered using laser guidance. Therefore, due to the boring process, only pipes with a circular cross-section can be used.
Microtunneling Systems
Microtunneling Guidance
For most microtunneling projects, a laser-controlled guidance system is used, which offers real-time information to the operator for superintendent steering operations.
The motorised laser target unit helps to identify the vertical and horizontal position as well as the roll of the MTBM and the pitch. Curved drives need guidance systems like the ones used on longer bores, however, standard laser sights can be used to keep the machine on course in a straight drive.
Not to mention, curved alignments that accentuate the drive length by avoiding intermediate shafts and obstacles.
Microtunneling can be used to achieve both vertical and horizontal curves. Horizontal curves ensure pipeline projects can follow the curved public rights-of-way without too many short straight segments or manholes.
Correct Use of Guidance
The guidance system with the camera is extensively checked, calibrated, and put together before launch as the guidance system camera is the main reference point for the MTBM operator.
At the back end of the MTBM, the target location is checked and the grade of the alignment is established. Besides, the roll sensors and inclinometers that are checked to ensure they are working properly and calibrated appropriately.
Finally, the theodolite is checked for collimation and tilt offset and also during the operation to identify whether the MTBM encounters disturbance, a bump, or strong vibration.
If you require microtunneling services, give us a call on 01279 276 030. We will be happy to explain the process in further detail.