Definition - What does Guide Rail mean?
A guide rail is an important part of pipe jacking and microtunneling operations. It is used in trenchless operations to ensure accuracy during excavation and pipe installation. A properly installed guide rail ensures that the pipeline is correctly installed on the designed line and grade.
The use of a guide rail is an alternative to employing a jacking frame within the pit.
Trenchlesspedia explains Guide Rail
In trenchless methods that involve jacking operations it is essential to correctly establish the jacking direction before work is started. For this purpose, guide rails are accurately set to designed line and grade in the jacking pit and set in concrete, especially for large pipes.
The backstop installed at the back of the pit is also designed to be strong and sufficiently large to distribute the high jacking forces to the soil and provide uniform support. This also prevents the pipe from being pushed out of alignment.
The guide rail might be compared to a short railroad track. The pipe rammer is placed on a steel track that ensures that it strikes the pipe at the proper angle to advance the pipe further through the bore.
Once the pipe jack reaches its full extension with the first casing, the jacks are retracted and a new casing or pipe is positioned on the guide rails. The main jacks push the pipe against the rear of the previous pipe. The line and grade of the pipe are constantly checked during the jacking operation, and necessary adjustment to the guide rail is made.