Appendix C.Telescoping Casing Sections

The Model 6600-1TS is a telescoping tube section for applications that are expected to experience settlement or heave of the ground.

The telescoping section can accommodate up to 152 mm (6 inches) of movement. The most common application is for conditions where settlement is expected. For this application, the telescoping section should be installed in the fully extended position.

17:    

Figure 17: Model 6600-1TS Telescoping Tube Section

Installation Methodology

Where settlement is expected, the telescoping casing sections are extended after the bottom of the casing has been secured using a casing anchor, grout, or by adding sufficient weight in the interior of the casing.

Once secure, extend the telescoping casing section(s). Make note of the original height of the top of casing, and then, based on the number of telescoping section, calculate the height of the casing after pulling it up.

For installations where heave is expected, or where the bottom of the casing may sink (e.g., tunnel passages), then the telescoping sections should remain compressed during installation. A wrap of duct tape, applied to the joint of the telescoping section, will help keep it compressed during installation.