About the Tenbusch Insetion Method (TIM™)
The TIM™ system is a unique pipe replacement method that jacks (pushes) new pipe in place of the existing deteriorated pipe. Unlike other trenchless methods, the TIM™ system utilizes the column strength of segmented jacking pipe. Lead equipment positioned ahead of the new pipe penetrates, fractures, and expands the old pipe. The lead equipment consists of five sections:
- lead - a heavy steel guide pipe which maintains the alignment within the center of the old pipe,
- cracker - which fractures the old pipe,
- cone expander - which radially expands the fractured line into the surrounding soil,
- front jack - a hydraulic cylinder which provides axial thrust to the (above) penetration and compaction pieces, and
- pipe adapter - which provides a mating surface linking the new pipe to the front jack.
The pipe adapter is fitted with a lubricant injection port where a lubricant (typically polymer and/or bentonite) can be injected into the annular space surrounding the new replacement pipe.
Required jacking loads are reduced by lubricating the outside surface of the new pipe, especially for pipe replacement in soft sticky clay or wet sandy soil conditions. Dual flexible hose sections transport lubricant and hydraulic fluid to the lead equipment and are fed through each new pipe section. Each new hose section is connected to previous sections and to the operator's control panel with quick-disconnect couplings.
The front jack advances the lead equipment into the old pipe, independent of the advance of the new pipe, by using the new pipe as a support column. New pipe segments are jacked behind the lead equipment piece by piece by in the work pit. The primary jacking unit applies the required thrust to advance the new pipe column, as the front jack is allowed to retract. Instrumentation and controls at the operator's control panel in the work pit allow the operator to "feel" his way through the existing pipe as the new pipe column and lead equipment are "inch-wormed" into the existing old line. Upon completion of the line replacement, the lead equipment is disassembled easily inside a typical 4 ft diameter (~1.2 m) receiving manhole and the new pipe is jacked into its final position.
An animation of the above process is available on CD-ROM, Please email firstname.lastname@example.org to request a copy