Thrust Pit Mean?
A thrust pit, also known, as drive pit is an excavation at the launching point of a pipe jacking or auger boring trenchless pipeline installation project. The pit has a thrust wall at the back end in addition to a place for men and machinery to work safely.
The thrust pit helps spread the reaction loads evenly on the walls of the pit while the pipes are jacked into the ground.
Trenchlesspedia Explains Thrust Pit
Thrust pit and reception pits are mandatory in pipe jacking operations. Thrust pits are excavated depending on the excavation methods, requirements of the drive and the budget. A thrust wall is constructed at the back of the thrust pit to provide a reaction against which the jacking is done.
A thrust ring is provided around the pipe being jacked to ensure that the jacking forces are evenly distributed around the pipe circumference. The pipe jacks in the thrust pit are aligned by positioning guide rails on which the pipes are laid. Alignment accuracy is maintained by using a steerable shield that is periodically checked for line and level from a reference point.