Definition - What does Liquefaction mean?
Liquifaction is the tendency for water saturated soil to become unstable and subside. When liquifaction occurs, it creates an unstable environment for underground piping and the potential for breakages and cracks to occur as the foundation beneath the pipe gives way. Trenchless construction must take into account the extent to which liquifaction is possible and trenchless repair may have to overcome the effects of liquifaction that has already occurred.
Trenchlesspedia explains Liquefaction
Liquifaction can be caused by a number of environmental factors including earthquakes, excessive rain, and compacted soil in which the pipes are laid. If a breakage in the pipe occurs it is possible for the liquified soil to flow into the pipe causing blockages or leaks. Trenchless technology enables inspection and situational repairs, or pipe replacement, to damaged areas so that the expense and time required to dig up the entire pipe can be avoided.