Trenchless technology

It can be defined as "a family of methods, materials, and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities.

"[1][2] Trenchless construction includes such construction methods as tunneling, microtunneling (MTM), horizontal directional drilling (HDD) also known as directional boring, pipe ramming (PR), pipe jacking (PJ), moling, horizontal auger boring (HAB) and other methods for the installation of pipelines and cables below the ground with minimal excavation.

In cases where the soil is sandy, the water table is at shallow depth, or heavy loads like that of urban traffic are expected, the depth of excavation has to be such that the pressure of the load on the surface does not affect the bore, otherwise there is a danger of the surface caving in.

Mechanical spot repair is applied where damaged pipelines require the reinstatement of structural integrity.

In the UK, the United Kingdom Society for Trenchless Technology (UKSTT) was established in 1993.