Underground utility extensions in dense urban centers are increasingly using microtunneling techniques with jacked steel pipe liners to minimize surface disruption. In London's West End, a 600 m microtunnel delivered 900 mm DI and steel pipe segments beneath historic streets without traffic closures. The pipe jacking method employed pre‑lubricated rings of carbon steel pipe, each precisely welded to achieve tolerances within ±5 mm over the entire length.
Tokyo's sewer modernization program pursued similar tactics. Contractors used 1,200 mm diameter steel pipe segments, each outfitted with gasket seals, jacked behind a slurry‑balance microtunnel boring machine. The steel pipe rings resisted ground pressures and ensured an immediate, watertight lining, eliminating the need for secondary concrete lining.
In Australia, Melbourne Water completed a Victorian Water project using stainless steel pipe jacking to install brine feed conduits with minimal excavation. The 450 m drive achieved a record‑setting average of 30 m per day, thanks to advanced thrust frames and zero‑overcut steel pipe annuli.
North American transit authorities are now evaluating microtunneling for stormwater management. In Chicago, pilot drives using DN 1000 steel pipe joints demonstrated minimal settlement and rapid convergence restoration, preserving heritage building foundations. The high strength of the steel pipe allowed for thinner segment walls, optimizing hydraulic capacity while maintaining jacking load limits within 3 MN.
As urban utilities modernize, microtunneling with jacked steel pipe liners offers a low‑impact, high‑precision solution for delivering essential services beneath busy cityscapes, combining trenchless efficiency with structural reliability.
