The underpinning technique is used when ground water is minimal. The shaft is constructed by excavating the ground and installing precast concrete segments and is often used in harder ground conditions.

Secant pile shaft construction is usually circular and uses a series of overlapping primary and secondary concrete piles. Typically, only the secondary piles are reinforced as they are constructed by drilling through the primary piles. Secant piles are an effective method to build a watertight shaft. They provide greater wall stiffness than other methods and can be used in difficult ground conditions.

Soldier pile shaft construction uses vertical steel H piles and horizontal wood or concrete lagging to create the retaining wall. Soldier piles can be temporary or permanent depending on the project’s needs, but are primarily used for temporary construction. This method is efficient and cost effective, and can accommodate various shaft size and dimensions.

Sheet pile shaft construction uses pre-fabricated steel sheet sections that interlock to create the shaft walls. They are typically driven into the ground using vibration. The shaft is excavated once all the sheet piles are driven into the ground, installing internal bracing to support the sheet piles depending on the shaft depth. For harder ground conditions and deep installations, predrilling may be required. Sheet pile shaft construction is widely used and the piles come in a variety of shapes and sizes. This method can be difficult in ground conditions with cobble stones and boulders.

Shoring Box shaft construction uses prefabricated steel panels and cross struts to support the ground. They are most suitable at depths of 6m or less in stable, reasonably self supporting, ground conditions. This method is an efficient and cost effective shaft solution.