Segmental shafts

Segmental shaft linings provide a safe and efficient method for construction of permanent and temporary shafts for sewer, ventilation and tunneling launch and retrieval shafts. Standard segment designs are suited to shaft depths of up to 30 metres.

The range includes two types of segmental shafts to suit both caisson and underpin installation methods.

The caisson method is suitable for soft soil conditions, where the shaft rings can be constructed above ground and pushed down from the surface using jacking force.

The underpin method maintains the same strength and benefits of the caisson method but is more suitable for hard soil conditions where shaft jacking is not feasible. Shaft rings are constructed progressively at the base of the excavation.

Both types of shaft feature two tapered segments per ring which allows for efficient closing of the rings.

Humes segmental shafts have been pressure tested to show that the seals between segments resist infiltration pressures of greater than 350 kPa.