There are many types of joints involved in the construction of an immersed tunnel:
• Immersion joints between the tunnel elements • Segment joints between the segments of a concrete element • Terminal joints at the ends of the immersed section of the tunnel • Closure joints, which are the last joints formed in the immersed part
of the tunnel • Seismic joints, which are variations to all the above joints in seismic
regions • Construction joints between concrete pours
This chapter explains the different types of structural joints used and describes the main features and aspects of their detailing and construction that need to be considered. It deals with the joints in the main tunnel structure; joint features that are located within the ballast concrete are described in Chapter 15, Finishing Works, and although the shear keys are described to a degree in this chapter, they are described more fully in Chapter 9, Design Principles.