Applying closedcavity thinwalled components is crucial for the lightweight design of large
prefabricated components for underground structures. The closedcavity thinwalled components were first
used in prefabricated metro stations′ lining structures
in Changchun, Qingdao, and Shenzhen. Presently, no applicable codes and
standards exist for underground structures′ closedcavity thinwalled components. Based on
theoretical research and practical engineering application, the principal
technologies for designing closedcavity thinwalled components of underground structures are discussed. First,
from mechanical characteristics, joint structures, joint waterproof, and
durability of prefabricated underground structure viewpoints, the lightweight
design method of prefabricated components is analyzed, and the advantages of
lightweight closedcavity thinwalled
components. Second, a comparative analysis with Tshaped,
Ishaped, and boxshaped
section components with ribs revealed that closedcavity
thinwalled components have similar mechanical
properties regarding the shear lag effect and shear stress distribution. A
typical shear lag effect occurs in closedcavity thinwalled components, but the influence degree is low. Furthermore, the
primary influencing factors are analyzed, and the shear lag coefficient is
proposed for closedcavity thinwalled components. The longitudinal rib plate shows section shear
stress. Finally, the primary structural characteristics of closedcavity thinwalled components and their
influence on the mechanical properties of the components are discussed.
Structural indices such as flange plate, longitudinal rib plate, diaphragm,
endplate, and internal cavity rate are put forward. The critical points of the
structural design of closedcavity thinwalled components are developed from calculation analysis and design
methods.
