Safety Assessment of Tunnel Shield Construction for Existing Adjacent Bridges

Table 4

Symbol definition in checking formula.

σst	Normal tensile stress of concrete at the edge of section of crack resistance checking calculation of members under the action of frequent combination
σpc	Normal precompression stress of concrete caused by preloading
σlt	Normal tensile stress of concrete at the edge of crack resistance check section under quasi-permanent combination
σtp	Principal tensile stress in component concrete
σkc	Normal compressive stress of concrete produced by the standard value of action
σpt	Normal tensile stress of concrete caused by prestress
σcp	Principal compressive stress in component concrete
ftk	Standard value of axial tensile strength of concrete
fck	Standard value of axial compressive strength of concrete