Bridge pile in bending

[SayGoodDay]

Hi guys

When we design piles(fully submerged in ground)in bending, do we still need to consider the crack control in serviceability limit state (AS2159 CL5 doesn't mention)? If yes, why? In my understand, the crack control (AS5100.5, CL8.6) limiting the reo stress is used to control the crack width to protect the reo. But if the pile is fully submerged in gound, there is no air, means the bar won't be corrosion. Right?

Thanks.

Saygoodday

 

[apsix]

Especially near the surface you probably still will have air within the pore space. If not air, there will be water with dissolved oxygen and/or low pH, both ideal conditions for corrosion to occur.
There is also the possibility of other corrosive elements such as soluble salts within the soil.

 

[OzEng80]

As apsix outlined the surface conditions are quite different. A 'wetting and drying' condition is likely to occur which is a particularly nasty corrosive environment.