For stress analysis of buried piping system in CAESAR II, if there is any valve pit or any other other pit in the route, how the the puddle flanges of the pit would be modeled in CAESAR II? Should it be considered as a full anchor? However, that will create very very high axial force as well as moments, and resulting stress would be high. Or any finite stiffness should be imposed for the anchor?

If yes, how the stiffness of composite slab (RCC + stell plate) may be estimated?

Hi
for the worst case you can thake that as a anchor support.