Hello, Please how does Ram concept interpret horizontal line loads? I modelled 2 shear walls between three columns has shown below and I applied 2 different horizontal line loads at different elevations. I would expect the horizontal line loads to cause moments at the base of the column/ column-mat intersection. When I checked the punching shear results, it says the moment is zero as shown in picture 1. Please why is this? However, if I convert the portion of the line load on the column to lateral load and apply that value to just the column, with the line load only on the shear wall, the moment is not zero as shown in picture 2
Horizontal loads at an elevation are connected to the slab centroid through vertical rigid links at the nodes of the mesh (like stiff flagpoles) and they will induce moments into the slab.
Walls above tend to stiffen the slab like an upturned beam and can redistribute those moments. See: https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/221910/ram-concept---modelling-upstand-beams/681392#681392
Punching shear design is based on the column reactions at the slab (refer to the program manual section 73.2 How does RAM Concept handle punching shear?)
Yes I know all these. let me simplify my question, If I apply a point horizontal load of 100 kip at an elevation of 5ft on a 24in square column (Case 1), if I apply a horizontal line load of 50kip/ft (100kip/column width of 24 in) on the column at an elevation of 5ft in ram concept (Case 2), mathematically I would expect both loading scenarios to induce approximately the same moment in the slab. But when I checked the punching shear results, the moment at the column that I applied the load as line load was zero. Any reason for this?
As noted in that section of the manual, point loads applied at the column center are discounted from the punching shear demand, but line loads are not.
Sorry if I am bothering you. Your statement and the manual sounds opposite to me. The manual says "line loads are not considered", but your statement states that "Point load applied at the column center are discounted but line loads are NOT discounted"? Just making sure I am not missing this up.
If line loads are not included in in punching check then that will explain why my model with line load shows zero moment at the base of the column and the model with lateral point load showed induced moment
Sorry, I'll not use the word considered. Point loads are subtracted in the summation of the column reactions and point loads, so they are deducted from the punching shear demand reactions. Line loads and surface loads are not deducted.