Applying line displacement to a beam

Question

Hello, 
 
 I want to apply a uniform "10mm displacement to the right " to the embedded beam below (the purple vertical line between nodes 1 and 2). However PlAXIS tells me that this is not allowed as the line is already assigned to a beam and cant be assigned to a line displacement as well.

Other things I have tried: 
 1. Adding two point displacement to only node 1 and node 2 => this works but the displacement in the middle of the beam wont be exactly 10mm as the displacement is not applied uniformly in the entire beam. 
 2. Adding a couple more point displacements in the middle of the beam (between point 1 and point 2) => for some reason the model fails before even applying the displacements and I dont know why? 
 
 Is there anything I can do about this? 
 
 Cheers

Edit: Sorry dont know why its been posted twice! idk how to remove it...

Vasileios Basas · Answer

Hi Farbod, 
 In a finite element model, embedded beams are superimposed on a continuum and, therefore, 'overlap' the soil. Therefore, an embedded beam's primary connection point (and point of interaction) can be either at the top or the bottom. Any intermediate point of the embedded beam row does not exist on the mesh, so PLAXIS will not allow a line load or line displacement along its length. 
 You can try replacing the embedded beam with a plate element. Otherwise, you can experiment by applying the line load at a small distance behind the embedded beam. However, due to the soil's stiffness, the embedded beam might only partially undertake the imposed displacement. Therefore, the "10mm horizontal displacement" will displace the embedded beam at a smaller distance than 10mm.

Vasileios Basas · Answer

Hi Farbod, 
 1. I wouldn't expect the same results because there are fundamental differences between the plate and embedded beam elements. For example, for embedded beams, you can define the out-of-plane spacing, skin/base resistance and beam shape (circular or square, hollow or massive, user-defined), while those options are not available for plates. Make sure to check our reference and material models manuals for additional information on their differences. 
 2. Again, as mentioned earlier, the only interaction points for an embedded beam are either at the top or bottom. Are you sure you are applying those point loads on the embedded beam, not the soil? If you search the coordinates of the point displacements in the "Select points for curves" tool, you will find that there are two nodes for each location: one corresponding to the embedded beam and the other corresponding to the soil (point displacement).