I have to design a channel of height 12.75m, width 32.0m. The side walls are having 1.0m thick at the top and 2.5m at the base. the base slab is 3.0m thick. I modeled the structure in STAAD using plate elements. Spring support is assigned for the base. Channel is subjected to earth pressure from the outer side and water pressure from the inner side. I found the top node of the side wall is having the nodal displacement of 180.0mm.
1) I would like to know the permissible limits of deflection for the above case.
2) Ways of reducing the deflection.