I NEED A HELP ON MAT FOUNDATION DESIGN STAAD FOUNDATION ADVANCED UPDATE

I was designing a Mat foundation ,the thickness of my raft which i wanted was 350mm thickness and the depth of the beam to be 900mm or 800 mm depth with width of 1000m, but when i run the design, the mat and the beam fail under punching shear even if i try to increase the depth of the beam to 1500mm.But when i increase the depth of my raft to be 900mm with or without beam inside it, the punching shear check will pass.

Iam using Staad Pro Update 5.I have attached my model i need a help what is the reason behind

55375.Structure1_foundation.sfa

04548.Structure1.STD

Parents Reply Children