الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 79 |  |  |
| | | from | 79 | | |
Abstract
It is recommended in BS 81103 that a ribbed flat slab should be designed as a plain flat slab. The design codes for flat slab structures assume therefore that a ribbed flat slab behaves essentially in the same manner as a plain flat slab under load. However, there are significant differences between the behavior of a ribbed flat slab and a plain flat slab. The plain flat slab has a constant moment of inertia across the whole span, but the moment of inertia for a ribbed flat slab changes from the solid regions around columns into the rib cross section. As a result of this, the coefficient of moment distributions for a ribbed flat slab can differ from a plain flat slab. A theoretical study of the moment distributions within ribbed and plain flat slab panels has been carried out, and the theoretical moment coefficients for an internal panel are presented. It is concluded that the code recommended coefficients should be modified for the design of ribbed flat slabs. The effect of solid regions around columns is considered, and it is shown that solid regions attract higher moments in the column strip than are allowed for in existing design coefficients. The effect of rib section depth and topping thickness are considered. The effect of column size is considered also.