ABSTRACT
The BS8110 (1985) is the revised version of CP110 (1972) and is used for the design of reinforced concrete elements. In order to maintain safe designs, partial safety factors are applied to material properties as well as the loadings on the structure. Studies have shown that these factors result in high investment and inconsistensy in the safety level for varying design parameters and practical uncertainties. The work in this thesis provides FORTRAN-77 modules for the design of one way slabs at uniform reliability level using the first-order reliability method. Based on the results obtained from the program, plots of reinforcement ratio versus load ratio and reinforcement ratio versus effective depth for each set of design input parameters are provided. It is shown for uniformity in reliability level, there must be a linear relationship between the reinforcement ratio and effective depth. However, a non linear relationship exists between the reinforcement ratio and the ratio of dead to live load. Equations showing these effects are also developed and can be used directly for safe designs. Within the requirements of BS8110 for one-way slabs and practical uncertainties, the results of this study show that calculation and processing time is greatly reduced. Also, safety of the designed element is known a priori and problems of over -and /or -under designs are eliminated with a trade-off between safety and economy. Summarily, the design of one way slabs at uniform reliability level can be carried out using one of the following: (1) the computer program; (2) the plots presented or (3) the use of the equations determined.