ABSTRACT
The provision of a safe structural system is an object of structural design. Therefore the way safety is prescribed in design is concern for Engineers. It is generally agreed in codified designs that decisions are made under uncertainties and as such safety consideration is best done in a probabilistic format. It is only in this way that consistent and uniform safety level can be ensured. The limit state method assumes a probabilistic concept and it is on this basis that BS. 8110 (1985) for reinforced concrete design was developed. However the implicit reliability in designing to the code specification is not obvious in practical designs. The BS. 8110 (1985) is assessed using a two span reinforced concrete beam to ascertain the consistency and uniformity of reliability level of designs to the code specifications. It is found out that reliability indices depend on the design input especially the load ratio, meaning that under variable load the reliability will be inconsistent. The results also show that the conventional method will produce designs with reliability index taking on a value among many possible ones. This implies that the designer does not have control over the choice of a required reliability level. Consequently, the work provides reliability plots that can be used as design charts to specify design variables for known reliability levels.