A limit state design procedure supplemented by design tables and charts was developed
for dimensioning reinforced concrete water-tight sections according to the Egyptian code
for concrete structures (ECCS 203-2001). The process involves the following two stages:
(1) Obtain the section total depth by satisfying the requirements of the cracking limit
state. (2) Obtain the required area of steel reinforcement from satisfying the ultimate
strength limit state. The procedure omits the calculations required for determining the
material under-capacity factor of concrete tensile strength, η. The η factor is a function of
the section total depth as well as the state of stresses that the section is sustaining,
through the code Eq.(4-69) and the code Table (4-16). The paper introduces a new
concept of bending moment about the boundary of the inner core concrete section, M k ,
that proved helpful for sections subject to eccentric tensile or eccentric compressive
normal forces.