All RCC columns, as per the code IS-456, shall be designed for minimum eccentricity, equal to the unsupported length of column/500 plus lateral dimension/30, subjected to a minimum eccentricity value of .................... mm.
3)All RCC columns, as per the code IS-456, shall be designed for minimum eccentricity, equal to the unsupported length of column/500 plus lateral dimension/30, subjected to a minimum eccentricity value of .................... mm. ans - 20 mm Concept As per IS 456:2000 , for RCC columns, the minimum eccentricity to be considered in the design is given by the following formula: e min = l u 500 + d 30 e_{\text{min}} = \frac{l_{\text{u}}}{500} + \frac{d}{30} e min = 500 l u + 30 d Where: l u l_{\text{u}} l u is the unsupported length of the column. d d d is the lateral dimension of the column (the smaller of the two dimensions). However, IS 456:2000 also specifies a minimum eccentricity value of 20 mm . This means that, regardless of the result from the above formula, the minimum eccentricity should not be less than 20 mm . Let me know if you'd like more details!