Annex A[Clause 3.3.2.1(b)] Illustrative Example Showing Reduction of Uniformly Distributed Imposed Floor Loads in Multi-storeyed Buildings for Design of Columns

A-1 The total imposed loads from different floor levels (including the roof) coming on the central column of a multi-storeyed building (with mixed occupancy) is shown in Fig. 21. Calculate the reduced imposed load for the design of column members at different floor levels

using 3.3.2.1. Floor loads do not exceed $5.0\mathrm{kN / m^2}$.

A-1.1 Applying reduction coefficients in accordance with 3.3.2.1, total reduced floor loads on the column at different levels is indicated along with Fig. 21.

FIG. 21 LOADING DETAILS

PART 6 STRUCTURAL DESIGN — SECTION 1 LOADS, FORCES AND EFFECTS

• $H_{\mathrm{s}} =$ Height factor for resonant response
• $H =$ Height above mean ground level on the topography feature
• $I =$ Turbulence intensity
• $I_{\mathrm{h,i}} =$ Turbulence intensity at height $h$ in terrain category $i$
• $I_{\mathrm{z,i}} =$ Turbulence intensity at height $z$ in terrain category $i$
• $IF =$ Interference factor
• $k =$ Mode shape power exponent
• $k_1, k_2, k_3, k_4 =$ Wind speed modification factors
• $\overline{k}_{2,i} =$ Hourly mean wind speed factor
• $K =$ Force coefficient multiplication factor for individual members of finite length
• $K_{\mathrm{a}} =$ Area averaging factor
• $K_{\mathrm{c}} =$ Combination factor
• $K_{\mathrm{d}} =$ Wind directionality factor
• $l =$ Length of the member or larger horizontal dimension of a building
• $L =$ Actual length of upwind slope
• $L_{\mathrm{e}} =$ Effective length of upwind slope
• $L_{\mathrm{h}} =$ Integral turbulence length scale at the height, $h$
• $m_0 =$ Average mass per unit height of the structure
• $M_{\mathrm{a}} =$ Design peak along wind base bending moment
• $M_{\mathrm{c}} =$ Design peak across wind base bending moment
• $N =$ Effective reduced frequency
• $p_{\mathrm{d}} =$ Design wind pressure
• $p_{\mathrm{z}} =$ Design wind pressure at height $z$
• $\overline{p}_{\mathrm{d}} =$ Design hourly mean wind pressure corresponding to $\overline{V}_{\mathrm{z,d}}$
• $p_{\mathrm{e}} =$ External pressure
• $p_{\mathrm{i}} =$ Internal pressure
• $r =$ Roughness factor which is twice the longitudinal turbulence intensity at height $h, I_{\mathrm{h,i}}$
• $R_{\mathrm{e}} =$ Reynolds number
• $s =$ Level on a building/structure for the evaluation of along wind load effects
• $S_{\mathrm{o}} =$ Factor, which depends on $H$ and $X$, used for the evaluation of $k_3$ factor
• $S_{\mathrm{t}} =$ Strouhal number
• $S =$ Size reduction factor
• $V_{\mathrm{b}} =$ Regional basic wind speed
• $V_{\mathrm{z}} =$ Design wind speed at height $z$
• NATIONAL BUILDING CODE OF INDIA 2016