Building to resist the effect of wind, v. 2 : estimation of extreme wind speeds and guide to determination of wind forces

THE FIRST REVIEWS THE THEORETICAL AND PRACTICAL CONSIDERATIONS PERTINENT TO ESTIMATION OF PROBABILISTICALLY DEFINED WIND SPEEDS. RESULTS OF THE STATISTICAL ANALYSIS OF EXTREME WIND DATA IN THE PHILIPPINES ARE PRESENTED AND INTERPRETED. RECOMMENDATIONS BASED ON THESE RESULTS ARE MADE WITH REGARD TO POSSIBLE REDEFINITION OF WIND ZONES. TENTATIVE CONCLUSIONS ARE DRAWN REGARDING THE ADEQUACY OF DESIGN WIND SPEEDS CURRENTLY USED IN THE PHILIPPINES. THE SECOND REPORT DESCRIBES SOME OF THE MORE COMMON FLOW MECHANISMS THAT CREATE WIND PRESSURES ON LOW-RISE BUILDINGS. A PROCEDURE IS OUTLINED FOR CALCULATING DESIGN WIND SPEEDS. IT INCORPORATES THE EXPECTED LIFE OF THE STRUCTURE, THE MEAN RECURRENCE INTERVAL, AND THE WIND SPEED AVERAGING TIME. PRESSURE COEFFICIENTS ARE TABULATED FOR VARIOUS HEIGHT-TO-WIDTH RATIOS AND ROOF SLOPES. THE STEPS REQUIRED TO CALCULATE PRESSURES, TOTAL DRAG, AND UPLIFT FORCES ARE SUMMARIZED, AND AN ILLUSTRATIVE EXAMPLE IS PRESENTED.