低矮房屋体形系数的修正及风荷载计算方法研究

Study on Pressure Coefficient and Wind Load Calculation Method for Low-rise Buildings

低矮房屋在强风作用下倒塌破坏给村镇区域造成严重损失,因此研究低矮房屋表面风荷载特性和分布规律,建立有效的抗风设计方法尤为重要。对10种屋面倾角、3种高深比、3种宽深比,共60个双坡低矮房屋模型进行了风场数值模拟研究,采用分区法获得屋面最不利风荷载分区体型系数,并分析了屋面倾角、高深比、宽深比对风压分布的影响,利用最小二乘法对各分区体型系数进行了屋面倾角、高深比和宽深比三参数的拟合,并将拟合公式和多国风荷载规范给定值进行比较,验证了拟合公式的可靠性。以拟合公式为基础,给出了我国荷载规范中风荷载分区体型系数的建议值,并用于屋面风荷载的计算,改进我国荷载规范中平均风压的计算方法,给出了合理的抗风简化计算公式。

Strong wind often causes severe damage to a mass of buildings especially the widely existing low-rise buildings.Therefore it is necessary to make clear the distribution law of wind pressures on such kind of buildings and accordingly to find the corresponding wind-resisting means.Numerical simulations were conducted on 60 gable roof low-rise buildings with 10 pitches,3 height-depth ratios and 3 width-depth ratios.According to the test results and the foreign load codes,the surface of the buildings was divided and the most negative region shape coefficients were given.The effects of pitches,height-depth ratios and width-depth ratios on region shape coefficients were analyzed,and the region shape coefficients were fitted with pitches,height-depth ratios and width-depth ratios by least square method.The computed values using the fitted formulas were compared with load codes of different countries.So the reliability of the fitted formulas was verified.Then the region shape coefficient values,wind-resistance design method and simplification formula,which were used to calculate wind loads of main wind-force resisting system in Chinese load code for the design of buildings were suggested in accordance with the test values and ASCE7-10 load codes.