双向偏心受压矩形基础的基底压力

Foundation pressure of rectangular footing under bidirectional eccentric loads

受双向偏心荷载作用的柱下独立基础,当基础底面与地基脱开时,传统的设计方法难以计算其基底压力,基础尺寸设计偏保守。通过分析地基反力的基本图形,建立了对应不同偏心距的基底应力计算模型,推导了基底应力和零应力区面积比例的计算公式,编制了可快速求解的设计图表。分析表明,采用新的允许出现零应力区的设计方法,双向偏心受压基础的安全性和经济性均有较大提高。

For the bidirectional eccentric foundation,traditional design method is difficult to calculate the foundation pressure when the bottom surface is detached from the ground.The foundation size is conservative.Based on the analysis of the subgrade reaction graphics,the foundation pressure models corresponding with different eccentricities were established.The formulas of foundation pressure and zero-stress zone percent were derived,and then the design charts were presented.The analysis shows that the security and economy of bidirectional eccentric foundation can be improved greatly when the new method of considering zero-stress zone is adopted.