（中国建筑科学研究院地基基础研究所 北京100013）
【提要】 根据Mindlin解所得的Geddes应力公式将桩端阻力、桩侧阻力简化为集中力。对于长径比较小的短桩，按其计算结果导致近桩端平面以下的应力集中，此时计算竖向应力系数与实际考虑桩径影响的结果相差甚远。按Geddes应力公式计算时小桩距群桩带来的问题较小；用于计算单桩、单排桩、疏桩沉降将使计算深度范围内的应力大大超过土的强度，使土进入塑性状态，导致计算失真。推荐的应力计算方法考虑了桩径的影响，用于计算单桩、单排桩、疏桩沉降取得了良好的效果。
【关键词】 Mindlin解 应力系数 沉降计算 Geddes应力公式
New Stress Calculation Method for Mindlin Formula Considering Impact of Piles Diameters/
Wang Tao(China Academy of Building Research, Beijing 100013, China)
Abstract:Geddes stress formula deduced from Mindlin solution simplifies the shaft resistance and tip resistance into centralized force. For short piles with low ratio of length to diameter, calculation results will make the stress concentration in the near tip of the piles, which is much more different from the actual results. Geddes stress formula will result in small problem in small group piles. When Geddes stress formula is adopted to calculate the settlement of single pile, oneline pile and sparse pile foundation, the stress will significantly exceed the strength of soil and make it into plasticity state. So the calculation is distorted. Therefore, this article calculates Mindlin stress factor considering piles diameterimpact. This method can be used in signal pile, oneline pile and sparse pile foundation settlement calculations and achieve good results.
Keywords:Mindlin solution； stress coefficient； settlement calculation； Geddes stress f
ormula