路堤柔性荷载下的粉喷桩复合地基内的附加应力分析

Analysis on Additional Stress in Composite Foundation of DJM Pile under Flexible Load of Embankment

路堤柔性荷载作用下粉喷桩桩身与土上部的位移不协调即桩顶及桩端的刺入变形,宜采用弹性力学中的Mindlin解与Boussinesq解联合求解,计算粉喷桩复合地基内的附加应力和地基沉降。工程实例计算表明,应用上述方法求解的复合地基沿深度的附加应力曲线,与用单一Boussinesq解求解的天然地基沿深度的附加应力曲线差别很大。应用此方法求解总的附加应力及所计算的最终地面沉降,与工程实例的实测结果吻合较好。

Considering the DJM pile itself is not coordinate with the displacement of the upper part of soil under the flexible load of embankment,i.e.the piercing deformation of pile top and pile end,it is appropriate to use Mindlin solution combined with Boussinesq solution of elastic mechanics to find the solutions of the additional stress and foundation settlement within the composite foundation of DJM pile.Based on the calculation in project experience,it shows that big difference exists between the vertical additional stress curve of composite foundation solved by the above mentioned method and the vertical additional stress curve of natural foundation solved by Boussinesq solution,and the final ground settlement calculated based on the total additional stress solved by the former solution is rather identical to the practical results measured in projects.