基于单桩静荷载试验的群桩沉降预测研究

Settlement of pile groups based on static load tests on single pile

通过单桩静荷载试验的Q–s曲线推算各级荷载下土体的等效弹性模量,建立单桩桩顶位移与等效弹性模量的函数关系,利用Mindlin位移解计算群桩相互作用,并引入一个修正弹性理论误差的经验公式来计算群桩的沉降。计算群桩沉降时认为土的等效弹性模量与单桩在相应沉降量下反演出的土体等效模量相等,以此将弹性理论的方法推广到塑性阶段。最后通过一个实例验证本文算法的可行性。

The Q-s curve of static load tests on single pile is used to calculate the equivalent elastic modulus of the soils under load at all levels. A function relationship between the displacement of pile head and the equivalent elastic modulus is established. The Mindlin solution of displacement is used to calculate the interaction of piles, and an emirical formula is introduced to correct the shortcomings of the elastic solution. The equivalent elastic modulus used to calculate the settlement of pile groups is equal to the elastic modulus calculated from the static load tests on single pile with the same settlement. So the elastic theory can be applied in the plastic stage. Finally, the validity of the proposed method is verified by the field tests.