中砂融沉位移与单桩负摩阻力关系的试验研究

基于模型试验，分析了饱和中砂融化沉降位移随时间的变化、单桩负摩阻力与融沉位移的关系．在析冰融化阶段，试样析冰表面位移与时间呈近似线性关系，而在颗粒重分布阶段的位移数值甚小；与此两阶段相对应，试样颗粒骨架表面位移可分为近似线性和非线性两部分，非线性段的贡献来自于融后颗粒重分布；单桩负摩阻力随融化过程呈良好的线性关系，但在两阶段中负摩阻力产生和增加的机理不同．在颗粒重分布阶段，颗粒骨架表面位移虽仅占其总位移的９．７％ ，但负摩阻力却增加了近１８％ ．

Test Study on Relation Between Thaw-Collapse Displacement of Medium Sand and Negative Friction of Single Pile

Based on the simulation tests, the change of thaw collapse displacement of saturated medium sand and the relation between negative friction of single pile and thaw collapse displacement are investigated. In the separating ice and thawing stages, the relation between separating ice surface displacement of sample and time is linear similarly. But the displacement is too small in the redistributoin stage of grains. Corresponding to these two stages, the displacement of sample grain framework surface can be divided into linear and nonlinear parts similarly. The contribution of nonlinear section comes from grain redistribution after thawing. The negative friction of single pile shows good linear relation following thawing process. But the producing and increasing mechanisms of negative friction are the same in two stages. In the stage of grain redistribution, the displacement of sample grain framework surface occupies only 9.7% of total displacement. But the negative friction increases 18% or so.