软土地基预制桩沉桩对桩周土体扰动研究

Disturbance of surrounding soil by pre-cast pile sinking in soft soil foundation

预制桩作为挤土桩或部分挤土桩,在沉桩过程中会挤压周围土体、扰动土体结构。就软土地基预制桩沉桩对周围土体的扰动,采用有限元CEL方法对软土地基预制桩沉桩的全过程进行模拟,得到沉桩过程中和沉桩完成后桩周土体位移规律,并分析了土体弹性模量和泊松比对桩周土体位移的影响。结果表明:沉桩过程中,靠近桩身的土体受桩体拖曳作用,径向位移先增加后减小;沉桩完成后,桩周土体水平位移分布沿径向呈对数形式衰减;随着弹性模量的增加,桩周土体竖向位移逐渐增加;随着泊松比的增加,桩周土体径向位移和竖向位移均增加。

Precast piles,as squeezed soil piles or partially squeezed soil piles,will compress the surrounding soil and disturb the soil structure during the pile sinking process.In order to study the disturbance of the surrounding soil caused by the sinking of precast piles in soft soil foundations,the finite element CEL method is used to simulate the entire process of precast pile sinking in soft soil foundations.The displacement law of the soil around the pile during and after the pile sinking is obtained,and the influence of soil elastic modulus and Poisson′s ratio on the displacement of the soil around the pile is analyzed.The research results show that during the pile sinking process,the soil near the pile body is subjected to the dragging effect of the pile,and the radial displacement first increases and then decreases.After the pile sinking is completed,the horizontal displacement distribution of the soil around the pile decays logarithmically along the radial direction.With the increase of the elastic modulus,the vertical displacement of the soil around the pile gradually increases,and with the increase of the Poisson′s ratio,both the radial displacement and the vertical displacement of the soil increase.