基于透明土材料的异形桩拔桩过程对比模型试验

随着地下空间的逐步开发,既有桩基拔除问题及其拔桩过程对周围构件物影响的问题日渐突出；针对拔桩过程中桩对周围土体的位移场及影响范围的研究相对较少,而针对异形桩的研究更少。基于透明土材料和PIV（Particle Image Velocimetry）技术,开展扩底楔形桩的拔桩过程模型试验,测得拔桩过程中桩周土体的位移场变化规律以及拔桩影响范围；同时进行等直径圆形桩和楔形桩的拔桩模型试验并对比分析。研究结果表明：扩底楔形桩的拔桩扰动范围明显比楔形桩和等直径圆形桩大,其数值接近等直径圆形桩的2.0倍；楔形桩拔桩过程中水平向位移扰动比等直径圆形桩大,竖向位移扰动比等直径圆形桩小。

Comparative experimentation on pulling process of profiled pile by using transparent soil

With the development of underground space,pulling out problems of the existing pile and its impact areas become more and more prominent. However,the researches focused on displacement field and impact areas of pile pulling out process were relatively little,not to mention the study about profiled pile. Base on transparent soil material and PIV（ Particle Image Velocimetry） technique,experiment on pulling process of the belled wedge pile was carried out,and the displacement field of the pile surrounding soil,and impact areas during pile pulling out process were non-intrusively measured. In order to conduct comparative analysis,experiment on the equal cross-section pile and the tapered pile with the same concrete usage was also taken. The research results show that the impact areas of belled wedge pile are obviously larger than those of equal section piles and tapered piles,of which the value is nearly 2. 0 times of those of equal section piles. In the process of pulling out belled wedge piles,the horizontal displacement of the tapered pile is larger than that of the equal section pile,while the vertical displacement of the tapered pile is smaller than that of the equal section pile.