削减桩基负摩阻力的室内模拟试验

为探明桩基混凝土不同涂料对桩基负摩阻力的削减效果,通过大型剪切试验,以塑限18%的黏性土为试验土,着重研究了试验土含水率变化以及桩基混凝土侧面不同涂料对桩基负摩阻力的影响。结果表明,当黏性土含水率略大于塑限时,桩基负摩阻力的削减效果较好,此时在混凝土表面涂石蜡机油混合物、聚合物纳米材料或者油漆产生的削减效果基本一致;当黏性土含水率与塑限含水率相差较大时,采用石蜡机油混合物作为桩侧混凝土涂料对于桩基负摩阻力的削减效果最佳;可通过不同方式对中性点位置进行确定并采用不同适用条件下涂料对桩基负摩阻力进行削减。

Indoor simulation tests on reducing negative skin friction of pile foundation

In order to find out the effects of different coatings on the reduction of negative skin friction, the cohesive soil with a plastic limit of 18% as the test soil is studied based on the large shear tests. The influences of the moisture content and different coatings on the negative skin friction are emphatically studied. The results show that when the moisture content of the cohesive soil is slightly larger than that of the plastic limit, the reduction effects of negative skin friction are better, and the reduction effects of paraffin oil mixture, polymer nanomaterial or paint on concrete surface are basically the same. When the moisture content of cohesive soil differs greatly from that of the plastic limit, using the paraffin oil mixture as the pile side concrete coating has the best effects on the reduction of negative skin friction. The position of neutral point can be determined by different methods, and the negative skin friction of piles can be reduced by different applicable conditions.