挤密桩在红黏土地基中挤密效果影响因素试验研究

Experiment study on influencing factors of compaction effect of compaction pile in red clay foundation

基于室内桩孔水泥土夯击试验,研究夯锤形状、夯锤落距和夯击次数对挤密力和压实系数的影响规律,建立拟合数学模型。研究结果表明:平底锤对桩底的挤密力最大,锥底锤对桩侧的挤密力最大。挤密力和桩体压实系数与夯击次数、夯锤落距之间存在对数函数相关性,用对数数学模型计算挤密力平均误差不超过7 k Pa,压实系数平均误差不超过2%;根据桩体压实系数的数学模型和挤密力随夯击次数的规律,以夯击能作为考量标准,提出最优夯击方案为锤底为锥形、30 cm落距和每层夯击30次。

Based on cement-soil compaction experimental study in pile holes, using compaction force and pile compaction coefficient as control index, some influence factors were studied, such as hammer shape, tamping times and hammer drop distance, and then influence law was determined by regression analysis method. Some conclusions were drawn： Flat bottom hammer has biggest bottom compaction force and cone bottom hammer has biggest lateral compaction force. The relationship between compaction force and compaction times, hammer drop distance can be estimated by logarithmic mathematical model. The compaction force average error of the calculated value is not more than 7 k Pa, and the pile compaction coefficient average error is less than 2%. According to the compaction coefficient mathematical model and compaction force law, taking tamping energy as measure standard, the optimal scheme of using cone bottom hammer, 30 cm drop distance and 30 compaction times is put forward.