合肥黏土地区静压管桩单桩承载力时效性研究

Research on the timeliness of bearing capacity of static pressure pipe pile in Hefei clay area

对合肥黏土地区119根静压法沉桩开口管桩的基桩静载试验数据分析研究,采用对数曲线分别拟合出桩径400 mm, 500 mm和600 mm的管桩单桩竖向抗压极限承载力增长率与休止期的回归方程,研究表明管桩桩径越大,其极限承载力随时间增长越快,得出了在休止期25 d以内,单桩竖向抗压承载力极限值增加较快,25 d后单桩承载力增长速度放缓,建议静压管桩竖向抗压静载荷试验宜在休止期不少于25 d后进行。

Based on the analysis of the static load test data of 119 open-ended tubular piles driven by static pressure in Hefei clay area,the regression equation between the growth rate of the vertical compressive ultimate bearing capacity of single pile with pile diameters of 400 mm,500 mm and 600 mm and the rest period is fitted by logarithmic curve.The research shows that the larger the diameter of tubular pile is,the faster the ultimate bearing capacity increases with time.It is concluded that the limit value of the vertical compressive bearing capacity of single pile increases rapidly within 25 days of the rest period,After 25 days,the growth rate of single pile bearing capacity slows down.It is suggested that the vertical compressive static load test of static pressure pipe pile should be carried out after the rest period is not less than 25 days.