超长大直径桩压浆后的承载性能研究

Study on bearing behavior of super long–large diameter piles after grouting

苏通大桥为取得可靠的工艺参数和设计参数,共进行了4次试桩试验,其中包括7根压浆前后对比桩。根据自平衡静载测试结果,桩端压浆不仅可提高桩端阻力,还可改善桩周土和桩土接触面的性质,使桩周摩阻力也得到提高。苏通大桥试桩经过压浆,总侧阻提高幅度为12.39%～52.87%,端阻提高1.46～6.21倍。侧阻力增量对桩极限承载力的贡献为56%～88%。

In order to get reliable construction parameters and design parameters of Suzhou-Nantong Yangtze River Bridge, 4 tests of piles were taken, including 7 piles with grouting. According to the results of self-balanced static load tests, not only base resistances were improved after grouting, but also frictional resistances were improved by bettering the characteristics of soils and interfaces between piles and soils. After grouting, the frictional resistances were increased by 12.39%-52.87%, and the base resistances were increased by 1.46-6.21 times. The ratios of frictional resistance increment in the ultimate bearing capacity increment were 56%-88%.